yet another track day for the '81. once again, she ran nearly flawlessly. i say nearly because she kind of gave me fits all day saturday. she would run great (relatively speaking) for the first 6-8 laps and then she would go away, start sputtering and misfiring. i could not track this problem down. i thought it might be a clogged fuel filter so i changed that, didn't solve the problem. figured it might be ignition so i pulled the cap and found the rotor screws coming loose, enough to rock the rotor significantly. i figured that was surely the problem, but that didn't solve it either. after checking multiple other things, i finally bypassed the jacobs ignition module and didn't have a lick of problem for the rest of the weekend.
she ran strong and i'd like to think earned a little respect from quite a few of the c5 and Z06 drivers.
not surprisingly, i was yet again the only c3 out there. there were a few c4's even a couple ZR-1's but by far the majority was 5th gens.
there was a photographer out there taking some pictures and i got an absolutely beautiful picture i'll post later. he also got some "diagnostic" pictures yesterday, which i did not buy, that show just exactly how much i'm loading the car. HOLY CRAP!!!! i thought the suspension was alot tighter than that. if i had to guess, i probably had something like 4* of body roll. i was really throwing her around hard. the guy said he was going to post some of those on his website later. i might link to them later so you guys can see just how hard you can pitch a c3. and most of you know i've done quite a bit of work to get this car to handle better. everything is still the conventional design (i.e. no reengineering) but everything is upgraded.
special thanks to the guys and gals out at spring mountain. they're working hard to improve that facility and (very near) future plans are to extend the track to nearly 4 miles. they put on a great event and i think just about everybody had a good time. (except the Z06 driver that put it in the wall!) they're looking to have the new track extensions complete in time for the may corvette days.
i'll post pics shortly

 

Poor z06 owner. That must suck. I would love to see some pics of your car running though. Sounds like a lot of fun.

 

What spring rates are you running?

 

Cool, it sounds like you had a great time. The whole body roll/camber gain issue is one that I think needs more attention. Photos like what you are referring to would be very useful. I would certainly like to see them.

 

Sounds like you were driving and having some fun with the ole girl

 

Sounds like fun. Hopefully you earned some respect for the C3.

 

i'd like to think so too but them cars are built like race cars and with the ABS and active handling they can make a real idiot look like a good driver and that pisses me off. What fun is it to let the damn computer drive the car?

I'd like to see your pictures. I'd really like to see you do an in car video. What tires were you using? I still think you need to install the 550 springs.

I'm glad you decded to bang your head on the wall and drive the C3 instead of your new C5. The C3 section will benefit from your misery.

 

I prefer road racing to any other type, so post those pictures. Thanks, Joe

 

Would love to see pictures as well.

 

well, here goes. i just uploaded a few of these to my photohost account. all the photos i bought are from saturday. the photographer sold photos by the day and i decided not to buy sundays photos because they weren't as pretty. they show the suspension better than these though.
yes, i hate these tires. this is a pretty good picture showing the push. you can't tell from it, but i'm inside the car screaming, "bite, you bitch, bite!". and, no, i'm not feathering off the gas just because the front tires don't like it.

this one is me really leaning on her through turn 4. i didn't know the suspension had that much compression left in it. there are several more from the next day that really show the suspension compression.

i call this one the money shot. i figure if chevrolet were actually building a sports car in 1981, a photo like this would have been used in the brochures. the s/o says i'm biased but i think that this was the prettiest car out there. i got a special 13x19" glossy poster of this one made up it's so pretty. it's going to be in my signature soon!

oh, if anybody is interested, there are more photos at www.trackday.net. just scroll down to where it says 'schedule/gallery' and then to "2/26/05 and 2/27/05 corvette trackdays"

 

i would say from the looks of the pictures your rear spring is too soft as compared with the front springs.

that jives with your complaint that your car pushes (tight) (understeer)


My car is the opposite (loose, oversteer), its tail happy so i need to install a softer rear spring. I'm gonna try the fiberglass i got for christmas.

P.S. I would think that you would want to keep the bias slightly towards understeer as that allows you to charge the corners hard with more confidence. I think this is one of my problems as you just have to drive a loose car more conservatively.

 

what size tires are you running, and also what kinda of suspension mods do you have done? this is something that i am just starting to do to my car and wouldn't mind knowing what you have already done to get your 81 to handle like it does. thanks a lot,
Ryan.

 

Understeer can also be caused by too big of a front sway bar. C3's don't really like big front bars in tight turns. Some understeer can be tuned out by dropping the front tire pressure or increasing the rear pressure, stiffer rear spring as mentioned, wider front tires, or slower corner entry speed. Also adding a rear bar or heavier rear bar, but I don't recommend this route, I would consider this a last resort.

 

I was just going to ask how you keep from hitting the top of your helmet on the T-Tops---a problem that I ran into when I did a little Autocross

SEMPER FI--1970 Dave

 

Clutch,

How many hours of track experience do you have?

 

Looks like you have the chassis set up fairly well. Lots of sidewall flex,with little chassis roll. I would love to see mine on camera during hard turns like what you're pulling.That's what these cars were built for.

 

Looks like you are really unloading the inside front tire. Too much front bar or not enough rear bar. Maybe something like the factory Z71(?) bars would work? You'll pick up speed if you get it a little loose, too. Joe

 

First off - Way to go GARY!

I went to the site and I guess that they didn't post you there.

Is this the Parrumph race track? What is your max speed? It also looks like the pavement was very green from all the latest rain and no rubber down yet?

 

update on current mods to the car: all poly everything, cut #460 front springs, #330 rear spring (i think), koni shocks, 1-1/8" front bar, no rear bar (not hooked up, at least), VP spreader bar and smart struts. i have as much front camber in as i can get, about 1.5-2* and about 1-1.5* in the rear. tires front and rear are 275/40-17 eagle F1 (non-supercar) take-offs from the school.
yes, george, this is pahrump.
the first picture shows my bad habits more than anything. you can tell i'm off my line by a good 2'. at this point on the track, i should be at least to the white line but the car was beginning to push and instead of feathering the throttle to get her back on line, i just kept feeding gas. that's part of the reason the front appears to be lifting like it is, the rear is squating a bit under acceleration.
oh, and if you check out the trackday site, you have to go to the intermediate group to find me and i'm listed as 'white with stripe' or something like that.
turtle, i have done somewhere around 50 open track events in addition to a hundred or so auto-x's.

 

real quick story you guys might appreciate... on sunday, i had switched over to my 245 front tires because i wanted to finish them off. they had what i call "memory tread", which means there's an outline where i remember there being tread.
anyway, i get out there and i'm running hard. i let a couple Z06s go past as they were experienced drivers with modded cars. but i like to go "hunting", looking for cars with more capabilities but less experienced drivers (SMMP is my 'home track'). so i catch a c6 and a c5 both decide to pit rather than allow me to pass. that's fine. up ahead about 200 yards is another Z06 so off i go. i catch him after about 2 laps and we're going at it. he kept pulling on the straight sections and had a little better cornering than i did, not to mention this was about the fourth session of the day and i could feel the tires going away. we did this little dance for about 4 laps. he was hitting the corners a little conservatively and i was leaning on it, plus i'm familiar enough with the track to know where to make up for some lost ground. so we are at it and he keeps getting 2-3 car lengths on me every time we go through start/finish but we're running just about the same times (2.00-2.03 laps). anyway, we get checkered flag and as we come back in the paddock i stop and talk to him. he says he wasn't planning on driving that hard because his tires were old but there was no way he was going to let that c4 pass him. CEE FOUR!!! i said, "oh no, it was a c3 that was going to pass you!" oh was he upset!
so after i park, go look at his "worn out" tires. hell, i wish my tires looked like that. instead, this is what they looked like:

anyone still want to argue we get plenty of negative camber gain under compression? bear in mind, this is with an initial setting of about -1.5*. maybe our good friends at VBP could come up with a solution for this. there's probably enough of a market for a bolt-on if they can figure one out.