Running a 3.62 diff with a DCT

[DrFerry]

Originally Posted by nycplumber

Anyone supercharged with a 3.45?

Yep. Harrop + DCT + 3:45 + SSP Spec-R clutch pack + Quaife LSD. See signature.

[nycplumber]

DrFerry How's traction through first and second? Any regrets or downsides beside highway cruising?

[DrFerry]

Originally Posted by nycplumber

DrFerry How's traction through first and second? Any regrets or downsides beside highway cruising?

Traction in 1st and 2nd gears is difficult to modulate in ambient temperatures below 50F - but pretty good in warmer temperatures. Still get some minor wheel-spin in summer unless running Drag Radials (see later below). I can mitigate traction loss on PSS somewhat with lower inflation pressures. I think I've gone as low as 28 cold in the summer with a 4psi hot pressure climb after 10 miles or so of driving. Additionally, MDM (the M-Dynamic-Mode in iDrive) is also reasonably good at modulating traction unless one is stamping on the throttle. I find a smooth and quick throttle application off the line is more effective than just stamping on the gas and shocking the drivetrain.

I run an 18X11 inch wide wheel rim on the rear axle with an effective offset of 32mm and with 295/35ZR18 XL (103Y) Michelin Pilot Super Sports. These particular PSS are a Mercedes MO spec version (with one of the softer OEM 'tuning' compounds available within the family of tread compounds 'allowed' inside the PSS product line). So traction with the 3:45 is massively dependent on the tires being used. Definitely avoid all season shoes. I had the most fun running DOT legal Drag Radials on the street in the summer. I think they were = Nitto NT05R in the 285/40R18 size. Not great for handling but they grip like velcro in a straight line (experiment with pressures if you ever run them)....

I don't really have any big regrets - other than where I sourced the Diff from. Though I must say the half shaft diff seals seem to weep more than they did with the OEM diff. Perhaps that's due to the Quaife LSD which is a real tight fit inside the pumpkin and needs special hardware (source = driftflo's thread). I suppose the higher RPM in 7th gear on the highway does use slightly more gas - but it's hardly been noticed by me.

The seat of the pants change in torque off the line is noticeable to someone with a good buttometer, but it's not huge by any means. Hope this helps.

Edit:
If you do decide to get one I recommend buying from driftflo rather than where I got mine from.

[nycplumber]

@DrFerry That's great info thank you