M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: Nomadic on November 19, 2009, 02:08:44 AM
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I'm considering swapping my open 4.10 for a 3.91 iX viscous LSD. It's rainy season in Seattle, and my E30s tail has been stepping out unexpectedly in the wet, fish-tailing etc..
I understand the viscous LSD's don't start locking till one wheel spins and the fluid heats up. I'm curious if the iX diff helps with wet cornering stability. Anyone have experience with these units on a RWD BMW? How do they compare with clutch type LSDs in the wet?
Thanks!
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Well, if your car kicks it out now, a LSD will only make it more tail happy IMO. Open diff cars are a little more stable since you can't get the two rear wheels spinning at the same time for the most part. Even in the snow, it had hard time doing anything fun. It wouldn't even do a dount cause the power was sent to the inside wheel giving the outside wheel better traction killing my dount fun! :( In my old 318is I really had to try to kick it sideway in the winter...or rain.
LSD will cause the rear to kick out soooooo much easier. Trust me I know. I had a 325i with LSD in the winter and it was so easy to kick it sideways in the snow. It was alot of fun, but also kinda scary at times. LSD is going to be better for acceleration too since both rear wheels will spin, but you will have to be careful cause usually the rear will slide one way more so than the other.
I don't know if I am thinking about this the right way, but this is from my own experience. Basically, unless you want the car to get sideways easier, go lsd....or just slow down a little bit in the rain.
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Interesting. Thanks.
I did some further searching and folks seem to agree that clutch type LSDs can lead to surprises in the wet when pushed harder. Some folks suggested that worn LSD clutches don't engage smoothly... jerking traction away from the remaining tire. The iX's viscous LSD locks gradually so it shouldn't have such problems... but I wonder if it allows enough wheel spin that it doesn't really help either.
I used drive a Volvo 240 Wagon with a Dana LSD axle and that was quite stable in the rain & snow... especially compared to my old 2002. The rear camber on BMWs makes our machines a hand-full in slick conditions. My guess is that a dropped car would be even more tail happy in the wet.
Another question is the durability of the iX viscous LSD. Some say its very durable as there are no wear parts and the unit is sealed, BUT many miata folks say their viscous LSD's fluid wears out after 75k, making it act as an open diff.
How durable are these iX LSDs?????
They seem like a good cheap "street" LSD solution... (in theory).... and with M42 friendly ratios (3.91 & 4.10 )
Anyone out there playing with iX LSD in the rain?
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I too used to have a Volvo 240 wagon and found it to quite stable in any condition with Kumho Ecsta ASX tires. That car was awesome, it was the beater I couldn't break. Back on subject, I don't know about you but I enjoy driving around in my E30 when its raining out and sliding the ass end around. My car is plenty stable with an lsd if i drive it like a normal person, I would be interested to know what tires you have and the tread depth.
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I always assumed that they were the same as any other 4.10 LSD.... Hmmm.... :?
As far as durablity, I am sure that they are more than strong enough to handle the m42. I figure if they can take the beatings that I put down on it with a m20, it should be no problem for your car.
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I would be interested to know what tires you have and the tread depth
Tires are probably a big part of the issue... Toyo Spectrum Touring, 60%+ tread depth but they've hit their limits on rear camber wear. I was holding out for 15" or 16" rims before upgrading.... but maybe I should throw down on 2 new tires to keep me pointed in the right direction.
I'm still very curious about the iX LSDs. There's a local low-milage one available. I want to keep this thread alive... could be a good solution for us 4 bangers on the street..... or perhaps a big waste of time.
The question is do these iX LSDs work past 80k... or are most of them cooked now from us hooligans????
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It should be fine. Mine has 180k on it and still functions perfectly.
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TorSen style LSD is a good option as it's open until it loads up then it can transfer torque up to the design ratio (e.g. 25:75), I think Quaife use this technology. I have an OE 4.1 LSD in my IS and it does behave quite oddly, doesn't seem to always lock, behaves differently when turning left and right, same with the 3.9 I used to have.