e34 525i converted to manual - possible problems

[Faiz]

Hi all...Recently did the auto to 5-speed manual conversion...all needed parts sourced and changed by my mech except for the rear diff which is still 4.1... I'm still looking for a good condition 3.23 or 3.15. Pls let me know if one is available... Found a couple but 3.73 (with LSD) or 3.45...still too tall I'm told.Driving short distances for now ok but 90 km/h at 3K rpm! Fc has defiitely improved though from about 12.5/100l to 11.3 or so with mixed driving...What bothers me is the lack of power in gears 3 and 4...surprisingly 5th seems to have alot of oomphh if not for the high rpm! My mech says the manual tranny came from a similar 525i but I'm begining to wonder if he might be genuinely mistaken or it's just me since the rear diff is too tall?Sorry guys for the rather long post. Any views to help welcome. Thanks and cheers.

 

[ssmann]

Interesting....some issues to consider

1. What gearbox are u using, this this come with a paired M20 or 50 engine? What engine are u using? Gearbox 220/40/60?

2. Diff ratio is real important based on the issues you have highlighted. Higher/lower has its own merits/drawbacks. Finish gears quicker or top end....you need to decide based on your own needs...I used a 3.64 LSD mated to a M20 gearbox on a M50 engine...hahahaha...finish gears superquick, but suffer top end after 220kmh

3. Exhaust system - in order? Enough back pressure?

 

[Faiz]

Re: e34 525i converted to manual - possible problems

Thanks bro ssmann for the comments... Will certainly check the gearbox code if there's a way to do it and will ask my mech, and the exhaust back up pressure too. Just wondering...the exhaust issue concerns certain gears only. Also by finishing gears you mean the individual gear ratios in the gearbo? The engine is an M50B25TU. Cheers.