Anybody have accel. videos for diff. comparison

[brn2ply7]

My e30 will be my dd though i am one of those beat on it all the time guys. I am currently running 205/50-16 star specs. It seems that the 3.25 would really wind up in the right area (hwy rpm vs. accel.
). I currently live in the d.c metro area but will be moving to greenville, n.c. soon where there is alot less city driving and alot more 55mph two lane roads. Thanks for that break down wanganstyle.

[sleepingbeauty]

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.

well thats funny because I have both… straight up, i took the gearing from the web of my tranny, a zf, and plugged it in with my 3.73 and those are MMMMYYYYY numbers. maybe not yours, but MINE because I am running bigger wheels. all I know, I plugged my info into a gearing calculator and that is what it is. u don't like those numbers with 215/45/17, then this is an argument that you need to take up with diffsonline.com because im using their calculator.

[Mr.SWISS]

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'

So what's 5th @70? I have heard diff things (pun) about the 3.73, which is what I currently have. previous swap I had a 4.10 open then went to a3.25 lsd. 4.10 was between 3500 and almost 4K rpms 65-70. I am hoping the zf+3.73 will be down to 3400@70 which would be ok until I find a 6spd.

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.

I agree, smells like bullshit.

[nrubenstein]

I'm currently running a 3.46 with the G260. 1:1 5th in the ZF got kind of annoying on the highway, as did the craptacular shift quality.

It's a little slower, but frankly, I'd rather just add power than deal with the highway buzzing. (I'd love two more gears in the ZF - a second overdrive around .5-.6 would be perfect for cruising.)

[Wanganstyle]

So what's 5th @70? I have heard diff things (pun) about the 3.73, which is what I currently have. previous swap I had a 4.10 open then went to a3.25 lsd. 4.10 was between 3500 and almost 4K rpms 65-70. I am hoping the zf+3.73 will be down to 3400@70 which would be ok until I find a 6spd.

I agree, smells like bullshit.

chart:

5th gear in the ZF with target 70mph and 3400 RPM?

assuming OEM e30 195/65/14" tires (diameter = 23.98")

3.73 @ 3400 rpm in 5th gear (1:1) is: 65.05mph
3.64 @ 3400 rpm in 5th gear (1:1) is: 66.66 mph
3.46 @ 3400 rpm in 5th gear (1:1) is: 70.13mph
3.38 @ 3400 rpm in 5th gear (1:1) is: 71.79 mph
3.23 @ 3400 rpm in 5th gear (1:1) is: 75.13 mph
3.25 @ 3400 rpm in 5th gear (1:1) is: 74.66 mph

[brn2ply7]

bought a 2.93. We will see when shes running.