Craig Jorgensen

I just started driving a 89 GXL. Under full throttle acceleration the car seems to turn by itself. It pulls to the right under full load, and pulls to the left if I let off abruptly.

Any idea's???


Note: the car has stock suspension and about 300 hp@flywheel.

Icemark

worn suspension and the need for a LSD.

Craig Jorgensen

Replace with rubber bushings? Poly bushings?

How does the rear suspension work? This is my first RX-7

Craig Jorgensen

Replace with rubber bushings? Poly bushings?

How does the rear suspension work? This is my first RX-7

Craig Jorgensen

"lsd"=limited slip diff???

I don't think tire slip is the problem, the problem is the worst during of 30mph "roll on"

I am planning on more power. (about 400@flywheel) how strong is the diff on an 89 GXL?

I am running a 6 speed manual with stock axle shafts and ring&pinion

Suds7

300hp on an N/A? Is it PP? I am building a bridge for my 91 n/a, would like to make at least 250. How did you do it?

kllntyme

Where did you get the 6-speed?

Icemark

Yep a LSD is a limited slip differential. You should have one anytime you are running more than 200 HP on these cars.

A six speed manual??? I think you need to list what you have done to make the car such a mutant, because it now screams to me that you have krammed some sort of alternitive power plant and it is flexing the body.

kllntyme

Or... if you have mated a 6 to a rotary please tell us how.

That's a good kind of Frankensteining.

Craig Jorgensen

sorry...
look, before anyone gets pissed at me... I think Turbo rotary engines kick ***. Period. Power vs. displacement vs. weight. RPM range... number of moving parts... the turbo rotary is a killer engine. But I paid $200 for my car because the apex seals failed. The N/A engine could not be rebuilt to 300-400 hp without spending at least $3000.00 (maybe alot more, I never really even considered it.). I installed a piston engine($400)...with a 6 speed($900) and about $500 in misc. parts.

No B.S. total: $200 car, $400 engine, $900 trans&clutch, $500 misc.

I admit, the car is nose heavy now. I would really like a big turbo rotary for my car. But cost vs. performance it just doesn't payoff.

Note: I am a mech. engineer, and installing a T-56 on a rotary would not very difficult.

Icemark

As I suspected...

I imagine its the wieght shifting in the car from the mutant engine and a lack of any sort of LSD.

To top it off the rear end (particluary the half shafts) is only rated for about 225 HP on the series 5 NA car.

I think you need to revise your motor mounts, and build up the rear end. You may need to use a rear strut bar as well.

BTW: it is pretty common to find a Jspec 13BT for about what you paid for the tranny, and for less than what you paid for the engine a T2 rear end and tranny. You probably would have spent less going with a rotary.

Of course you wouldn't have 300HP but you wouldn't be over driving the exisiting NA suspension and drive line.

Craig Jorgensen

I don't really have very much money in this car, and I would really consider a turbo rotary, but I don't really want the complex vaccum tubes & emissions that the car had when I bought it. I am planning a 380 cid piston engine w/carb & MSD for about $3000. I don't think I can build any rotary with 400 hp for that $ on pump gas.

I say again. I like rotary engines, I would like to use one, but I don't think ANYONE in Louisiana wants to rebuild a rotary (even stock) and salvage yards here don't even know what a rotary engine is.

Starting from scratch, how much money to build a pump gas 400 hp. rotary????

Icemark

Why do Piston engine guys always try to justify and say the same thing

Anyway back to your problem... as I said, using the stock mazda parts you are radically under suspensioned and a lack of sufficent rear driveline with that engine.

I also suspect that the engine is moving way too much in the frame. There may be other balance issues to placement of the motor and tranny as well. Most of the better conversions re-weight the suspension and change to coil overs to try and balance out the extra mis-aligned weight. You may have to do that as well.

bz7

What exactly did you swap in? An LT1/T56 combo? I'm also planning 300hp+ GXL build up. You definitely need to get your hands on a TII diff and halfshafts if you plan on getting any of that power to the ground.

If you haven't done so already, go to:

http://www.torquecentral.com/forumdi...?s=&forumid=11

And avoid yourself a flamewar...

bz7