[Maniac0908]

Ooo mfactoryyyyy where areee youuu. We need upgraded front difffssss

[exclucid]

great talk... always talk... this is why RWD guys look down on AWD. This Chassis is begging for this capability, and it would be awesome, but we just talk and don't follow through. Bummed.

[Chris@BoostConcepts]

Out of curiousity, what in the xi front diff is the most common failure point? is the housing too weak, the gear set? the spider configuration? the housing would be fairly simple for me to upgrade with a billet unit, the gear sets could be heat treated if the base metal allows for additional heat treating. ebyind that custom gear sets get expensive. if the gear break due to a lack of housing rigidity that could be overcome. an updated lsd diff from MFactory with 10 confirmed orders seems like a fantastic offer.

I currently have two BMW's a 135i and 335i shop car but unfortunately neither is awd to have a look at fitment, but they are fairly affordable now so grabbing one for R&D isn't out of the question, and I would not mind playing around with an awd car. seems like an 8hp70 + upgraded front diff could make for a wicked setup.

Mod's I have not been a supporting vendor for some time now and I might return as one shortly, but until that time do i need to change my call sign? I do not want to upset the applecart.

Chris

[MechEngineer]

Originally Posted by Chris@BoostConcepts

Out of curiousity, what in the xi front diff is the most common failure point? is the housing too weak, the gear set? the spider configuration? the housing would be fairly simple for me to upgrade with a billet unit, the gear sets could be heat treated if the base metal allows for additional heat treating. ebyind that custom gear sets get expensive. if the gear break due to a lack of housing rigidity that could be overcome. an updated lsd diff from MFactory with 10 confirmed orders seems like a fantastic offer.

I currently have two BMW's a 135i and 335i shop car but unfortunately neither is awd to have a look at fitment, but they are fairly affordable now so grabbing one for R&D isn't out of the question, and I would not mind playing around with an awd car. seems like an 8hp70 + upgraded front diff could make for a wicked setup.

Mod's I have not been a supporting vendor for some time now and I might return as one shortly, but until that time do i need to change my call sign? I do not want to upset the applecart.

Chris

I'm currently looking into this myself I have an F22 BMW I want to put a front LSD in.

Some useful information upfront; the front diffs before ~2007 had bolted ring gears. There is a Quaife LSD that already fits them. (Not home so I can't look up part numbers). After 2007 they moved to a welded ring gear. However the diff cases are interchangable, so if you want to run a front LSD that's the way to go. My goal is to fit a bolted E90 front diff in an F22 front diff case.

I bought a spare F22 3.08 front diff (they are pretty cheap) and a 3.08 bolted front diff from a 2006 E90.

What I've learned so far:

The bolted 3.08 diffs are incredibly hard to find. I bought maybe 1 of 2 used online. You can still get new ones from BMW but they are $1700. 3.46 is more common.


Bearing sizes and diff size is the same, spline count is the same. However, the shape of the differential is different, so unfortunately it's not a 1:1 swap into the F22 case. I have heard that the bearings are a weakness on these.

The diff case shape and hole pattern is a bit different, so you can't bolt the E90 front diff into the F22/F30 oil pan.

One option is to make an adapter so I can bolt the E90 diff case the the F22 oil pan (This is easiest, but it would move the diff case outboard, which increases the driveshaft phase angle).

The other option is to make a billet diff case for the half that bolts to the oil pan. It's actually a relatively small component, so I don't think it would be too expensive.

Send me a message if you're interested in collaborating, I will be 3D scanning these parts in the next couple weeks.