Anybody have accel. videos for diff. comparison

[brn2ply7]

I was wondering if any of yal fine 24valvers had some acceleration videos to post up. Maybe give people a better feel/ more informed decision. I know differential ratio choice seems to be one of the most pondered things for expecially zf cars. So if anybody has any videos to show say the punch of a 3.46 but the hghway buzzing, or a 2.93's long first and second and mild highway manners please post!

Thanks,
Zach Buchko

[lbreevesii]

I've got a buddy who is working on reworking his speed calculator for bmw transmissions and gear sets. I'm thinking 3.34ish is going to be ideal.

Might keep the 4.10 every now and then just for fun. just not on the highway...3750rpm at 60mph sheesh!

[e30_325es]

293 isn't "long". It's close to an m20 with a 373. I prefer it for autoxing. Don't have to shift out of 2nd. was bouncing off the limiter a bunch with a 325.

[brn2ply7]

293 isn't "long". It's close to an m20 with a 373. I prefer it for autoxing. Don't have to shift out of 2nd. was bouncing off the limiter a bunch with a 325.

Thats interesting i had herd people did not like 2.93 for autoxing. Ive been in a mental pickle over this my whole build. Autox vids would be nice as well. The problem i have faced is what e30 swap videos there are out there do not really get into such details.

[Adrian_Visser]

Then you haven't looked hard enough. It has been covered more times than I care to mention. There are also gear ratio calculators online and with a bit of searching the ratios of zf and getrag trannys can also be found.

[87e30]

They aren't THAT expensive, you can try swapping around too since you can buy/sell different ratios.

[etxxz]

^^ i agree with him.

i actually have videos of my s52 with 4.10 gears and 3.25 gears. they are not onboard, but you'll get the idea. 4.10... and 3.64 for that reason is stupid short. The "first run" vid was right after my swap. Search "etxxz" in youtube. Post what you want..

My point is that since all 24v cars are going to be pretty different (weight, power mods, software, tire sizes, rim/weight etc etc etc). Look at the same car if you want an accurate rep.

best way is probably to look at stock e30s with 3.73 vs 4.10 gears. lots of those around... 3.64 is too short, even for city driving. You'll spend more time shifting than accelerating ie. you'll feel faster, but actually be slower.

[e30_325es]

I've got one video online but you cant tell much as far as accel or anything is concerned. I will say my e30 is lightened (not sure how much) and is ~250whp.

[sleepingbeauty]

who ever talked for a s52 with a 373, let me give you the correct opinion from someone whom owns the setup…. stupid short. going with a 3.25 (a little compensation to a 2.93) and I also loved the numbers it puts out for my application (215/45/17). anyway, some numbers for you to think about, my numbers, w/ 3.73 second gear redlines at 56mph and top speed of 137mph. to sound appropriate "normal" (and it does sound normal ish) besides the poor gear to gear ratio from the box to final drive giving a bog under acel. I would have to drive in forth gear at 30mph which is just under 2k rpm wise. in 3rd gear I am at 2400rpm with the 3.25 2nd gear redlines at 66mph and top speed of 160mph. 30mph in 3rd gear is 2100rpm and 4th at 30 would be 1600rpm. 3.73 is to quick, gears pop like candy, 1,2.3..4 coasting. flooring it it seems like you would be able to get a lot better 0-60 time with 3.25 as a proper gear, just second gear and your climbing to 65mph it lines you up perfectly for the s5x power band 4.1k+ (vanos kicks in) once your in 3rd your pretty much gone.
1st gear, 38mph @ 7.1k
2nd gear, 38mph @ 4.25k - 65mph @ 7.1k
3rd gear, 65mph @ 4.8k - 96 mph @ 7.1k
4th gear, 96mph @ 5.25k - 130 mph @ 7.1k
still want to go faster?
5th gear max 160mph @ 7.1k ---- you wont be traveling at these speeds 9/10
This is a little "longer" so to speak then your m20 w/ getrag stock setup, but still really wont feel so because of all the horses to back it up.

keep gear ratios in mind at what you tranny gears are, mine zf m3 tranny
1. 4.20
2. 2.49
3. 1.66
4. 1.24
5. 1.0
you are going to need to be in that high rpm range getting best use of horse power for gears 3/4, 5 of course not need be said.

anyway, pretty high is why I think I have gotten so in-depth on the topic, that and I have researched it pretty thoroughly and is what I personally decided would be my ideal setup. that will vary upon driver. I hope this helps you out any.
play with your tire size, tire size calculator (--- google that, mazda has a good one
go to custom diffs online, diffsonline.com and customize the calculator to your setup. proper gear ratios for tranny tire size etc. use google, great tool for any question you may have. and for shits and giggles. my current setup with the 3.73 as a diff.

1st gear 33mph @ 7.1k
2nd gear 33mph @ 4.1k - 56mph @ 7.1k
3rd gear 56mph @ 4.75k - 84mph @ 7.1k
4th gear 84mph @ 5.35k - 112mph @ 7.1k
5th gear 112mph @ 5.7k - 138mph @ 7.1k

so yes, have not made it to putting in the 3.25 although its ready, I am now thinking about making a video of the 3.73 thorough detail vs the 3.25 thorough detail

goodluck'

[brn2ply7]

Yeah i have gear calcs and graphs printed out all over the place. Its still just tough to decide on the trade off. I drove a buddies 95 m3 that was ~220whp and a stock 3.15 and it felt sluggish more so than i thought. I work at a company called flemings ultimate garage and get to drive 396 camaros and 427 cobras all the time and well it seemed to sluggish. My s50 is schrickd and should be in the ~250whp range. i have mainly personally gotten between the 2.93 3.25 3.46. But i am most recently leaning back 3.25.

[etxxz]

who ever talked for a s52 with a 373, let me give you the correct opinion from someone whom owns the setup…. stupid short. going with a 3.25 (a little compensation to a 2.93) and I also loved the numbers it puts out for my application (215/45/17). anyway, some numbers for you to think about, my numbers, w/ 3.73 second gear redlines at 56mph and top speed of 137mph. to sound appropriate "normal" (and it does sound normal ish) besides the poor gear to gear ratio from the box to final drive giving a bog under acel. I would have to drive in forth gear at 30mph which is just under 2k rpm wise. in 3rd gear I am at 2400rpm with the 3.25 2nd gear redlines at 66mph and top speed of 160mph. 30mph in 3rd gear is 2100rpm and 4th at 30 would be 1600rpm. 3.73 is to quick, gears pop like candy, 1,2.3..4 coasting. flooring it it seems like you would be able to get a lot better 0-60 time with 3.25 as a proper gear, just second gear and your climbing to 65mph it lines you up perfectly for the s5x power band 4.1k+ (vanos kicks in) once your in 3rd your pretty much gone.
1st gear, 38mph @ 7.1k
2nd gear, 38mph @ 4.25k - 65mph @ 7.1k
3rd gear, 65mph @ 4.8k - 96 mph @ 7.1k
4th gear, 96mph @ 5.25k - 130 mph @ 7.1k
still want to go faster?
5th gear max 160mph @ 7.1k ---- you wont be traveling at these speeds 9/10
This is a little "longer" so to speak then your m20 w/ getrag stock setup, but still really wont feel so because of all the horses to back it up.

keep gear ratios in mind at what you tranny gears are, mine zf m3 tranny
1. 4.20
2. 2.49
3. 1.66
4. 1.24
5. 1.0
you are going to need to be in that high rpm range getting best use of horse power for gears 3/4, 5 of course not need be said.

anyway, pretty high is why I think I have gotten so in-depth on the topic, that and I have researched it pretty thoroughly and is what I personally decided would be my ideal setup. that will vary upon driver. I hope this helps you out any.
play with your tire size, tire size calculator (--- google that, mazda has a good one
go to custom diffs online, diffsonline.com and customize the calculator to your setup. proper gear ratios for tranny tire size etc. use google, great tool for any question you may have. and for shits and giggles. my current setup with the 3.73 as a diff.

1st gear 33mph @ 7.1k
2nd gear 33mph @ 4.1k - 56mph @ 7.1k
3rd gear 56mph @ 4.75k - 84mph @ 7.1k
4th gear 84mph @ 5.35k - 112mph @ 7.1k
5th gear 112mph @ 5.7k - 138mph @ 7.1k

so yes, have not made it to putting in the 3.25 although its ready, I am now thinking about making a video of the 3.73 thorough detail vs the 3.25 thorough detail

goodluck'

YOU THOUGHT THAT WAS STUPID..
how about 4.10 gears!

http://www.youtube.com/watch?v=64RadsqTJyM

:mrgreen:

running 3.25lsd now, its what the e36 m3 came with. It really is the best ratio. I drove 3.64 e36 m roadster and is retarded.
oh, i'm also running 17" rims (245/40or45?). People don't think about it, but your tires are essentially the last gear.

[rav320uk]

Here you go.

http://www.youtube.com/watch?v=hLvPICXl4mE

[e30_325es]

Sleepingbeauty: I'm not sure on your math. Every gear calculator I've seen has those speeds way lower. In fact, my s50 with 2.93 gears and a zf trans has similar speeds to those. This leads me to believe either you don't actually have a 3.73 or you don't have a zf trans.

[Mr.SWISS]

I ran a 4.10 open with the NV and the g250, it was STUPID short. 70 was like 4K in 5th. The 3.25 LSD i got out of the 535is was cool, but cut the power down big. To me, I think 3.46 is perfect for the zf's/g250's 240's.

[Wanganstyle]

Yeah i have gear calcs and graphs printed out all over the place. Its still just tough to decide on the trade off. I drove a buddies 95 m3 that was ~220whp and a stock 3.15 and it felt sluggish more so than i thought. I work at a company called flemings ultimate garage and get to drive 396 camaros and 427 cobras all the time and well it seemed to sluggish. My s50 is schrickd and should be in the ~250whp range. i have mainly personally gotten between the 2.93 3.25 3.46. But i am most recently leaning back 3.25.

if your s50 is cammed, you will be chipping it to ~7200rpm cut?

how much tire can the e30 hold?
whats the primary use? track, DD, mountain, autox, etc?

track cars with 7,000rpm s52+ZFsg320 (1:1 5th gear) with tires (255-275mm slicks) and chassis prep (e36m caged) usually run 3.73's or 3.64's depending on track. 3.91 is too short for 7200 rpm, you need 8,000 rpm to push a 3.91 with 1:1 5th gear box. 6 speed is great with 3.91

usa S50 comes stock with 3.15, its a bit long - takes a while to get into the hot zone.
usa S52 comes stock with 3.23, its not bad but takes a while to pick up on track. This is good for e30's with small tires (under 235mm). S52 makes enough torque to break loose 255mm dunlop slicks post apex corner exit uphill (turn 5 laguna seca).

S52+ 5 speed ZF sg320 dd/street/hpde hot setup is 3.38 or 3.46 final drive. Good compromise gearing, very popular. For the most part not too short not too long almost always in the zone. I'd be riding rev limit in 3rd in the back of buttonwillow clockwise before the carousel, but that was dog fighting with E92m :)


My suggestions for ratios of any DOHC+ZF 1:1 5th gear trans + e30:


If you have a show car:

3.23 99-03 Z3M with finned pimptastic cover



If traction limited with standard e30 wheels:

2.93, 3.07, 3.15 and 3.23

If you have some rubber and want to have the hot setup for street/dd/HPDE:

3.38, 3.46

If you want to put down lap time and have the gear to do it (no tire limitations:

3.64, 3.73

If you are doing tarmac rally / hill climb:
3.91, 4.10, 4.27, 4.45.

If you are going to add turbo/supercharger (increase torque and need lower gearing for turbo spool up, etc):

3.07, 2.93, 2.79, 2.65