Erdin

Has anyone got a supra 6 speed gearbox on there FD if so what do you think of it, wear you happy with it.

Cheers

Erdin

ForceFed

Can you easily mate a Supra Getrag to the 13B-REW? If so that would be pretty nice seeing as how durable that tranny is and having that extra cog would be nice. I could be the hit of the town. Everyone will throw a parade for me, hot girls will throw their thongs and g strings at me, maybe the Mayor will even give me the key to the city. Wouldn't that be nice?

poss

iTrader: (5)

This has been talked about many times, but I don't think anyone has actually done it. Sounds like a good idea to me, except the whole ppf and mating it to a 13b-rew thing.

Erdin

A lot of guys have them in the Australia on there drag cars, you can get a adaptor for the bell housing so you can retain the fd bell housing and parts but you will have to do some fabrication work on the power plant frame and the drive shaft. I’m seriously thinking of having this done to my car but I want to hear from people who have it already I know the ratios are different but what if we change the final ratios in the diff what would it be like then.

mattyice

those tranny's are expensive as hell though you could prolly get the GReddy 6 speed kit for the FD and it uses the stock tranmission casing, you can get it at www.rotaryextreme.com

Erdin

In the uk there priced at about £750 second hand so il Probably go with one of thos because its cheaper then one of the up rated boxs and it can take over 600bhp.

broken93

Plenty of reading material:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-anybody-368441/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-tranny-367155/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-353774/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/legendary-6-speed-transmission-352138/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/would-rx8-6-speed-transmission-bolt-into-my-3rd-gen-292014/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/heres-6-speed-will-fit-fd-266191/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/six-speed-rx7-262491/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/rx7-six-speed-tranny-my-car-229733/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fd-6-speed-gearset-216669/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/rx8-6-speed-into-fd-216705/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-fd-175912/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/3rd-gen-6-speed-trans-swap-189999/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/complete-6-speed-dog-engagement-gearkit-191737/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/ever-offered-6-speed-tranny-166060/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fd-6-speed-tranny-133854/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-transmission-adapters-now-available-fds-130563/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-128847/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-tranny-103527/
https://www.rx7club.com/showthread.php?t=60701
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-rx-7-a-15244/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-sequential-tranny-42514/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-trans-fd-37069/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/6-speed-30659/

Erdin

Man i was gona go bad

dgeesaman

iTrader: (7)

Broken, I think he's aware that 6-speeds don't bolt up.

There is some discussion about it on www.scuderiaciriani.com as well as stuff in the archives here. Like the others said, it involves fabrication or adapters for every single interface. Not cheap or easy.

But last, it begs the question, why? Unless you're over 500hp and busting drivetrain parts, the FD or FC T2 trannies are plenty tough and versatile.

Dave

rynberg

Jesus, this has been covered so many times.

The stock tranny can handle a LOT of power -- most of the guys out there with 400 rwhp+ are running just fine with stock trannies, even in drag situations. Secondly, a 6th gear is pretty useless, given the FD's gearing and powerband. There's shorter fifth gears available or different rear end ratios if you want to alter your gearing.

So, basically, it would be a lot of expense and effort to accomplish zero.

travisorus rex

I have even heard stories about FDs with 400+ horsepower running the stock transmission. Plus, the gearing on the FD was made to work with the FD.

jsplit

I've still yet to figure out why people want 6 gears to begin...

Erdin

well il let every one know how i get on when its Fitted unless anyone knows somthink i should. the supra box is alot cheaper then the HKS or greddy products and i know it can take the sort of power i am looking at, so lets see how i go.

Thanks every One

turbojeff

iTrader: (30)

I can imagine some old guy saying the same thing back when they came out with 4 spd trannys replacing the 3 spds in the 60-70s (or was it the 50s?).

I think dropping in any old 6spd is not a good idea. A 6spd with close ratios could help keep the engine closer to it's peak power for maximum acceleration. A CVT has infinite ratios, like a snowmobile drive, and can always keep the engine at peak power for max acceleration.

poss

iTrader: (5)

Gear Ratios
Supra:
1st 3.827:1
2nd 2.360:1
3rd 1.685:1
4th 1.312:1
5th 1.000:1
6th 0.793:1

Ours:
1st 3.483:1
2nd 2.015:1
3rd 1.391:1
4th 1.000:1
5th 0.719:1

As you can see, they fit an extra gear in between our 1-4. This might not be faster down the 1/4 mile, but it would surely make it easier to stay in the powerband on the track.

TrueSlideXL

At the power levels where a Supra would have a 3 or 4 speed (~700+ if it's a drag car) the rx-7 wouldn't benifit from a 6 at all. Why do you want to "stay in the powerband" if the other FD and FC T series trannies are good up until that point?

turbojeff

iTrader: (30)

They look shorter. What diff gears does the Supra have, I'm assuming it isn't a 4.10:1?

poss

iTrader: (5)

they have a 3.133 final

turbojeff

iTrader: (30)

I'm not sure if I'm following you. A turbo car like the FD or especially the 700hp (single turbo?) you are punished by huge losses in power if the revs fall below the point where turbo is not making boost.

I'm not just talking about drag racing either, it could be road courses.

Closer gear ratios reduce the drop in revs at each shift and make it easier to keep the engine at peak power levels.

This isn't to say that an additional shift may or may not hurt lap or strip times either.

jimlab

Well, it would certainly be a good way to make your gas mileage worse, for the 99% of the time you weren't at the track...

jimlab

At least at stock power levels, a 5-speed FD is actually a little quicker to 60 mph and 1/4 mile than one with the gear ratios of the Supra's 6-speed. Of course, that extra strength and extra gear come at a penalty that no one has mentioned... weight. Not to mention the requirement for a differential brace, transmission mount, bellhousing adapter plate, flywheel, clutch, clutch slave cylinder conversion, and so on.

Since CVTs aren't practical or available (at least yet) in high power applications, let's stick to discussing real world gear ratios. Maximum acceleration is achieved by dropping to or near peak torque... which is why the FD came with the gear ratios it did. And the Z06, and the Viper...

teamstealth

Lest we forget CVT's make the engine run at maximum revs all the time. Not so sure the rotary would appreciate that too much

I dunno, the stock 1-4 gearing seems pretty good to me, and the JDM 5th helps with the top-end accel.

turbojeff

iTrader: (30)

Sounds good. I never claimed that the FD would benefit from a 6spd in a 0-60mph sprint.

The idea of more gears available keeps peaky engines closer to thier power peak. Maybe a 5spd is ideal for the FD in a drag race, but some road courses it may benefit from closer ratios, it all depends on the course, the engine's powerband, etc.

Remember during acceleration the engine that is kept closer to it's peak power will accelerate the car the fastest, all else being equal. That is why I mention a CVT, they are tuned to keep the engine closer to peak power rather than peak torque.

jimlab

With a standard transmission, automatic or manual, the car will accelerate fastest by dropping to or near the engine's torque peak in each subsequent gear, and accelerating to the point at which torque at the axles in the current gear drops below torque at the axles in the next gear higher. This is not subject to debate or interpretation. It is fact, it is is easily demonstrated under real-world conditions.

Maybe you should buy a snowmobile...

turbojeff

iTrader: (30)

I agree with you shift point example/method. I'm not debating you.

Peak engine power puts the most power down to the wheels. No debate here either right? Power is what moves the car.

Your graph in the other thread that shows a ~5x reduction in torque at the wheels, not power. If there was a 5x reduction in power at the wheels the drivetrain would have to deal with a lot of waste heat.