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Originally Posted by sperry
The suspension is awesome. About eleventy billion times better than those blown Konis.
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Sweet.
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Originally Posted by sperry
Sunday morning I went back to my 20mm rear bar and it really helped the car turn... but I'd like to avoid tuning the balance w/ swaybars, and do it "right" with spring/damper rate.
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I wouldn't shy away from tuning balance with bars. Ideally I'd tend to worry more about finding the best spring & damper rates for ideal compliance & overall grip on that particular track, and then trim the handling balance with the bars, alignment, aero, etc.
They're also obviously just one of the simplest & easiest ways to make balance adjustments at the track, which has its own value...
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Originally Posted by sperry
For the alignment the car came out at:
Front -3.0 camber, +5.0 caster, 0.0 toe
Rear -2.2 camber, 0.0 toe
I will probably go to -3.5 camber in the front, and accept the little toe-out that comes with it, as the car needs a touch more front-end bite, and since I can use the differental setting under braking to dial-out the twitch that comes from toe-out.
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That alignment looks like what I'd roughly expect. On the yellow car we were using 2-4mm toe-out in the front to get the car to turn in, and typically 2mm toe-in rear for stability (once we switched to the IRS). I also had the bumpsteer response tuned where I wanted it in front and rear, and could adjust them with different thickness spacers. The rear bumpsteer had a large effect on mid-corner to corner-exit behavior as power was applied. Course, it was a RWD car...
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Originally Posted by sperry
Like I said, I think I want a bit more rear spring rate... but I can probably achieve the same effect by going softer at the front... better to add grip to the front, than to remove grip at the rear to tune the handling, right? 650f/550r, or 550f/550r might be close to what I need.
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It's usually better to add grip rather than take it away, just keep in mind what roll stiffness changes will do to your dynamic camber. Take a look at your hot tire temps & pressures for some insight; if you've already got a nice even temp spread across the tires (5-10*F hotter on inside than outside) then you can probably tolerate some extra roll and softening the front could work well. If you don't have a nice temp spread, it might not work. Also, how you measure the tire temps is critical.
I don't know how you're doing it now, but you really need to have 1-2 people waiting for you on pit road with the pyrometer & a clipboard; it goes faster if 1 person measures and shouts the numbers to the other person writing it all down. You pull in immediately off a hot lap (no cool down time at all if possible), stop on pit road and have them measure temps first, starting with the outside front tire, and then pressures second. Seconds count here as far as getting an accurate measurement; if the track has a really long pit road (like cali speedway) your crew needs to be near the pit entrance, not exit or the data will be junk.
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Originally Posted by sperry
I really think it's time for me to stop being a bitch, and loosen up the car for trials. I have an (un)natural fear of snap oversteer offs, so I know I'm running the car w/ too much rear-grip. If I can get used to hanging the rear-end out a little, I'm sure the car would corner at much higher speeds, and bring my lap times down.
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I think that's a pretty natural fear. It's a bad feeling in the pit of your stomach when the car starts rotating around at high speed. There was only one time I ever got nervous riding along in the yellow car, and it was during some bad high speed oversteer. Croutcher was driving while we were testing some different rear shocks at Buttonwillow CW, and one set would throw the ass up in the air coming out of the esses when you touched the berm. After a few laps he really clipped that last berm hard right at the apex (I think we were going 100+mph at that point on the track) and the rear got light and started slowly (in that time-slowing-down-impending-car-wreck sort of way) rotating around towards my side, sliding towards the dirt...
I had enough time to look over to my right at the dirt and rocks, think about how long we had been sliding, and realize that it was probably going to hurt when we went off sideways, dug in and rolled over.
Fortunately Mike kept his foot in it, steered it back straight enough and we only clipped the dirt and kept going.
So I guess the moral of this story is, do you have a roll cage and a real harness yet?
