ITS RX7 with FM Engine??

[CapnTuna]

What year rX7 should I buy so that race using a Formula Mazda 13b engine and be in conformance?
Thanks,
Bob

[wlfpkrcn]

I believe that engine is a 4 port 13b. That should put you in GT2. I think they made the 13b legal in GT3 with a SIR and street porting. You would need to check the rules. Any year RX7 is legal in GT.

[Chris Wire]

I think that you should be able to use the "short block", which would be the same as the 1985 GSL-SE. If the FM application uses dry sump and all that you would have to return it to a stock-type set up.

That model RX7 runs in ITS. It is not, however, very competitive here is SEDiv.

[CapnTuna]

What do you think puts them at the low end of the class in performance. Weight to power ratio? Do you know about what HP they are running?
Bob

[NCRX7RACER]

The gsl-se engine is 6 port not 4 port. I'm not sure if the formula engine is 4 port or not.

[jrx13]

I was under the impression the formula mazdas run the rx-8/renesis motor.

[bldn10]

Bob, why [and perhaps what] do you ask? Are you able to get a good deal on a FM engine or what?



Per the GCR FM can run either a 6-port 13B or the Renesis and they are built and sealed by SCCA-approved builders "with no modifications to the engine or any of its accessories or components."



Sounds to me like a pro-built ITS 13B would be faster.

[wlfpkrcn]

Bob, why [and perhaps what] do you ask? Are you able to get a good deal on a FM engine or what?



Per the GCR FM can run either a 6-port 13B or the Renesis and they are built and sealed by SCCA-approved builders "with no modifications to the engine or any of its accessories or components."



Sounds to me like a pro-built ITS 13B would be faster.
[/b]

I was always under the impression a FM had a street ported 4 port. Thanks for the info!

[seckerich]

If it is still sealed it will bring good money. Sell it and get a real motor built. Building a car around a motor is a sure way to failure. Used these bring about $2500 for spares.

[CapnTuna]

Thanks for the replies! I am currently crew (head goupie, wrench fetcher and rig driver) for a friend that races FM. I was at VIR this last weekend and just can't stand watching anymore. We were talking about a low cost way of getting me out on the track and thought maybe we could put his spare motor into an old RX7 that I could buy cheap with no motor. I'm talkin' like $500 cheap. The RX7 ITS chart shows (13 under it but the FM 13B is a 4 port engine. I'm not thinking that it will be a problem though. No one is going to protest me as long as I get out of everyones way! Later, as I learn more, I can start investing in the car more. So that's my plan, so far.

Oh, BTW, it is the old FM, not the Star Mazda FM. But it is indeed sealed.

[CapnTuna]

I was just told that no 4-port non-turbo engines were available in US between 84-91. So I guess I can't do this.

[NutDriverRighty]

Since you're already a rotor-head, could I interest you in a 1st gen ITA/IT7 car? I can't do the $500 thing, but Captain Who and I have a good entry-level package that finished 2nd in class in the SARRC race at CMP April 1st. Fresh rebuild by Sunbelt/OPM/Dale Caldwell, spare car, spare tranny, rains, spare wheels/tires, and the list goes on. PM me or Captain Who if you're interested (or anyone else, for that matter!)

Scott Franklin
www.NutDriver.org
ITA/IT7 and SPU
CCR of SCCA

[tom_sprecher]

I was under the impression the formula mazdas run the rx-8/renesis motor.
[/b]

The newer ones might but FM has been around for quite some time now vs. the renesis which is only a few years old.