I have most of the parts I need for my 5-speed swap into my 525iT. What differentials will work? If it will work, I am considering the 3.46 from the manual 535i. Or would it be better to just get a 3.23 from a 525i?

Also, how bad will the revs be on the stock 4.10, if it will bolt right up?

I'm hoping this will be my summer break project

What transmission did you end up getting? What is the gear ratio in 5th gear? I believe the E36 M50 5-speed trannies are non-overdrive, so that would have an effect on what rear gear you're looking for.

I'm running 4.10's behind my Getrag 260/6 (I think that's the right code, it's the E34 535i tranny) and it gets out of the hole VERY QUICKLY. :) Runs about 3500ish RPM on the interstate at 75mph, so it's not terrible, but I run out of RPMS pretty quickly on the top end. A non-overdrive transmission would REALLY be spinning that motor hard with a 4.10 rear.

I'm running 4.10's behind my Getrag 260/6 (I think that's the right code, it's the E34 535i tranny) and it gets out of the hole VERY QUICKLY. :)

Is it me or is 4.10 with a stock 535 tranny really tall? my dad has a 3.91 and i thought that was tall:eyecrazy how does the 4.10 get you to 60 compared to the stock 3.45 or 3.64?

What transmission did you end up getting? What is the gear ratio in 5th gear? I believe the E36 M50 5-speed trannies are non-overdrive, so that would have an effect on what rear gear you're looking for.



Not sure what trans it is, I haven't picked up the car + trans yet from PUMECAR.

If its a 525 (m20) and you are putting a 5sp from another m20 than you have the optimal set up for accel, with the 4.10. However, and I dont know this for a fact, I would think your top speed would be at least modestly compromised.

If its a 525 (m20) and you are putting a 5sp from another m20 than you have the optimal set up for accel, with the 4.10. However, and I dont know this for a fact, I would think your top speed would be at least modestly compromised.

It's a '92 525i, so it has teh M50, not M20

I drove my car around with the 4.10 after converting from auto to manual. First gear was almost useless, so I would just start in 2nd. When driving on the hwy. the engine was screaming. I now have a 3.46LSD.

Okay, I've been crunching numbers on an engine calculator and found this out using the 3.23s and 3.46s on a 1:1 transmission output on a 25.5in OD tire (roughly a stock 205/65-15)

Rearend 3.23 3.46 4.10

60mph 2550 2750 3250rpm
70mph 2990 3200 3800rpm
80mph 3400 3650 4325rpm
100mph 4275 4550 5425rpm

So I don't think the 3.46 will be too extreme, if it will be a direct bolt in swap. Will the acceleration difference be highly noticable over the 3.23?

I was told on .info that the 5-speed for the M50 is a 1:1, there is no overdrive.



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I drove my car around with the 4.10 after converting from auto to manual. First gear was almost useless, so I would just start in 2nd. When driving on the hwy. the engine was screaming. I now have a 3.46LSD.

That's on an S50/52 correct? Would you recommend the 3.46 over a 3.23?

I dont know man... I think 3650 is a little high to be running at 80 mph in 5th.

Nick

When I made the comment earlier I did not realize you were using a 535 tranny, I saw the number crunched & Id feel bad doing that to my engine everyday. Sorry for the not so good advice

When I made the comment earlier I did not realize you were using a 535 tranny, I saw the number crunched & Id feel bad doing that to my engine everyday. Sorry for the not so good advice

I don't think it's a 535i trans:confused (don't think it would even bolt up), it is either a 525i or 325i from what I know. I just PMed PUMECAR for the part number (I won't see it for about another 3wks)

And a 250rpm increase at 80mph doesn't seem like it would be that bad.

That's on an S50/52 correct? Would you recommend the 3.46 over a 3.23?

I like the 3.46 because of the better acceleration around town. It does seem a little high when cruising on the interstate.