M50 finished, maybe change diff, what ratio?

[EOS]

Well finished the beast now, well not finished but MOT's on the road etc... and the gearing is very close as i still have my E30 318 diff in place, had a bit of a play with a cossie 80mph onwards (private track and all that) couldn't change down a gear like he did so put my foot down in 5th stayed with him then hit my rev limiter at 110mph. Now i don't really want to go 140's plus but i'd like to get above 110mph for when i start going on track days etc...so i was wondering what diff can i stick in to change my gearing to get nearer 130mph. Not to worried about a LSD at the moment. Any help would be appreciated as i don't know much about diffs and there ratios.

Thanks

[Ant]

assuming you're using the M50 ( e34/36) gearbox you'll be wanting a 3.64 diff, will still be quite short but a big leap from the 4.1:1 you'll have @ the moment

[EOS]

Cheers, but how do i know/find out what diff has which ratio etc? thanks

[Rory]

can u tellm me just what is needed 2 fit thw 24 v in e30

[JAMZ]

can u tellm me just what is needed 2 fit thw 24 v in e30

Start a new thread Rory in this section.. you might get a better responce

[ste]

Try typing with your fingers rather than your forehead too.

[Demlotcrew]

Try typing with your fingers rather than your forehead too.

[ste]

[stevetigger]

yep

3.64

tis what I have

Top speed 125 but gets there very fast!

[EOS]

3:64 so what car did this come in?

The diff i got at the moment is killing my petrol consumption ha its about 4000rpm at just under 70mph

@stevetigger 125 would probably be ideal.

[e30_Turbo]

3:64 so what car did this come in?

The diff i got at the moment is killing my petrol consumption ha its about 4000rpm at just under 70mph

@stevetigger 125 would probably be ideal.

I think TECH 1 sports had 3.64, later had 3.91 IIRC.

There is always the M3 3.25 which will be much longer but also twice as expensiive to buy!

HTH, Mark.

[EOS]

Im not to fussed at the moment if its a LSD or not, just want to change in asap, as its getting a little annoying driving so slowly on the way to work. Cause i come straight out onto the 127 and the cars not warmed up at all so not to happy driving @4000rpm constantly whilst its cold.

Is there somewhere that lists all the diffs and there ratios and what model year they was fitted?
Was just thinking of going to the breakers and getting a normal 325 diff hoping that lowers the gearing enough?
Never played around with diffs before so have no idea on the one i need or what car its from

Cheers for the replys so far guys

[stevetigger]

That will be fine!

A 325i Diff should be a 3.64 open

[EOS]

Cheers Steve

[andyborris]

If you're playing around with gearing, this is a useful program.

http://www.cartestsoftware.com/cartest4.5/index.html

Scroll down to the free DOS version, I use it a lot and it's pretty accurate too, I've checked it against road test data published in the more reputable magazines!

Andy

[stevetigger]

and this

http://www.unixnerd.demon.co.uk/bmw.html

scroll down the left part, near the bottom

gearing calculator

[lentec]

Was just thinking of going to the breakers and getting a normal 325 diff hoping that lowers the gearing enough?

I havent seen a 325i in the breakers round this way for quite a while.
Prob best going to canvey and see what they have

[jonb]

your box has a 1.1 5th.

you need a 3.25 ratio or there abouts.

my cousin has this engine in his car. he has an e30 m3 diff fitted.

forget using anything lower than this. 3.64 will be useless also.

steve, you cant comment on anything. your turd doesnt even drive. got to be worth 6k though.........

[DanThe]

Im using the M3 3.25 diff on mine and still think its a bit short

[stevetigger]

steve, you cant comment on anything. your turd doesnt even drive.

Been driving it around now for ages thanks!

Im using the M3 3.25 diff on mine and still think its a bit short

You think??

Mines fine, would prefer slippy!

Maybe not so good on motorway but who needs 150mph+ in a convertible?

[jonb]

rubish dude.

drive it to aces or gay-don, and i will eat my words.

i got more chance of growing a fanny on my forehead than you turning up in your car.

[stevetigger]

Im going to santa pod in it, so start growing!

[maxfield]

Steve what is the RPM at 70mph i guess its 4k or there abouts

[stevetigger]

Steve what is the RPM at 70mph i guess its 4k or there abouts

about 3200rpm at 70mph, which is ok in my opinion!

[DanThe]

Is that all Steve? I was expecting it to be higher

Mines doing 3000 rpm at 70

[stevetigger]

Sorry my mistake, its about 3500