M Factory Limited Slip with 3.46 – Anyone do this one?

[qxangelxp]

I went with the MFactory 2.81 pumpkin in my car, and I absolutely love it.

I'm running fbo mhd stg2+, and plan on going upgraded turbos with e85, stg3 fuel pump, PI, etc. and I KNEW that the stock 3.08 gearing was going to be a problem.

First gear was already useless, and I also disliked cruising on the highway at 80mph with the rpms riding around 3400+

When I did the LSD, I did get an ABS & DSC light for a little bit, but I think that had to do with my alignment (I had also done control arms & other subframe stuff) OR the car just had to re-learn some stuff,. I don't really know because the light went away on its own after a while, and I got my ABS & DSC back.

I will say, you should code-out the e-diff setting using coding software (I used Protool w/ a Thor adapter) now that you have an LSD, so the car doesn't try to brake one side of the axle (which was okay to do for open-diff)

I highly recommend taller gearing for higher power applications. (If you're mainly street driving.)
Even at fbo stg2+, 1st gear w/ the 2.81 is still too short and nearly non-useable for launching spiritedly, but it, and every gear after it is a lot better than before. I ONLY use 1st to take off and drive up the first 10mph or so, then I can book-it from 2nd gear & on. All the gears are much improved, and I feel like it should have come this way from factory.

[Wegz]

Originally Posted by BruceThomas

Hey Guys,

2011 135 - 6 MT - PS2 roughly 400 WHP

After much deliberation I to have decided to go for the 3.46 MFactory helical LSD.

There are pros and cons to staying 3.08 and/or going 3.46

I decided to go 3.46 because, I use the car exclusively for canyon driving and currently, the car is off boost too much of the time.

Initially I had a tune that SUCKED. Even to the point that I regretted putting the PS2 on. As Wegz said, I put the PS2 on to get a much bigger and usable power band. But the car was so laggy and would take forever to hit boost. Thankfully worked with one of the guys from on here and he got me boosting much earlier and way more linear. However, the car can still drop out of boost if you don't keep the RPM and momentum going.

So decided to give 3.46 a try. My concern could be running out of gear too much, and it being counterproductive to my initial PS2 goal of giving the car a longer power band. But it could be the lesser of two issues: late spool or shorter power band.

If tracking the car, 3.46 would seem almost a necessity, especially if running an upgraded turbo/s.

LSD is being fitted on Monday. I will share feedback over the next few weeks.

Thanks

What do you think of it?

I'm having a Pure Stage 2 put on my car right now. Going to use a Wedge tune with MHD.

[lowbudgethero]

im going to give a positive review for having 3.46 gears and exhaust + tune

a little bit of a handful when it's cold but when the tires are warm in the summer it hooks up well

gives the car a lot better response

i drive mostly on tight back roads and my suspension setup is softer than most run here