3.91 Vs Stock diff

[AryM]

Sweet bro. Hook me up on Gtalk sometime.

No worries, will do:
The Diff will shave off at least 0.2 - 0.4 of your 1/4 mile I'm told.
Makes a world of a difference and revs up quicker too!

Just interested:
Does it bring down the reliability and engine life of our motors?
Thats besides going through rear tyres quicker than normally!

 

[STREETRACER]

getting technical it will coz you run at higher revs, more gear changes etc.. but that might take 100km of your cars life!
but it saves your clutch, coz it takes less load of your drivetrain! its like pulling away in 3rd burns your clutch so 1st is better coz its shorter, now 1st gear is even shorter so it will save it more! but now the car is more fun to race so it will not last as long! this is cat and yarn theories going back and forth back and forth!
no yes or no answer!

In my opinion, you affect your engines life when you raise internal pressure or raise rev limiter.. staying in the stock limiter or pressure bracket and you nurture your car when cold.. your life span of your engine will not be affected!
hope this answers it..

 

[quattro]

Main problem with the 3.91 diffs in the V10's is that most of them tend to whine. I have an Evosport unit with trick internals that has now also got noisy and needs to be sent back for warranty repair.
The extra 8% torque available everywhere in the rev range is just WONDERFUL and it will still run run serious top end at 8600rpm.
May refit the original diff while the 3.91 is away for repair and it will be interesting to see if the car now feels a bit "flat". I'll try it's new Dinan intake system at the same time which will offset some of the difference from the original diff being in again.