17 inch wheels and 3.77 or higher R&P

Jack Houpe

GT40s Supporter
I am stuck at 125 MPH doing open road racing due the to fact Z, Y, W tires are not to be found in 15 inch. Avons are V and thats what I have now so I am in the market for some 6 pin 17 inch wheels for my MK1 which will be just for racing. I also am looking for a 3.77 or 3.07 ring and pinion as I don't like to hear the engine scream for 120 miles. I have a bunch of interesting Ferrari parts, some lambo parts for trade or cash works. If someone has a Good ZF with 3.77 that wants to trade with mine and I will add some cash thats OK too.

Its a shot in the dark but you never know whats on some peoples garage shelves.
 

Ian Anderson

Lifetime Supporter
Hi Jack

V rated are good to 150mph
(Actually good for constant 150mph for at least 2 hours)

But I hear what you say about the better diff ratio

Ian
 

Kelly

Lifetime Supporter
I also am looking for a 3.77 or 3.07 ring and pinion as I don't like to hear the engine scream for 120 miles.

Big difference between 3.07 and 3.77. Not sure you'll make a big difference by changing wheels/tires but don't know what OD you are starting with. I have 17" Halibrands repros on my car from Vintage Wheel with 315/35/17 Nitto NT01 Skins. I raelly like them and the Nittos are a great tire at a reasonable price (~$215 each).

If someone has a Good ZF with 3.77 that wants to trade with mine and I will add some cash thats OK too. Its a shot in the dark but you never know whats on some peoples garage shelves.

Jack, if memory serves, isn't your box an M1 version of teh ZF? If so, that is a very desireable ZF. Think you may be best served to find the R&P combination that suits. I picked up a low mile 3.77 R&P last year but it's in my box now.

Best,
K
 

Jack Houpe

GT40s Supporter
Ian its the rules of the open road race, my tech speed (speed you can not exceed) is 144, but my average speed for the 118 miles should be exactly 125 MPH, then I win. :)

Kelly your right my ZF is an M1, the only reason I would change the wheels is so I can get tires that are higher speed rated. I plan on keep my Avons and just use 17 inch wheels for racing.

Thanks Guys!
 

Ron Earp

Admin
Hi Jack,

you will be able to find 15" Z rated tires here:

Hoosier DOT Road Race Radials

R6s are what you want and these are what we race on each SCCA weekend. I drive them on the street with my RCR T70. You don't find anything stickier. Just stay out of the rain, although you can spring for Hoosier rains too.

These tires should work for the open road time trial as they are DOT approved. Occasionally though you'll see organizations disallow them specific as they know what an advantage they have over a "normal" performance tire from the various manufactuers.

I run the 275 in the rear and 225s up front for the T70, 225s all around on my Z. Works great. You can get 12-15 heat cycles out of the new R6 compound which is much different from the R6 compound of a few years ago.
 
Ian its the rules of the open road race, my tech speed (speed you can not exceed) is 144, but my average speed for the 118 miles should be exactly 125 MPH, then I win. :

The rules are that your tire's speed rating has to be higher than your tech speed, right? Your tech speed is 144, your current tire's speed is 150?

What about Dunlop vintage racing tires? After all, that's what the original GT40s run at Le Mans etc. I don't know what their speed rating is though.

http://rogerkrausracing.com/racetirepricing/index.php?dir=Dunlop+Race+Tyres%2F&download=Dunlop+Vintage+Tyres.pdf

The only problem with the Hoosiers is that the largest you can get is 275/50, which is pretty short. It would have the effect of lowering your gearing even further. :huh:
 

Jack Houpe

GT40s Supporter
I found my 3.77 from this tread! Next year will be a different at Big Bend for me. :)

Thanks Ron and Drew for the info on tires. Let me fill in some blanks of Open Road Racing. They are very cautious and that is understandable as Silver State has lost several lives and most due to tire failure.

Last year as a rookie I could not go any faster than 110 mile average with a tech speed of 124, this year I could go up one category and my max speed I can dial in is 125 with a tech speed of 144 max. Next year with the addition of a roll bar I can dial in 150 mph max and must have W rated tires or an approved Z rated tire. If I continue (which I hope so) to the next category its 160 MPH max average and mandatory Y rated tires. The unlimited category I will never race in, its a little to hairy for me and requires far to much modification to my car in terms of roll cage standards.

At least 50% or better of the 160 racers are late model Corvette's right of the show room floor with a couple mods although the unlimited record holder is a corvair powered by a SBC. I really would like to at least get into 155 class in time, with at 3.77 and Y rated tires I can. Worst case is I could borrow Kirby's tires and wheels. :)

Last year on the return leg (two 59 mile legs) it was hot, almost 100 and the heat coming off the black top was killing me as I was waiting in line to launch, (fastest cars go first) so I got out and walked to the front a couple cars and there was a new corvette with the 650 HP engine in it sitting there idling with the occupants taking a nap with the AC on. That sort of pissed me off. HA!
 
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