Differential Time, 3.91 vs 4.10 on 6 speed ZCP

[0-60motorsports]

Bumping this thread up. I have 3.91's on the M3 and misplaced my stock 3.62's. Finally found a set of 3.62's and will be installing them, really thinking i should pair that with a wavetrac as I getting a good deal on it.

With the wavetrac they recommend New diff output flanges which I see no reason to do. Any of you using the wavetrac and 3.62 combo? I really like the point Obioban made about the wavetrac.

Anything else I should change while doing this job? I got output flange seals and all new OE diff bushings as well.

[Obioban]

I have 3.62s with my wavetrac. I’m strongly of the belief that BMW got the final drive ratio perfect on this car.

[Gt4]

Bumping this thread up. I have 3.91's on the M3 and misplaced my stock 3.62's. Finally found a set of 3.62's and will be installing them, really thinking i should pair that with a wavetrac as I getting a good deal on it.

With the wavetrac they recommend New diff output flanges which I see no reason to do. Any of you using the wavetrac and 3.62 combo? I really like the point Obioban made about the wavetrac.

Anything else I should change while doing this job? I got output flange seals and all new OE diff bushings as well.

Maybe they suggest new output flanges so no wear on the splines to match the new LSD?

[0-60motorsports]

Maybe they suggest new output flanges so no wear on the splines to match the new LSD?

Yeah Maybe, Im really not getting new ones as my car is fairly low mileage at 90k Kms. So im 100% sure they are fine LOL.

[Gt4]

What’s the best aftermarket LSD for a street/track car? I have 4 diffs I need to rebuild with different pinion/ring ratio and one of them I want to try an aftermarket LSD as it will mainly be used for track.

[0-60motorsports]

What’s the best aftermarket LSD for a street/track car? I have 4 diffs I need to rebuild with different pinion/ring ratio and one of them I want to try an aftermarket LSD as it will mainly be used for track.

Like I said im going Wavetrac

[Gt4]

Like I said im going Wavetrac

What’s are the main difference of Wavetrac vs OS Giken or others?

[0-60motorsports]

What's are the main difference of Wavetrac vs OS Giken or others?

The biggest attraction to me of the wavetrac is that I don't have to worry about rebuilding it etc.

[Obioban]

What’s the best aftermarket LSD for a street/track car? I have 4 diffs I need to rebuild with different pinion/ring ratio and one of them I want to try an aftermarket LSD as it will mainly be used for track.

For a street/track car, I think the Wavetrac is the best option out there. Silent, smooth, works well in 0 traction on one tire situations (ice, lifted tires, grass, etc), doesn't need rebuilds.

For a MAINLY track car (as in, that's the cars purpose), you can get more track performance (does not apply on the street) with a clutch based diff. It'll have worse low speed manners, need rebuilds again, etc-- but it will perform better. Also might be a good time to ponder if you're building a track car (DEs) or a lapping car (time trial/racing), as ultimately... going for that last bit of performance actually only matters if your in something competitive and it fits within class.

My car is street/track in equal measures for sure (and nothing competitive/classed), so Wavetrac is an easy winner for me.

What’s are the main difference of Wavetrac vs OS Giken or others?

Gear based vs clutch based.

[EthanolTurbo]

What’s the best aftermarket LSD for a street/track car? I have 4 diffs I need to rebuild with different pinion/ring ratio and one of them I want to try an aftermarket LSD as it will mainly be used for track.

Drexler. Drives like stock on the street, not noisy or rough at all, but going through corners or on track it's magical. Makes the rear end feel telepathic and has so much grip.

[Projecte46m3]

Drexler. Drives like stock on the street, not noisy or rough at all, but going through corners or on track it's magical. Makes the rear end feel telepathic and has so much grip.

I second the motion!! Drexler diff is absolutely amazing and behaves like stock on the street if you using the oem rubber bushings.

[maupineda]

I think you need different output flanges because the LSD carrier is of a different dimension compared to stock and so stock flanges can either be too short, or too long.

[bigjae46]

Maybe they suggest new output flanges so no wear on the splines to match the new LSD?

Does a wavetrac use equal length axle stubs? That could be why.

[bigjae46]

Drexler. Drives like stock on the street, not noisy or rough at all, but going through corners or on track it's magical. Makes the rear end feel telepathic and has so much grip.

Same downside as a ZF or OS Giken - needs rebuilds since it is a clutch-based diff. Many underestimate how much of a difference a better LSD makes. It's one of the most significant things you can do to an E46 if you're willing to push the car a little bit.

[Gearhead55]

Same downside as a ZF or OS Giken - needs rebuilds since it is a clutch-based diff. Many underestimate how much of a difference a better LSD makes. It's one of the most significant things you can do to an E46 if you're willing to push the car a little bit.

Seconded. A proper built diff transformed how my car behaved on track, both on corner entry and exit. Magnitudes more predictable and stable.