Category ArchiveSCCA

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:

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.

Positive Ventilation Part 2

Well, really not part two, because I’m not changing anything, just reporting back.

I am happy to report that after this past Sunday’s KYSCCA Event at the Kentucky Fair and Exposition Center, my PCV solution works. The car did’t puke any oil out of the breathers. Victory!

New Seats!

So let’s talk about seats for a bit. Seats are important. Seats keep you in front of the steering wheel while you’re driving. When you turn, seats, combined with the seat belts, keep you from shifting around inside the car. In a crash, seats and seat belts keep you from getting crushed, either by slamming into the rear seat (or the passengers that might be there) or eating the steering wheel. They’re very, very important.

That said, the seats that came in GM products of the ’80s were designed to meet safety standards of the time as well as the desire of the typical ’80s customer for a smooshy, compliant seat. While the Grand National got a decent set of buckets for the period, the foam is still smooshy and the bolsters are set up for a person much wider than me. In a recent autocross, I was using my grip on the steering wheel to keep in place, and the tilt mechanism gave out. The wheel dropped into my lap, and I nearly spun the car out. Not good.

Not too long after that, an acquaintance of mine was racing his Malibu in Lexington, and his entire column failed, and he actually did spin the car. No bueno.

So I bought some seats. What I chose were some black buckets from NRG. I got the pair at Amazon for $299. They’re a ripoff of the Recaro bucket seat you could find in the 2000 Honda Integra Type-R. I picked them because I remember my friend’s Type-R and how well I fit in those seats. Honda made them to fit smaller Japanese customers, not fat Americans, and I fit in them perfectly.

Step one was removing the stock seat, and vacuuming up all the dog hair that was under them.

After removing them, I bolted down the brackets I sourced from Wedge Brackets. These things saved me gobs of time. Fabricating brackets would have taken me hours, and Wedge makes brackets and sliders for OEMs, so I have a bit more confidence in the safety of these in a collision that something I would have made myself.

Next step is getting the sliders bolted onto the seats. The NRG seats came with their own double-locking sliders, so I used those.

The NRG seats showed their Chinese-ness here. The bolt holes for the sliders were covered by fabric, I had to locate them by feel, then use an awl to punch holes in the fabric for the bolts to run through. Annoying.

After that, it was a matter of bolting the seat/slider assembly to the car.

Thoughts on these seats? They’re cheap. The fabric isn’t top-notch. The foam is very firm. In fact, I’ve gotten a new appreciation for how stiff my suspension actually is. The old seats sucked up a lot of the smaller bumps. The lack of squish in the cushions also means I’m sitting slightly higher in the car than I was. I may need to swap out for thinner sliders. The bolsters are fantastic. My skinny posterior fits perfectly and they upper bolsters seem to contain my shoulder and midsection pretty well. I’m able to take corners at speed with just fingertips on the wheel, and that’s using just the three point seat belt. Final verdict on how well they hold is reserved for the next autocross. I’m hopeful I can get away without a harness, because I need my back seat to remain usable.

These are also light compared to the stockers. With sliders, they’re 25 pounds each. The brackets are about 2-3 pounds. The stock power driver seat was over 50, and the passenger seat was close to 40.

But the best benefit? My irreplaceable stock seats are now wrapped in plastic and in the basement, safe from sweat and spilled drinks for the foreseeable future.

Wrapped for storage!

 

My fastest run from the CAM Challenge

Enjoy!

 

CAM Challenge East

I had the honor of participating in the first Speedway Motors CAM Challenge East, hosted by the SCCA at Grissom Air Base in Peru, Indiana, this past weekend.

To say it was a blast is an understatement. The course was fast, the cars were incredible, and the people were fantastic. The contrast between this event and the National Tour event I ran way back in 2003 was astounding. These CAM folks are fun to be around. Everybody enjoyed themselves. The “ringer” cars that whiney people said would show up and clean everybody’s clock showed up, and some clocks were cleaned, and NOBODY GOT UPSET. Because this crew appears to show up to have fun, not win. That is a novel concept for a national-level SCCA event.
The G-Force! from left to right: Andrew Scott, Lance Hamilton, Dave Nutting, James Bishir
One of the highlights was meeting up with some fellow G-Body owners. We had four: Myself, Lance Hamilton, Dave Nutting, and James Bishir. James is especially notable because this was his first ever autocross event. He was the perfect n00b. He asked questions, he talked to people, he listened, and he improved every single run. His first run, he was ten seconds off pace. By Sunday morning, he had beaten me by seven hundredths of a second.

Another treat was getting to watch Robby Unser and two-time Indy 500 winner Al Unser Jr. up close. They were both running in beautifully engineered machines built by Speedway Motors, and they were both blisteringly fast. But much to what should be the consertnation of the CAM doom and gloom crowd, the Unsers didn’t prevail in CAM-T on Saturday. Nope. They showed up with pit crew in professionally built race cars, and themselves were professional race car drivers with multi-decade careers. On Saturday they got beat by a kid – Cody Mason. And nobody was mad.

Takeaways for me? I need more tire. A lot more tire. I was running on 245mm tires, and was probably on the narrowest tire of any car at the event. Dave Nutting was also on 245s. James Bishir was running 275 in the front, 295 rear. Lance Hamilton had 275 all around, and everybody that beat all of us was on 305-315mm tires. Steamrollers. Thanks to being able to eyeball Lance and James’ cars, I can start planning on what I need to do to run similar sized rubber next year.

Here’s a link to my Google photo album from the weekend:
PICTURES!

So that Watts Link thing? Yeah, it works

So, there was an autocross yesterday. The day started quite rainy, resulting in a low turnout, but things cleared and we had a fantastic afternoon for an event. Seven runs, done by 3. Perfect.

Except on my second run, somebody came running up to my car to tell me I’d let loose of a large bolt on course. A quick peek under the car revealed I’d lost the bolt holding the propeller on my Watts Link.

Using a borrowed wrench and some scraped elbows, I disconnected the Watts bars from the axle clamps and removed it. Back to stock rear suspension, and right back out on course.

Observations? Well, oddly , I went fast. A lot faster. But I’d only run two runs so far with the Watts, and was still figuring out the course. It’s possible that gain was all Watts, but also possible it was all me being better.

What was stark was the car’s behavior. It was LOOSE. really loose, except when it wasn’t. There was very little consistency. In one corner it would push. In another it would try to step the rear out. When the rear did slide out, it didn’t gracefully slide back into line when I lifted the throttle or steered into the slide. Nope, it snapped back the opposite direction. Each run I found myself madly sawing at the wheel trying to get the car to go where I wanted it to go.

The takeaway for me was that I’m likely faster with a loose car, but the Watts adds a large level of predictability. I’ve ordered new parts to replace what fell off and will have the Watts back in place for the next event at the Corvette Museum. I’m going to raise the center link pivot one hole to see if I can keep the predictable handling while also loosening it up a bit.

We shall see.

How does this thing work now?

So, all this work, and no updates on how well it did… until now:

Driving impressions? Very good. The day before this event, I taught at the local drivers’ school. Aside from student that showed up with a bone stock Evo X, my car handles better than everything else I drove that day. A lot better.

Now, that said, I was still puking oil everywhere. Turns out I had a very slight head gasket leak. I’ve just replace the driver side head gasket and will be putting it through its paces this week in preparation for the next event on June 28th.