JeremyGSU

I have done the following on my '04 Z and have been pleased with the handling of the car.

Lowered on stock bolts
Johnny O’Connell stage 1 sway bars
Doug Rippie Custom Valved Bilstein shocks
Track alignment
OE 18" wheels in the front on 285/35/18 slicks

This did not cost me much and reduced the amount of understeer the car came with stock. I really like the way the car handles and feel it is very predictable and is still very streetable.

One of the things that becomes a challenge is how much do you want it to handle on the track versus ride on the street? I realize if I went to stiffer sway bars, coilovers, camber kit, and bushings it would handle even better but it's also going to be more uncomfortable on the street. Since lately I drive it more on the street I prefer the latter.

RDnomorecobra

just make sure you run 1 quart of extra oil on track as per the manual.

lefrog

02s and early 03s are known to have valve spring failures. If they were never changed, change the valve springs and the seals ($100 deal) to be on the safe side.
Also watch your temps and do the regular maintenance, it will go a long way.

SouthernSon

9 out of 10 of us (if not more) wish we had kept our stock cars stock. A track car that does duty as a DD is a compromise. You can put a lot of money into upgrades that lower the resale and, yet, never quite satisfy as much as a car that is already modified with roll cage, race seat and fire suppression system. Save yourself some money and run what you have. Buy a used track car in a couple of years after lots of seat time and save yourself a lot of money.

Nowanker

Bingo!
It's a slippery slope! Almost everyone I know that tracks has made the same mistake. You take a really nice street car, start improving it for the track... then it becomes a wretched street car, and the only time you drive it is to the track.

SunnydayDILYSI

That's where I am, darn good fun at the track though...

SoDiezl350

While I generally agree with this sentiment, some mods improve both street and track driving characteristics. I honestly hated the way a base C5 coupe drove on the street. Tons of roll, no steering feedback, unsupportive seats, terrible shifter, giant steering wheel, and a tendency to lose traction over any bumps while turning.

The only mod that I've done to my primarily track C5 that I wouldn't do to a street car is removal of the airbag and poly bushings. I also wish I never bothered with long tube headers, street or track.

tytek

+1

SouthernSon

That's funny that you should mention headers. I really enjoyed my Melrose headers when car was used as DD. But, to list those things of benefit that did not hurt ride quality as DD I would have to include the Honker intake - first mod I did to my '03 Z06 that added 13hp and 11 torque. Next, the headers and lastly, some adjustable shocks. So basically, that would be it if I were to start over again with a DD Z. I agree with no polys for street. But then, I also run 1023 pound spring front and 870 rear and lowered. Great on track, not pleasant at all on street.

Soloontario

Personally, I find the stock shocks to be underwhelming and would love to get something more substantial. Considering that I find the car understeers quite a bit , I would like to try a rear sway bar which shouldn't hurt ride too much. Anybody just run a rear bar or do you always need to front as well ? Fortunately most rear bars seem to be adjustable anyway.

QKSLVRZ

I had a 02 Z06 that I AutoX'd a few times, but I was very impressed with the traction the front of the car had. That car was very drivable as delivered (factory Z06 alignment, much racier than standard Vette).

I did drop it down on the stock bolts, should have weighted it.

So, if your Z06 understeers, and you're not really over driving the car, get the alignment set. You can get a lot of quality time with it stock.

I sold it before I got around to it, but headers would have made the LS6 sing.

SouthernSon

Let us look at two time periods:

Present - "I probably need to add some good shocks so I can go even faster. Then, I really ought to look at lowering the car, maybe polys. I am pretty sure I ought to add some good heavy springs. I probably need to add that $5K brake system to stop even quicker."


3 or 4 years later - "You know, I spent a lot of money on all kinds of aftermarket stuff and I don't think the car is really any more fun than it was when I first bought it. People still pass me, I still need to learn more about car handling and now the resale value is shot to heck. And, after all is said and done, I still need a good cage."

Moral of the story: Go buy a good track car that is fully equipped if that is what you want and leave the car you have in its stock configuration. You will then enjoy the track car more and you haven't hurt the resale of your stock vette.

Soloontario

2 seasons ago, I ran the car with a square set up and neg 2.5 degrees camber up front as well a bit of toe out which produced a fairly neutral car. This past season, due to some rule changes in the time attack series I run in, I ran a staggered set up and stock camber (neg 1.2 degrees). The car was easier to drive but understeered like a pig and was a whole bunch slower.

QKSLVRZ

I only did a couple AutoX in my Z, but I couldn't believe how well the front stuck. Now that was coming from cars that really understeered. I came away thinking if I ever had any understeer on the street I was going way to fast. Though I do know that -2.5 will have more traction than -1.2 will.

SouthernSon

On the subject of understeer: If one installs a really stiff spring the tire requirement goes way up - you will need sticky tires. Same goes for stiff sway bars. Every part must work in conjunction with the other in order to turn. Unfortunately, after the car is set up for a really sticky track tire, some of us, from time to time, try to save money on a set of HPDE tires for track events and get those that are sort of an in between rating and the understeer raises its ugly head. Also, that "toe out to turn in" does not always apply. Some have found success with zero toe on front. Just a couple of other things to consider.

Bad Karma

I think there's a line you can cross before you are unhappy on the street with the mods you have done to be faster on the track. But for me keeping it stock is not that line, not even close.

In my opinion the basic bolt on mods enhance the car and do not sacrifice the car's street-ability. I have added the following:

Doug Rippie valved Bilsteins
Van Steel sway bars (front & rear adjustable)
Wilwood W6A front brake kit w/ DRM/Quantum spindle ducts
Borla exhaust
Callaway Honker intake
MGW shifter
DeWitt's Radiator
Fixed back race seat and 6 point harness (3 point still functional)
SKF HUBs
Aggressive alignment

*Headers waiting for install

I feel the car is better now than when I bought it, both on the street and on the track. I even prefer my racing seat to the factory seat, I just put the stocker back in for a day road trip where I was in the car for about 9-10 hours and I don't think I was any happier in the stock seat than I would have been in the racing bucket. The only thing that's easier in entry/egress with the stocker, but I think GM failed big time in their seat choice on the C5 Z06. My '90 C4 was a 10 times better seat that what I got when I bought the C5Z.

Now I will admit there's not much more for me to do before I am dangerously close to crossing that line of more track car than street car.

QKSLVRZ

Soloontario

Agree that sticky tires (Hoosier etc.) need sig more spring an/ or sway bar. Not sure in my case, how much of my new found understeer was due to lack of camber and how much due to the staggered set up (275 front and 295 rear BFG Rivals) . Real question is whether addition of sway bars if balanced appropriately, will be successful or even necessary given that I will return to more appropriate neg camber. I would think T1 bars would be way too stiff for my situation.

Either way, none of these mods should make the car worse or less streetable.

Nowanker

There's a balance with neg camber too. Even disregarding tire wear and 'dartiness' on the street, there's a point where braking ability is compromised.