TonyG

The problem with shimming up the diff super tight is that you get good trail brake characteristics... but you get push under throttle. And these cars push at the limit anyway... so it just makes it worse.

With the 50/80 diff.... you get the best of both worlds.... great trail braking without the diff induced push. Plus it's WAY stronger than any factory 951 diff.

These 50/80 diffs definitely make a difference in lap times.

TonyG

vt951

Anyone willing to scan that in?

MAGK944

I have heard that but never quite understood what "harder" meant. Could you not just cryo first and second and achieve the same result for little $'s ?

bdesai7

You guys don't think I should buy the torque biasing differential from guard? It is MUCH cheaper than the LSD (1350 vs 2300), and may be ok for my daily driven application (mostly street car with a few track days).

Any thoughts?

And please do scan in that article from Excellence, thanks.

knfeparty

I found an LSD NA transmission that the seller was unaware of the goodies inside so I got the whole think for a couple hundred dollars shipped. I originally put the whole tranny in but it was kind of beat (unknown miles) so ultimately I removed the LSD, rebuilt it (the parts are surprisingly not very expensive) and put it back in my other transmission. It is PERFECT for autocross and it was nice at VIR S too. I still got some squirming in the braking zone for the straight but that was probably due to the pavement as much as anything.

TonyG

The torque biasing is the worst differential you could install for track use as it acts like an open differential under braking.


TonyG

bdesai7

I never really understood what benefit there is to having an LSD and having the rear tires rotate at the same speed during braking. The front brakes work independently and are used even more than the rear ones aren't they? They are not affected by not having a front lsd because the car isn't front wheel drive, but they still work fine.

Can someone please explain to me what difference there is between braking with or without an LSD??

anders44

tried getting hold of it here in norway, seems like anogo, anyone got a sccan?

Techno Duck

Please PM me and i will send you the scan. I have not done it yet, but will in a day or two when i get a chance.

gt37vgt

it would make sense that with an lsd with a little lock on trailing throttle may be less likey to lock an inside wheel when going deep under brakes...
for it to be affective it requires some engine braking so i would imagine tony with his big hi comp engine should see double the effect the rest of us would ..
trailing dif lock seems to be more popular the more wieght a car has in the rear ...
so it seems more popular in trands axle cars than front grear boxe cars
and more popular again 911's ..

Oddjob

Locking the rear end under hard braking keeps the back end straight - w/ an open diff, you can get a lot a tail wagging which really unsettles the car. A lot of neg rear camber helps, but the best way to stabilize straight line braking to to increase rear diff lock.

black951

i installed a turbo s lsd in my open diff box. rebuilding and shimming the lsd is pretty easy. i made mine slightly stiffer than stock- its a street car. the hard part is installing the differential in the trans. i used new differential bearings. these require re-shimming the differential. lots of installing and removing. i had to build my own special tools and dial indicator adaptors- it took me two weeks to get the job done. i have typical DIY skills. i i had to do it again- i would just reuse the open diff bearings on the new lsd. I dont think there would be any reason to re shim the differential- assuming the differential is the same size. the factory turbo manuals show how to do this whole procedure. i might have to do this again soon- i think the rennlister who sold me the trans lied about the mileage- the trans is super noisy. their is no metal in the oil- its just loud! we'll see how long it lasts