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-   -   transmission upgrades?? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/transmission-upgrades-753183/)

mazdabill 05-02-08 03:44 PM

transmission upgrades??
 
With the single turbo and all of the upgrades, should anything be done with the transmission??

Rotors R Cool 05-02-08 03:57 PM

I've been told that the factory transmission in 3rd gens is one of the strongest transmissions to ever be put in a production car. This however, is not the case when the transmission is abused. The only thing I can think of is the 5th gear synchro issue. Talk to Rotary Performance about what you can do to cure that issue before it even arises. The pervious owner of my car had something put in the transmission to prevent that failure but I don't know exactly what it is.

Rotary Performance's 9 sec drag RX-7 uses the factory transmission. Even uses the factory rear end (but don't quote me on that).

grimple1 05-02-08 05:02 PM

swap it out for an automatic.



----------------------------------------------


in all seriousness.... clutch, flywheel in addition to the above posters 5th gear syncro comment.

dgeesaman 05-02-08 05:14 PM

Generally, no there is not a readily available upgrade for the transmission. The drop-in upgrades cost the same as 10 good used trannys, so IMHO it's easier to go through a couple of stock ones before seriously considering the "next step up". In fact with the weak dollar this next step up is even a higher jump than before.

While the FD tranny is often run in 300-500hp cars, I would never group it among the most durable production trannys. It's not bad, but compared to the beefy boxes of the muscle car era, it's fragile. It's not as strong as the supra getrag and T-series trannys of the modern domestic monsters. But it's not bad. There are plenty of modern sportscars with a reputation for fragility. Unfortunately it's not easy to fit one of these to the FD drivetrain.

If you have an FD tranny out, consider replacing 5th synchro and the 5/R check plunger assembly.

Clutches are not part of the transmission but do need upgraded when pushing more torque. The original clutch fork should be replaced with the clutch.

The differential and axles can also become a weak point at higher torque levels. Upgrade the diff bushings at the very least and consider adding some kind of diff brace.

Rotors R Cool 05-02-08 05:29 PM


Originally Posted by dgeesaman (Post 8155611)
Generally, no there is not a readily available upgrade for the transmission. The drop-in upgrades cost the same as 10 good used trannys, so IMHO it's easier to go through a couple of stock ones before seriously considering the "next step up". In fact with the weak dollar this next step up is even a higher jump than before.

While the FD tranny is often run in 300-500hp cars, I would never group it among the most durable production trannys. It's not bad, but compared to the beefy boxes of the muscle car era, it's fragile. It's not as strong as the supra getrag and T-series trannys of the modern domestic monsters. But it's not bad. There are plenty of modern sportscars with a reputation for fragility. Unfortunately it's not easy to fit one of these to the FD drivetrain.

If you have an FD tranny out, consider replacing 5th synchro and the 5/R check plunger assembly.

Clutches are not part of the transmission but do need upgraded when pushing more torque. The original clutch fork should be replaced with the clutch.

The differential and axles can also become a weak point at higher torque levels. Upgrade the diff bushings at the very least and consider adding some kind of diff brace.

^This guy is super smart^ :icon_tup:

dgeesaman 05-02-08 09:30 PM

No, I've just been here too long.

finnicky7 05-02-08 09:39 PM

And he totally knows how to use the search button. ;)

teachermechanic 05-03-08 07:05 AM

1 Attachment(s)
Updated select shift spindle #w501-17-7250

mazdabill 05-03-08 12:48 PM

Thanks for your help, big time, I need it

mazdabill 05-03-08 12:50 PM

Diff brace? what do you mean?

Mahjik 05-03-08 01:01 PM


Originally Posted by mazdabill (Post 8157291)
Diff brace? what do you mean?

http://www.banzai-racing.com/products_diff_brace.htm

Ottoman 05-03-08 03:27 PM

you can buy a drop in Gear set for your tranny

changes ur gear ratio (if u want it to)

and can basically convert it into a Dogmission...

will be much stronger than original as well.. but not much of a DD after that

it will also run u about 3 grand..

there is also version that are a beefer gear set with a larger input shaft but still synchro'ed i believe


OS giken, Ikeya, are a couple brands off the top of my head

Rotors R Cool 05-03-08 03:38 PM


Originally Posted by Mahjik (Post 8157313)

Is the diff brace an alternative to better diff mounts? Or should I do both those things while I'm at it? And how much does that brace hurt ground clearance?

kiwi fd3s rs 05-03-08 03:49 PM

If you had a spare 10k australian dollars, these boxes are the mutts nutts

http://www.ppgearbox.com.au

viviorunitia88 08-25-08 05:17 PM

not to bring a thread back from the dead but how is the dogbox no streetable. Also as well as would there be any real diffrence if i just sent it out for a complete rebuild with cyro treating to if i just bought a new one. Not concidering price.

IRPerformance 08-25-08 05:49 PM

Very noisy, notchy, and not designed to be constantly changing gears such as in street driving. I've driven one and it was pretty cool but it is definitely more suited for drag racing.

viviorunitia88 08-26-08 12:00 PM

now better question would i really see any advantages if i switched over to a os giken gear set over a stock one that would be cyro treated. also does anyone make any upgraded parts for the transmission such and siftforks or doubled sided syncoros.l

cewrx7r1 08-26-08 11:21 PM

Depending on your driving, you might consider the shorter JDM 5th gear.
It does lower mpg but when cruising over 60 and you floor it, it is almost like you where still in 4th gear. Instant spoolup and acceleration.

If you need more acceleration and less top speed after 4th, it is the way to go.

Jaime Enriquez 08-26-08 11:45 PM


Originally Posted by viviorunitia88 (Post 8493485)
not to bring a thread back from the dead but how is the dogbox no streetable. Also as well as would there be any real diffrence if i just sent it out for a complete rebuild with cyro treating to if i just bought a new one. Not concidering price.

They whine like mad, notchy (as aforementioned), are are designed for power upshifts with a lift of the gas...no clutch. PM damian, he just put dog-gears in a T5 tranny (a few posts down in the race section). Ask him what it is like to drive and shift in the pits?

61620B Rene uses an FD trans behind his 500+hp 3-rotor, so I think they can handle some decent power.

Hitokiri_Gensai 08-27-08 12:05 AM

The FD tranny really seems to be able to handle a lot but...

the only other offering is G-force tranny's or some of the set ups from GReddy or HKS... which are crazy expensive...

i believe the HKS 6 speed for the FD was 11k USD?

viviorunitia88 08-27-08 03:03 PM

well the 5th gear really doesnt matter i have a single setup that is going to be making right around 500 on pump 550ish on race so im trying to weigh my options for winter are the jdm gears stronger at all

Gorilla RE 08-27-08 08:03 PM


Originally Posted by Rotors R Cool (Post 8155327)
I've been told that the factory transmission in 3rd gens is one of the strongest transmissions to ever be put in a production car. This is FAR from the truth my man...

Rotary Performance's 9 sec drag RX-7 uses the factory transmission. Even uses the factory rear end (but don't quote me on that).

The better question is how long is that stock trans lasting in a 9sec FD?

-J

Six Rotors 08-27-08 08:42 PM


Originally Posted by internal comsucktion engi (Post 8500827)
The better question is how long is that stock trans lasting in a 9sec FD?

-J

Well you could always ask ErnieT!I think he said about 6 passes when I was talking with him a couple of weeks ago.

Gorilla RE 08-27-08 08:44 PM


Originally Posted by Six Rotors (Post 8500937)
Well you could always ask ErnieT!I think he said about 6 passes when I was talking with him a couple of weeks ago.

I knew the answer..... That wasn't my point.

-J

dgeesaman 08-30-08 06:42 AM


Originally Posted by viviorunitia88 (Post 8499710)
well the 5th gear really doesnt matter i have a single setup that is going to be making right around 500 on pump 550ish on race so im trying to weigh my options for winter are the jdm gears stronger at all

No.

The only upgrades you could consider for a streetable car would be the gearing upgrade from OS Giken or similar. What you really want is a bigger/stronger synchromesh tranny with helical cut gears. But they don't exist as a bolt-in for this car.

FYI, before you spend $10k upgrading your tranny here are the basic features of aftermarket trannys:
1) Straight-cut gearing
- stronger than the stock helical gearing
- whine like mad
2) Dog-face engagement (stock = synchromesh engagement)
- shifts faster
- higher torque capacity
- very noisy
3) close-ratio gearing
- better gearing for the track
- lower fuel economy

If I were serious about that, I'd install a T5 like Damian but put heavy-duty synchromesh gearing into it.

Dave


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