autocrossing engine choice

[chicago240z]

Hi All, What I have is a 240z and well 2, 240z one is being built to race vintage and the other is my street car. I would like to start autoxing the street car from what I understand in the rules I can use any of the L blocks but if I went to turbo, it would put me into the next higher class. Can I use a stroker motor? or am i limited to the stock sized l28. Coluld the race car be used?or is it too built for standard class in autox? I've read somewhere that full interiors are needed

Thanks for any help

[SteveJ]

What rule book do you want to go by? SCCA? NASA? What class are you shooting for? When you say you have a car being built to race vintage, again, by what rules? Be specific or you can't get good recommendations. Also what type vintage racing?

Edited November 14, 2010 by SteveJ
Added one more question.

[chicago240z]

Ok the race prepped car is going by S.V.R.A. rules it will be SCCA prepped also lets just leave that out then itll be built for one purpose.

All I was aking is can a stroker motor be used L28 bored to 3.1, 3.2 or would that put me into a more modified class? its my understanding of the rules that I can use any of the L series blocks since they group the 240,260,280 into one group. Im not wanting to go that route if I was id put a vq35 in that I have or a v8

Thanks for any help

[jmortensen]

You can download the SCCA rulebook from their website for free. I suggest you do that before you buy anything. If you autox in stock or street prepared, strokers are not allowed, unless your club has an open street prepared class which is a catch all that basically allows anything on DOT legal tires. The Z is not competitive in stock and is tough to compete with in the SP classes. John Thomas has dominated F Prepared for a LONG time in his Z but the competitors are knocking on his door. X Prepared looks like it could be a viable option for a 4 cylinder turbo Z car. I'm building a V8 Z car for X Prepared and it probably won't be competitive, but it sure as hell will be fun...

[gnosez]

I don't believe SVRA will allow you to stroke that engine my friend nor will they let you run a V8. The rules on car classification are very well written so take the time to re-read them.

[conedodger]

I don't believe SVRA will allow you to stroke that engine my friend nor will they let you run a V8. The rules on car classification are very well written so take the time to re-read them.

He is building two cars. The race prep car will be built to SVRA rules, the street/autocross car is the one he is considering the stroker motor for.

[gnosez]

My bad...

Well I hope to see you at one of the SVRA events next year.

[TomoHawk]

Before the last time I was at an SCCA autocross event, I looked up the class my stock 280Z would go into, class D IIRC, but at the event, the registration guy had me go into class E, which was fine, since I was the only one in that class on that day

[tholt29]

Here is the easy answer list:

If you run Stock class you will be in ES and you have to run the original engine for that year model, no engine mods beyond an air filter.

One of the hottest new classes that the Z is legal for is STR, That still requires an original engine but allows headers and cold air intakes etc as well as suspension mods and real street tires.

For Street Prepared you will be in BSP (that might change next year) but you can run any engine that came in a 240Z-280ZX, but that does not allow strokers.

SSM is where you will end up if you run a stroker. You can run any Nissan block engine and do anything you want to it. It's a pretty brutal class in some areas of the country.

F Prepared is the Z's happy place. More here than any other class, but the stroker is not legal here. you must run a stock stroke and bore is limited to 1mm over.

X Prepared will allow you to run Any engine you want. V8, Rotary, Allison V12, you pick it. But all of the Prepared classes allow you to gut the car, run race slicks etc... it's not a street class.

STR is probably the best place for a street Z.

Tom