B4CHawk

I've been looking at maybe giving a go at B street with a C4 vette; I'm partially inspired by Scott McHugh's success in A street when he had to contend with S2000s back a few years ago (and a few rides in his car).
I think with good driving it could still hold its own against the 370z, C5 base, and s2000.

My original plan was to run a RX-8 in C street, but finding a RX-8 that hasn't been or isn't about to pop is difficult.

So my question; what wheels do C4s have available? I see very little in the way of wheels in 18x9.5 +54. I'm sure everyone is aware of the sever lack of tires in 275/40/17 these days...

BrianCunningham

B Street prepared?

B4CHawk

Just B street, prepared makes my wallet cry.

RX7 KLR

The easy button for 17"s is C4 Grand Sport or ZR1 fronts (real not heavy knockoffs that crack), or C5 Z06 fronts.

If you want to go 18" there are a few options... The Motegi MR120 comes in a +56, weighs 24lbs, $187 at Tire Rack.

theseal

I think it's a great choice. 89's are good. 86-87's are the best. Forget all other years. C5 Z06 front wheels are light strong and cheap.

The 86-7's handle as well as a c5, put down power better. Have better gearing for most courses with the 4+3. They are lighter with more front tire and a lot less width and wheelbase.

The c5 has such good chassis stiffness the ultimate grip and transition quickness may be a tad better.

Finding good pads is an issue. High end power a big issue compared to the c5, but bottom line I think a well prepped and driven 86-7 can beat a c5 on many courses.

troyguitar

Oem base C5 "thin spoke" rears are 18x9.5 and around that offset.

RX7 KLR

Always seems to stir a debate... But the last time a Stock class 86' won was before the 89' came along. Takes nothing more than looking at past Solo Natls results to see that.

B4CHawk

I think the problem with the 17" is the fact that the only available tire is the R1R; a good tire, but I'm not sure it can handle the weight and power of a C4, I could see them overheating midcourse on a hot day. The Motegi seem like a good option

theseal

No doubt. But no serious national effort has been made. Matteucci was top 5 in one ON TOYOS, when his fuel pump crapped out. And McClure was way up there too when the c5s first csme out. And hed be the first to tell you it was not a full tilt effort.

My subjective experience is that for autocross the 86-7 is lighter with better gearing for most courses, with MUCH more front end grip and better turn in. Time will tell. Maybe i'll bring mine out. But it needs work.

l98tpi

I would recommend a 90-96 depending on your budget. 6spd trans and stick with 12" rotors. You are not going to overheat tires in autocross unless it is 90+ degrees and you are running race compound such as the Hoosier A6. I would stick with 17" wheels.

theseal

My 90 was 290 lbs heavier than my 87 despite what the 'books' say. 90-91 are the worst years of all.


6 speed is a big liability for auto x. 89 was 'ok' because of optional 3.54 gear, but all other years are soggy and heavy in 2nd gear with that 40 lb flywheel. 96 is still too heavy and soggy even with lt4. It was about 200 lbs heavier than my 87, 90 lighter than the '90.

All 88-up cars have the screwed up front end geometry to make the car ride nicer and brake more smoothly at the expense of front grip. A big issue for an autocross car.

One example, a friends unprepared stock shock worn out 87 on fried hoosiers was 1.1 faster than my fully prepped lt4 car on fresh hoosiers in a 50 second fast autocross with me driving both.

If you really want a 88-later car get a zr1 and pray for a 1st gear course.

BrianCunningham

Just a reminder if you're in the STOCK class you need to keep the stock sized rims.

So no 18in

dhowdy

Street allows +/-1" diameter, same width, within 1/4" offset. Stock doesn't exist anymore.

69autoXr

Almost. Starting this year the offset allowance is +/-7 mm.

strano@stranoparts.com

Ahh, time to be brutally honest (and probably pay for it).

I cannot fathom any reason I'd want to run a C4 vs. a C5 in B-street. None, it's not nearly as good a car in comparison. In 2000 I ran Super Stock. A C5 won, a Boxster S was 2nd, and RX7's in 3rd and 4th (Strelnieks and myself). I don't think an RX7TT is a good B-street car today either. They were developed, the C5 in 2000 wasn't.

And right, Stock is dead. It's "street" now. The rim rules have changed to allow a +/- 1" variance, and the offset is now ok to vary 7mm vs. the previous 1/4" (6.25mm).

McHugh had a good run in the C4 but it was years ago. And he's kind of tied an anchor to his foot the last few years in the Z06 by sticking with Kumho's. I'm 100% sure he didn't forget how to drive, but his results aren't there and that just because of the tires, not saddling himself with a car that's out of it's league.

C4's are cool, but C5's are faster.

BrianCunningham

I've driven C5's, quite a few

Not my cup of tea.

strano@stranoparts.com

Not sure how that changes things.

B4CHawk

I always appreciate honesty, Sam. I actually got the same advice from Tom Berry at our club christmas party this last weekend... I'm just weighing the options. Anything is better than my current H street ride!

FAUEE

Isn't the C5 classed in A? Or did that recently change? I was under the impression the C4Z and C5 were in A, the C5z and C6 were in S.

If the C4 and C5 are in the same class, there's no reason to run a C4. I own one and will admit it, it's simply not as fast of a car. You could walk all over a well prepared C4 with a bone stock C5, it's simply a better platform. Which was why they weren't in the same class.

dhowdy

C4 and C5 base is in B street, C5Z and C6 (base, GS, Z06) are in A street, ZR1 and C7 are Super Street.