rolling road info

[stifler1603]

can a gtir be tuned on a 2wd rolling road? ie by disconnecting the propshaft? because now there is finally a dyno in my country but its for 2wd vehicles so i was wondering if it can be used to dail in my engine

 

[vss irvine]

If you disconnect the prop youll get no drive (or very limited) to the front wheels.

And theres a good chance youll over heat the diff in the gearbox.

 

[stifler1603]

damn !!!!!!!!! and i see some guys with evo's and wrx's doing it . good thing i asked first lol

 

[The Doc]

Still not sensible on there cars, the centre diff will be taking a hammering and can ultimately fail .

 

[PobodY]

Is it slightly better when there's an electronic centre diff that can be disabled? Or does that just mean it fails in 10,000 miles rather than 1,000?

 

[The Doc]

It all depends on type of 4wd, the Haldex system in the vw camp Is basically a clutch that disconnects the rear wheels...so no centre diff and the car is always front wheel drive unless the ecu detects it needs to be 4wd...this could be 2wd dyno'd , a similar system is used by the skylines to power the front wheels .....so they can be dyno'd on 2wd rollers, where as the some lancia,Subaru,Mitsubishi and nissans use variable silicon filled centre diffs and ferguson couplings that vary drive front and rear all the time and having 2 wheels under load and the others not will destroy them very quickly from over heating and also give you a false power reading.

 

[PobodY]

Thanks Doc! - I thought it was something like that because you often see GTRs running in RWD only when there should technically be power going to all four wheels.