What mods/upgrades have you done specifically for Autocrossing ? and did the mods give you the results that you expected ?

Thanks

 

It all depends on what class you want to be in.
I can't remember all the classes and rules, but I think my dad was in D2.
I watched my dad autocross alot when I was a kid, and I can't wait to do some on my own.
He built a 75 just for autocrossing, and he ran a mild 355 with hooker side pipes, a 411 rear end and an M22 tranny. With some slicks, that car was pretty bad *** for short autocrosses with out a lot of long speed spots. My brother drives that car around now, and it's a lot of fun, and loud as hell.

trw

 

I have yet to mod my car [specifically] for autocrossing. Working much harder on modding the driver.

 

I lowered it, stiffened it, lightened it and added fat tires... but this was my C2 with fender flares at all 4 corners. C2/C3 chassis is basically the same.

 

Before I would start modding the car I would enter in some autox's in the stock class. You get some experience and learn more about the car and you as a driver.

But if you want to know some mods go with mostly suspension upgrades. The mod I felt was most effective on my car was upgrading the front sway bar and adding a rear sway bar.

 

The only mod that I made specifically for autocrossing was my alignment setup. Your best bang for your buck on setting up a C3 for autocross is a good alignment setup and a set of modern tires and wheels (16-17"). There's lots of other little things that will help as well but I believe these are your best for the price.


Pat Kunz

 

The best mod you can make is to jack up the gas cap and slide a C-4 or C5 under it!!!

In SCCA you can have a lot of fun, but unless you can find a very unique class to compete in, the C3 just isn't very competitive. Now if you want to build a race prepared car, that may be a different story, but in anything else your competition is just well ahead of the C3. This is primarily due to the C3's early 60's suspension technology.

Don't be discouraged, as I said you can have a lot of fun, but be realistic in your expectations. Been there, done that!!

GUSTO

 

Is this car new to you? Unless work has been done in the recent past you can just figure that all the soft parts are shot and worn.

At the front replace all the ball joints with MOOG. Install all poly bushing on the a-arms. Replace all the steering arm ends. Install better shocks. If all you have is money for cheaper shocks. The KYB gas adjusts are a good value, put them on all four corners.

From Vette Brakes and Products purchase the rear Smart Strut unit. Have the rear trailing arms rebuilt by Van Steels. Reinstall them with all Stainless steel shims to "ZERO" rear toe.

Setup the cars alignment specs with the base line settings out of the VB&P cat. Always place equal weight in the drivers seat during alignment with 1/2 tank of gas. I put two 90 pound bags of cement in the drivers seat. Try running within 4-6 psi of max tire pressure in each tire. So they say max of 44 have 40 in them to align and later when you first show up to race.

Then go out and get some advice from a racer watching your car. If it's got to much lean. Sways and springs are in order. Keep exacting records. But you have to start with a base line. Get used to it and beat the car up. Only you as the driver with familiarity knows what the car is really doing or not doing. So any change you make you'll better understand.

I didn't put all my crap on in one day! I've had 25 years of changes.

First make it a solid plateform to measure against - then push it! I never counted the times i've lost it so bad that you might as well let go of the steering wheel and stomp on the brakes and just find out where it wants to go.

When I was younger my friends used to laugh at me because I never sold a car - I retired them! Lot's of single car totals and racing accidents.

 

i thought we all decided a while back that the smart struts are not desireable in road racing and autocrossing because you don't get any negative camber gain under spring compression.

 

Well i bought the ST in the late 80's I did things looking at the amount of tire scrub on the side walls and with a tire temp gauge across the face of the tire. If your getting an equal temp or the same amount of tire roll under your using the max adheasion.

Something very strong that can keep both tires as flat as you can through a max "G" turn is best. The Smart Strut on the lowest position keeps the trailing arm from bending the least. Steel hiem joints has less deflection than my Poly setup. But I also drive my car many miles. I've also just never invested in a 6 link.

I always just used the biggest tires and wheels and a wider wheel track for max grip. 6 inches of additional rear track keeps a car planted so well that you can be on the gas hard way before your exiting a turn. Your cornering speed is so much higher.

If I ever tried to install skinny tires and stock stuff I'd be in loop city My 420+ pound rear springs are made to flat track. It's really a good feeling in a 5 point seat bolted flat to the floor all the way back to the battery box. Your like part of the car. When the rear wiggles your so close to the rear center of movement you can tell what's up

 

All these are excellent suggestions, but driving skills are stills are 70% of what makes a good autocross driver. I would suggest getting with an experence driver and learn how to drive autocross.
Dan

 

Hey gkull---that was a great post--NOW THAT POST DEFINITELY BELONGS IN "TECH" I played around a little with autocross a few years back and have thought about it again a few times--reading your post kinda gave me some ideas and kind of rekindled that itch--thanks

SEMPER FI--1970 Dave

 

We put VBP gymkhana springs in the rear and front with kyb gas-ajust shocks, also got 17by12 three piece rims for all four corners, 315s in the back, 275s up front. Its like the car is glued to the road. Also did a bunch of weight saving, tossed out A/C compressor, condenser, heater box, front bumper supports, flip up headlight assembly, aluminum intake manifold, forged aluminum calipers.