Rotary Car Club - View Single Post - Accepted power/torque limit for S5 TII-tranny?

RICE RACING · 03-12-2012, 10:57 PM

So this works out to 520Nm (remember that is a car running a long time) in a 1070kg FB chassis (old RICE factory car from 1997).

Since Power (watts) = N (rpm) x T (Nm) / 9.55
^ 381kw (511bhp) @ 7000rpm on my old yellow car, peak power happens another 500rpm later.
*This set up did ~550bhp engine power* at this low boost setting (sub 19 psi see dyno Autronic data log that was off above dyno run)..... on the street I ran it regular @ 23psi and well over 600bhp!*

You can see the answer to the "how much power" is proportional to the engine speed for peak Tq.
I have seen some FD's put down 700rwhp (exaggerator 3000 dyno's) and run for fucking ages on the stock gearbox, but this is on extend ported motors with big turbos revving to 9000rpm.

It gets tricky in this respect, on the street with a metric cock load of jizz power you accelerate SO QUICK in 1st, 2nd, and 3rd! that the box is not under that much load, in 4th gear you are going direct through the gearbox (not using ANY gears) and so the power is basically unlimited as to what you can feed into it! This is where the WEIGHT plays an effect in the 2nd and 3rd gear especially you load up the car for longer at the high boost (say 30psi) and it really stresses the gearbox, when you do it often enough you will see the case hardening wear off the main shaft and counter shaft 3rd gears especially.....

Hope this all makes sense to you?

Moral is you can get away with a huge fuck off amount of power on one of these boxes, and most people do. Others don't the answers can be numerous and varied as to why, but most people have zero issue running a honest 600bhp through a S4 S5 or FD gearbox

03-12-2012, 10:57 PM	#3
RICE RACING Don Mega Join Date: Dec 2008 Location: Utopia Posts: 1,688 Rep Power: 18	So this works out to 520Nm (remember that is a car running a long time) in a 1070kg FB chassis (old RICE factory car from 1997). Since Power (watts) = N (rpm) x T (Nm) / 9.55 ^ 381kw (511bhp) @ 7000rpm on my old yellow car, peak power happens another 500rpm later. This set up did ~550bhp engine power at this low boost setting (sub 19 psi see dyno Autronic data log that was off above dyno run)..... on the street I ran it regular @ 23psi and well over 600bhp!* You can see the answer to the "how much power" is proportional to the engine speed for peak Tq. I have seen some FD's put down 700rwhp (exaggerator 3000 dyno's) and run for fucking ages on the stock gearbox, but this is on extend ported motors with big turbos revving to 9000rpm. It gets tricky in this respect, on the street with a metric cock load of jizz power you accelerate SO QUICK in 1st, 2nd, and 3rd! that the box is not under that much load, in 4th gear you are going direct through the gearbox (not using ANY gears) and so the power is basically unlimited as to what you can feed into it! This is where the WEIGHT plays an effect in the 2nd and 3rd gear especially you load up the car for longer at the high boost (say 30psi) and it really stresses the gearbox, when you do it often enough you will see the case hardening wear off the main shaft and counter shaft 3rd gears especially..... Hope this all makes sense to you? Moral is you can get away with a huge fuck off amount of power on one of these boxes, and most people do. Others don't the answers can be numerous and varied as to why, but most people have zero issue running a honest 600bhp through a S4 S5 or FD gearbox __________________ www.riceracing.com.au Worlds best Apex Seals Coil on Plug Water Injection ECU Calibration Last edited by RICE RACING; 03-12-2012 at 11:23 PM.