My diff is on its way out and I need a new diff.


I'm curious whether to stay open diff or slap on the OEM LSD's.


I read somewhere that the OEM LSD is pretty bad - esp as a DD.


Would appreciate your thoughts and opinion.


TIA!

 

look into a wavetrac. its a worm gear diff instead of a clutch style diff. about 1200$ plus install. very streetable

 

The oem unit is very good, especially as a dd. However, the clutch packs can wear quickly with regular track work, a lot of guys install the porsche motorsports clutch pack when/if it ever needs a refresh.

 

I DD my turbo with the OEM LSD, its great, no issues at all imo. This being my first car with a limited slip I must say I love it. I drive in the winter and on snow it really helps with traction. And it always make the car behave better going sideways

 

In July, while at the track, I was talking with Pwdrhound who asked what type of LSD I was running.

"OEM LSD", I replied. He smiled and opined it was probably an open diff by now since OEM's are known to fail after a few track days. Mine has seen 75+.

Went home and rummaged thru my YouTube files and found this "How to Test Your LSD" ( ).

Tested mine and it was shot so off to the shop for a rebuild. Everything needing replacement was replaced with Guard internals (http://www.guardtransmission.com/). The total cost was ~$2200 and the difference is amazing on the track although it's quite transparent on the street. Had the unit been an open diff oem the cost to upgrade to LSD would have been ~ $4500.

When I picked the car up my mechanic said the oem lsd is very weak in keeping with a street car application but likely would have had a beneficial effect in normal driving in the rain or perhaps light snow but been completely useless for track duty or aggressive driving. It's not something most of us spend a lot of time thinking about but if you are a track rat or fancy yourself as a "spirited" driver, perhaps you should check yours out. Hope this stuff can help someone out there!

 

I would have never thought an LSD would mean you couldnt spin a tire while in the air.

 

I'll be installing one at some point, probably when I have to do the clutch which I'm guessing might be next year. I have never driven an AWD car with an LSD but in my RWD racecar and in an M3 I used to have, it really helps "kick" the car off corner exits. I'm not a drag racer type but supposedly they help launch traction quite a bit. And braking stability too, although the 911/997 platform is already unbelievably good under braking.

 

My poem led works fine, though it don't see track driving (maybe once a year only), but I love how stable and predictable it feels when both rear tires lets go under the torque from the tt

 

The motorsports packs will make the oem a lot better.

 

The problem with the stock 997OEM LSD are not only the clutch packs but also the ramps which are very mild. On top of that the preload is very weak all of which results in a rather useless diff. The Guard clutch packs and ramps are the way to go and reasonably priced. I have the Guard Billet 40/60 diff and with close to 100 hard track hours it's still going strong. This is one of the most overlooked performance mods out there....

 

How different are the guards clutches and ramps vs the motorsports clutches and ramps?
I always thought they were comparable

 

Not sure what the 7cup ramps are but the 6cup ramps are 40/60. I think the 7 ramps are a bit more aggressive. Guard will supply whatever ramps you request.

 

Good to know!