I had an AutoCross the weekend before last. I drove alone on Saturday. On Sunday, my adopted brother codrove with me. He's a VERY good driver, started off in Karts when he was young and was exposed to racecars his whole life, unlike me. So I had no doubt he could do very well in my car. It's the first time he's driven this one in 5 years, and I have made a LOT of changes since then, but he adapted really quick to it.
That weekend was a special event with folks coming from 4 different states (Arkansas, Louisiana, Mississippi, and Tennesee). So there were a lot more people signed up than usual. Usually the out-of-state people that attend this event are very serious about AutoX (and tend to be very fast, too), so I usually place a little lower. That was expected. What wasn't entirely expected was just how
terrible the car would be.
If you recall from my last post about the August event, I said, "I was fighting a massive shortage of front grip. I will probably need to make some changes to the car. Jack from Maximum Motorsports had told me when I was planning this build that my Steeda 35mm front bar would likely cause some understeer issues. I had not experienced that until this event. I need to go shopping at my dad's little salvage yard and get some bars to test out."
The problem with changing after that event is that, as my cousin pointed out, the course at War Memorial is much tighter than we usually run (it's much smaller, so there's a lot of overlapping sections of course) and it's on asphalt. So making changes to the car based on that one event may not be the right move, since we only run there once a year. But at our normal location, it still had the same issue, like I thought it would. It was really hard to drive around. I tried braking early and just going slower so that I could position the car for the next element and get back on throttle faster. That yielded slow times. I tried staying off throttle all the way, occasionally even lightly on the brakes, in an effort to keep the front end loaded, still not very fast. The car just wouldn't catch any traction up front.
About the only thing that worked and turned decent times was good, old-fashioned gas-mashin. Turn the wheel to get into the turn. As soon as it started to push, hammer down to rotate the car and get it pointed the direction we wanted, then countersteer and back off the throttle so the car would hook. That was faster, but still not fantastic.
I did phone in to Jack at Maximum Motorsports about the issue yesterday. My curiosity was about why the car started exhibiting such bad understeer after I put the K Member and new FCAs on. If it was
just too much sway bar in the front, shouldn't I have had the issue at the June events?
I gave a brief explanation about the car, the issues I had, and some questions. His first question was whether I had properly bumpsteered the car when I installed the new 99-04 spindles and K Member. I sheepishly admitted that I hadn't, I had bought the gauge he sells and planned to do it eventually (at the same time I did a corner balance), but for right now I just set them where they looked right and moved on. His thought is that that's the cause of a lot of my understeer on the car.
So my projects for this week/weekend:
- Pick up a factory 94-98 GT front sway bar.
- Jack's exact words last year were, "In the front use the stock 1994-98 30mm swaybar along with the 1” rear swaybar. That should only result in a small amount of understeer."
- I'm gonna go ahead and put the lighter bar on to hopefully gain some grip back up there.
- If I still have troubles at the next AutoX, I'll take the tools with me to raise the Watts link at lunch time and then try again. If that setup gets me good front traction, I'll lower the Watts link a notch; with as much power as the car has, I need as much rear grip as I can get, but I still need the car to be driveable, not plowing off course with the tiniest amount of turning.
- Resquare the K Member
- My first attempt apparently wasn't very good, as I have -3* in each side of the car and both camber plates are maxed out...in the same direction...
- Ensure that the heights on the front springs are even on either side.
- When I put the K Member back in and lowered the ride height, I prioritized getting the front control arms perfectly level. Jack indicated that this may lead to some funky corner-jacking that may affect the handling.
- Lower the rear ride height to where the rear arm mounting locations are even and the spring heights are the same on either side.
- This should get me an acceptable antiquat percentage for now.
- Eventually, when I corner balance the car, I will figure out CG numbers and IC location and all that to make sure that I get it around 60-70%.
- Install Stiffler's transmission crossmember
- I've had it for a while, just haven't prioritized the install, but I do need to...
- Check and adjust pinion angle
- A part of that adjustment is going to be trying to get the tail of the transmission up as high as I can. I have noticed in the past that the pinion angle I should be at gets the driveshaft very close to the emergency brake cable bracket. I am almost to the point in making changes to this car that it may make sense to remove the entire emergency brake assembly anyway. It's not exactly a street car anymore and I rarely street drive it that way. But I would like to be able to street drive it more, so it stays for now and my quest to get all the little bugs worked out so it's reliable continues.
- Align the front end
- Check and adjust bumpsteer to get it into the acceptable range of toe change
- Adjust toe as needed
That's about as much as I will probably be able to get done this week/weekend.
I do have a 94-04 Cobra brake setup and Eaton TruTrac sitting here that needs to get installed. But the need for that isn't as immediate as making the adjustments outlined above.
If you read this far, I'll let you in on the secret that my brother ended up beating me on Sunday by 4/10s of a second.
