Is there a company that specialize in the ring and pinion for our Turbo2's? Is there anything else for the Turbo2 beside the 4.1 that comes stock in our cars?

Im looking to build a freeway beast, and i would like to get lower gears for the car. I would perfer 3.73, 3.9, or something close to that. I think Tri-Point does some custom work for the rear end, but im not completly 100% sure.

With anything lower than 4.1, I wonder if we have the torque to get it moving from a stop light because of our small displacement engine?

I can change out the transmission to the s5 TII tranny because of the 5th gear, but to replace tranny and the counterweight, just to get maybe 10mph, is not worth it to me.


What do you think?

 

You have terminology bass ackwards. You want something geared HIGHER then the standard 4.1 gearing, NOT lower. Lower would be 4.3 ring and pinion which would get you off the line quicker and sacrifice top speed. You’re looking in the opposite direction "freeway beast".

The auto n/a came with a 3.9 gear, but you'd have to swap to an n/a rear 3rd member that would be a downgrade from TII and would be weaker and so would the axles you'd have to use too. I know the TII was available in Japan in auto form (not available in us), but I have no idea if they were 3.9 ring and pinion though. The U.S. 3rd gens came in auto form and had a 3.9 ring and pinion as well, but unfortunately, the ring and pinion are NOT interchangeable with TII's although the center differentials are. Sorry for not giving you an answer for "yes, you can use XX ring and pinion", but at least I'm eliminating more questions or other uneducated suggestions from others.

it would be fine leaving from a dead stop. Having a lighter then stock flywheel would make it even more difficult.

Lets be realistic here, or maybe you havent driven a car at HIGH speeds. You will never take advantage of the s5 5th gear higher ratio while racing (the main advantage would be better gas mileage during cruising). If you intend to freeway race (interstate or race from a roll) you'll be using 3rd and 4th gear. I truly don't forsee any race requiring 5th, 4th would take quit a while to top out, both in length, time and horse power.


~Mike..........

 

The counterweight is dependant on engine, not tranny, so you don't need to replace it.

Besides, when are you actually going to get the car to top speed? Can you even max out 5th now? Where do you plan on doing this, Boneville? Doing it on the road is stupid and extremely dangerous, you'll quite easily kill yourself and several innocent people doing that.

If you're planning on going that fast on the street I hope they arrest you and lock you up for a very long time.

No I don't think there's any other ratios other than 4.1 and 4.33.

 

You can run 3.90's iirc. possibly out of an automatic 3rd gen?

 

No, read 2 posts up, the FD R&P can't go in the FC diff housing.

 

Sorry for backward *** writing.

Acceleration suck with 4.10 at 160+ MPH.

 

What's the issue you're trying to fix? Your original post isn't very clear to me.

If you are happy with 0-150 mph, but want more oomph at 150+, just swap the 5th gear. I did a 0.719 -> 0.806 5th gear for my FD and I think the FD is fundamentally the same case as the FC TII, so I don't see why you couldn't do that too.

Changing out from a 4.1 to something else will make ALL the gears pull harder or softer, but 5th will still suck compared to 4th.

 

So... there is no company beside Mazda make anything else besides 3.90?!

 

What are you trying to do?????

~Mike............

 

Race my brother and my friend's supra on the freeway.

They have 3.73 and 3.13 gears, and what do i have...4.10. The race will be over as soon were approaching 160mph, and at that speed, they're still pulling HARD!

 

I've got to agree with Black91n/a the freeway is not the place to race....at least find a nice track somewhere to keep things safe. You're going to get someone killed doing that.

The rx-7 is not a top end car, take them to an autocross event and show them how to really drive.

Drive responsibly.

 

I know it is dangerous. But there are other things that are as or more dangerous that we take for granted that we do everyday.

Im sorry if i offend any of you guys, but for RX7 not for being a top end car, go tell RACING BEAT that.

But my goal is set up a car that can compete in the SilverStateClassic, and the TEXASmile.

 

That's a bad arguement and you know it. There are things more dangerous, and they are usually out of your control. Whether you race or not on the streets is totally within your control.

I had 4 friends die in an accident because they were ******* around racing at lower speeds than you are planning on trying for. They could have just as easily killed another family along with themselves. If you think that racing on the streets is a good idea because there are more dangerous things out there you should not have a car, nor should you drive a car.

 

You may be willing to accept the risks, but by doing it you're deciding for everyone else at the same time, and you have no right to do that. They don't think the risk is acceptable. How much fun will it be to spend the next 25 years in prison with the knowledge that you killed several people, possibly freinds of yours, most likely innocent people. That'll be with you your whole life.

It's not worth the risk and you have no right to make that decision for others, so don't do it.

If you want to go super fast, go to the Silver State Classic or Boneville.

 

So is snorting coke, shooting up crank, having unprotected sex, smoking cigerettes, drinking alcohol, and raping little boys will get you 25 yrs too and/or death in your short lived life.

IT IS ALL IN WITHIN YOUR CONTROL!

People die more from overdosing, lung cancer, and AIDS, more than someone is going 150+mph, and it is all within their control! Don't you think someone that is going 150+ know what they're getting themself into and maybe they prepared for it?!

I know what im doing im NOT SAFE. Im not trying justify what im doing is right, but quit act like you have a concern, when you let your family members smoke and they're doing drugs behind your back.

Again, I KNOW IT IS NOT SAFE, and my original question was answered, so let's quit the MORAL/LAW preaching.

 

And do you know how overdosing on drugs and lung cancer are different from driving on the street at 160mph? The difference is OD'ing on drugs kills you, lung cancer kills you, AIDS kills you and the person who chose to have sex with you, but they made that choice as well to engage that sort of risky behavior. The only thing in your control on street racing is the speed at which you are driving. You cannot control the surface of the road, traffic, or debris. All of which means you have a lot less control than you think you do.

Other drives on the road had no choice in your decision to drive that speed. They may be a law abiding citizen obeying posted speed limits. They have no choice if something goes wrong because you chose to drive that speeds. You can kill others because of your irresponsibility and your poor choices when you drive like that on public roads. Others who could care less how fast your car is. Others who had a date that night, families out seeing a late night movie. Killed because YOU wanted to go fast.

That is how it's different. There's a reason states are getting tougher and tougher for street racing laws, several now you go to jail, do not go home, do not kiss your girlfriend at night. I have every reason to be concerned. I could have friends or families on the road where someone is racing who could be killed for being in the wrong place at the wrong time.

That being said there's a difference between racing on the track and racing on the street. If you notice, I said take it to a track where it can be done safely without risking other lives. Track surfaces are specially prepared and cleaned to handle speeds. Oil spills are burned off with torches to prevent slick spots, pot holes are smoothed to prevent loss on control at high speed.

I'm not saying don't drive fast. I'm saying do it responsibly someplace that has been designed and prepared to drive fast. If you think that the morality behind being safe and smart is wrong. You will get someone killed racing on the streets. I've seen the results of it, which I've said before in a previous post here. The first time you lose a friend or two in a street race accident, stop back in here and read. Then you'll understand.


All that, I've yet to see any other gear ratios but a 3.909 and a 4.3 for the 86-88 drivetrains. You could probably get a custom one fabbed for a god awful chunk of money though.

 

Im sorry to hear you have lost friends of this.

Thanks for your inputs everyone!

 

The 3.909 is for the AT and I'm not to familiar with their compatability. SOmeone more knowledgeable should have a better idea.

 

So what is your current 5th gear ratio?
Have you considered a taller rear tire diameter?

 

changed my mind

 

What would be the difference between the FD and FC R&P, as far as swapping them? Would it be easy or not worth the effort.

 

The FC has a long pinion gear, the FD's is shorter and won't work. I suppose you could probably graft the FD pinion gear onto the FC pinion shaft like the racers do to get a 5.12 diff, but that's a difficult thing to do right.

 

At those speeds aero improvements will do more than changing a rear gear. The cheaper option would be MORE POWER. And make sure you have the power at the rpm you need it.

And when you take it to the salt flats or run the Silver State be safe. Keep it off the streets, its not your speed it will be the person that doesn't see you coming at that speed. And guess who's fault that is.

 

This kid and his friends dont deserve drivers licenses. this is THE best reason for stricter control over who gets to drive and who doesnt.


BC

 

So you want to go faster than 160 mph so that you can outrun your buddies in top speed runs.
Changing to a 3.90 gear won't make you go any faster. It will just make your same top speed happen at a lower rpm, and it will take longer to get to that speed. If you went to 4.30 gears, you'd still have the same top speed, but you'd get there faster.
With stock diameter tires, stock TII 5th gear, and 4.10 gears, you should be hitting close to 190mph at 8000 rpm.
Want to go faster? Rev higher. At 8600 rpm you'll be above 200 mph.

Right now, you're not speed limited by your gearing. You're speed limited by your aerodynamics and your power. Want to go faster? Make more power. For aerodynamics, two easy steps are: Lower the car so its only a few inches off the ground, but keep the rear end slightly higher. Make the underside of the car as smooth as possible with undertrays.
Then, make more power. However you want to do it is up to you.

But simply switching to different rear gears will not make you accomplish you goals.