Acid666

So I finally got to autocross the Z06 this last weekend. This is going by SCCA Rules and classes. For backstory, I used to autoX my 08' VW GTI a good bit in STX, and sold it and put the money towards a C5Z that I looked for about 6 months for.

I'm posting here partially to see if I can learn anything from this, or to just find out if I got sandbagged like hell in my class.
So yeah, I raced in AS. Car just has intake, axle back, short throw, and Forgestar F14s with Hankook Ventus V12 rubber.
This was a fairly fast track (at least from all my experience in the GTI), and had 2 deceivingly late apex u turns that were hard to negotiate with.

First run was a smooth and super slow 59s. The next 3 runs were all 54s. The other 3 cars in my class were a 2014 Porsche Boxster that ran 54-56s (with cone hits), a 2006 Porsche Cayman S which I believe ran 54-55s.... And a 2010 Grand Sport which consistently ran 48s.
So you've got 3 people running 54s, and one guy 6 seconds ahead of the pack. I expected him to be quicker, but Jesus Christ... He was running the same times as the guy in SS running a C7. Does the GS have that much of a jump over a 14 year old Z06? It was my first time really getting to test the limits of the Z, but I was expecting him to be maybe 2 seconds ahead of me. I'm sure his experience played a huge roll in it, but it's hard to grasp 48 seconds compared to 54. When I replay my runs, I found a few spots I could of hammered it out of a turn a little earlier, but I think at best I'd maybe get 1 solid second off my time. I lowered my tire pressure down each run starting at 45 and ending at 35, pushing the car harder each run.



Had fun though. I got the car as a weekend driver and racer, so it gives me something new to obsess over. I'm going to fully detail the car since the race is over, and get into replacing oil and fluids. I already upgraded to SS lines and new pads before this event.

dhowdy

None of those are legal in AS.

No, C5Z is just as competitive in AS. In an ideal world with prepped cars, even an HS FiST would only be 2 seconds back... so that 6 second gap is coming from somewhere else.

Acid666

This is what always throws me off with deciding where to classify myself.
So are all the Street categories supposed to be completely stock? I really wish there was more help with this.


Super Street Class (SS)
Chevrolet
Corvette Stingray (C7) (2014-16)
Corvette Z06 (C7) (2015-16)
Corvette ZR1 (2009-13)

A Street class (AS)
Chevrolet
Camaro Z28 (2014-15)
Camaro ZL1 (2012-15)
Corvette (C6, non-ZR1) (2005-13)
Corvette Z06 (C5) (2001-04)

Or should I have run in
Super Street R Class (SSR)
Chevrolet
Corvette Stingray (C7) (2014)
Corvette (C6, non-ZR1) (2005-13)
Corvette Z06 (C5) (2001-04)

The only thing is for SSR it describes Tires, Wheels, and exhaust. But all the says about the exhaust is that it must be routed to the stock exit location. Which is why I signed up under AS.

3.Exhaust
The exit of the exhaust in the
original location (Section
13.10.C) is not compulsory.

Acid666

After a little more searching, maybe CAM woulda been more suitable? There was only one other CAM guy there in a Mustang GT/CS

dhowdy

I had bolded the modifications to your car above that were not legal for AS.

Your car is close enough to stock that if you wish to be competitive (since you have a competitive car), it would be better to make it compliant to the ruleset to run AS. Otherwise, yes, CAM-S.

Street class rules: http://www.scca.com/downloads/13600-...ory-b/download

The gist of it: shocks, one sway bar, axle back exhaust, and you can change wheels so long as they are +/-1" diameter and have an offset within 1/4" of stock but maintain stock width.

You do also have the option to run SSR if you'd like to slap on a set of hoosiers. Pretty much the same rules as street, but then you have to run stock size wheels (not sure if there's an offset allowance).

Acid666

Yeah I got that, I just couldn't find anywhere in their descriptions where it specifically stated that. It's like a subcategory of a category that I didn't know where to really dig into to find specific info. This helps a ton. Appreciate the info

rhneff

A suggestion would be to go to scca.com and find the Solo Rules under that section of the web site; section 13 of the SR describes the allowable modifications for Street category cars. dhowdy is correct that your intake and aftermarket shifter are not legal for Street category but incorrect regarding the exhaust (downstream from the cats is free as long as it exits in the stock location and passes sound). Aftermarket wheels are fine provided they retain stock width/offset and are within 1" of stock diameter, tires must be 200TW or greater. All that's detailed in the Solo Rules.

With your mods you would likely be better off running CAM-S.

Acid666

This all helps. I bought the car to road race and occasionally AutoX so I want to find a class that I can stick with and stay within the bounds of with future mods.

dhowdy

I didn't say his exhaust was illegal, I'm not incorrect. I know his wheels aren't compliant because forgestar doesn't sell the F14 in a 17/18/19x10.5. There is a 1/4" offset allowance.

Unless you have immediate plans for further modification, my honest recommendation is to go back to street class. CAM is silly.

Acid666

My only future plans would be long tubes and a tune, and possibly some stock Z06 rims or a square setup to run a different set of tires to specifically run for Autocross.
Other than that, just small things like upgrading bushings, but no coilovers or other major changes.

dhowdy

Depends on your priorities then. If you want to run at the track and autocross is a side thing, then mod the car without concern for rules and run CAM. If you wish to be competitive in autocross, forgo the mods and run AS. You'll be happy either way, just comes down to what you want.

Acid666

Yeah I hear ya. It's a weekend cruiser/streetlight racer so it's kind of a mix of "fun-mobile" and "serious racer". I'll likely do more Autocross than Road Racing. I'm gonna dig through more of the class specifics and then see how far within those boundaries I'm willing to go. AutoX events around here are usually several hours away, so I don't hit up too many.

Matt_27

Those Ventus V12s are wayyy slower than a top level street tire. Multiple seconds of your gap slower. Get a real AS setup on that car and you will be closer. The C5Z won nationals in AS so if you are still not beating him you know you have driving to work on!

69autoXr

The rules tell you what you can do to your car in a given category. They don't tell you what you can't do, i.e. if it doesn't say you can do it, then you can't.

Conesmacker

I'm in a '11 GS, manual trans, on front RE71r and rear RE11 tars on the stock rims. I had tire $ this year, but not wheel $....

Last weekend in Indy, a dude in a '04 C5Z beat me by 1.2 seconds. Hi Lou! .... you on this site? He's running a square setup on all RE71r tars.

This is my first year competing in a Vette, and apparently the last 7 years in a non-turbo Solstice has badly miscalibrated my throttle foot. Lou's been driving Vettes for 20 years....so I don't feel bad taking 2nd to his 1st.

He was also 2nd on the PAX times for the day, so he's at the tip of the spear.

OP; I'd say to give it more than 1 event to start comparing yourself. Maybe the 6 second faster guy is nationally competitive and been running for +20 years....those guys are impossible to beat, but often like to help / instruct / give advice.

Next event, try talking to the grid chief, and get about 10-15 cars between yourself and that Vette Ace...and ask him to pretty please let you ride with him on a run. And then turn on your internal recording system to learn his habits / shift points / braking points / apex points, and see where you can improve.

SSR is for the guys who run on 50 tw Hoosier real racing tars. CAM is a checkbook class for guys who can't read a rule book. AS is for normal schmoes like me.

Acid666

Hah, that's pretty awesome. I don't expect for my Z06 to be doing all the work for me, but it's reassuring to know that there's a ton of room for improvement. I think my goal is to find a class that I can be competitive in with the couple of extra mods that I want to do, and then maximize my car to that class and then have some fun with it.

Tomswheels

Did you watch this video? https://www.corvetteforum.com/forums...11-2016-a.html
I watched yours and his back to back, you can see the speed difference more/better tires make. Plus he is tighter on almost every cone. Many many seconds can be made up in a C5Z, properly tired and wrung to its full potential... Oh and I run CAM-S and have a blast even though my car is really only AS prepped.

Acid666

Holy crap, that's pretty damn near amazing. You can just read the precision in his turns. My first run was super slow so disregard it. I started with higher psi in the tires, and was really testing the throttle/grip of the Z out of the corners. After that run I lowered the PSI a little and started hammering it. But when compared to this guys run, he really nailed those slaloms. When I took the slaloms I could feel the car pulling and losing grip and knew if I went in with any more throttle I'd have to brake and jerk really hard on the next set of cones. So the traction and speed there needs to be worked on.

Appreciate the link. Just watching it kind of opens your eyes. I think next event I'm gonna see if I can ride along with a faster vette and see what I can take from their lap.

theseal

at an elite level, the c5z would be faster. but if you don't left foot brake or are not really at the tip of the spear yet, it's preference.

Acid666

Yeah I wouldn't expect to be near that level. Would be killer though!