M90 gearbox limits?
 

Does anyone know of the bhp/ torque handling capabilities of an M90 box?
Also, more to the point, does anyone know how much power the standard T5-R clutch setup will handle? I have heard of one guy melting a T5-R clutch at 300bhp on the dyno.....
Have people been running the T5-R setup at 300bhp with no trouble?
The reason being is I am thinking of aiming for a slightly higher power figure, my main concern is the transmission!i know the rods need changing around 350bhp but I am wondering how much the transmission will handle up to that...

Torque is the problem, not bhp. I believe the R clutch is good for 400lb/ft but not 100% on that number.
M90 will be fine at that power, I'd do the 3rd gear synchro mod just in case.

Oh dear!! what's the 3rd gear synchro mod all about?

http://www.forums.turbobricks.com/sh...d.php?t=319573

3rd can poo itself with enthusiastic gear changes, that thread explains it perfectly.
I'll definitely be doing it for a piece of mind.

The R clutch is considered good for upto 420nm but if you are going to be pushing close of over a paddle clutch is the best bet. I have fitted a few of the 6 puck spring paddle clutches now and clutch feel is very good with them. Not overly grabby like some paddle clutches tend to be.

The 3rd gear mod is going to be a must for an performance use

I am very wary of paddle clutches, I once fitted one to my Pulsar GTI-R....it pretty much ruined the car. It was better as it bedded in but still pretty awful at any thing other than flat out driving.
I saw a member on here selling a ttv flywheel and an uprated 850R clutch a little while ago...I much prefer that option.
In order to be pushing 420nm of torque, I think I would need more power than what I am aiming for...especially from an 8 valve!

You can get well past that with a 8 valve

https://www.youtube.com/watch?v=z0Yq0Ba6Es8


but most of use are not going for that kind of power. The TTV flywheel and R clutch are one of my top selling items

i can confirm that a 300k mile m90 that rattles its nuts off in neutral and has no 1st gear syncro left, handles around 500nm with no signs of failure. but thats behind a d24 and doesnt rev above 5k rpm ever

my clutch is from CG motorsports, rated at 520nm cost me 350 quid including all the necessary machining to make it fit, pedal is heavy but it uses a standard ish 850 228mm friction plate, so drives beautifully.
:thumbs_up:

video from a while back at 400nm
https://www.youtube.com/watch?v=YXUmGIdY16Q&t=7s