The F25 was almost allways paired up with the V6 engines ( C25XE for example)
GM specifies maximum torque as the number X 10 in Nm = 250 Nm = 184 ftlb
here is the hard data....
http://media.gm.com/division/powertrain ... 03_f25.htm
Now everyone knows that Getrag makes a decent unit..... the F28 is capable of taking way more than the standard 280 Nm worth of torque.
I know that some of the Saab guys have converted to the F25 from some of the older transmissions but I never found talk about the limit of the F25 specificly.
I did find one Saab running just over 300whp that was using an F25 with Quaife internals.
All things considered the F25 can handle at least 25% more power than the F20
If I was to just take a shot in the dark here I'd guess the F25 would be capable of handling roughly 250 lb ft to 275 lb ft of torque without blowing up.
That may be on the conservative side but it all depends on how the power is being put to the pavement.
Obviously street tires will not hook up with that much torque unless the pavement is really sticky.
On the other hand a set of R compounds or drag slicks may just test the power handling capability.
The good news is that the F25 is fairly cheap and there are a number of them on Ebay.
I will try and get the Saab part number..... it will be something like FM55.... but I will have to check on that to be sure.
Personally..... I'm still more intersted in the Saab 6spd..... as they typcially mated the 6spd to the Viggen/Aero model which was their highest model.
I still have to think that the 6spd might be the F28 (or a slightly differnt version) but there is no way of knowing.
I have poured through allmost all the GM material I have and although there are many links to the F25 I have never found information on the Saab 6spd on any of the GM sites.
