Diff sizes / types / ratios

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D7UGE
E30 Zone Newbie
E30 Zone Newbie
Posts: 243
Joined: Wed Jul 21, 2010 11:00 pm
Location: Northumberland

Thu Jan 02, 2014 6:41 pm

I'm thinking of changing the open diff in my 318is for an LSD item but I'm unsure which size casing I need and which ratio diff would be best for the M42 engine.

Any info would be greatly appreciated.

Many thanks , Doog.
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Grrrmachine
E30 Zone Wiki / Team Member
E30 Zone Wiki / Team Member
Posts: 8043
Joined: Sat Feb 09, 2008 11:00 pm
Location: Warsaw, Poland

Thu Jan 02, 2014 7:18 pm

broadie
E30 Zone Regular
E30 Zone Regular
Posts: 560
Joined: Fri Mar 15, 2013 11:00 pm
Location: East Devon

Thu Jan 02, 2014 7:19 pm

Your stock diff should be a small case 4.1 ratio
Most E30 LSD's will be medium case all you need to do is shorten the propshaft on the propshaft adjuster.

As for the ratio thats up to you if you want the same gearing, or more top end 3.91, or more acceleration 4.27.

Best to check what ratio is in your car as it may have been changed. You don't want to pay big bucks for a LSD that not the ratio you want.
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