seansod

Does anyone out there autocross their C3. I am going to spend some money and set mine up for autocross. Does anyone have any information that might help me get the most bang for my buck. I am in the process of building another 350 to replace the numbers matching one. I am also looking at doing something to the suspension (either VBP Grand Touring Plus System or just the Grand Touring System) anyone have any thoughts on these.
Thanks for any help
Tony

tshort

I've autox'd once in mine and had a blast. Actually did pretty good for my first time. But I was doing it more for fun than to be competitive. But I was only like a few hundreth's of a second behind the guy ahead of me and he had a full roll cage and all sorts of hop-up goodies in his C3. I think a refreshed suspension and some newer tires on 17" rims would be the best bang for the buck. Our cars seemed to have plenty of horsepower to compete with the c5's but it was the handling that wasn't up to par. Although I did beat a few of the c5's out there.
Fun stuff! :yesnod: :steering:

seansod

I autocross mine with my Vette club monthly and do OK but I only have 190 ponies in mine and need more. I am going to build a 350 using the performer RPM stuff (cam, manifold and heads) this should get me around 400 hp. With this new power I know that I will need to upgrade my suspension. But hey it is great to autocross isn't it.

Tony

BeaterShark

We have some low speed auto-x events with our club. It's a blast. Here is some of what I suggest:
16" or 17" wheels and low profile tires
Tight (new) suspension
Good alignment (VB&P website)
Larger front and rear sway bars (need to play with this)
Lower rear strut rod bracket (either add spacer or get VB&P smart struts)
Spreader bar
More HP

For auto-x, I don't think the HP helps out much and in some cases keep you from getting traction.

SmokedTires

If you want to be competitive, you need either slicks for your 15" wheels or upgrade to larger wheels & new tech tires :yesnod: . Tires would be first on my list if all your suspension bushings are in good shape.

Then I would look at replacing/ upgrading the suspension with better springs, shocks, swaybars, etc.

I also replaced my streering wheel wth a slightly saller one for better feel & control.

Even if you have the fastest car at an autocross, don't expect to be beating everyone. There is a lot of practice & skill required to get a car to go fast at one of these. They are a lot of fun & from my own exprience, easier on your car than drag racing.

To pass NCCC specs, I had to instal a rollbar & scattershield into my vette because of the aluminum intake & angle plug heads I had on my engine. Before you go too far into your 350 buildup, see if you can contact a spec person & tell them what your planning to see if you'll need anything else to be lagal to race. I had to sit on the sidelines & watch the 1s year :( .

gdh

I agree with BeaterShark, I went once last year, and had a great time. If I were to get into it in a serious way, BeaterShark has the right ingredients. I have a fair amount of hp and with my 15" T/A's on slightly wet pavement I lost the rear end on more than a few occassions.

73 LS-4

Everyone has given very good advice. Bigger wheels and stickier meats are the biggest bang for your buck. Don't worry so much about power, especially in the short tight courses. I went for the first time this last October and the course was tight I really didn't get much opportunity to exercise the Rat much. Also I found that the driver is more important then the car in a lot of cases. I was getting beat by some cars with a lot less power and suspension work then I was running, kinda humbles you as a driver. But as they say "seat time, seat time, seat time" so I plan on racing a lot more next year.

:cheers:

Pat Kunz

flynhi

Before you start making major mods to your car, go to an area autocross and talk to someone who knows about the various classes and what is allowed in each. By installing too many or the wrong mods, you can put yourself in a class against cars that have owners with more money than sense and you will have no chance of winning.
This happened to me, I installed the usual street rod mods and found myself competing against C4s and C5s with major mods. I wasn't close to being competitive with them.
With fewer mods, I would have been competitive in a different class with other C3s.

Desertdawg

I autocrossed mine last year, Stock. And had a blast....

seansod

Thanks for all the good info. I autocross every chance I get. My club autocross once a month and then there are 2 scca sponsered events every month also, so as most of you suggested "seat time" is something that I will be able to do. We have a very knowledgeable group of autocrossers in my Vette club so I will do as you guys also suggested and ensure that I keep my mod's toned down to ensure that I stay in the class that I need to be in. Once again thanks

Tony

dshrack

I built mine for the street but knowing that I would autocross a lot. I have been to many meets and I would agree with Flynhi- go to a few events first and then build up from there. For your car's sake, make sure that you have good bushings and UJoints (not a lot of load from autocrossing but a new powerful engine could cause a failure at a very bad time) and don't forget a front spreader bar between the shock towers. From there- just go have fun. After your first race you'll know where to spend your money. Tires will probably be first on the list. Shocks springs and swaybars or a steering overhaul will probably be next. The VB&P kits look good but you'll want to tailor your kit to fit the car.

I would be glad to share more of my experience- just drop me an email. I found that every part interacts so muich with other parts its hard not to keep adjusting to get it just right. For example, I am now getting ready to drop the size of my rear sway bar after adding some new grippier tires. For now, just run what you brung and have some fun.

seansod

Thanks for all the information. We are autocrossing again this Sunday 12th, I will make sure to ask some of the more experienced drivers what they think about some of my mods I plan on doing. Once again I am always open for ideas of what worked with everyones setups and of course what failed.

Thanks
Tony :steering:

VegasJen

all good advice so far. the one thing i didn't hear anyone mention is brakes. in auto-x, brakes are as important as power. toss the OEM style organic pads and go for a set of hawk or perf-fric. as to the issue of rules, see what they limit you to in brakes and do as much as you can. if you can, install an adjustable proportioning valve and braided brake lines, do so. the valve will make the biggest difference as you can 'adjust out' the rears tendency to lock up so early and provide more braking force to the front.
inspect your bushings and if they need replacement, go with poly. in this case i say screw the rules. if it's against the rules for your specific class, just don't tell them. make someone challenge you but don't go with rubber if you plan to do this alot.
a good progressive rate shock should provide the best compromise if you also do alot of street driving.
springs-already covered.
anit-sway bars-this is just my opinion but if you have one on the rear now, disconnect it at your next auto-x and see how you like it. i think that rear anti-sway bars can make the rear end too tight for the fast transistions encountered in an auto-x. with additional power, it will make it even more difficult to get full throttle coming out of a turn. like i said, this is just my opinion.
tires-go as big and as sticky as you can. i have had my butt handed to me more times than i care to recall by 95hp hondas with victoracer tires.
corvettes are big cars, period. from a performance standpoint, they are much more suited to a large track than something as tight as the typical auto-x course. even so, a c-3 can run with c-4s and c-5s if you know how to drive one ;) i beat an '02 Z06 with an experienced driver at my last auto-x :yesnod:

gkull

You ask which system:) I originally purchased the VB&P Street & Slalom. I would also ask for sway spring end links front rear if it doesn't come with the kit and substitute a 5/8th rear sway.

Go to page 8 http://www.vettebrakes.com/

The most important thing is to take the slop out of the existing suspension.

Moog ball joints and poly bushings everywhere.

Then get alignment settings like the suggested baseline in the catalog.

As soon as you change the tires and wheels or modify the motor you jump up into the top classes!:(

Years ago when I first started I was right in with all the trailer queens on racing wheels and slicks

Darkness

If you wnat a little more ummph you can do gears instead of getting a better engine and then going into another category. Just do gears and it will be alot better. No less than 4.10's for a daily driven :crazy: :D

Paul

seansod

Thanks for all the help the only question (not really the only one) I have is are 4.10's really streetable.

groovyjay

I would put my money on these:

VB&P Performance + suspension
Better Brakes
Bigger wheels and slicks
Steeroids Rack n pinion steering

Then just :steering:
:cheers:

Darkness

Depends, you got an overdirve? If not, then no, but if you do then yes.

Later :cheers:

Mansier

All good information. We won a few state autocrossing championships in BSP with a 1973, and a 1978. Here are a few things we learned:

Go with the heavier springs for the front - 550lbs. We cut off half a coil.
Go with the 8 inch spring bolts in the rear, and get a fiberglass spring. We used 330 and 360. Think the 330 was better for autocrossing to get the power down.
Put a cage in the car. These chassis flex quite a bit, and a properly built cage makes all the difference. We seam welded the frame, gusseted everything the power manual said to. Built the cage to go through the fire wall, and to the rear shock mounts. Makes a huge difference. Add a spreader bar.
Go with a bigger bar in front, and about a 9/16 in the rear.
We use Performance Friction pads, and they downright work.
We have used anything from C4 wheels and 255/50/16s to 17x11s with 315/35/17s (yes they fit under the fenders, but barely). All worked, but won the championships with the 16s (maybe they heated up a bit more from being skinnier?)
We run a 3.55 or 3.70 rear with 375 HP.

That's about it. Hope it helps. I love these cars. Look for a NASA road racing class: Vette/Viper Challenge soon. My car will be there!

seansod

You were able to do all those mods and still stay in BSP. I thought the cage itself would take you out of BSP. Not doubting you but am unsure of the extent of the mods I can do without moving up to big boys.

Right now my car is completly stock (L48) and numbers matching. I am building another smallblock 350 to replace the originial. The car has the original 4 speed (not rock crusher) not sure what gears are in it assume its prob. the 3.08. Planning on changing the gear also to 3.70 not sure yet.

On the moter rebuild would like it to still allow of the occasional night out the Wife (that way she won't ask why all the summit boxes keep showing up) I am still trying to figure out the combination I want to go with.

As said above I plan on ordering the package from Vette Brakes but will be calling about the availability of changing out some of the compents with ones that I want (spring weights ect). Thanks for reminding me about the brakes with the new found HP's I hope to get I will need the extra stoping power. I did plan on installing the steel braided lines. But will upgrade to the better pads.

As you can see I am just getting into this project. The good thing is that since I am building a different engine I will not be without my autocross ride for any real length of time.

Thanks for all the info
Tony
:steering: