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The Tale of an Engine Build, Part 2

When we left off back in December, I was waiting on a small base-circle camshaft to clear my stroker rotating assembly. It came. It cleared. Hooray.

With that done, it was time to assemble in earnest. The first step was to bolt the heads on and measure for pushrod length. I won’t go into detail on that process, because there are a ton of tutorials already out there. Suffice to say, I ended up needing 8″ pushrods. I ordered a set from Smith Brothers, and promptly installed the valvetrain.

Valverain installed

Also installed was the front cover. This is a blueprinted cover from Boost Crew Motorsports. The oil pump has been ported and clearanced, and it was spot faced for my roller cam button.

The balancer went on next, followed by other items like the oil pickup, the new lightweight (10 pound savings!) start motor, and the oil pan.

Getting the balancer installed required making a plate to go between the bearing on the balancer installation tool and the balancer. The bearing was just a tad too small and wanted to ram itself inside the balancer. No bueno.

Balancer installation

The flexplate went on next, and then the engine went in the car.

Engine back in its proper place

One would think, “Hey! It’s in the car! Easy from here, right?”


First off, the fancy SFI approved super-duper flexplate didn’t line up properly with the torque converter. When I zipped the bolts in, they kicked sideways and cross-threaded the converter holes. Bad. So the engine had to come back out, I had to helicoil the converter, and enlarge the bolt holes on the flexplate. This wasn’t easy. Both the converter mounting flange and the flexplate are made of super high strength steel, so cutting into it was very difficult.

But I got it.

Then, I was staring at a pile of dirty accessory brackets and accessories. Not acceptable. So a can of Dupli-Color aluminum engine enamel and several coats of clear and a lot of patience netted me some pretty blingy parts. The accessory bracket cleaned up really well, and I even disassembled and painted the alternator.

Accessory bracket, painted

Painted alternator!

Completed accessory drive

With the accessories complete, it was time to bolt the intake manifold down.

And it didn’t fit. Since the block has been decked twice and heads milled twice, the bolt holes didn’t line up anymore. Back to the machine shop it went to have 0.010″ taken off each flange. While they had it, I had the manifold completely ported and the EGR tower cut down and epoxied shut.

While waiting on that, I undertook the extremely frustrating act of wrapping my headers. It was difficult. This stuff is so maddening to deal with. You get a wrap started, and just when you’re ready to tied it off, you slip and it loosens and you  have to start over again. Nevertheless, I persisted, and they didn’t come out half bad.

Wrapped header. The wrap ate up ALL available extra clearance. It was a really tight fit.

After that two week delay, the rest went together pretty quickly. I made a small bracket to mount my new boost control solenoid.

Boost solenoid and bracket

I dressed up the wiring and got almost everything buttoned up yesterday. I’m waiting on a few push lock fittings and new battery cables to show up in the mail, and we’ll be set for a first start in the next week or so. I also have a new coolant overflow bottle on the way to replace the one I melted last year.

Mostly complete engine





The tale of an engine rebuild

If you follow my blog, you’ll remember my posts back in August (here and here) detailing the failure of my engine at the Optima Search for the Ultimate Street Car event in New Jersey. I started my rebuild story in another post back in October. Many may be wondering what happened? It’s been over a month!

Well, as it turns out, parts for this car are getting hard to get. Added to the availability issues are the nature of the build. High strength, non-standard reciprocating assembly, and custom fitting billet steel main caps resulted in an extended stay at the machine shop.

But the time to move forward has finally arrived! The block and reciprocating assembly came home just after Thanksgiving.

I had intended to make this a single post for the whole build, but it turns out that’s probably not going to work. I’m breaking it up.

In case you were wondering what kind of machine shop work goes into a build like this, here you go:

  • Disassemble/vacuum test heads
  • Resurface heads .010
  • Size piston wrist pins
  • Clean connecting rods
  • Check/polish crankshaft
  • Balance assembly
  • install 2 pieces mallory metal
  • Degrease and inspect block
  • Hone block
  • replace freeze plugs
  • replace oil galley plugs
  • resurface block .005
  • Check block height
  • Clearance for stroker kit
  • File Fit rings
  • Main cap fitting
  • Block line bore
  • Cam bearing install

All of this work took eight weeks to complete at two different machine shops and cost almost two grand. For just labor. Let me say here that this will be my last Buick V6 engine build. If it pops again, I put an over the counter reman long block in it and sell the car.

And while we’re doing bullet point lists, here’s the parts list, at least the fun parts:

  • 4340 Forged Steel Crank, 3.625 stroke crank
  • Molnar 4340 Forged steel 6.350 H-beam connecting rods
  • Carrillo Forged pistons (custom wrist pin height, standard dish)
  • PAC valve springs
  • Erson roller lifters
  • Comp 264HR grind roller camshaft
  • Double roller timing chain
  • Cometic MLS head gaskets
  • All bearings Calico coated
Like the new bench top?

Like the new bench top?

With everything in house, I began putting stuff together. An hour with the valve spring compressor and the heads were assembled. Yes, an hour. I had to take them back apart once I realized I’d misinterpreted my machinist’s cylinder numbering and had put the valves in the wrong holes. Sue me.

Assembled heads

Next came attaching the pistons to the connecting rods,  which resulted in a pretty fantastic engine-porn shot.


The next part was assembling the short block. A 3.830 inch diameter ring compressor made this much easier than it was the last time I put this engine together. What had been a frustrating few hours with the ratchet type compressor ended up being about half an hour this time around.

I bolted the main caps on and checked the diameters. The clearances are all between .0015 and .0020 inches. Right at the tight end of the acceptable range, which is what I wanted. My intention is to run it tight and use really good oil instead of running it loose and filling it with 50w sludge.

These single-piece piston ring compressors are worth every penny.

Once the pistons were loaded, I spun the assembly around to make sure everything cleared, especially the #1 rod. It interferes with the main oil feed galley coming from the pickup to the front cover. My machinist clearanced the block and took a bit off the bolt head and it clears. Barely.

Notch showing clearancing required for the stroker kit

This the only clearancing the block needed. Other rods may require more. I picked the Molnars specifically because they clear really well.

I checked the endplay. .005″. Exactly where I wanted it. Tight.

Dial indicator and huge screwdriver is all you need!

What didn’t clear was the camshaft. There was interference between the rods and the cam lobes. I was able to get it to clear by advancing or retarding the cam six degrees, but I didn’t want to run the car with the cam that far out. So, the cam went back, and I ordered a custom small base circle version of the same profile.

And with that, here stops this installment. Stay tuned! Once the cam shows up, we’ll be installing it, then the lifters and heads, then measuring for custom pushrods!

I’m also hitting up PRI this week, so I’ll likely do an entry on that.


C-clip eliminators

Most that have dealt with C-clip rear ends from GM and Ford know all about the good things. C-clips are easy to work on. It only takes a few minutes to get an axle out of the car. The bearings on the axle ends can be serviced with a slide hammer and rubber mallet, no need for a press or a trip to the machine shop.

What they don’t do well is cooperate with disc brakes, and all of the lateral load imparted on the axles hits the carrier bearings in the differential center section.

The axles float a tad, which is fine, except when the wheel hub is attached to the axle. Lateral movement allowed by the slop inherent in C-clip retained axles will cause pad knockback, even with a floating caliper. I’ve had trouble with it since I put the disc brakes on the back end of the car.

And lastly, since the axle is retained by the clip inside the center section, if you happen to break an axle, there is nothing holding the outboard section (and your wheel) in the car anymore.

Enter the C-clip eliminator kit. NHRA requires them in many instances as a safety item. They consist of a bearing block and bearing set that are pressed onto the axle, and then the assembly is bolted to the axle flange. Voila. No more C-clip, and the axle is retained at the outboard end, so if it breaks inside the housing the wheel stays on the car.

It also has the potential to reduce brake pad knockback, since all that slop from the c-clip design is eliminated. That’s the part that was attractive to me.

I looked at several C-clip eliminator kits. I first checked Moser, and they had one. But the instructions for the kit specifically stated they were not for street use. The end bearings were of a needle type, and had no ability to manage lateral loads well. These were drag-race only.

Strange had the answer. They offered a kit with both roller bearings for drag racing, and a street/track kit that used a tapered bearing.

The kit includes all the required parts and a single page (back and front) instruction sheet.

I’m not going to go through the install step by step, since that’s what the instructions are for. But I will offer a few tidbits here that weren’t in online writeups and youtube videos.

First of all, you have to drill on the axle housing. I found that the easiest way to get the holes right is to enlarge the lower holes in the flange, then bolt the inner guide plate to the lower holes, which enables you to use the upper holes in the guide as a jig to locate your drill.

A Harbor Freight 12-ton shop press is plenty for pressing the bearing assemblies on. At $99 with a coupon, the press pays for itself in a single use.

Bearing assemblies pressed onto the axles

And finally, the “button” on the inner end of the axles, where the c-clip normally would slip on, must be removed. I was able to cut it off easily with the axle in a vise and a quality metal cutting blade in my reciprocating saw. The same saw also made quick work of the bearing housing on the end of the differential housing. That cut doesn’t need to be pretty.

If you’ve been careful with your drilling, it will bolt right on.

All bolted together!

Now, here’s where my experience may help you:

I have a disc brake conversion. These kits are for cars with drum brakes. The caliper mount plate is much thicker (0.250″) than the standard sheet metal drum backing plate.

No worries! It can work! Before you perform the final assembly, slather some grease on the splines of your axle, and mock the thing up with the caliper plate in the sandwich where the instructions tell you to put the drum backing plate.

Then pull the axle back out. The grease should have been pushed down the splines and tell you just how much engagement you have with the center section. If you have at least 1″ of engagement, you’re good.

If you don’t have 1″, then you’ll need to call up your favorite axle vendor and order longer axles, since by the time you get to this point in the install, you’ve already cut up your housing and there’s really no going back.

Mine worked out just fine.

Also, with the disc brake plate in place, you’ll want to make sure the bolts that bolt the bearing plates to the the housing end are long enough to properly engage.

I’ll report back in the spring with whether these actually work out as expected. If they don’t, I’ll probably have a very broken and/or wrecked car. The big unknown is the strength of the flange on the axle housing. The GM 10 bolt assemblies in the G-bodies have a very flimsy (as compared to a Ford 9″ or a Chevy 12 bolt) flange.

However, I have a 0.250″ disk caliper plate sandwiched in the assembly, which should give it some additional strength.

All buttoned up!


The Rebuild

So, this entry marks the beginning of my documentation of my engine rebuild. Any big project needs some goals. Without goals, you have no idea if you’ve been successful, or even if you’re complete.

With that in mind, let’s back up and talk about my goals for next year:

  • Multiple Optima USCA events, possibly as many as four
  • Multiple National-level SCCA events
  • MidWest Muscle Car Challenge
  • Enough local events to be competitive for a regional trophy

This is an ambitious list, but it tells me what I need to get out of this engine build:

  • Reliability – this new engine needs to be bulletproof.
  • More power – If I’m going to play in the Optima playground, I need more juice. The transmission can take it.
  • Less weight – The car is too heavy. Shaving a couple of hundred pounds will make everything better. Better handling, more tire life, less load on drivetrain and suspension parts, and on and on.
  • Better brakes – The brakes are inadequate. Even with ducting added, I cracked a brand new rotor at NJMP. One event per set of rotors simply isn’t sustainable

So those are the goals for the winter build. In this entry, I’m going to talk about the first two: reliability and power.

There’s an adage: fast, cheap, or reliable: pick two.

I have decided to pick fast and reliable. My last build was fast and cheap, and it is now going to cost me dearly. But if I do this right, I won’t have to touch this engine for three seasons, and at that point I should be just looking at a bearing and gasket refresh.

So what am I planning to address the reliability issues? Well, if you read my earlier posts diagnosing the failure, I need to address boost control, head sealing, crankshaft flex, and very likely heat.

The crankshaft flex leads to an obvious solution: a better crankshaft. This build is getting a 4340 forged steel crank.

Forged steel crankshaft

4340 forged steel has double the tensile strenght of cast iron, and 50% more than cast steel. This crankshaft won’t bend like my stock crankshaft did. This will leave me with even bearing wear, less vibration, and an ability to handle much more power without twisting.

Connecting the crank to the pistons are the connecting rods. Since I trashed one of my OE rods, I needed a new set anyway. I again spring for forges pieces. Molnar H-beam connecting rods.

Molnar forge H beam connecting rod

Being forged, these rods are at least twice as strong as the original cast rods. These rods feature ARP’s highest quality rod bolt set, and the small end is bushed in brass. Brass is an interesting alloy. It’s porous. It will actually absorb oil, then release it in situations where the oil supply is reduced, effectively lubricating itself. Plus the metal is soft, it will yield where other metals would scuff or even tear. This reduces friction at the small end of the rod. Less friction is less heat is less load on the oil and cooler piston which is less likely to detonate, and the wristpins are much less likely to break under extreme use.

Complementing the crankshaft and rods will be a JH SFI-approved neutral balance flexplate to replace my bent stocker, as well as a BJH SFI-approved neutral balance harmonic balancer. The SFI approval ensures the parts are a) actually balanced, and b) won’t explode at extreme RPM ranges. They’re tested to 12,000 RPM, double what this engine should actually see. That’s a large safety margin. On top of all of that, these new pieces are lighter than the OE parts by a couple of pounds. A pound off the crank is worth something like 3-4 horsepower to the ground.

Speaking of power, astute readers will have noticed the stroke marked on the crankshaft. 3.625. This is a increase in stroke of 0.224″ over the stock 3.4″ stroke. The rods are also longer to compensate for the stroke, and I’m currently waiting on a custom set of pistons to fit everything together.

This extra stroke is where I’m getting my extra power. It should be worth an easy 150-200 additional ft-lbs of torque and 50-70 horsepower. This additional torque and the airflow that comes with it will help the car’s ability to accelerate out of low speed turns on autocross courses, and the turbocharger will spool faster.

I will also be replacing several of the main caps in the block with billet steel units, to hold this new crankshaft firmly in place.

All together, these bottom end improvements will go a long way towards increasing the strength of the engine.

Stay tuned for future installments, where I’ll talk about the valvetrain, oiling, heads, how to keep it from detonating again, assembly, and tuning.

Anatomy of a failure

So, after my disappointing engine failure at the Optima NJMP event, I was left with the big question:

What happened?

Well, after pulling the engine and tearing it down and reviewing the data logs from the event, even having an oil sample analyzed, the answer is clear:

Several things.

Dealing with things like this requires patience. I want to understand what broke and why it broke. Without fully understanding those things, I’ll just break it again.

Pulling the engine

Step one is getting the engine out of the car. Not a big deal. This is my second time doing it. Had it out in just a few hours. Before I started pulling it, I drained the oil, taking a sample to have analyzed. No water came out, which was encouraging. But the oil did settle in the pan with a nice metallic sheen on the surface. That wasn’t encouraging.

After getting the engine on the stand, I got the intake manifold off and saw the first hard evidence of what I was dealing with. The passenger side head gasket had clearly failed at the top of number six.

Busted head gasket at number 6

It managed to push the gasket out far enough that it contacted the pushrod, likely contributing to the noise. Once I got the head off, the effects were more obvious.

Head off, steam cleaned piston!

You can see pretty clearly the damage to the gasket. On the bright side, the water that got into the cylinder steam cleaned the top of the piston for me. The gasket also mostly re-sealed, which is why I was able to drive the car off the track and onward to the paddock and eventually onto the trailer. Yay?

The driver side showed signs of damage, too. But not nearly fantastic enough for pictures.

At this point, I was feeling encouraged. Maybe I got away with just a head gasket? Time to flip it over and pull the oil pan!

Oh God.

This isn’t good

That, my friends, is bearing material. Lots of it.

The number one cam bearing was damaged, as well.

Number one cam bearing

I pulled the number three main, and it was trashed.


Number three main bearing shell. That groove at the top is supposed to go all the way around.

At this point, I just took it to the machine shop so they could clean it. They found the top shell of the number one rod bearing was missing. The rod journal had been ground down 0.018 inch from the original size, and the cap and journal were discolored from the heat. The crank was trash, and so was at least one rod. The wear on all of the bearings was offset, too.  The crank bent. I bent the crank. The crankshaft bent. Holy crap.

So, that’s the physical damage. But what caused it?

Well, figuring out why the head gaskets failed was easy once I saw this chart:


The green line is the knock count. As boost climbed past 20psi up to 24psi, it starting pinging. A lot. I couldn’t hear it when it was happening. When it hit 24psi, the heads lifted off the block and the rest is history.

But the bearings?

OIl analysis, check out the highlighted numbers

OIl analysis, check out the highlighted numbers

Yeah, bearing wear. And checking out the slightly elevated number on the 8/5/2016 sample, it appears they’ve been wearing since I put the engine together. I think I screwed up something in the front cover and oiling system when I built the engine last time. They wore, and then the detonation event just finished them all off.

So, the total damage? Trashed crank. Trashed rod. Block is fine but will need some finish machining. I’m going to need a rotating assembly, new cam, and a properly constructed front timing cover and oil pump.

So what’s next? A lot. As is usually the case, it costs almost the same to put upgraded stuff into the thing as it would cost to just rebuild it as it was. I’m forging it all. All the things. Forged. FORGED!!!!!

And a few other plans. Stay tuned.


Optima Search For the Ultimate Street Car, NCM Edition

You may remember my post last year about attending the Optima Search For the Ultimate Street Car event at the National Corvette Museum Motorsports Park. You may remember that weekend ended with the car on a trailer being towed home after some serious electrical issues disabled the ECM and later, the cooling fans.

That is not what happened this time.

I did it! Not only did car and I complete the entire event, I placed ninth! Out of thirty one in the GTV class!

Arrival Friday was uneventful, in stark contrast to last year, when I had to immediately change the diff fluid. Nope. This year I parked the car under the Discount Tire Dangerous Curves Motorsports pop-up tent and changed my tires in the shade.



After that, it was a trip to the tech shed. Tech inspection was slightly different this year. In addition to the normal safety stuff, they went ahead and went through the standard part of the D&E judging, verifying lights and horn and A/C and stereo worked. I got docked a point for non-functioning reverse lamps. As it turns out, the parking lot fix I had to perform to get the shifter working at Putnam Park a few weeks ago disabled the reverse lights. I’ll need to get that taken car of soon.

Another change this year is the fire drill. I had to get into my full road course get-up, with my driver suit, shoes, helmet, neck restraint, and gloves, strap myself completely into the car, and then escape it within 12 seconds. I think I got out in less than two.

After that, I hung out with the Dangerous Curves Motorsports team, walked the autocross course, and had a couple of beers before retiring to the hotel for the night. Which was a nice place. Brand new, I think I must have been the first person to use the room I was in. Way less stressful than last year.

Saturday morning started bright and early. The format was slightly changed from last year. The Autocross and Design and Engineering judging were the only things happening. The Speed Stop had been moved to Sunday. I got in line to get the D&E out of the way early. I wasn’t really prepared for it this year, and I forgot to point out a lot of the stuff I’d done to the car, so my D&E score was really lackluster compared to last year’s top ten finish. Oops.

Then on to the autocross. It was a fairly simple course, about thirty seconds long. I started out in the mid-32 second range, but tips from my new best friend Paul got me down to a 30.56, which was good for 11th in the GTV class. The first place car had a 29.022, just 1.4 seconds faster than me. Which is a lot in an autocross, but I’ve significantly closed the gap. A year ago, these guys were beating me by nearly six seconds.

Autocross results

The car performed flawlessly. In fact, the new front swaybar made a huge difference. The car was even packing the front wheel digging out of turns, so I may need to stiffen the back up somehow.

Also, it was hot. But not as hot as last year. My best run follows:

Another cool item is my second best run. I captured data from the ECM using my Powerlogger and an old phone, and managed to merge that data with my Harry’s Laptimer Data, and overlaid it with Dashware:

You can see in the second video I have working throttle indicator, manifold pressure, and tachometer. I also meant to throw in oil pressure, but I forgot. The six year old Samsung Reverb smart phone I was using ended up not being able to run reliably for the entire day, but at least I proved out the concept. I’ll need to get a better Android device for the next event.

After the autocross, we did the “Road Rally,” which was less a road rally, and more of a 40 minute jaunt south to Franklin on I-65 and back again. Dinner was a decent BBQ spread, which I ate. But then I went back to the Dangerous Curves Motorsports pit box and ate Troy’s food. The event catered BBQ was really good. But Troy’s was fantastic. So I ate both. *burp*. We hung out until dark chatting with some local friends from Bowling Green that had come out to hang.

The next morning, this had happened in the parking lot of the hotel:

Four decades of GM power!

Yup, a split-window Stingray, a Chevy SS, my car, and a C5. The pinnacles of GM performance for the 1960s, the 1980s, the 00s, and the current. Pretty cool. Especially the SS. You don’t see many of those. The blue Corvette also had a great weekend, placing very high, I think possibly winning a class, but broke on Sunday. I heard it making sad knocking noises and eventually being pushed into its trailer.

Sunday was the Hot Lap challenge and the Speed Stop. Where last year the speed stop had been a single-car at a time blast through the sinkhole on the east course of the race track, this year they set up a small side-by-side autocross with a drag tree start. Reaction time and 60′ weren’t measured, but it made for good TV.

It also rained. A lot. There was a dry period after an initial downpour, but I wasn’t able to get dry speed stop runs. Amazingly enough, my wet ones were still good for ninth in the class, and many of the cars I beat had dry runs!

Then the Hot Lap challenge. Woah nelly. Butterflies. I’d heard about how technical the NCM course was. Blind corners and elevation changes that easily catch unsuspecting drivers out and send them careening into gravel pits and ARMCO barriers. My new best friend Paul to the rescue again. He gave Peggy and I a good brief on the course and pointed out the tricky spots. It helped. A lot.

In fact, some of my other novice friends didn’t have a Paul. One of them nearly wiped out right in front of me in a blind turn during the orientation lap. So thank you again, Paul!

Once we got going, the course was a blast. It was technical. There are several turns that don’t behave the way they look, which made it a challenge getting them right. But I improved steadily through the first three sessions, with the second and third sessions actually being on a dry track. My best lap time of 1:47.2 was good for 11th.

That’s the Dangerous Curves Motorsports Mustang in front of me. Super nice car. I wish my chassis setup was as good as theirs. Their tires must last twice as long as mine. Easily.

Compared to Putnam Park, NCM was much harder on the brakes. However, unlike at Putnam Park, my brakes worked really well. The new compound pads were a really big improvement, and I had no fear of the car not stopping by the end of the first session.

The car handled fantastically. The back straight ended up being longer and faster than expected, and I know I could pick up nearly a second there by not chickening out and lifting so soon. I also left a lot of time in turn one. No more heat issues in the engine bay, thanks to some heat wrap and reflective tape. The front brakes, however, got cooked. The rotors were grooved and annealed, and the anodizing on the calipers became discolored.

Hot rotors turn blue, and black calipers turn purple

I’m currently installing new front air dams on the car with brake ducts to hopefully ameliorate  this issue. If the ducts don’t work, I’ll be investing in some big brakes.

After my third lap session, the skies opened up. Then lightening halted the event. The race track shut down. The Speed Stop was re-opened for a while, but it never dried out.

Rain, rain.

The awards were moved up to 4:20 pm, and everybody got out of town. It was a long, wet drive home, but the weekend was well worth it. I’m seriously considering the event in New Jersey in August, and Road America in October. I think with a few more tweaks to the car and a lot more driver tweaks, I can go faster. With an improved D&E performance and dry Speed Stop runs, I easily could have moved up several spots.

I’m finally trusting the car, and when you trust the car, you can drive it harder. It’s been a long road getting it to this point, but I’m happy with the results so far.

Midwest Muscle Car Challenge 2017 – It finally made it

This past weekend I had the distinct honor of participating in the the Midwest Muscle Car Challenge, brought us by the good folks at Bowler Transmission. There’s so much to unpack from the weekend, so I’ll start at the beginning.

First, the event format. It’s a track day combined with a highway cruise combined with an autocross. Very similar to the Optima events, but way more laid back. Successfully completing this event was rather satisfying for me, as it was the culmination of two years of car prep, including a failed attempt at an Optima event last year.

I’m going to start the story last early last week. I was faced with a dilemma: Rain was predicted. My street tires were old Dunlop Direzza Star Specs with just 2/32s of an inch of tread left, and my racing tires were year old Rival S tires with between 3/32 and 5/32 left. Neither of those were going to work well in the rain, and having driven on the Direzzas in the rain a few months ago, just getting to the event was going to be dangerous.

So I spring for a set of the new Continental ExtremeContact Sport. It’s a new tire that’s been reported by One Lap of America participants and a few magazine reviews to have near magical wet weather capabilities, while still being competent in the dry. And they are a 340 treadwear tire, so they’ll last a while. A call to my local Discount Tire, and I had them mounted by Thursday in time to leave.

The drive up to the event hotel in Cloverdale, Indiana was uneventful. But when I pulled into a parking spot at the hotel and pushed my gear lever into park, the shift cable snapped, immobilizing the car. Damnit.

Broken Shift cable, oops.

So what do you do? Broken shift cable on a thirty year old car, and it’s 7pm on a Thursday? You start calling parts stores . Amazingly, an Advance Auto Parts in Terre Haute said they had one. We dropped the trailer off a friend’s truck and drove the thirty miles and acquired the cable.

Once we got back, another good friend had unloaded his trailer, fired up his generator, set up lights, and was ready to help. Getting the old cable out was a breeze, but the new cable didn’t fit. Turns out the parts store had sold me the shift cable for a THM200C, the three speed transmission, not the cable for the TH200-4R that I had.

After cussing a bit, we used some hose clamps and zip ties to make the cable work for the weekend. The car had park, reverse, neutral, and drive, and that’s all I needed. It worked perfectly all weekend.

The next morning was Friday, and we all showed up at Putnam Park

The Paddock at Putnam Park, Team Chick Magnet Racing in full effect.

road course at 7am sharp. It was damp and misty in the morning, but quickly dried. There was a novice class room session for green people like me, and then about ten in the morning, we set off on our first session.

What a rush. I took it really easy, because I had no idea what the car was going to do. My instructor was really patient and very helpful. Between my worst lap and my best, we cut six seconds off during the session. I learned that the brakes were iffy, but grip was fantastic. The car handled really well, doing nothing untoward.

The second session started on a very wet track. The new tires showed their worth. My fastest wet lap was faster than my fastest lap from the previous session. These tires work so well in the wet that this novice driver didn’t have to make adjustments for the conditions. The car never slipped or broke traction. I was able to go full throttle down the entire length of the front straight and brake for turn one without any issues, and cornering was basically the same as it had been the first session. Sure, I was green and not pushing hard enough to need to make adjustments, but it was nice being able to concentrate on the line and not have to worry about also adjusting for poor traction.

The third session, I finally mustered the courage to mash the gas and really try to attack things. My times improved by another few seconds, and the brakes got even worse. But wow was it fun! 110mph before lifting for turn one. Sadly, I was having to brake at the 500 foot mark, and really early for most of the other corners because, well, my brakes are just too small for this car.  But on the other hand, they got me through the day. They didn’t fade out, they just took awhile longer to stop the car than my fellow session mates.

The fourth session, I was able to go for broke. I got the car down to 1:31.6 with a lot of brake fade towards the end of the session. I even managed to get two wheels off at turn 7. I pitted in early after noticing that I was out of gas. Oops.

So, after four sessions totaling over 70 laps – nearly 120 miles of driving at wildly elevated speeds – the car survived without a burp. Though when I got home, there were some items to address. More on that later.

To say I was overjoyed is wildly understating things. I had my first real hit of the go-fast crack pipe. My friend Eric lamented the day. He was hoping he wouldn’t like it, because track days can be expensive. He loved it, and so did I.

Big props to 10/10ths Motorsports for running the track day. I had been quite nervous leading up to the event, and they made it run smoothly. I had the most fun I’ve had in an automobile since high school, and that fun didn’t involved the car moving anywhere.

After the track day wrapped up, we drove the thirty miles or so to Raymond’s Performance in Plainview, Indiana for dinner. The food was good, lots of really cool cars showed up in the parking lot, but it broke up a bit early. I think everybody was tired.

The next morning was the autocross at the Terre Haute International Airport. The course was a GoodGuys type due to limited space. A forty second first gear course made up of switchbacks and a slalom. The lack of my Rivals was apparent. I wasn’t competitive at all. Worse, after my third run, the heavens opened up, and that was that. About an hour later, there was a break in the rain, and they ran the challenge to determine the event winners, we had lunch, we did awards, and it was over.

The grid at the autocross in Terre Haute

With the event over, it was time to go home.

The next day began the post event inspections. And, umm, wow.

The tires looked great. The front brake pads were shot. My ghetto-fab transmission overflow setup worked, but also picked up a rock or

Pinhole leak in my fabulous transmission overflow setup.

hit the ground and got a pinhole leak, so I had a puddle of transmission fluid under the car. Better in my garage than on the course.

But the most surprising find was under the hood. I melted some stuff. Specifically, the plastic things on the passenger side of the engine bay took some abuse from the downpipe. My radiator overflow tank was deformed, as was the inner fender liner and some plastic insulation on the A/C lines.

Slightly melted coolant overflow tank

Very much melted plastic A/C line cover

Obviously, this was less than ideal. This let me know I needed to raise the hood in between sessions, and we needed some heat shielding. Lacking time and patience to fab a proper one from metal, I used heat deflecting tape to wrap the offending areas. This should help it get trough the Optima event next week, and then I can spend June fabricating something prettier.

Temporary protection

This should also be a wake-up call to my friends running alcohol injection and using the coolant overflow tank to hold their methanol. Last year at this same event, a friend of mine had an oil cooler line go which started a small fire, which turned into a big fire after the coolant tank breached and the methanol ignited. My experience shows that you don’t have to have a fire to damage the coolant tank.

If you have alcohol injection, move your methanol tank out of the engine bay!

I also fabricated a bracket to protect the transmission overflow bottle and keep it from dragging the ground.

New overflow bottle mount

So, the car survived with minimal problems. I’ve since also repaired the shifter with the proper cable, and new brake pads will be here shortly, this time stepping up to the Hawk DTC-30/SR compound to see if some extra Mu on the pads can improve things enough that I won’t want to go drop $1900 on a big brake kit.

Stay tuned for an update after the Optima event. Now that I can consider the car to be fully tested, I’m excited to begin that event without having to worry about the car.

Big thanks this weekend to some people that made it possible for me to actually participate: Eric Brown, for the ride to Terre Haute, and lugging around my Rivals that I ended up not using; Troy and Peggy Higginson, for all the help Thursday night getting my transmission cable patched up, plus some damn good food Friday; Lance Hamilton, for a great place to hang out Friday night; Gene Corbett, my track instructor, for patiently bring this n00b from terrified greenie to competent by slow not-as-much-a-greenie.

Stay tuned for my update after the Optima event!

More fortifications!

A big theme of the last few years with this car has been fortifying it to survive motorsports better: Transmission kits, coolers, brake work, better seats, the new giant radiator – all of it an attempt to make it easier to drive and more reliable.

This post is about another item that won’t necessarily make the car go faster, but it will be much less liable to blow up. And that’s important. You don’t have a chance to win if you can’t even finish.

Over the past couple of years, I’ve coveted a setup Bray Lay showed me. He’d figured out how to use a machined aluminum spacer under the plenum with push-loc fittings to replace the vacuum lines. This setup imparts an enormous amount of confidence. One of the worse things that can happen to one of these cars is the fuel pressure regulator losing the reference signal from the intake manifold. Another big buzz-killer for my friends running speed-density ECUs is if the MAP sensor also loses signal. Both conditions will cause the engine to suddenly go lean.

In my case, the vacuum lines would often work their way loose from the vacuum block on the top of the engine.

Vacuum lines

The stock vacuum line setup, I had already pull the lines out, but this is exactly what they’d do.

I’ve also had the line come off the fuel pressure regulator.

Now, I’ve been lucky. Unlike a drag run, where you’re full-throttle and full boost for somewhere between 9 and 13 seconds, with autocross, you’re never at WOT for more than a second or two at a time. This aspect of my chosen hobby has prevented calamity. I’ve had these lines pop off – despite numerous zip ties and clamps – many times at events. However, I’m signed up for a couple of track days this year. Going WOT down a straight that’s nearly a mile long is in my future. A hose popping off under those conditions will be the end of the engine.

So, replacing these with push lock fittings is a no brainer. I had been looking at piecing a kit together myself, but recently Don Cruz at Cruze Perfomance has started offering a package with all the hard-to-get parts. And his kit is cheaper than putting it together yourself from Amazon and Fastenal. You may have to add a few things like some 1/8 NPT nipples, but you can get those at any hardware store.

The other item that needed addressing is what I believe to be my last oil leak: the turbocharger drain. The drain line on these car is notoriously difficult to reach when replacing it, so leaks are common once it has been disturbed. A click over to GN1 Performance out of California netted their turbo charger oil line kit, which uses a -4 supply line, a 60 micron filter, and a -8 drain. It’s expensive, but it is way cheaper than dealing with an engine fire.

So, first step in all of this? Tear down the top and front of the engine:

Engine after stuff removed

Engine after stuff removed


  1. Remove the ignition box and coils
  2. Remove the plenum and throttlebody assembly
  3. Remove the intake piping
  4. Move that upper radiator hose out of the way
  5. Move the lower radiator hose out of the way
  6. Remove the thermostat housing
  7. Remove the coolant tempurature sensor that’s to the passenger side of the thermostat housing
  8. Remove the turbocharger

With all of this out of the way, you can begin.

At the base of the block is a brass fitting that houses the oil pressure switch for the light in the dash and the feed line for the turbocharger. Clean it up, and remove the feed line from here:

Turbo oil feed line block connection

Turbo oil feed line block connection

The line kit comes with several shiny bits:

GN1 Line kit

GN1 Line kit

The oil line kit comes with two adapters:

Adapters. The one on the left goes into the fitting on the block, the right goes in the turbo.

Adapters. The one on the bottom goes into the fitting on the block, the top goes in the turbo.

The fitting on the bottom of the picture goes into the block fitting. The one on the top goes into the turbocharger. If you have one of those brass 90 degree fittings that adapts the turbo’s feed from NPT to a flared line, remove it. If, like me, you have a non-oem turbo, you may need a different adapter (I did, -4 AN to 1/8 NPT).

After getting those adapters in, flip the turbocharger over and clean all the gasket mess off the drain pad. Then attach the -8 AN male fitting with the included gasket and the old hardware.

On the engine side, remove the drain line fittings from the block. The black adapter in the kit screws directly into the block. Be sure to use some high-temp PTFE sealant for all of the pipe-thread connections, or they’ll leak. Don’t use the teflon tape, it won’t hold up under the heat.

Now comes what was the hard part for me. I installed the -8 line with the 90 degree swivel at the block side. The 45 degree is not a swivel end, so lining it up with the fitting on the turbo was a bear. GN1 recommends loosening the bolts on the turbo so you can clock the center section to line up with the drain lines. sadly for me, one of the bolts on the exhaust side was stuck, so I couldn’t pull that off.

I carefully screwed the fittings onto the turbocharger before I bolted it to the manifolds. That allowed me to wiggle it around and get the threads on the drain line started. Once they were on (but not tight!), I bolted the turbcharger back into place, then carefully tightened the fittings. Be aware, and make sure you don’t crimp the drain line.

Installing the feed line was much simpler. Depending on your exhaust routing, you may want to run it either behind or in front of the turbo. Your choice. Just make sure the filter and lines aren’t touching any exhaust parts or rubbing any sharp corners.

Oil drain line

Oil Feed Line

Oil Drain Line

Oil Drain Line

With this part done, it was time to move upwards to the vacuum lines. Here’s kit:

Vacuum line kit

Vacuum line kit

It comes with an intake spacer (I got the 1″ thick option, drilled for an IAT sensor), 25 feet of nylon line, a block off plate kit to go where the stock vacuum block goes, and all the fittings.

Now, since I’m running a regular MAF based ECU, I don’t need to buy a fancy MAP sensor that can take the fittings, I’ll use a clamp on that guy, but the fuel pressure regulator needs to be modified to accept a push-lock fitting.

Fuel Pressure Regulator with new fitting.

Fuel Pressure Regulator with new fitting.

This was tricky. The fitting on the regulator was tiny. I carefully disassembled the regulator, then used a drill press to enlarge the hole in the top half, then tapped it out to 1/8 NPT. Then carefully reassembled it.

If you aren’t secure in doing this without ruining the regulator, Don Cruz will do it for you if you mail your regulator to him.

From this point, things were pretty straightforward, except for one or two little nags. You basically assemble it:

Plenum spacer installed

Plenum spacer installed

Now, looking closely, you can see my new IAT sensor. You can also see how close it is to the idle air controller housing. Yup, the IAT cannot be connected. If you are doing this, and you are running a stock throttlebody, ask Cruz performance if they’ll drill your IAT hole on the side or the back, not the front. Big clearance problem. I won’t be able to use this new sensor until I change to a different throttlebody.

PCV Lines hooked up

PCV Lines hooked up

Hooking up the PCV is simple enough.

The system comes with this cool vacuum distribution block. I had to make a bracket to mount it next to the plenum.

Distribution block on home-made bracket
Distribution block on home-made bracket

Distribution block mounted

Distribution block mounted

With this mounted, it’s a matter of connecting stuff. The two clamped rubber lines you see are fitted to 1/8 NPT nipples, with one going to the MAP and the other going to the vacuum lines that power the HVAC vents, evap canister, and cruise control.

The two push-lock fittings go to the fuel pressure regulator and the blow off valve, respectively. The open hole will be closed up using a pipe plug.

On the topic of the ignition. If you have a stock ignition system, it should clear the plenum fine after installing the spacer. I, however, have the Bob Bailey TR6 ignition, and the box is larger. I had to enlarge the holes on the ignition box bracket so I could slide the ignition box back enough to clear the plenum. A drill press is your friend here.

Finally, carefully install the orange O-ring in the channel on the block off plate (I used a little bit of Vasoline to get it to stay in place), and install it. The screws appear to be stainless, so I put some anti-seize on them to hopefully prevent them from galling into the aluminum throttle body housing.

Block off place

Block off plate

And really, that’s it. Hook up all the hoses, fill the radiator up, energize the fuel pump and set the pressure (since you screwed up the adjustment when you disassembled the FPR to drill it, remember?), and start it. Check it for leaks. To recap, you have disturbed the following:

  1. Upper radiator hose
  2. Lower radiator hose
  3. Thermosat neck
  4. Water temperature sensor
  5. Turbo feed line
  6. Turbo drain line
  7. All the vacuum lines
  8. All the intake piping

Double check it all, and start the car. Enjoy not having to worry about vacuum lines or oil leaks again!*, **

* Remember, -AN lines are not steel lines. They don’t last forever. You need to inspect them yearly, and replace the braided hose every five to ten years. Possibly more if you really put some miles on it.
** The Nylon line used in the push-lock fittings will get brittle due to heat. Inspect it and replace as necessary.




Installing a proper swaybar on a G-Body

“If you can raid the NASCAR parts bin, do it.”
– Dennis Grant

So, in my last entry, I barfed out my thoughts on sway bars for my car. Today’s entry is me actually acting on those thoughts. Today is a step-by-step on how I put a three piece swaybar on my 1987 Grand National.

Underside prior to removal of OE swaybar. Note the diagonal braces. They'll have to go.

Underside prior to removal of OE swaybar. Note the diagonal braces. They’ll have to go.

First, the underside as it was. Please pardon what appears to be an oily mess. The car has the factory undercoating on it, and while it currently doesn’t leak, all the previous leaks have turned the undercoating into what can only be described as black slime.

You can see in this picture the stock 32mm conventional swaybar, along with some add on chassis bracing. The diagonal jounce bars you see will be deleted to make room for the new bar.

Original rubber sway bar bushing

Original rubber sway bar bushing

In this picture, you can see the original sway bar chassis mount, and the 30 year old rubber bushing. The bar is supposed to be able to pivot in this mount as the suspension moves. It didn’t without considerable effort.

All the stuff I had to take off/

All the stuff I had to take off.

And here’s all the old stuff off the car. This is all you have to remove. The bar, mounts, endlinks, and that bracing if you have it.

What I’m installing is no less than a full-on NASCAR road race sway bar setup. Instead of a bent bar mounted in rubber mounts with a sandwiched bushing scheme at the ends, this bar is mounted in brass-raced pillow block bearings, with rod ends connecting the bar to the lower control arms. This setup will eliminate any bind from the crappy rubber bushings sticking and should sharpen steering response since the car will no longer have to wait for bushings to compress before the bar starts to work.

I used a 37.5″ torsion bar from Speedway Engineering. The bar is 1.25″ on the ends, but thickens to 1.5″. This meant the pillow blocks needed to be set a tad wider than the stock mount holes. I also needed to set the bar about an inch forward of the factory bar to clear the idler arm and pitman arms.

The original GM mounts were simply screwed into holes that had been drilled and threaded directly into the frame at the factory. This seems a bit sketch, but if the bar is set up correctly, the body mounts really should not see much load other than holding the assembly to the car. If it was good enough for GM, it was good enough for me. I mocked the bar and pillow blocks in place, and marked the rear mount hole locations.

Drilling new holes for the pillow blocks.

Drilling new holes for the pillow blocks. Don’t use this as a guide on yours, MEASURE!

I then drilled them and tapped them to 3/8-24, and mounted the pillow blocks.

Pillow Block on new rear mount.

You can see in the picture that the frame slopes upward away from the mount. A spacer had to be made. In my instance, a lug nut ground to the proper angle to sit flush on the frame while also providing a level mount for the pillow block worked perfectly.

The next step is the bar arms. I got my from Coleman Racing. They’re 49 spline and 17″ long, with a 30 degree bend in the vertical plane. However, to clear the frame and meet up with the end links, they needed to be bent 45 degrees outward. Since these bar arms are 0.75″ thick steel, that was a concern. I considered trying to heat them and bend them with a hand sledge, but that didn’t look like it was going to pan out well. Thus came the only really specialty service required for this install: a 50-ton press.

I got lucky, really. The good folks at RLC Fabrication had a few down minutes and were able to bend these arms for me. Much thanks to them.

New bar arms after bending.

New bar arms after bending.

Now, this being a non-standard install, it’s important to mock stuff up every single step of the way. Here is one of the bar arms on the end of the swaybar for the first time. It looks great, right?

First mock up

First mock up

Wrong. There were issues. First off, the bar arms would hit the steering box bolt heads on the driver side. Shifting the bar over to the driver side to clear the bolt heads rendered the passenger side nearly immobile as it hit the frame on the way up. When you get down to the finished pictures you will see that I flipped the bars side to side. It provided way more frame clearance that way.

Now, after getting the arms in place, I used a piece of baling wire jammed into the rod ends as a sort of variable length end link. I used this to set the end link length, and mark the arm bars for drilling. You want the end links as close to vertical as you can get them at ride height. Once I had an overall length, I cut some threaded rod to fit and assembled the end links. Don’t forget jam nuts!

Once you’ve marked the spot, drill the holes. With metal this thick and tough a drill press is mandatory. Use a lot of cutting oil or you’ll dull the bit. We drilled a small pilot hole, then stepped up to the 3/8″ we needed.

End link mocked into the arm. The spacers provide room for the rod end to articulate.

End link mocked into the arm. The spacers provide room for the rod end to articulate.

Here’s the end link on the bar arm. Note the spacers. Without them, you lose a lot of articulation range on the rod end.

Now, right at this point is the important part: Make sure you have clearance. Mock it up, and articulate the suspension to make sure nothing hits. If something makes contact while you’re driving around, you will at the very least break something. At the worse, you’ll crash the car. Do not screw around with this step. Don’t save time. Don’t shave corners. Make sure the suspension can cycle through its entire range of motion with the wheels at full steering lock in both directions. If there is any interference anywhere, fix it now.

Powdercoated the arms chrome. Blang Blang.

Powdercoated the arms chrome. Blang Blang.

This is the purty part. We powdercoated the bar arms chrome. I think they came out quite nice. Mirror finish. With a Craftsman powdercoating gun from Sears. How about them apples?

Finished product. Arms had to be flipped to provide extra clearance close to the frame.

Finished product. Arms had to be flipped to provide extra clearance close to the frame.

Here’s the driver side snugged in. In the picture, you can see the pillow blocks, the shaft collar used to keep the bar from sliding side to side, the bar arm, and the end link. This photo was taken with the suspension at full droop. Even at full droop with the wheel cranked over to full lock, there is plenty of clearance between the bar arm and the tie rod.

All Done!

All done!

So there you have it. Total install time was about six hours, not including travel time to the store and to get the bar arms bent. I think with all the parts and properly bent bar arms ready to go, I could do this install again in about two hours.

Driving impressions? I’ve only had it around the block, and there is really no way to to test it properly on the street. But what I did get is that the setup is very responsive. It’s also more comfortable. With the new setup, the sway bar is not involved until the car rolls. So hitting expansion joints on the highway? Way better than before. The old bar was definitely binding up. However, street impressions are for naught. The real proof will come a the first event of 2017. During 2016, I was routinely pulling 1 to 1.1 lateral G in the car. It would understeer and wash out quite a bit as the inside front tire came off the ground.

If this bar succeeds in keeping the tires planted, I expect a front end grip improvement that should be measurable. Keep an eye on this space for an update in the spring.

Here’s a photo album with additional photos:

And now, the parts list. I got the actual sway bar, the bar arms, and the pillow blocks from Coleman Racing. Other parts as noted.

1x Speedway 1.25/1.5 Hollow torsion bar, 608-49-150
2x Coleman Racing Products Sway bar arm, steel, 30 degree, 21915
2x Sway bar pillow block bearing, 12328
2x aluminum shaft collar, 1.25″ inner diameter,
1x 12″ fully threaded 3/8-24 rod, McMaster-Carr
2x (for me, you might need 4) Rod end, 3/8-24 female shank, 3/8 ID, McMaster-Carr
4x Steel unthreaded spacer, 3/8 ID, 3/8 length, McMaster-Carr
1x Pack of 4 Grade 9 3/8-16×3 hex head bolt, McMaster-Carr
1x Pack of 10 3/8-16 nylock nuts, McMaster-Carr

There you have it. A big shout out to my Dad for the lift, heated garage, tools, time, and you know, raising me. Also RLC Fabrication for getting me out of a bind with the bar arms; and Coleman Racing Products.


On the topic of anti-sway bars

Anti-sway bars are the stuff of myth and legend. Especially for the General Motors Metric mid-size platform (the G-Body). You can search and read forums and old magazine articles until your eyes bleed, and you will come away with the distinct impression that nobody really knows how to deal with them. How do they work? how big do you need them to be? Is the bar from supplier X going to be enough? Will it be too much?

When it comes to swaybars on the GM G-body, the conventional wisdom (and the product offerings) seem to center around going slightly bigger. If you’re fortunate enough to have a G-Body that came with the F41 suspension package, you have a 32mm solid front bar, and a smaller rear bar attached to the lower control arms. The aftermarket supplies 34 and 36mm solid and hollow conventional (1 piece bent) bars, and that’s about it, except for Ridetech, which can sell you a NASCAR style torsion bar that’s 1.5″ (38mm) in diameter.

So what do you really need? My opinions – and these are my opinions, but I’ll explain them – follow.

The answer to which swaybar you need? “It depends.”  But I’ll go ahead and spit out one answer early: If you are not racing the car, the F41 front and rear bars are all you need.

The more I dig into the actual engineering on this car,  the more I’m impressed by GM. Some of the perceived deficiencies in the platform are really the result of cost cutting or compromises made in the name of comfort, not bad engineering. The frame is a good example. It’s a c-channel structure. People knock it for being floppy. It turns out, GM engineered the frame to work with the body as a system. If you replace the squishy rubber body bushings with a better bushing material, all that frame flex goes away and the car feels as solid as a new unibody model. There’s no need to add weight or cost by boxing the factory frame, or replacing the frame entirely with a costly aftermarket frame. Once you identify and address the compromise (soft body bushings) things work as designed, and the design isn’t bad.

The suspension on these cars is no different. The geometry was parts-bin engineering, a metric-converted version of the A-body from the late 1960s. The design goals were cost and comfort. The front suspension was built without a lot of caster. Why? Caster stresses the power steering system. They’d have had to add a power steering cooler to all these cars if they’d run the kind of caster modern cars run. And all these modern cars have power steering coolers on them now.

With the F41 package, GM definitely subscribed to the soft spring, stiff bar mentality. And it works beautifully. So I’ll say it:

Unless you’re racing the car on race compound tires, the F41 swaybars are exactly what the car needs. Any more front bar without changes to the front suspension will make it push, and any more rear bar will make the car’s snap oversteer problem even more snappy.

Now, what if you’re racing? Things get more difficult. To keep the car planted and all four tires on the ground in a turn, you need to understand the geometry in the front, your shocks, and your tires. Fix the geometry and the tires, and the car will start heaving further, and will eventually start picking the inside front tire up. When you get your car to this point, it’s time to step up in front bar size.

Buick Turning hard

Buick in a Turn, check the inside front tire

It is obvious from this picture that the car is going to require more anti-sway of some kind to keep the inside tire planted, and transfer load from the outside tire, which is getting overworked.

Doing this with springs won’t help. Controlling roll with the springs limits the suspension travel without providing any load transfer to the inside wheels. Doing this with springs also requires some serious shocks.

So, do it with the anti-sway bar.

Why? First, you keep your softer springs, which keeps your ride tolerable and keeps your costs down by allowing you to run with a less expensive over-the-counter shock package. Second, Newton’s Third Law of motion means that in roll, the compression on the outside of the car will twist the bar and push the inside tire down onto the pavement, increasing the grip on the inside tire. More grip is what we want, not necessarily less roll.

That gets us to “which bar?”

Here, too, I will provide my answer: “Not the one in the catalog you’re looking at.”

To do it right, you need to give up on a conventional single-piece bent bar like you’d get from Hotchkis. Their 34mm bar isn’t big enough. Also, conventional-style endlinks that use poly bushings won’t work. The additional rate destroys the bushing material and creates slop in the links, which makes your bar not work at all. Additionally, the conventional frame mount bushings have a lot of friction and also complicate making your bar work.

To do your swaybar correctly, you need a three-piece unit like they use on actual race cars. Ridetech came to this conclusion when they designed their Musclebar(tm), but their design was built to be an easy bolt-in, so they make some compromises. Namely they welded stuff where it could have been bolted.  I can only assume they did this for durability on a street application where people wouldn’t be checking the clamp fasteners often enough. They also only have two choices for the center bar, and my friends have found it to not be enough for autocross.

So hit up actual race car part suppliers. Speedway Engineering and Schroeder Steering offer splined torsion bars in a large number of sizes. Once you fab up the mounting and get your sway bar arms bent right and lined up, you can easily swap out the torsion bar. Instead of having to buy a whole swaybar from Ridetech for $600 each time, you just swap out the torsion bar for $150-$300.  The torsion bars also don’t take up much space, so you can just throw them in the trailer. If need to make an adjustment at the track that can’t be accomplished by moving the link mounts, you can just pull out a whole different bar and swap it in a few minutes.

My suggestion is to go bigg-ish, with a bar rate somewhere close to 500-600lb-in, then increase the size until the car starts to push in corners. Then back off a step.

But what about the rear? I’ve not seen an instance where a stiffer rear bar will help this platform. In fact, you need to allow the rear to articulate as much as possible. Stiffer rear anti-sway bars will actually cause the car to pick the inside rear tire up off the ground (solid axle!). You’ll lose traction coming out of the corner and it’ll tear up your differential having that inside wheel freewheeling.