reddozen

iTrader: (1)

I know that some people have swapped in the T56, the 5 spd, and FD transmissions, as well as the gear-set from the Australian company. What I'm wondering about is what exactly fails in our transmissions in the 350~400 HP range? A friend of mine suspected it was the input shaft gear. Has anyone taken apart one that died from high horsepower and identified the weak points?

I'm trying to avoid a $6k gear-set if I can have a couple parts made at a local machine shop for less.

dannobre

iTrader: (3)

Mine spun teeth off 4th Gear going up a hill...

I wouldn't even try and fix a 6 speed...if you are going to play around go to the 5 speed RX-8 box or an FD box ( basically the same inside)

So far mine is holding up to 450 WHP road course. Drag launches and things will break for sure

reddozen

iTrader: (1)

Good times... so I'm hearing full gear set or swap. Thanks for the info.

dannobre

iTrader: (3)

The problem with trying to swap in gears sets is usually the strength of the case is an issue...often more of an issue than the gears.

Brettus

iTrader: (2)

My 6 speed trans never failed with 325whp going through it for 100,000kms . But I never did any drag launches or burnouts .
The rx8 5 speed trans I have now seems fine as well at closer to 400whp. The syncros fail on these from abuse more than from 400 plus whp.

dannobre

iTrader: (3)

I think if you are careful the 6 speed is good for 325 to 350

Mine died quickly with slicks at 450....

So far the 5 speed is working great.... I was thinking about going to a T56 based unit...but they really shift like a truck

Ian_D

Some people prefer the S2 6-speed MT both S1 MTs. I find this strange as over here in the UK the S2 6-speed MT is seen as relatively fragile; however, this may be because people are assuming there is a general issue from complaints over the inadequate 5th & 6th gear synchros on earlier R3s.

As an aside, over here in the UK there are plenty of the better-spec 5-speed transmissions to use in a turbo swap if/when the 6-speed transmission breaks. That, I suppose, is some consolation over the extra issues we have trying to plumb a turbo around out RHD steering column.