m52/zf trans + 2.93 = too low?

[evil_twin]

Hey guys, I am going to try out a 2.93 diff on my car. I was wondering if you guys think that the motor/trans combo with a 2.93 diff was a good choice? Or should I go with a 3.25 differential?

[mooseheadm5]

2.93 should work just fine with that 1:1 5th gear. I have a 3.25 in that green car you saw, and it revs a bit high on the interstate and gets crappy fuel economy. It is a rocket out of the hole, though. If you need, I have a 3.25 open to sell you cheap.

[Uber E30]

ZF+2.93 is about equal to a g260 and a 3.73
ZF+3.25 is about equal to a g260 and a 4.10


I personally had a g260 and a 4.10 as a DD and it sucked. I had to shift like a madman in rush hour traffic and at cruzing speeds on the highway i was reving at like 3.5-4k consistently. Thats why i chose a 2.93 for my ZF.

[mooseheadm5]

Forgot that because the E36 has taller tires, it would rev lower than the E30 with the same gearing.

[BenM]

2.93 w/ 1:1 = about 80mph @ 3000rpm. It's a very good ratio is you do a lot of highway driving. If track work, a 3.25 or even 3.46 would be more appropriate.

[GK-E30M3]

how but me guys M52 + ZF boosted mostly track use 3.25 or 2.93 wich one

[Jean]

For track / autox it really depends on the layout, is it mostly short straights where shorter gearing will be beneficial or longer? Now if it's for DD, that's different.

Should make an adjustable diff in the range of 2.0 - 5.0

[rThor432]

For what it's worth, I run a 2.93 with my S52 and G260 transmission. It is great for a daily driven car. I get around ~33 mpg. The 2.93 gives the car really long legs, so it isnt a rocket from a standing start. Once the power starts coming on at 3500 it pulls very nicely and between 5500 and 7300 it is very fast. I can do 70 in second, which is nice too.

The 2.93 should be a great match for the ZF transmission though.

I'll be putting a 3.25 in soon and running that for the track events I do this year, because the extra gearing helps a good bit down low. I'll rebuild the 2.93 in the meantime and put that back in in the fall/winter.

[z31maniac]

WOW, that low with a 260?

I'm trying to source a 3.64 right now!

[BenM]

how but me guys M52 + ZF boosted mostly track use 3.25 or 2.93 wich one

Would depend on the track, but I would go with the 3.25. I recently tracked my dad's M42 Turbo car that has a ZF attached to it w/ a 3.07 diff, and at LRP I found myself off boost going threw turn 3, then coming on boost very abruptly while partially through turn 4. With closer gearing will cause you to stay in boost more often.

WOW, that low with a 260?

I'm trying to source a 3.64 right now!

w/ a 260, I think the 3.46LSD is the perfect ratio for DD use. That's what I use on my E28 and love it. 3.64 is an awesome ratio too, and IMO is perfect for spirited driving. They are rare as hen's teeth though (3.64LSD) and are only confirmed to be in the 88-89 635csi w/ manual tranny. '84-'85 318i used them too, but they are small cased.

[rThor432]

WOW, that low with a 260?

I'm trying to source a 3.64 right now!

Yeah if you arent in the powerband it is somewhat dog-ish. When you are in the power (5500-7300) it pulls about like an E39 M5.

It's great for a dd that sees 99.998% highway use, but because you dont shift much it is easy to break the law into little bits without realizing it. 65-100 in third is very quick and if I punch it in 4th at 80 I'm doing un-Godly speeds before I know it. I'd feel very immature to get a ticket at those speeds, but going 120-130 is nothing for this car. I need to get my tii done so that I can start daily driving something that fun but not so quick. The E36 M3 just isnt fun for me anymore..

[evil_twin]

Currently I'm running zf and a 373 welded diff. It sucks on the highway, but the car will see many days on the track. I'm running out of my power band too quick with my 373.

The guy that has both diffs is letting me use the 2.95 first, see how I like it, and if I don't then I will be using the 3.25 out of an e28

[sushipower]

currently running; ZF with 3.73, doing 3000 @ 60mph. It's my weekend car so no problem. If you using it for track purpose this would be a great set-up, because I'm pulling out of turns in 3rd gear and it pulls pretty hard. I think 1st and 2nd gears are useless for 24V swap.

[evil_twin]

Really? I hate having a 373 in my car. Also I plan to be going turbo in the future, so if I can just keep 1 diff it would be great lol.

[sushipower]

even 3rd will break loose if not careful. Before I got the motor from a friend it was rated 273whp.