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LSD diff strentgh

Posted: Fri Jun 12, 2009 10:30 pm
by rob_htid
ive smashed 2 3.64 lsd diff's ... im after an upgrade due to the fact it will have 4 times the power of lastime!

quaife atb's are up and out there... where would i get one from, how much, what are the alternatives?

aslo i imagian this would just be the lsd pack id be buying what about the gearsets?


thanks Rob

Re: LSD diff strentgh

Posted: Fri Jun 12, 2009 10:33 pm
by fuzzy
what power do you have? :eek:

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 3:01 pm
by rob_htid
will be arround 750bhp

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 5:16 pm
by leee111
what u got in there a jet

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 5:19 pm
by fuzzy
quaife diffs are around £650 iirc, kaaz lsd's are slighly cheaper. good for 750bhp though? i dont know.

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 7:42 pm
by rob_htid
bigspec m20b28 turbo. is that just the lsd unit or the full gear set too?

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 10:23 pm
by mt1104
probably want a large case one as well (if they fit), as I imagine that'll be stronger.

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 10:56 pm
by rob_htid
dont think they fit, might look into abit of fabrication, mate of mine has a jaguar rear beam on his 3dr saff

Re: LSD diff strentgh

Posted: Sat Jun 13, 2009 11:52 pm
by e301988325i
Diffs are 'only' good for 400BHP, you'll need a large case.

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 12:49 am
by rob_htid
does anyone know anyone thats fitted a large case diff and whats the complications?

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 12:04 pm
by stonesie
I remember seeing pics of the modifications needed for the rear beam but I can't for the life of me remember where, I did find this though wich is a for sale add but has nice clear pics of a large E34 diff and a E30 medium diff for comparison.

http://www.performanceforums.com/forums ... t=67216634

Off to leaf through my old issues of total BMW :mad:

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 1:05 pm
by rob_htid
hmm, well it looks asif i could have a brackt fab'd to be able to hang the diff but it looks wider, are the input shafts the same as the e30 too or is the diff wider aswell?

thanks rob

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 1:22 pm
by E30BeemerLad

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 2:20 pm
by Barx325i
Just a thought, but fitting a bomb proof diff is a small part of dealing with 750 horses surely?

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 3:53 pm
by rob_htid
it is a small part of dealing with the power yes but it is definitly one that needs to be delt with.

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:00 pm
by fuzzy
will driveshafts and the prop be upto 750bhp? ive seen bigger power cosworths twist and snap shafts like twigs.

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:04 pm
by E30BeemerLad
I can't see it having much of a problem as you're not going to have any traction whatsoever with that power, I mean like lighting the rears up in 4th gear at 100mph

like this mo fo

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:06 pm
by rob_htid
in a word yes... touch wood. the thing with this build its very much trial and error on drivetrain components etc... if it brakes, fit bigger and better. im just currently replacing the obvious as i go..

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:08 pm
by fuzzy
yep, mine is a handful with only 330bhp. traction even at 280bhp was a problem.hard driving/racing in the wet wasnt the safest way to spend your day.

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:13 pm
by rob_htid
i imagian it is a handfull, a few mates of mine have big power rwd and its not for the faint. ive always had drilled into me from a young age... if you are going to do something do it properly or its not worth doing at all and i still stand by that now :twisted:

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:45 pm
by fuzzy
what are you planning to do to control traction? i looked at 4 wheel drive using cosworth running gear.

Re: LSD diff strentgh

Posted: Sun Jun 14, 2009 4:52 pm
by rob_htid
sticking rwd, 235 tyres.. i dont want to go much bigger yet as the cheapest form of give is tyres, when they go il build up in size and brake more and more...

i will be useing a apexi boost controller to limit boost untill higher speed to aid traction.

Re: LSD diff strentgh

Posted: Mon Jun 15, 2009 7:06 am
by Jonsku
Use typ210 diff, they can take 750hp. Fitting one needs some fabrication, E34 M5 middle part of rear axle can be fitted quite easily. Also the driveshafts have to be worked with, e30 ones can't take lot more than 300hp for long..

Image

Re: LSD diff strentgh

Posted: Mon Jun 15, 2009 8:17 pm
by rob_htid
basicly i need a rear beam, diff and driveshafts off an e34m5? as for the driveshafts what do you mean worked with? shortend?

thanks

Re: LSD diff strentgh

Posted: Tue Jun 16, 2009 6:14 am
by Jonsku
rob_htid wrote:basicly i need a rear beam, diff and driveshafts off an e34m5? as for the driveshafts what do you mean worked with? shortend?

thanks
Yes, those parts you do need.

I don't know what to do with the driveshafts. The main problem you have is that the "bore" of the "wheel-end" of the driveshaft is different in E30 and E34. Also the lengths are different.

E30 driveshaft "knuckles" won't hold up for long, those are the weakest points.

There're quite a lot of discussion and pictures on project threads on www.pure-pf.com / forum / projekt. It's in Swedish, though. Google translator is handy ;)