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3.46 variable lsd installed

4143 Views 7 Replies 5 Participants Last post by  karlblomquist
I received my final drive back from Metric Mechanic yesterday via Fed-Ex (well-packed, no box/packaging damage).

Spent the better part of the evening installing it. It was lot easier getting off than getting back on! Aligning this upper bolts while on a creeper on the ground (car on ramps) was not fun considering the 80 lb block I had to work with. But eventually it went in OK.

Took the opportunity of having the mufflers off to replace them with Supersprint DTMs. Questions about that later.

Re the final drive - I had the following done by Jim Rowe:
- gear change to 3.46
- extra clutch plate
- mod Limited Slip (25%) to Variable Limited Slip (20-100%).

Re the feel - launches are tremendously better. I expect this is mostly because of the variable mod. Jim says that when pushed his mod allows the clutch grab to creep up to 100% lockup. I can launch much more aggressively now and not see a flicker from DSC.

With the new gearing red-line comes up noticably faster in 1st & 2nd gear. I'll need to adjust my timing for enthusiastic shifing. :)

Takeoff might seem a little better (probably more the lockup than anything), but where I really see the difference is around 3rd and 4th at highway/secondary road speed. Downshifting into 3rd at 130 (km/h) and cranking it produces noticably more pull than before - and the pulling is relentless all the way to redline. The car could really use an extra 500rpm of red-line in my opinion.

Similarly, 2nd gear at 70-80 and stepping on it produces tremendous amounts of thrust.

I agree with Ron - 3.46 gearing is such a better mate to this vehicle.

My only remaining concern is that now sharp corning seems to kick the DSC on more often than usual. This could be a function of the increased torque to the wheels causing easier wheel spin on sharp corners, or perhaps the new clutching needs to "break-in". I'll be keeping my eye on this new trait - maybe it just requires adjusting my throttling through corners. Of course, I can always turn DSC off, but I've gotten too used to it saving me from myself. :yikes:

Re the Supersprint install - man those things are hard to get lined up the same. After 2:00am rolled around I said screw it and just tightened them up. They're not well-aligned right now, but I just wanted to drive a bit before tackling that again.

Anyone have any tips on methods to get these mufflers lined up properly? The passenger side one hangs too low and pulls to the driver side. I have the mod'd bracket per Ron's note about passenger side hanging. The driver side is not too bad.

Cheers , Karl
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what about a 3.46 on a '99?

The S52 engine in the 98/99 M coupes don't have quite the RPM range but I find that at the end of 3rd gear and into 4th the car really feels slow.

Would anyone like to give an opinion about the benefit (or lack there of) of putting it a 3.46 in a pre-01 M coupe?

after running a 14.33 in the 1.4 mile at the local track I am looking for ways to give the car a little more "umph"

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