Looking at swapping a 2.93 lsd from a 4.10 into my e34 s52 that will be running 400hp. what is everybodys thoughts on that ratio would it be to low mind you its a daily driver that will see some track days here at COTA.
Is it too low? Absolutely not, unless you're using a super-tall trans like some T56. My 525iT with a tired and bone-stock M50 has a 3.07 and a 37BZ trans (4.23 first gear, 0.85 sixth). It feels on the tall side of reasonable, gets 28-30mpg at 70-75mph, climbs hills in sixth with some cargo. Here's a shot from just yesterday, straight level cruising:
Picture 3009.jpg
Previous 544iT used a 2.65 for a while, with 264hp/296ftlb at the wheels. I liked it, could've gone even taller if there were a plug and play option. BMW does make taller diffs, but only for newer diesels (E46 330d 2.28, E39 530d 2.35).
I find many BMW, especially M50, to be ridiculously short-geared.
Last edited by moroza; 05-18-2020 at 09:18 PM.
That's a good ratio in my opinion. People seem to be obsessed with super short gearing for some reason, but I've always enjoyed longer gearing. One of my friends has an S50 swapped 525i with a 3.46 and at 90mph he's spinning at 4000 which is really quite annoying on a car with headers and a cat delete.
1995 525i 5-speed - Thread
Not enough information.
Its a BIG difference. COTA has some high speed portions, no? Are you running out of revs with the 4.10? Lots of ratios in between.
depending on your first gear ratio(auto, manual??) you may find your self slipping the clutch a lot or a sluggish take off with an autobox.
Last edited by ross1; 05-28-2020 at 09:03 AM.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
2.93 may be good with big hp but with 400bhp I’d suggest the popular 3.15. U may have big gaps in the gear ratios with such tall gears. (Assumed Manual 260g OD gearbox)
BMW’s
90 E34 M5
84 E24 M635csi standalone ecu with coil on plug
94 E34 540i/6 SC 5-17psi Flex fuel/standalone ecu
97 Z3 2.8
97 E36 M3 euro SC still u/c
OTHERS
11 Audi S5 APR stg2
19 Volkswagen Amarok V6
im actually running a zf trans from an e36 m3. but i got it figured out i ended up buying a diff from a e32 with a 3.64 ratio. its not as low as i wanted but ill prolly just swap the ring and pinion with a taller set in the future at some point. but thanks for all the help.
I am not sure I would swap out the 4.10. I doubt you will be running out of revs on a track with it.
Punch in your ratios and see where you land. Keep an eye on the rev drop between shifts. My guess is with a 2.18 you drop way off your peak power. I think I might have a 2.?? 188 ring and pinion in the garage but I think it takes a different carrier than the other gears.
https://www.blocklayer.com/rpm-gear.aspx
Last edited by flynfrog; 06-05-2020 at 01:22 PM.
ya the lowest i can run would be a 3.15 on the carrier which would be fine. the 4.10 is just to short even N/A sitting at 80 its at 4500 rpm I do drive this car everyday. Also the S/C I've ordered is the hyde motorworks one (https://hydemotorworks.com/shop/product-tag/m122h-kc/) so it'll be able to reach close to 600hp when the bypass is closed so theirs no way Id invest in a 4.10 lsd with that kit installed.
Last edited by Tristan36; 06-05-2020 at 04:27 PM.
Meh I was around 550 tire with a 4.10 through an auto and it wasn't so bad. Got tired of spinning 3k on the freeway though so i went to a 3.27. Are your gears that low in your trans? Probably a lot more torque than you are going to have too. Id guess that 3.46 will be pretty good.
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