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My understanding is that wheel hop is whats hardest on the gear set in 188mm medium diffs. Since the forced induction guys have run the most power through these suckers, who has actually blown one up, and how much torque did it take to grenade one? Im finishing my ls3 e28 build.

I have run 188mm diffs exclusively in all my turbo cars. Put 500rwhp through a 188mm on slicks with no issues.

My turbo m30 makes over 450wtq and I havent blown one yet. Its a daily driver, been to the 1/4 a few times. I dont 1/4 race too often, though, mostly roll race. It's also been 2yr 30k since going turbo, so I can say it takes the abuse pretty well

Don't be afraid of them they take good power. Just watch out for wheel hop, like you said.......... (wheel hop also destroys TONS of other diffs too)

I recommend reinforcing the diff mount due to a bad experience. Others have not had issues with it. The diff itself is stout as heck though. The clutch packs will wear out, but I don't know of any differentials that failed in a catastrophic manner on these cars.

I used big case diffs in the track car but due to limited ratios I switched back to mediums. The thing's had the living tar beat out of it and none have suffered any problems. I've snapped drive shafts and broken CV joints but never a diff. Big case diffs are heavy as hell, too.

Ok I apologize if this question or topic has been previously discussed, but I'm running a very laggy setup b34 bottom end/b35head and cam, RSI manifold, and 6266 (.81) turbo on 22psi boost (e85). I previously ran 745i setup made almost 100hp less at the wheels but car "felt" faster before. I have 3.73lsd and I noticed people that are boosted run 3.25, 3.15, and 2.93 will my car feel or be faster with a longer diff? Or should I stick with the 3.73? If any info is missing or this is a dumb question I apologize in advance.

I would highly recommend the 2.93 on a boosted car. With a 3.73 i cant imagine the turbo building any boost at all in 1st or 2nd. Even on a 2.93 I will get a small lag between the 1-2 shift, but it still builds full boost (21lb) in 1st. I have the exact turbo you have as well

As mentioned in the other thread, that top/bottom combo you are running is too low of compression as well (under 7.5:1).... even putting on a stock b34 head will cure a ton of your lag. I reach full boost at 33-3400

Do you think I will lose horsepower if I switch to a .58 or .63 a/r exhaust housing I really don't want to loose top end power but would like to gain a little spool I was expecting tons of wheelspin but my car has none I would actually prefer my car to struggle to keep traction it would be a lot more fun for me even if the car was not as fast

Hey I'm late to comment of the diff thing. You probably know this
but when it starts to wheel hop just STOP immediately.
That's the only way you're going to blow up your diff.

Mine blew that way at the track right off the light. It was hopping like crazy.
Mega turbulence and BOOM. The diff was open though. LSD I think there's more shit inside of
it to spread the damage around so it'll take more abuse.

Jeremy wrote:I recommend reinforcing the diff mount due to a bad experience. Others have not had issues with it.

Mine is not an e28 but I think it's the same type of mount.








Some people use the e36 cover with the two mounts and that seems to be a good fix.




Or an aftermarket thing. But the price is idk. 195 +40 for poly bushing. idk if I like that price though.

nope, sorry that is in no way how an E28 diff mounts...... BUT a great idea. now i'm wondering if that style rear cover could be adapted somehow onto an E28?