Ok, im in the process of sourcing the parts for a turbo vert, and want to do it right the first time. However, I am not against saving a buck here or there if it wont hurt the car. Anyway, I was wondering about a combination of parts, and how it would stand up over time.

Would it be possible to drop the torsen LSD pack from an S6 into the diff housing of an NA open diff? I know id need to bolt the original ring gear onto the torsen, but are there any huge obsticles in the way?

Assuming thats doable, Id then want to get the mazdatrix turbo tranny to NA diff driveshaft, and use the stock halfshafts. would any of these parts have trouble withstanding 250 to 300 rwhp down the road. I wont be going any higher than 300 with this car, i just want a quick, fun vert.

 

The S6 is a 8" ring, the S4/5 NA are a 7". A torsen from a miata would work, as well as one from a Honda S2000, or an lsd from a GXL model RX-7.

 

The S6 is a 8" ring, the S4/5 NA are a 7". A torsen from a miata would work, as well as one from a Honda S2000, or an lsd from a GXL model RX-7. The T2 rear is also a 8" design, so the S6 torsen would fit, however the T2 already has a LSD.

 

Ok, great! The miata or S2000 torsens or the GXL LSD would be capable of holding up to around 250 RWHP with very few, if any hard launches?

 

that, I am unsure of. I too have a T2 swap planned, however I'm planning on swapping rear ends to the T2 model, its the safest way, however it seems hard to find a T2 rear right now.

 

The Miata Torsen should hold up to that, especially if there's no drag racing. It's a very popular diff in the Miata world. My dad's got one and has 220whp and it holds up just fine, including launching it at the autocross. For more than around 250whp I'd look elsewhere, maybe an S4 clutch pack diff would be better, or swapping out the NA rear end for a TII one and getting the S6 Torsen, as I beleive it's stronger (it's bigger, so it should be stronger).

 

Super bump.
I think the s2000 diff would handle 300 hp fine. I've seen some stupid clutch drops in the s2k at 8k / 9k rpms and I've never heard about s2k diffs exploding. Then again, you could argue that its the torque that kills a diff, which the s2k doesn't have that much of, but I'd guess that 9000 RPM would be more likely to blow a diff to bits. (.5 * m * v * v anyone?)

Does anyone know for sure how well the s2k diff holds up? I'd like to use it in my track beater sbc350 which will push out circa 300 hp & 300 lbft torque. The advantage to the s2k diff is that its a torque sensing helical (torsen? not sure..)

 

Vehicle weight has a large impact on the lifespan and durability of driveline components, and an S2000 isn't exactly heavy.

 

Forget it. I answered my own question by reading www.honda-tech.com.

Do not bother doing this if you are building up a s4 with a non-t2 housing. Its just going to result in frustration and wasted money.

My solution will be: new T2 axles from mac auto on ebay, a $50 t2 diff housing from a junk-yard, a good FD-torsen unit, and a set of 4.3 gears. Cheap... and reliable...

 

skip the 4.3 gears. You'll already be running near 4k at highway speeds. Fun on the track, a pain on the street.

I used the entire driveline - I was lucky enough to find a whole T2 to use as a donor. SO I'm using a S4 clutch-type T2 diff. I have a Torsen from a 99 as well; but that's for my higher HP car. But, it would fit what I've got now.

You could save some $ by getting the axles with the diff from the junkyard - they rarely go bad, unlike a FWD axle.

 

Engine torque has little to do with differential or wheel torque, thanks to the tranny. It only affects things indirectly by increasing the horsepower. So just look at the horsepower numbers when making any drivetrain decision. Ideally you'd also look at the rotational speeds. High horsepower plus low rotational speed => high differential/wheel/etc. torque. And don't forget about the gearing in the diff, which will affect rotational speeds.