so ive got a really good running 12a rx7, 1980, but its really a 79 (manufactured 10/79) and i already have the full gsl se running gear, and im already ready for more. i wanna stay with the 12a cause thats the intake and exhaust i already have, but have another 12a that i want to build, and want to go all the way to bridge port. so i was wondering if i got the mazdatrix 4.875 final drive kit, and used these tiny 20x6x14 slicks that i have in my car without any sort of stripping of the interior what i might expect to run for 1/4 times...its gonna run on the racing beat holley intake setup, and im making a road racing header for it with the mazdatrix kit, gonna be 2 1/2 inch pipe, with maybe one rotary muffler and a fart can.

 

Its an overall good idea but the problem you will start running into is that such a small tire and that high a ratio will just keep you shifting. You would be better off sticking with the stock GSL-SE ratio. With an exhaust installed and no lightening I would put you in the mid to low 14s but you have got some driving to do to get it.

 

slicks on a sock rear end = axle breakage.you will need the 4:88's with a bridgeport,with a medium street port,48 ida weber,and some good street tires got my old 80 rx to a 13.9 @ 102 mph.but i had a 13b

 

yeh at extreme best i was thinking high 13, but usually a 14 something would be call of the day, but expect breakage as you will have to wring it neck off at the start line , good luck and get into it, you can only learn from doing it and growing your car from there

 

I would have to disagree with you on this one. All motor rotaries need really low gear ratio's in order to maintain the high rpm power band and also to compensate for the crappy stock gear ratio's in the trans. and low torque numbers produced by the engine. I'm not going to spill the beans on what I'm running but its well over 5.00.

I would say if your tune is on point and you have a good free flowing exhaust you should be able to run 13's. You can watch my vid in my sig of my 12astandard bridge to see what it can be capable of. Good luck.

 

I was just going by what he said he was going to install. Mainly the small tire, holley and not lighten the car. Anyone can say well if you did this and that you would get this. But I am listening to what the "customer" asked for and wants to do.