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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:

https://goo.gl/photos/enNV6Aki1ppkbELW7

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, Amazon.com
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.

 

CAM East and other musings

Last year, I attended the CAM Challenge East in Peru, Indiana. I wrote up that experience, which was overwhelmingly positive. You can take a waltz down memory lane here.

This past weekend, I went again. Plus more. To say the past four days have been a blur would be a vast understatement.  On Friday, I made my way up to Grissom. I had to leave a lot later this year than last due to a well check for my daughter. We got onsite just past six. Even then, I was able to tech, register, and walk the course. But there wasn’t much chumming about.

My daughter came along with me this time, and seemed to have a good time looking at the cars and playing with her stuff and reading. Oh my. The reading. Read three books front to back this weekend. I won the lottery with this kid.

As for the event, it was a repeat of last year. Fast course, lots of awesome cars, everybody having fun. Most of the points I made in my post last year carry forward. The high dollar equipment showed up once again. Once again, nobody cared. We were all there to have fun. And Fun Was had.

I had a co-driver. James Bishir, who I commended last year as an exemplary n00b, had some highly publicized car trouble at Putnam a few weeks ago. Circumstances conspired against him, and his car just wasn’t ready. So in exchange for lodging and breakfast, he co-drove mine. Wouldn’t you know it, the stinker ended up faster than me by the end of the day! I beat him overall at the event due to a quicker morning session, but he’s a quick study.  Once he gets his car back together, he’ll be able to hurt some feelings.

But CAM East wasn’t the only thing on my plate. After dinner Saturday, my daughter and I packed up and headed for home. We got back about 9pm. We both got cleaned up and passed out… only to get back up again at 6am Sunday. There was another event at NCM that I needed run in order to earn my regional year end points. My daughter was also slated to make her autocross debut in a friends’s kart.

So, we made it to NCM with plenty of time. The SCCA Targa event was finishing up there. It was interesting. Randy Pobst was there, and his introduction to the Kentucky Region of the SCCA included a demonstration on how to properly perform intercourse with an Exocet by one of our esteemed STR drivers.

Sadly, my daughter was met with some heartbreak. It turned out she was too small to safely operate my friend’s kart. She was crushed, but she’s a trooper. She bounced back quickly, helped me get my tires changed, and the rest of the day went smoothly. Until a good buddy accidentally locked my keys in my car while doing me a solid and rolling my windows up during a cloudburst. Ooops. It was nothing an old Corvette antenna couldn’t fix, though.

And here’s where we get to the car. This was the first event weekend since installing a recirculating blow off valve. At the Wilmington Champ tour, I was plagued by lag. Every time I had to lift off the throttle and then get back on it, I could count to two or three in my head before the turbocharger came back. On the Wilmington course, it had to have cost me at least two seconds.

So I put a Tial 50mm ventilator on the car.

TIAL 50mm Recirculating BOV

TIAL 50mm Recirculating BOV

For those not familiar, this valve allows pressurized air that gets blocked by a suddenly closed throttle plate to be bypassed around the turbocharger and fed back in the inlet side. This prevents air from reverting backwards through the compressor and stalling it. The result is the wheel keeps spinning while the throttle is closed, and when I mash the gas back down, I have to wait less time for the turbocharger to come back up to speed.

Here’s a datalog chart from the Wilmington Champ tour that clearly shows the problem. After a throttle closed event, the boost takes a long time to come back:

Arrows point to extreme lag events

Arrows point to extreme lag events

Here’s a chart from Sunday’s KYSCCA event:

Post BOV. No more lag.

Post BOV. No more lag.

As you can see, there’s no more lag. The car is responsive enough to actually drift around corners without spinning. That’s not easy to do with one of these.

The car placed higher than expected this weekend. At CAM East, I was in the top half after the morning sessions. I drove less well in the afternoon and fell to 21st out of 34. I would have been 41st of 67 if I’d been in CAM-C like I was last year, which compares very favorably to my finish from last year.

At the KYSCCA event, It was the same story. I won CAM-T easily, and would have been just a fraction of a second out of a trophy in CAM-C if I’d run there.

All in all, it was a fantastic weekend. Exhausting, but fantastic. The car performed flawlessly. It was a moral victory of the highest order.

And now, the videos. Here’s my best run from Peru:

And my best from the KYSCCA event:

A BMW Reflection

A post on Jalopnik today jogged my memory about an experience I had owning a BMW. Below, you’ll find an updated version of a tale I spun many moons ago over on 502streetscene.com. Enjoy.

Once upon a time, I bought a BMW. 1999 540i with the manual six speed transmission. I thought I’d made it. I had  a BMW. A desirable one. The Benchmark for a four door sports sedan. I thought I’d stolen it. Paid nine grand for it, and after replacing the clutch and the tires, I was cruising.

To this day, I still remember how well it drove. How you could drive it all day and not be tired because the seats were just that good. The stereo was shit until I replaced the speakers, but everything else about the car was amazing.

Then it all went downhill.

Rist off, it started idling like crap. The intake re-seal had to be done. It’s a typical item item, not a big deal. That was expected when I bought it. Knocked the job out in a weekend. No biggie, but the sheer number of fasteners and the low quality of the gaskets that crumbled to dust after just 100,000 miles was disappointing. Ford used much higher quality gaskets on my then-wife’s Sable. They were still nice and bendy at 110K when I replaced them.

Then I started getting Digital Throttle Control codes, and eventually it went to failsafe and wouldn’t move. Both TPS sensors in the throttlebody were fried. Root cause? The electrical connector on the computer-controlled thermostat leaked, and coolant wicked up the wires all the way back to the DME and shorted out a bunch of shit. Cost to repair that was a $300 throttle body, a $180 thermostat, a few connectors spliced into the wiring harness to stop water if it leaked again, and oh, I had to tear the top of the motor off and do the intake manifold re-seal all over again. Oh, and corrosion from the coolant shorted a pin that ran the secondary air injection pump to the #1 TPS… inside the DME. That meant unplugging the secondary air injection system, which is an emissions component, which means the car could no longer be registered anywhere that has emissions testing without a DME replacement.

Then the shitty plastic snap-on connectors they use on the radiator hoses failed catastrophically and without warning, dumping all my coolant out on the road in J-Town. Normally a cooling system failure is preceded by a leak. Not on a BMW. That shit just explodes.

THEN the real fun began. One day I start the car and it’s making this high pitch squeal. It’s coming from the driver side valve cover. Pull the valve cover, and there are chunks of what turned out to be timing chain guide all over the inside of the engine. BMW uses a very brittle and cheap plastic on the timing chain guides. If the tensioner isn’t replaced at the proper interval, the chain goes slack, beats the guides, and they crumble.

The kicker? There’s no replacement interval for the tensioner in ANY of the BMW service literature or the owner’s manual, which means most of these cars are running around with slack tensioners. From reading other peoples’ experiences on bimmerforums, the tensioner should be changed about every 50K miles or so.

But alas, it wasn’t on mine. Replacing the chain guides is a 23 hour job according to the book. It requires over a thousand dollars in special tools to block the cams and the crankshaft at TDC so nothing moves while you have the chain off, you have to tear the engine down to the bare longblock, and the car must be re-timed and the adaptations in the computer cleared or it’ll run like shit when you put it back together. The crank bolt must be torqued to 100ft-lb, then turned another 150 degrees in three more steps. I borrowed a torque wrench that did torque angle. It quit when I hit 500ft-lb on the bolt, and I was only halfway through the second tightening.

I did the guide replacement myself and then had it towed to Stein for them to re-time it. That lopped 15 hours off the bill, and it was still three grand.

Oh, and I spent an hour with a set of needle nose pliers pulling chunks of chain guide out of the oil pickup. Had that stray piece not gotten jammed in the right spot and made the noise and alerted me to the problem, I’d have never known, and the pickup would have eventually been completely blocked and the engine would have been oil starved and completely ruined.

Oh, and behind the chain guides is an oil separator. It’s made of brittle plastic and will break as soon as you touch it. Once it breaks, the car smokes like a freight train. Replacing it requires tearing the entire engine down again, because it’s behind the damn timing chain.

So, I got all that fixed. Car was running great… for a week. Then the steering interlock broke, immobilizing the car. Towed back to Stein, they had it two weeks waiting for the interlock, new keys, and a new ECS module. $600 more.

I put it up for sale right after that. In a single year, the car had cost me $7500 in parts and labor, $2000 in depreciation, used up all of my tows on my AAA membership, and was actually in-service for just 10 of the thirteen months I owned it.

I added it up after I sold it. I literally would have been cheaper for me to walk down to the BMW dealership and lease a BRAND NEW 550i than it was for me to own that E39 for a year. Literally. Lump together purchase price, parts, labor, and depreciation and divide by 12 and I could have driven a brand new car instead. Maddening.

As for doing the work yourself, a good friend once told me that a BMW owner needs but two tools: a cell phone and a checkbook. I used PTO to take many days off work to fix that damn car.

The only good thing, maintenance wise, about that car is changing the oil. With the canister filter and easy-to-reach drain, I didn’t even have to jack the thing up. Fifteen minute job… of course, by the time you buy the $30 filter kit and eight quarts of the $7.99 Mobil1 or Castrol Euro formula BMW LL certified oil, you have an $90 DIY oil change on your hands.

Like I said, I LOVED that car when it ran, I really did, but it made me pay for the pleasure.

The Road to (and from) the Optima Search for the Ultimate Street Car

Fair warning, this will be longer than a typical post.

Way back in February, I did something crazy. I entered the Optima Search for the Ultimate Street Car event schedule for the NCM Motorsports Park the weekend of June 10th. At the same time, I ordered my big Weld RT-S71B forged 18×9.5″ wheels. I was feeling giddy. A big name event, actual track time, big sponsors, lots of photo ops, and high-dollar competition that was surely going to crush me, but would be awesome to be able to compete against.

The best part? No work assignments! The second best part? I had five months to prepare! Easy?

Turns out, not so much.

My entire mission the past year or so has been to make changes to the car to reinforce it. After the engine rebuild, it’s been about longevity and reliability. I got new front suspension arms not because what I had didn’t work (it did), but because the new stuff was stronger and had 15 years’ more engineering know-how put into it. I built an engine that can make 500-600 horsepower on race gas and 30psi of boost, and have elected to (attempt) to run it at 17psi on pump gas, because I don’t want it to blow up. Instead of taking the leap to a Megasquirt, I jumped on an opportunity to simply add a blue-tooth enabled connection to my Powerlogger so I can monitor the engine without a lengthy development effort or cutting up the dash to fit more gauges.

So in the run up to the USCA event, it’s all been about evaluating the car and fixing stuff.

The first thing to fix was my new wheels. One of them ended up not being round.

Now, I have no idea how that happened, but Weld took the wheel back no questions asked and fixed it, so good on them. However, they couldn’t get it fixed and back to me in time for the USCA event, so I ran it on my old 245mm Dunlops. Omen #1.

Omen #2 was a trip down to Lexington for an autocross in May. It was hot. 90 degrees. On the way home, I had my handy new Bailey Engineering Scanmaster-G set on the coolant temp, and noticed that I was running 195 degrees on level ground. When cruising uphill at 70mph, the temperature climbed above 200. Not good, especially when I was anticipating having to run boost down a 1 mile long straight at NCM a month later.

So, after I got home and let the car cool down, I popped the radiator cap and looked inside.

the crusty insides of a 29 year old radiator

the crusty insides of a 29 year old radiator

Yup, thirty years had taken its toll. The tubes were crusty and full of deposits, the oil coolers were covered in slime. Once I had it out of the car, I found several pinhole leaks that had sealed themselves with corrosion. All in all, this radiator had lived its useful life. So I ordered a new one from GNS Performance. The radiator they sent me was a work of art. All aluminum, dual 1300+ CFM Spal fans. Lovely.

new radiator next to the old one, note how much thicker the core is

new radiator next to the old one, note how much thicker the core is

If this didn’t fix my cooling issues, nothing would. Thankfully, it fixed them. I did have a battle with the relays, though. The mounting brackets are crap. If you buy this radiator, zip-tie the relays to the brackets before you attempt to install it. Otherwise, they’ll come off the brackets and drag on the ground.

Omen 2 dispatched.

Omen 3, and the one I should have taken to heart and withdrawn from the competition and gotten my money back, was when I noticed my passenger side axle was leaking. Figuring the bearings where shot, I got new bearings and seals. When I popped the rear cover to get the C-clips out, I found this:

Missing ring gear tooth

Located missing ring gear tooth

Yes, there was a tooth missing from the ring gear. Conveniently, it had found its way to the magnet on the back cover and not done any further damage.

There’s a lesson here: DO NOT LEAVE OUT THE MAGNETS when you overhaul stuff. They were put there for a reason. There is no way to tell when that tooth broke. It had been at least three years since I popped that cover, maybe more. If that tooth hadn’t stuck to the magnet, instead finding its way back in-between the ring and pinion, the rear would have locked up, then shattered, and the car would have spun off and likely hit something unpleasant.

When my Dad and I pulled the wheel bearings, we found the passenger side bearing had, in fact, spun. Oops. It’s likely that whenever that bearing stuck, then spun, that’s when the tooth came off the ring gear. Or not. Hard to tell.

Anyway, we found this Tuesday night the week of the event. After a judicious application of the plastic wrench (thanks for the metaphor, Rich), I had a new ring and pinion on the way from Summit. It got here by 10am the next morning. Along with a new installation kit.

The next day, as we were installing the new ring and pinion, we discovered the installation kit had come with the wrong side bearings. GAH! Thankfully,  a local truck parts house had the proper bearings. My good friend, Tom Bell of Bell Motor Service helped me get stuff pressed off/on, and we got the diff back together Wednesday evening. Summit racing even took back the incorrect bearings and refunded me $58.

Then came the really hard part. Ring and pinion sets must be properly broken in, or they will fail. I needed to put 500 miles on the car by the time I got to Bowling Green – less than 36 hours from the time we buttoned the diff up.

So, Thursday was a driving day. My daughter packed up some books and videos and her MP3 player, and we climbed into the Buick early Thursday morning. We took the back roads to Newport and ate lunch at the Haufbrau Haus, then took I-71 back home. That got us 350 miles.

Friday morning, I packed up and headed for Bowling Green, again taking the back roads to extend the mileage and vary the speed. I arrived at the track just past noon, having put just over 500 miles on the ring and pinion. I paid $100 for a garage and parked the car so it could cool off. If you’re ever doing a track day event, pay for a garage. Being able to get out of the sun is worth every cent.

While it was cooling off, I took some time to walk around the event.

This twin turbo Camaro could have its power level dialed in anywhere from 500 to 1300 horsepower!

The equipment present was fantastic. It was also HOT. I don’t think it go below 90 degrees at night.

Anyway, I changed the differential fluid at the track, and thought all was well.

The next morning was the Speed Stop challenge. We started on a section of the road course, accelerated down a hill, up another hill, and had to stop the car in a box just over the crest. Much tougher than it sounds. I got one good run, then the car started stalling and sputtering. It wouldn’t rev past 3000 rpm, which, coincidentally is when the fuel injection system switches from sequential to batch fire. That’s important. Remember that.

After making a few more attempts at runs, I finally limped it back to the garage. I pulled the logs from the runs out of the Scanmaster and found that, curiously, when the engine burped, every single sensor spiked. This was good. It meant this was a problem internal to the computer, not a problem with the engine. So I pulled the computer out.

It was so hot to the touch, I nearly dropped it. After setting it on the concrete floor to sink some heat out of it, I opened it up. I wish I took a picture, but what I found was amazing. A ground had completely burned up inside the ECM. Now, since these ECMs sink a lot of current, they have a bunch of ground pins on their connectors, since one pin with a single 16ga wire isn’t enough to handle the multiple amps that ground through the computer. One of those pins had overloaded and melted, leaving the ECM with insufficient ground capacity. The epoxy that’s used to weatherproof the unit had melted in places. It had gotten hot, and likely had one or more internal short circuits.

This is where the 3000 rpm thing comes in. The car was stalling at 3000 rpm. When the fuel injection switched from sequential (1 injector grounded at a time) to batch (6 injectors grounded) the current overloaded the ECM and caused it to reset. At best, the car stumbled. At worst, it stalled completely.

Now this is where a small miracle occurred. Where do you get an ECM for a 1987 Buick Grand National on Saturday? In Bowling Green? Not at a store, that’s for sure. I called them all.

But wait, each year Bowling Green hosts the Buick GS Nationals! There had to be somebody nearby  that raced Buicks that had an ECM on the shelf. I called my friends at Boost Crew Motorsports, and within an hour, a kind soul brought me a loaner ECM.

So, while my Speed Stop runs were poop, I had a new ECM and an afternoon of autocrossing to get done. I also had the Design and Engineering portion, which I crushed. Top Ten finish in that section. Go me.

The autocross was HOT. The Dunlops didn’t like the heat and washed out halfway through my first run. I got two more runs done before the brand new cooling fans quit.

That’s right. 98 degrees and I had no cooling fans. It was at this point I threw in the towel. It was too hot and I was too tired. Racing further risked damaging the car worse or me losing my temper. I wasn’t having any fun. It was time to go home.

My good buddy Dave happened to be at the event working, and he’d brought his truck. A quick call to U-haul for a car trailer and we were loaded up and headed home.

Northbound and down…

Ironically, this would be the second time Uncle Dave had bailed me out of a racing-induced failure two hours from home. He was the one that got me home in 2014 after I blew my head gasket at IRP. I really need to get my own truck and trailer.

Once I got home and had time to properly troubleshoot, I found the root of the problem:

Melted!

Let me take a paragraph to explain what you’re looking at. It’s a ground, melted into a loom. The ground had gotten hot, probably from working loose and arcing after I installed the new fans (which grounded through this ring). As it melted the plastic, the plastic eventually encased the ring and separated it from the bolt head that was grounding it to intake manifold. This severed the ground and disabled the fans. I think it also re-directed a bunch of current through the ECM, which is what burned it up.

Needless to say, this particular ground has been fixed, and fixed right. A reman ECM was sourced and a spare I had in the garage has gone into the trunk “just in case.” The entire weekend, including the radiator, ring and pinion, entry fee, and hotel cost me over two grand.

That said, I didn’t do too badly. Thanks to my top ten Design and Engineering score along with Autocross and Speed Stop times that were above the bottom third, I managed to not be DFL despite scoring a big fat 0 on the road course portion. That’s a big deal.

I plan on trying again next year. I think with my big wheels on the car and all these other gremlins sorted, the Buick should turn some heads next year.

This thing actually works pretty good!

So, there have been more than a few posts on here regarding  my foolish endeavors prepping my Grand National for SCCA autocross competition. Some regard it as silliness, most others think it’s pretty badass. I’m having fun with it, though, and that’s all that really matters.

That, and results. Is what I’m doing working? How do you tell?

You tell with data. You collect data, and you analyze it, and the data will tell you if what you are doing is working or not. Without data, I’m just talking out of my ass.

So I got some data, then overlaid it on this video:

This is telemetry collected using superimposed on a video feed from my Go-Pro. If you watch the little g-meter in the bottom left, you’ll see the car hit 1.1g lateral acceleration, not in a crazy offset, but a sustained turn.

1.1g. Sideways. In a 1987 Buick Grand National.
Granted, this was at the Wilmington Air Park in Ohio, which is concrete. This car would not be able to do that on asphalt. Or would it?

That one was on asphalt, on a really cold day. It hit 1.0g. I’m happy with it.

What put the car over the top? What made this possible? Tires.

Big, beefy, sticky BFGoodrich Rival S tires. In 275/35R18. The biggest I could fit under the car without cutting it up.

Rear view of new tires

Rear view of new tires

Front tire at full left lock

Front tire at full left lock

What made getting this much rubber underneath a car that came with 215mm wide tires originally? Careful measurement and custom offset wheels. I aquired a set of Weld RT-S71B forged wheels for these meats. Getting them on the car and balanced required on-car balancing, since these rims are lug-centric. Weld can also only manufacture to a half-inch on the offsets. These wheels needed 1/4″ spacers on all four corners to truly get them to not hit stuff.

New Weld Wheels

The results are remarkable. I’m at the point now where I finally feel I’m in need of a bigger front swaybar. You see, the car is rolling a bit too much now and putting too much load on the outside front tire. It likely always has, but now I can prove it:

Trying to drive out of the tires

Trying to drive out of the tires

This photo was captured by the people at autoxpix.com, and shows quite clearly the wheel attempting to escape the bead of the tire during the 1.1g turn in the first video. I’ll attempt to compensate for this with more front tire pressure moving forward, but a better front anti-sway bar is going to be the real fix. Anti-sway bars don’t just make the car roll less in turns, the extra roll resistance actually transfers load from the outside wheel to the inside wheel, allowing the inside tire to handle more of work.

I don’t know when I’ll be able to get that done, I need to treat my property for termites soon, and that costs about the same as the swaybar I need. Oh, the woes of being a grownup.

Cadillac CTS-V and the steering thing

My Cadillac CTS-V sprang a really bad power steering leak the other day. Big leak. Giant puddle on the floor. Turns out it was the pinion seal on the rack and pinion assembly. Changing in the car would be a bit insane, so I had to pull the rack.

Now, there’s no procedure for removing the rack and pinion in the factory service manual, and I haven’t been able to find one on the internetz. So I’m writing one. Now. Step by step. No pictures, because you really don’t need them.

  1. Raise the front of the car as far as you can, set it down on jackstands positioned under the lift points on the subframe  (there are little arrows on the skirt showing you where).
  2. Remove the front wheels
  3. Remove the brake calipers and hang them off the upper control arms using wire or zip ties.
  4. Remove the brake rotors. Don’t beat them off with a hammer, they’re held on with a little torx head screw.
  5. Separate the tie rod ends from the spindle. I did it by running the nut almost all the way off, then whacking them with a ball peen hammer.
  6. Now is where it gets fun. Set a jack under the engine cradle, then remove the two driver side engine cradle bolts (21mm heads). Gently lower the driver side of the engine cradle onto a jack stand.
  7. Loosen the motor mounts from the engine cradle. The rear motor mount nuts are 21mm. The fronts are an 18mm nut welded to the frame and you’ll need to get a wrench on top of the bolt, that’s 13mm.  Loosen them as far as you can without taking the nuts off.
  8. Raise the engine with a jack, being careful not to crush anything up top.
  9. Remove the bolt holding the steering shaft to the pinion.
  10. Trace the wires coming out of the black cylinder that’s screwed into the rack gearbox portion to a connector right in the front of the car next to the ABS module. Disconnect and pull the wires out.
  11. Unscrew the black cylinder, being careful not to twist the wires. They’ll break if you twist them, and if they break, you’ll have to buy a whole new whatever that thing is.
  12. Disconnect the two power steering lines from the rack gearbox.
  13. Remove the anti sway bar.
  14. Unbolt the two bolts on either side that hold the rack down.
  15. Wiggle the rack out by moving it forward into the space vacated by the swaybar and pulling it out through the driver side wheelwell.

It’s not difficult, but it is time consuming. Take your time. Reinstall is reverse of removal.

Tensioner woes

The 1984-1987 (and 1989 Turbo Trans Am) engines had something that was relatively new to GM in the 1980s: A serpentine belt with a tensioner to drive the accessories. All the other G-Body powerplants (305 V8, 231 non-turbo V6, and the 4.3L V6) used multiple V-belts, with the tension set by feel.

The Grand National, with its fancy fuel injection and turbocharger, required something new. So, instead of a bunch of V-belts, it got an inch-wide serpentine with a tensioner to maintain tension on the belt instead of prying at accessories with a screwdriver.

This was all well and good, until my tensioner started making noise. Terrible noise. And it wasn’t the bearing in the tensioner pulley, no. the spring-loaded tension mechanism was popping and grinding and making a terrible racket. It needed to be replaced.

Problem: they don’t make it anymore. GM discontinued it. All the parts store no longer had them in stock. Turns out the tensioner assembly was unique to this engine, so it’s NLA. Thankfully, the good people at White Racing has created this new billet tensioner to replace the discontinued stock unit. It’s expensive considering the OE tensioner used to sell for $60, but this is an old, niche car. Gotta pay to play.

So I got one.

New tensioner on left, old and busted on the right

The first thing you notice is it’s shiny. The second is the massive amount of metal around the bolt holes compared to the stock unit. Where the stock unit has thin cast-in gussets, this new piece has been machined leaving as much material around the bolt holes as possible. This was done to alleviate a nasty habit the stock pieces used to have: they’d break. A popular thing to do with the Buick V6 was to put an eyebolt through the alternator, then hook that eyebolt to a ratchet strap that was attached to a hole in the frame. This kept the engine from rocking over to the passenger side and breaking the driver side motor mount. The problem came when people started making big power, all that force got transferred through the alternator case to the tensioner (which the alternator attaches to). The tensioner would then break. Not good. This tensioner is manufactured with a lot more metal hoping to avoid this situation.

Installation was pretty straightforward. Disconnect the battery, take the belt loose, get the intake tube that runs from the MAF to the turbocharger out of the way, unbolt the alternator and swing it out of the way, then remove the two remaining bolts to pull the old tensioner. Installation is reverse of assembly.

After installation, all of the undesirable noises and vibrations that had been coming from the front of my engine are gone. That includes not just the popping, but a persistent click that I had assumed to be a lifter. It was the tensioner all along.

Positive Ventilation

Turbocharged Buick V6 engines are famous for many things. One of them is puking oil out of every possible spot when the engine is under boost. They blow the dipstick tubes out. They force oil past the rear main seal. They spray oil out the valve cover breathers.  Mine even was forcing oil out of the PCV valve grommet under the intake plenum. They can be a huge mess. Even my newly rebuilt engine is doing this. It’s blowby. Gas getting past the rings when the engine is under boost. My first few autocross events, I was coming into the grid smoking after my third run from oil escaping the valve covers and pouring onto the exhaust. It was embarassing, it made a mess of the lots we race in (BAD), and made a mess of the engine compartment. I have been determined to fix it. After several attempts, I think I’ve nailed it. I’ve come up with a system using two catch cans and an industrial strength check valve. It goes a little something like this:

In this first picture, you see the passenger side of the intake manifold. Down underneath the plenum is an OEM PCV valve. The Goodyear hose runs to a catch can bolted to the side of the intercooler, then back up and through that brass check valve. The check valve is rated at 400psi, and is there to prevent manifold pressure from getting into the crankcase when under boost. Without that check valve, positive manifold pressure would easily overpower the OE PCV valve and pressurize the crankcase, which forces the oil out and makes a mess.

Now, the stock set up simply had a hose running from the PCV valve to the PCV inlet tube you saw the check valve attached to. The catch can keeps oil from making it to the check valve and gumming it up, as well as keeping the oil out of the intake tract.

But, there has to be another part. The stock PCV system had a vent in the passenger side valve cover that was connected to the turbocharger inlet. That set up mostly worked, but once you turn up the boost, that single vent simply isn’t enough. I’ve added a second vent.

Instead of one vent line, I ran two. Each valve cover has a Mr. Gasket breather cap on it and a 5/8″ line coming off of it. The lines go into a tee just behind the alternator, then run to another catch can.

From this catch can, we run out to a fitting that’s been screwed into the inlet pipe ahead of the turbo but behind the mass airflow sensor. This is important and I’ll explain.

PCV systems are basically a tuned leak. A port on the intake manifold provides a vacuum source, and a vent in the valve cover/intake tract provides a source of fresh air. Engine vacuum draws air into the vent, through the crankcase, and into the intake manifold where the crankcase vapors are burned in the cylinders.

In a computer controlled vehicle, this poses a problem. If you vent to atmosphere, say as if you’d used an open breather element on the valve covers instead of the closed ones I used, you would get extra oxygen in the cylinders that hadn’t been metered by the MAF. On a Buick using the stock computer, this extra oxygen is detected by the O2 sensor, and the computer adds fuel. In the Buick’s case, it adds WAY too much. So much that it washes out the rings, contaminates the oil, and eventually ruins the bearings. I didn’t want this to happen.

So, the vent is plumbed into the intake tract after the MAF. This ensures the air entering the crankcase through the vents has been metered, so when it shows up in the intake manifold via the PCV valve, the computer has already taken the air into account. It keeps the mixture correct, and doesn’t kill itself.

Under boost, the check valve on the manifold side closes, and the turbocharger inlet should draw out the crankcase gases via the breathers. In all cases, pressure should not build up inside the crankcase. It shouldn’t leak, and any atomized oil will condense in the catch cans and not foul up the turbocharger. All the air in the system goes through the MAF, and all should be happy. So is it?

Yes. In the screen capture below, you’ll see a grid on the right side. That is the Block Learn Multiplier (BLM) table. It’s basically a fuel trim table. If everything is absolutely perfect (70 degrees F, no leaks, perfect engine), all the numbers would be 128.  They’ll vary with conditions (temperature, whether the gasoline is RFG or not, etc.). If you have a vacuum leak to atmosphere, like you would with a PCV system vented on the valve cover to the air, you’ll see BLM numbers above 150, and that’s bad. These are all in the low 130s, which is pretty good.

The PCV system isn’t leaking in air from the atmosphere. I’ve already found a very slight amount of water/oil mix in the smaller catch can after a 20 mile drive, and I’ve got no leaking oil running down the valve covers or collecting under the intake plenum. Preliminary indications are positive, and I’ll report further after my next autocross event to see if this system stands up to competition.