flynavy78

I've got a bit of a dilemma on my hands. I've recently been bitten by the race bug, namely autox. I currently have a 13k mi, un-modified, unmolested C5 ('03 EB M6). It's so nice that I have a hard time taking that step to really 'driving' the car like it should be.

Here's my question: Is it worth selling this car to buy a higher miles C5Z06 to get into autox, or keep my base C5, bite the bullet and mod/drive the heck out of it? Is the autox performance of the C5Z enough better to justify the swap, or can I get my C5 in the ballpark with standard mods? If I'm keeping the C5, what's the best way to set it up for entry level autox, knowing that seat time is obviously the first place to spend the $$/time!

Thanks for the advice. Btw, my C5 is currently listed for sale, until someone convinces me otherwise!

Jason

You will have a hard time hurting a C5 autocrossing it. No mods needed. Drive the hell out of it, you'll just be scratching the surface of what it is capable of for a long time to come. By then you'll be able to answer the question yourself.

gmccreary

Listen to Jason. He knows auto-x.

ltborg

I actually did the opposite. I got a C5 coupe to replace a C5Z for autocross. The C5Z is awesome, but you will have fun in either car. Now that there is a place for non-Z06 C5s in A Stock, either option can be competitive if you want to get serious about it. Just go out there and have fun.

SouthernSon

Transmission gearing favors C5Z for autocross but the regular C5 tranny ratios are better for road racing (according to some).

flynavy78

Why did you make the switch? Was it solely to run in the lower class? Is the C5 more competitive in AS than the Z is in SS?

Bill Dearborn

I doubt this will hurt you much at the beginning. Once you get some seat time the only thing I would do is put some C5Z rims on it with some R compound tires. That will get you closer to the C5Z performance. I used to run C4 GS wheels 17x9.5 front and 17x11 rears on my 97. When I bought my C5Z I just moved them over to it.

The transmission gearing becomes an issue since low gear on the C5 is not high enough to run a whole course and not low enough for a good start. C5Z low gear is good for the start and then a quick shift into second lets you run the whole course.

The most severe damage most autocrossers get is cone marks which can cleaned off with the correct cleaners. Other than that the car may get dirtier if you are at a dusty location.

Bill

TedDBere

They both can win their classes...SS for C5Z and AS for C5.

You'll need a front bar change, autox alignment, and an extra set of stock size rims (+ or _ 0.25 inches offset) for some sticky A6 tires. Then drive it like you stole it.

Have fun!

ltborg

I don't think the coupe is more competitive in AS than the C5Z in SS, they can both be competitive given the right setup. That's a bit of a guess for AS since it hasn't had the current classing as long as SS has.

I agree the C5Z transmission has an advantage to the base coupe, but the would only be an issue if you were running in the same class (like ASP). If you are sticking with the stock classes, it doesn't matter since you would be in a different class (SS vs AS).

Going to AS was the reason I started thinking about switching cars, but there were a lot of factors in the final decision. Overall, I just felt the coupe was going to be a better compromise for me and how things were looking at the time. You can't go wrong either way, they are both great cars.

What are you looking to do with this car (all out race car vs. weekend track toy)? If you are trying to build the car to be competitive in a specific class, you'll have to be careful about the mods you go with. Either way, just check the car often and keep it in good repair, then go get some seat time.

ipuig

I've owned both and autocrossed both the C-5 and the C-5Z. Both cars can be fun and very competitive. Driver skill can easily surpass any advantage the C-5Z has over the C-5 on the course in my opinion.
I sold my coupe and bought the Z because I've always wanted one and came across a very well maintained stock Z.

flynavy78

Is an autox alignment streetable, or is it only to be done prior to an event?
My goal for this car is to pretty much drive it daily(more than I do now), cut my teeth and eventually be competitive with autox, and run it at the track a few times a year (to remind myself how much I love the speed). Eventually, I see myself with a track only car, but this will not be the one. I definitely look forward to makeing some mods, mainly because I enjoy the work, but not go into debt over it (nothing extreme). Was just thinking that the Z would be a better starting position for all of that. Seems like I may have a hard time getting what I need out of my car to afford a decent Z anyway...

froggy47

IMO a full autox alignment (including tow out/in f/r) is not really going to be enjoyable to street drive for the average Vette owner & will certainly wear out tires at a fast clip. But you can put a compromise mild autox alignment on it & have a good time.

l98tpi

From what I have experienced at autox's. It seems that the C5z is the best Vette to use for autox. I too firmly believe that seat time and good experience is best and that it comes down to the driver. However, if you have two good drivers, it comes down to the car. Any Vette or any car for that matter can be upgraded, but upgrades cost money. So, you may be ahead by purchasing the C5z if the if the 5th generation Vette is what you like.

avizandum

My car is an AutoX weekend warrior and DD. I run -2.3 with 0 toe up front and -1.0 and 1/8 toe in in back and I have no wear issues whatsoever. NO TOE up front and run whatever you like.

NASAblue

to do it over, I would have sold the 97 with 35k miles on it for an 04 z06 before I started tracking it all over the place, but at the time I didn't think I had the money. Many many weekends on my back under a car on 14" jackstands later... the z06 seems clearly superior in every way, even for auto cross.

I spent all the $$ making the 97 as good as or better than a Z, which isn't hard, but extremely time consuming (cost associated with that too) and minorly expensive if you do your own work, but then labor intensive.

Can you have jsut as much fun in a C5, yep. Is a C5z a much more solid car, double yep: right down to the better suspension bushings, shocks, cam, oil pump, block, intake, heads, trans, clutch, exhaust manifold, solid top, stiffer body, upgraded sway bars, stiffer springs, rear brake ducts, hardened transmission output, gear ratio (dont forget the carbon fiber blocker rings that allow using synthetic fluid and updated synchros, shifter, torque tube diameter and guibo size) and 1000000 other little things seeing as how we didn't even touch on the weight reduction material.

04 is when they made the shocks a touch better and the bushings stiffer. The last year is always the best. I would stick with the electron blue or silver (has grown on me). Yellow is always cheeper if you want some center line cammo.

My friend got an 01 z. vs my 97c5 with a z51, it's like driving a different generation of car. Completely different experience. In RR they say z's are worth 4 seconds a lap faster, personally I think quite more. Now that's significant!

Hands down, your gut is correct, sell the 13k cruzer to someone who wants a polisher and to keep it stock and get the beast made for the beating.

Good luck!

flynavy78

Thanks for the advice from everyone, as expected we've got both sides represented. I think the trick will be getting enough for the C5 to basically make an even swap for the Z(wife imposed spending limit). Otherwise, I'll be happy with what I've got!

A couple more questions that weren't clear in the SCCA Solo rulebook: Are short-throw shifters allowed for AS/SS? Are Z06-width wheels allowed on a C5, considering them 'stock' size?

Solofast

Uhhh that would be a NO and NO.... You can change the shift ****, but not the length or the innards of the shift mechanism in stock...

Since the C5 is in A stock you can't upgrade the wheels to Z wheels...

Bill Dearborn

The aftermarket shifter won't provide any advantage and depending on you and the tech guys may or may not put you in a different class. AutoX in most areas is basically a two gear deal. 1st and 2nd. An aftermarket shifter will not help. Sure you get a shorter throw but the shift takes just as long since it takes more force and you move slower. The aftermarket shifters are most effective with people who ham fist the shifter and need help getting into third on the 2-3 shift.

Bill

flynavy78

Thanks Bill, I was really considering the daily driveability when mentioning the short-throw shifter. What are some typical mods when you look at the ASP class?

Solofast

In ASP for our kinds of cars the mods with the biggest payoffs are stiffer springs and sway bars, bigger wheels and tires, and poly bushings. Big dollar shocks (Koni doubles or Penske's) are a given even in stock class for a nationally competitive car, so I'm saying springs bars, and bushings are the next step beond that.

While you can add stuff for more power it really isn't a big payoff, a C5 has about all it can use in an autocross anyway. In SP you could add headers and that's probably a good thing, no so much from what you gain in power, but if you lose some weight it helps.

The C5Z is very close to as good as it gets for a stock class car. If you start from a base C5 the extra stiffness from bars and springs will help, but to be competitive in ASP with a base car you are going to have to go beyond the stiffness of Z springs and bars.

Remember that a car that is taken to the limt of street prepared rules isn't going to be very "streetable". It is going to ride like a buckboard on the street, and while you can put plates on it and drive it on the street, your wife sure isn't going to want to ride in it to go out for dinner and it's going to get old real fast if you have to drive it a lot.

JMHO but I always thought that the SP rules went a bit too far and all they really did was take cars that were marginal prepared class cars and give them a place to run. To do a street prepared car to the limit of the rules you have a prepared class car (read full race car) without any internal engine mods and the interior still in it. Can you drive that on the street? Well, yea, but not for long and not every day. To be competitive the car is going to be so darn stiff you would need a kidney belt to drive to the drug store.