Diff for 6 speed and m20 stroker

[adam.nonis]

I made a spreadsheet calculator that may be helpful. I was trying to figure out diff ratios for my N52 swap. Seems like I can't upload it here directly. If you're interested, DM me your email address. You can input tire size and rear ratio, change RPM and it'll output MPH and RPM after shift for G260, GS6-17BG and GS6-37BZ

[digger]

digger There has been many hinderances and distractions over the past years I've just brought the car and all the parts to where I live 10 months ago, to be fair washed it for the first time since 2016.

I've decided to start with 3.07 as well because if I build a fresh LSD it can be switched to higher ratios later and with the other offset casing I can only go 3.15 and lower.

Almost got the shifter/linkage sorted out.

i have a spare diff it was originally a 3.91, so 3.07 is the lowest that fits in the housing?

digger Got another option for a driveshaft ready e36 rear half + e46 front half: http://bmwfans.info/parts-catalog/26117518375/.
Got some stainless cut, bent and welded to start with the gearbox mount according to this (yet to confirm the fittment): https://hobby.farit.ru/custom-bracke...on-in-bmw-e30/
Right before Christmas got this from Australia: https://racehead.com.au/product/bmw-...e-molly-steel/
Need to measure things out, I'd love to fit clutch/pressure plate/release bearing from the Valeo kit I got in 2017. When this is confirmed and I find some spare time I'll rip the old gearbox out (need to change the rear main seal carrier as well).

thanks i also saw this FW in my research which starter should be used?

when you mix and match halves of the driveshaft i presume it need to be rebalanced?

[raudonis]

i have a spare diff it was originally a 3.91, so 3.07 is the lowest that fits in the housing?

I assume the diff housings are the same, but it has to be checked.
Satellite housings are definitely different both open diffs and LSD for ratios of 3.07 and less, because they increased the pinion gear diameter and had to offset the ring gear more.

thanks i also saw this FW in my research which starter should be used?

Not confirmed by assembly, but by cross-referencing gearbox, flywheel, etc. partnumbers and starter specs I found this starter to be the lightest smallest bolt on option, I have it ready in my pile of parts:

http://bmwfans.info/parts-catalog/12412354693/

https://www.elstock.com/en/product-search/?pid=26-3376

when you mix and match halves of the driveshaft i presume it need to be rebalanced?

Yes, driveshafts are balanced as a whole, so when putting halves from different driveshafts together, the new hybrid assembly has to be balanced.

[digger]

I assume the diff housings are the same, but it has to be checked.
Satellite housings are definitely different both open diffs and LSD for ratios of 3.07 and less, because they increased the pinion gear diameter and had to offset the ring gear more.


Not confirmed by assembly, but by cross-referencing gearbox, flywheel, etc. partnumbers and starter specs I found this starter to be the lightest smallest bolt on option, I have it ready in my pile of parts:

http://bmwfans.info/parts-catalog/12412354693/

https://www.elstock.com/en/product-search/?pid=26-3376

Yes, driveshafts are balanced as a whole, so when putting halves from different driveshafts together, the new hybrid assembly has to be balanced.

oh, so the limit is 3.15 with my original 3.91 unit? and its the lsd unit that differs not the housing?

[raudonis]

oh, so the limit is 3.15 with my original 3.91 unit? and its the lsd unit that differs not the housing?

I'm aware only of the satelite housing difference. ⩽3.07 housing can be used with ⩾3.15 ratio with an offset spacer for the ring gear, but not all diff builders will endorse such spacer.

[digger]

I'm aware only of the satelite housing difference. ⩽3.07 housing can be used with ⩾3.15 ratio with an offset spacer for the ring gear, but not all diff builders will endorse such spacer.

ok i presume the guts inside the satellite housing are the same so i should be able to use my spare