325is Diff In My 318ti

[Linuss]

Just wanted to know if a 325is lsd would bolt up and if the gearing would be ok in my 96 318ti. Or what parts i would need to use to make the switch.

[WPritchett]

Just wanted to know if a 325is lsd would bolt up and if the gearing would be ok in my 96 318ti. Or what parts i would need to use to make the switch.

It should not bolt up unless the 325is is an E30 chassis. The ti should have a single diff mounting point (same as E30) and the 325is will have two mounts as on standard e36. Gearing would be fine, and some folks have done custom work to get e36 diffs on the ti, but that is up to you.

[M-technik-3]

There is a difference in gearing between the auto and manual gearbox 318ti's as well. An automatic will be in the range of 4.45 and the manual will be in the 3.45 range so it's quite the difference.

Most e30's are 3.73 and later auto's and convertibles were 4.10 as was the E30 M3, The E30 has a huge gear spread in EU depending on gearbox and engine size.

[CompactHPDE]

I use an E30 325is rearend in my '97 ti track car and the gearing is 3.73. I run 245/50-17 tires and the best I can get out of it on the VIR straights is about 115-120 mph in 5th at 7,000 rpm. My ecu is reworked and the engine has mild mods. I'm disappointed in the top speed as I get passed a lot on the straights but it runs like a scalded ape through the turns. I did replace the original cover with one from an M-coupe (finned) and I use poly bushings. The only real requirement was to run E30 axles.

[M-technik-3]

Maybe you should step down to a 3.64 but then your lower end tq is going to suffer. Or change your tire size, do you really need 245mm with a m4x?

[Toby B]

What you really need is an E36 m52 engine. The 1.9l M44 is doing pretty good to hit 120 pushing that much car down the straight...

for reference, a mostly stock E30 325i (2.5l) is good for 130, and a well- worked over 2002 (160 bhp, more or less) can't quite keep up with it.

If you're in the 5500ish rpm range at top speed, you're aero limited. Unless, of course, you have a more than stock M44.

OP, as everyone else has said, you want an E30 diff. And you may be able to play with output flanges, or need to use E30 axles, depending on what you get.

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