96lt4cevette

So I had my first Autocross of the season in my 96 lt4 CE.
I ran on 400 treadwear street tires, kumho ASX all seasons, due to how much the surface at Wendover eats tires.

I started the day with a lazy 80 second run, and finished up with 2 low 72 second runs, both times really feeling like that was the jagged edge of these street tires.

I have a set of four 295/40/17 V710s mounted on some lightweight wheels coming, should be here today or tomorrow.

The question is, How much time can I expect the race tires to eventually shave off that 72? If I had been running them what would my times have been? Are they usually good for 3 seconds? More?

Thanks in Advance! and Remember Chevy: Like a Rocket!

TommyBoy72

Depends on the course and which street tire you are comparing it to. Could be up to 4 seconds on a 70 second course and the tire in question.

96lt4cevette

Oh Geez. I forgot to put in there the new tires are Kumho V710s.

Of course the reason I ask is FTD was a 63.xxx, I just wanted to know where I would sit, and how much more improvement I still need to that loose nut behind the wheel.

TommyBoy72

I think you were clear it was Kumho ASX vs V710. With what you said, I would gamble as much as 4 seconds depending on course. On my Z06 being able to put more power down was just as important (if not more) than the lateral grip I gained. Make sense?

mountainbiker2

The tires are 3 seconds faster. Now that's only if the driver can take advantage of that. If the driver still drives poorly and doesn't push the car to the limit on every corner then it will be less.

Steve

LehmanZ06

20 to 30 seconds on a 60 second course.....depending on weather

zo6chik

hey, had a great time at wendover!!!! im the kid with the red zo6. i put my 710s on my car for the last run of the day(only the rears). i ended up shaving 2 more seconds off my time. i ended up running a best time of 68 sec. with a whole set im sure they could be worth up to 4 sec vs your street tires. i was getting a push out of some corners with my street firestones up front. hope to see you at the next event. i think ill be running a set of toyo ra1s. we'll see what they do.

96lt4cevette

I dont mean to discount anyone right off the bat, but you really think a 60 second course can be cut almost in half with the right tire?

Of course thats what I wanted to hear, but seriously?

Z06Chik - Awesome to see you out! I still have a question however - WTF DID YOU DO TO A ZED TO MAKE IT SM2??!!??
I had an awesome time, the Vette is quite a step up from my old sts2 Honda. The Honda taught me to be a better driver, being smooth and picking better lines and brakepoints to carry the most speed.

TommyBoy72

I don't know if Lehman is just trying to be funny or not but obviously his answer is not serious. One point he may agree is that there is no scientific method other than actually running them back to back at the event on that course. The rest (including mine) are educated guesses but still guesses.

zo6chik

i can run a lower class with my car right now but im still not done with mods so i thought id run in a higher class. right now the list is ... dynatech long tubes, halltech intake, dyno tuned, short throw shifter, koni adjustables, hotchis sway bars, polyurathane bushings, and slicks. im thinking of a cam in the near future but man these tires for autox are going to kill me

Bimota Guy

Slicks are not legal for SM2...I assume you mean DOT legal "R" compound tires.

ltborg

on my 95 c4 i went from goodyear gsd3s (stock sizes) to 315/35r18 v710s all the way around. pushed me from averaging teens overall in the rankings to top 5 (6th overall the first time out) with the same group of drivers/cars. it was about a 5-7% increase in time (3+ on a 60 sec course). if the courses were tighter it was generally a little less. im guessing on a course that long coming from the asx's youd be looking at 3-4, maybe 5 (i didnt feel the asx's had much in the way of grip when i drove on them). but just like everyone said its very dependent on driver, course, weather, etc.

JaGsC5

perhaps one to many tonight?

zo6chik

bimota, the "slicks" i was talking about are dot r compounds.