Alludc

As I read it the following things would be acceptable for A stock.

K&N filter only.
catback
2010 z06 shocks
2010 z51 sways

now, as far as tires/wheels go??
I read that only stock size wheels/tires available on the corvette for the year of your car. Meaning, I have to run 18x9.5 & 17x8.5 with 275-40-18s and what 245-45-17? Ive noticed other Astocks running the z06 wheel tire combo though, is that because of the year of their car being 01-04?

If I am going to run a dedicated set of race tires, I sure would rather be runnin the 295 & 265s. Hell, id like to run 295s and 18x10.5s at all 4 corners but that would surely put me where....ASP or?

acrace

I assume that you're talking about A-Stock for SCCA and it's for a '99.

Wheels have to be stock diameter and width (stock = what came from the factory). There is a 1/4" allowance for backspacing - so you can put a spacer in if you want to widen the track. You can put any size tire on those wheels - you're not limited to the stock width/aspect ratio.

For shocks - and I'm paraphrasing - any shock is permitted as long as it meets the dimension allowances (I believe it's 1" extended length) and it mounts to the stock location. So you can use the shocks you listed, or Koni Sports (3013s - very popular for those on a budget) or go all the way to killer Motons, JRZs, Penskes, etc - but you're limited to only two adjustments.

For sways - the historical allowance was that the front bar was free. I believe that the rule may change so that you are allowed to change either the front or the rear, but not both. Most folks have run either a larger diameter Addco bar or a Pfadt front bar.

But the most fundamental thing you can do, other than learn to drive to the max, is to make sure that you get a good alignment and corner balance on the car.

Oh, by the way, don't lower it too much.


Al Chan

acrace

By the way, those running Z06 wheel/tire combos (wheel size, really) shouldn't be running A-Stock. Maybe they're running repros in the proper size but with the Z06 style?

TedDBere

What Al said.

You may change only one bar.

You must use OE stock size rims (+ or - 0.25 inches on the offset).

You can stuff any size tire you want to on the stock rims.

Shocks and catback are relatively free (no more than DA on the shocks and catback must meet sound restrictions).

Any filter you want (you may even run without a filter) but you can't change the intake.

Good luck.

Alludc

the tire thing is great to know! I was very unclear on that. So no problem running a 275/17 and 305/18 on the wagon wheels? may go 295 rear, not sure. didnt know it was an option but im excited it is! I ran street tires the past two weeks ( on z06 wheels ) in a stock and was within a 1/10th of the top SS Z06 and above another one. so im thinking of maybe just competiting in that class....if its an option

acrace

"Technically", running an A-Stock trim Corvette with Z06-sized rims puts the vehicle into ASP and isn't allowed in SS. Car should be "as built" factory correct configuration for Stock category.

Alludc

also good to know acrace.

Ideally im going to run the wagons with some 140+ treadwear tires so I can continue in the street class. thinking nt05s, but open to suggestions.

Alludc

nt05s not sounding so good on online reviews. maybe on to hankook rs3 or kuhmo xs, but the sizing leaves something to be desired for wagon wheels.

KBoltz

I've got a Z51 front bar (with the stock endlinks) from my 2008 that I'll sell to you for 35 bucks plus the shipping.

Alludc

from BC that shipping may be steep. zip code 85204, let me know total.

Alludc

got a set of (4) 295-35-18 hoosier a6s. that tire gonna work up front?

TedDBere

No, 17 inches up front.

Alludc

I know that running 18s all around wont let me stay in AStock, im just asking if the 295-35-18 will FIT in front.

acrace

Why don't you use those for the rear and pick up four properly sized Stock class tires for the front? You'll have two sets then.

Alludc

im lookin!

ltborg

They should fit fine in the front if you can't find any 17" front tires.

Gordy M

I currently run 275/40/17 fronts and 295/30/18 rears for all around--both autocross and HPDE. If I were going to only autocross I would go with the 315 rears, but found them somewhat unstable on high speed turns. Most important is to set rake (these wheels change ride height) align and counter weigh your suspension. Unfortunately, the most rear camber I could get-after moving the cradle was .80" inch so I set it accordingly on the right. If you drastically lower the ride height you can get more camber but lose suspension travel. For SCCA get a big bar in front 30 mm+ and you can use the metal endlins but get a copy of the parts update sheet from your dealer in the event you win your class.

GCMan

I know that using 295/17 and 315/18 on stock non zo6 wheels works very well for someone in our region in A stock. Make that a husband and wife team actually.

KBoltz

Since I am not running in SCCA but in the local PCA and Corvette Club, I run non stock wheels (TSW Nurburgrings) in 18x9.5 and 18x11. That's right, 18's in the rear and I have had no issues with the AH/TC because I turn it all off.

I have gotten to the point that I drive to the event, race and drive home. I got tired of changing tires. In your 20's it is no big deal. In your 30's hey it takes a little longer. In your 40's then the hell with that!! If I were competing for an SCCA title, then I would buy a damn trailer and trailer the car there.

ltborg

That seems to be the popular combination. My codriver and I ran 275/17 and 295/18 and that seemed to work well even though the rears are smaller in diameter than the fronts (with TC off, it doesn't seem to matter).