btr and gkn differentials, which is stronger?

[panic]

it happened that i was supposed to have a btr diff with 3.45 gears in my griff 500 '96 but instead i have a gkn with 3.31 gears...how come? i've always believed models from '95+ had btr differentials...

question: is the gkn diff strong enough to hold an engine uprate and a rear gear change to 4.41? or should i get a new btr diff? which is stronger? also, if i get a new btr in place of the gkn, will it bolt right into my '96 griffith, without mods?

thanks/Giuseppe

[Slacey]

My '95 500 has a GKN too.

[shpub]

BTR is not a drop in replacement for the GKN. There are some chassis mods needed. Not impossible though.

As for the stronger diff... difficult to say.

[spend]

There are more ratios available with the BTR diff as well as all service parts being available. BTR is used in quite a lot of cars, whereas the GKN was only used in a few TVRs and Maseratis. I would expect the BTR to be stronger, but the GKN has been used in a lot of Tuscan Racers (but they prob had regular oil changes and a cooler)

The chassis mods I dont quite understand? You could either adapt the chassis or make up new mounts surely. Having said that the later chassis mounts look a lot more solid. I'm not completely sure but I think with GKN diffs very early cars had a slightly different chassis mount than the later cars (the early one floats even more & needs Tuscan bushes).

Dave

[panic]

were not '96 cars supposed to have a btr diff? i bought mine in late '96, never looked at the diff really and just now when i wanted to swap in 4.11 gears i've discovered it's a gkn...!!

[spend]

96 would be when it was registered, your chassis number will tell you when it was manufactured

Dave

[trackcar]

Why do you want a lower ratio diff? so you can waste more hp in wheelspin into 3rd gear instead of just first and second? Surely you'd want to be going higher ratio not lower and get a decent cruising gear in there? .. it's not like you dont have too little traction anyway without incresing the torque through a lower diff ..

[panic]

i've tried low 4.11 gears in my 570hp vette and i love it...i wanted to try it with the griffith, only i'll need better rubber (on the vette i have dot sportcar hoosiers).

[RichardD]

panic said:

i've tried low 4.11 gears in my 570hp vette and i love it...i wanted to try it with the griffith, only i'll need better rubber (on the vette i have dot sportcar hoosiers).

Is the Griffith going to be a drag car?

My Griff as a road car, with peak power at 5k revs exactly and a 3.31 diff - would perform better with reducing that number rather than increasing it.

I have some software that calculates straight line performance rather well, PM me and can set-up a model of your car with different diffs / tyres (ie changing the coefficients of friction to simulate sticky tyres)...