Cellkid

I am just starting out roadracing my C4 I have driven other cars for many events but I only have one event under my belt with my stock 92. After that event I realized the car needed some work so I came to the forum for some advice and this is what I done so far. Thoughts? I also need some help on wheel and tire selection for this car since there are many diffrent opinions regarding this matter.

32mm Tubular Sway Bar-Front
26mm Tubular Sway Bar-Rear
88 Z51 Springs-Front and Rear
Bilstein Extreme Shocks Front and Rear
Replaced all bushings with Poly
Replaced Ball Joints and Hubs all around
J55 Front Brake Upgrade
Carbotech XP10-Front and XP8 Rear Pads
Stainless Brake Lines all around

Any furthur advice or something I should change? I am open to any ideas. Considering I am new to roadrace I think i may have gone a litte overboard to start.

Thanks in advance

Rob31

What type of events are you running ?
Sounds like a pretty good set up so far . I like that its all suspension and no motor stuff .

93Rubie

Sounds like a good basic setup.
Maybe air ducts for the front brakes.

315's at all four will ensure lots of grip. Popular with auto-x guys. Some of them running 315/335.

CCW's are nice wheels, but kinda $$$$. Light.

Personally I would get a used set or buy some aftermarket ZR1 replicas in 17X11.

Sidney004

I'd recommend geting (4) 18"x10.5" Z06 wheels and running a square setup. For a non autoX application, you're not going to get a better value(and speed) than the Pirelli 305/645-18 scrubs at around $100 a tire. Everything else looks fine.

jaa1992

Run a square setup! 275 or 315 (17 or 18 inch rims)

I assume you do not have a cage/ stripped interior / ie just at an HPDE level with my comments below
Use Street tires with 200 treadware or less for at least a year!
Be prepared to move to xp12/10 combo as your skills improve.
You'll go through a few sets of the 10/8 combo first.
GET AIR TO THE FRONT BRAKES! The Quantum plates are great to get the air to where you want it.

After you have some good experience and you can make the car "dance" its time to step up to better tires, lots of safety equipment and a good seat!

Cellkid

Thanks for all the input! Good to know I am on the right track.

Vettes&Bikes

I have a 93 with simular suspension mods. I recommend a bias spring for the master cylinder to transfer more brake power to the rears. Good brake fluid changed regular. Have the computer tuned to turn on the cooling fans sooner mine is set at 185 degrees and change thermostat. I ran a square set up on the wheels 17 x 9.5 and 275 Nitto NT05 for the last two years with good results. I plan to change up to a track tire for 2013 with a bigger brake package. Check your power steering pump and lines. Look regular for leaks at the back of the intake and the water pump. Enjoy learning the your C4.

Cellkid

Last question. Anybody do anything with gearing? Mine is a ZF6 3.54 ratio and was thinking of going to a 3.90. Pro's/Con's?

Rob31

The only Con will be that First gear will be too short . A 3:73 is pushing it .
Ill be the first guy to buy your 3:54 though

Vettes&Bikes

Keep the 3.54 gear a stock lt-1 does not have enough cam to push a lower ratio on most tracks.

Z07coupe

Cellkid
You have received some good advice from some of my friends. I don't disagree with any of it. I did the same type of improvements to my FE1 Ruby coupe. But, as Rob31 asked, what type of racing do you intend to do? What racing sanctioning body will you be dealing with? What class do intend to fit into? If you are required to maintain 'stock', with corvette optioned parts, that is quite different than running with 'non stock' parts. Also, are you looking at the best street tires for street tire class, or DOT slicks?
The rule book will help you determine what improvements to do. Several years ago I made the following improvements: 96 GS (black) front calipers and 13" rotors in front, no change in rear, Hawk HPS pads front & rear, Dot 4 fluid, SS brake hose, Z07 sway bars with poly bushings, TPIS shocks and camber brace. The camber brace moved me up to group 2 (NCCC). Since I am an old guy just wanting to have fun, and no thoughts of being the next Mario, (that shows my age) the group 2 didn't matter to me. And track days don't either, which is my favorite past time. Changing wheel diameters will also require class change as well as tire width. At the time I was not aware of the C5 to C4 front caliper brackets, if available at the time. The car was an excellent street, road trip car with the FE1 springs, and still handled very well. Two things I should have done was remove the radiator and clean or replace and added an oil cooler. It gets hot in the midwest. I was short shifting a bit due to 100k mileage.
I wish I had not sold that car to my brother.
Read the rule book first. Good luck and have fun.

jaa1992

If I ran with NCCC I'd be grp III RP and not have enough car
With NASA Time Trials my car fits right in to TT3 and with the suspension tweaks I'm now allowed I'll be mid-pack with the C5s

I'm happy because I do many more NASA and instructing days than I run NCCC

BrianCunningham

another nod to brake ducts

Do you have a PS cooler?
If not get one or you'll overheat for sure.

shinyandred

I have a 96 LT4 also an FE1, my usage is for track days, schools, HPDE, and to keep it as a street legal driver. The car just turned 112K miles
Perf Mods so far:
- 58mm BBK (previous owner)
- cold air intake
- all new OE wires and plugs
- performance tune and dyno by Carolina Auto Masters (308 RWHP - I want it to last so we chose not to push too hard)
- Racing oil pan (now holds 10qts)
- new bilstien sports (yellow non-adjustable) all the way around
- SS brake lines and fresh Motil 5.1
- hawk hps front and rear solid stock rotors in the front and vented on the rear (just trying them out)
- ran four days on Sumi HTZIIIs on after market Z06 18" rims. 255/40/18 F & 285/35/18 on the rear. I've looked at every other C4 at the track and the trend is to run 275/40/17s front and rear so I bought an old set of sawblades and am going to try that.

Future plans include new poly bushings, beefier sways as I get better, brake ventilation is on order, roll bar and maybe even seats. I've got the bug.

Lots more to do but one step at a time

shinyandred

Oh and how could I forget my new Melrose headers and cat package - great sounding and 3" all the way back to the Flowmasters

Cellkid

Fantastic info! Thanks guys. Right now I am still learning so car will be mostly HPDE until my skills improve and then I will have to evaluate everything again depending on where I want to go with it class wise. Right now I just want to learn and improve my skills and have fun on the track safely. I have plans to attend about 6-7 track days this year