darkducati

Forgive me if this is in the wrong place. I couldn't find a better place than this. Well, this is going to seem like a wierd question but I'll go for it anyway. I am somewhat new to rotaries, and I'm building a solo2 car for street modified. I am looking to do a bridge port for some pretty top end power. It will only be used for racing and probably never see the street(unless I get really bored one day). The question is this, what will be the best transmission to use? Should I get one of the Kennedy kits and bolt on a Borg Warner T5? Or maybe take a turbo II drive line and rebuild the engine with high comp. rotors and the bridge port etc? I am hoping for 260-280 horsepower, so it will have to be pretty strong. Weight is also a consideration. It's actually the reason I don't want to go turbo as I don't want all of the extra weight. Any input would be greatly appreciated. Thanks.

GMON

s4 or s5 TII tranny will bolt right up to both the s4 or s5 na engines. There are a few ways to go about hookin up the rest. You could use the TII tranny-NA Auto driveshaft-stock Na rear OR Swap the whole thing.



Hope that helps some.



Gregory

darkducati

Would this just use the TII flywheel and clutch? Thanks for the help.

Lynn E. Hanover

You could het 260 with a Weber and 44 MM chokes. With better flow, much more.



Whats wrong with the stock trans? Depending on the rear gear and the tire size you would be in 2nd or 3rd for the whole race, except for the launch anyway. So not much if any shifting, so you don't need dog rings. To get that power you will need to keep the revs close to 9,000 RPM. The engine needs to have racing main and rotor bearings to get away with this for very long. Then you may want more oil pump to keep up with the bigger clearance. Add a little extra oil 2 cycle to the fuel to help the apex seals. The next big change should be a rotor weight reduction and a spin balance.



Check the speedo as you hold a mear 8,500 RPM in first. The course should be tight enough to limit top speed to 55 or 60, whatever the rules and insurance require. So maybe just 1st and 2nd will do.



My first gear is 2.00 to 1 in one trans and 1.96 in the other. We could do the whole thing in 1st. This about where a tall 2nd or short 3rd would be in a stock trans.



Learn to double clutch the downshifts and your trans will last forever. Also the best insurance for a transmission is the super light clutch disc. Like a Tilton triple disc. If the organization won't let you spin the tires on launch, stay with a large diameter street racer clutch. And a heavy flywheel.



The picture is of a Saenz dog ring trans. Made in Argentina. Shifts as fast as you can move the lever. Three inch throw total.





Lynn E. Hanover

darkducati

Thanks for the info. I am concerned about the launches more than anything. I plan to build this engine from the ground up to be able to take the abuse all day long. The car will only weigh about 1900lbs and probably be running 255-265 width autocross rubber. The weight will be easy for the tranny, but the launches will take their toll over time. Just for more info, I plan to run a the lightweight version of the racing beat two disc clutch and flywheel package. Thanks again for all of the help.

Travis R

Planning on running in FP?

The next fastrack should have some updated info with respect to weights.

I thought about the T5 conversion also. What does a T5 weigh compared to the Mazda trannies (turbo and NA)? Do you know how much the adapter is from Kennedy?

Depending on the gears in the rear end, 2nd gear on an NA with a 10K rpm redline should put you at about 72MPH. So it is unlikely you will ever need to go to 3rd.

Good luck

darkducati

Actually, I am building this for SM. 1980 Mazda GLC. Walk softly and carry a 50lb sledge hammer. I am not sure of the weight on the tranny to be honest. I may actually do some research on that. At any rate, it should be a terror. Thanks for the responses.

Travis R

Whoa! That sounds like a cool project. I thought a Supra powered Starlet would make a good SM car too.

1900lbs is the minimum weight for an NA FC in F-Prepared, that's why I guess FP.

darkducati

Yeah, the Starlet would be cool. But I would think it to be a bit front heavy. I also thought about using my MR2 20v, but I can do the GLC for much less. My mistake on the weight. It will have to be 2200lbs. I was thinking force fed SM2 weight. I think I might need some lead to get that thing up to 2200. Hmmm

j9fd3s

the na tranny is about 65lbs and the t2 tranny is about 85lbs, so its not as much or a wieght penalty as you would think.



in a 1900lbs car id prolly still run the na tranny, should be ok. in a heavier car it wont last though