what diff s50b32?

Post Tue Nov 22, 2011 11:14 pm

hi guys,

what diff ratio would give me a good mpg with s50b32 swap (daily driver)? no theories please, cheers!!!

Riz

Post Tue Nov 22, 2011 11:15 pm

What gearbox?

Post Sat Nov 26, 2011 12:50 am

e36 5 speed

Post Sat Nov 26, 2011 8:25 am

2.93 3.07 3.08 3.15

Post Mon Nov 28, 2011 3:13 am

ive got a crown and pinion for 3.25, any good? which one will give me best mpg???

Post Mon Nov 28, 2011 7:23 am

3.25 will be OK, 2.93 would be better for fuel economy.

Post Mon Nov 28, 2011 4:15 pm

maynee007 wrote:ive got a crown and pinion for 3.25, any good? which one will give me best mpg???

You are swapping in an S50 and are worried about MPG?! Errr.. Did you not think this through?!

Post Mon Nov 28, 2011 4:32 pm

duh!!!....relatively speaking.....please refer to above statement quote "best mpg" i.e. the most efficient i can get from a s50b32.....i wouldnt be talking about my audi 1.9 diesel on an e30 forum would I? plus i dont know how u figured i was worried about mpg....the word 'best' refers to the pinnacle of a situation, anyways, thanks to dan and penton for the positive input....i was told by fritzbits that with 3.25 i would be revving 3500-4000 at 75mph, any opinions will be appreciated as i know nothing about this, thank you!!!

Post Mon Nov 28, 2011 4:39 pm

Think about it. You have dropped in an expensive, powerful engine. I assume to go quickly, not sure why else you would do it. Therefore reasoning your diff choice on MPG is a little err. Odd. Well I figured it from the fact you were choosing your diff over it. Duh.

Well I can tell you Fritzbits are slightly out. 80 is ~3500rpm.

Post Mon Nov 28, 2011 4:39 pm

how bout 2.79??? theres this on ebay at the mo

http://www.ebay.co.uk/itm/bmw-e30-lsd-d ... 45fee8476d

Post Mon Nov 28, 2011 4:41 pm

wouldnt be going that quick in a convertible....the engine is being swapped to justify the badge!!!

Post Mon Nov 28, 2011 4:43 pm

wanna get it right first time....isnt 3500 a bit high for 80???

Post Mon Nov 28, 2011 4:45 pm

ive bought this off ebay even though the guy doesnt know the ratio, gonna stick the crown/pinion in it, what do u think??

http://www.ebay.co.uk/itm/290636760178? ... 1439.l2649

Post Mon Nov 28, 2011 4:47 pm

maynee007 wrote:wanna get it right first time....isnt 3500 a bit high for 80???

Not really.. Standard ZF box runs a 3.15 in an M3. So basically the same.

Post Mon Nov 28, 2011 4:50 pm

That is an e36 diff.. It wont fit an e30.

You will need an e30 open diff, and you could get the internals swapped with a new CWP ratio.

If it is what it says it is, it is a bargain. However he hasn't even been informed what the diff is correctly so I would be very wary. Plus @200 it's cheaper than a fooked old slipper.

Post Mon Nov 28, 2011 4:55 pm

maynee007 wrote:ive bought this off ebay even though the guy doesnt know the ratio, gonna stick the crown/pinion in it, what do u think??

http://www.ebay.co.uk/itm/290636760178? ... 1439.l2649

That add is the biggest load of bollox I've seen for a while!! It is a e36 casing, And probably a welder too

Post Mon Nov 28, 2011 4:56 pm

its an e30 diff casing with e36 mounting/end case

Post Mon Nov 28, 2011 4:58 pm

maynee007 wrote:its an e30 diff casing with e36 mounting/end case

Not it isn't. He is full of shit on that. Hence my concern on the rest of the supposed spec.

Post Mon Nov 28, 2011 4:58 pm

maynee007 wrote:its an e30 diff casing with e36 mounting/end case

Its not mate, It is a standard e36 diff.

EDIT... to slow, But Jhonno is spot on!! Hence our concerns about it being a open/welded/LSD too.

Post Mon Nov 28, 2011 5:23 pm

gonna do some investigating to confirm your suspicions, will get back to u....cheers

Post Mon Nov 28, 2011 5:38 pm

Not the best picture but this is a e30 diff.

Post Mon Nov 28, 2011 11:21 pm

YEP!!!.....Hands up, you guys were right!!!! definitely e36, anyway, just dropped the bad news to the seller, he did have a rant but was understanding, anyone want £220 for a lsd????