OBD1 s52+3.46 lsd+ZF 320 = OMFG!

[e30polak]

yeah 3.73 with a ZF

thing is im really used to it oddly enough. i had a civic si from 2000 till 2008 (original owner) and it has a close diff also. at 80mpg i was at 4600rpm.

as long as i can get rid of the drone ill be fine. and after the sweet resonator i saw at the performance show over the weekend....and that is coming in today. i think i wont have any. :D

Ya that's a little too short of gearing for me, but Jesse likes his, so you're not alone. :loco:

[mazur]

Just to let you guys know, you're slowing yourself down with the 3.73. It may feel fast, but what's the point when it isn't?

I know it doesn't sound intuitive, but a 2.93 will make your car a lot quicker than with a 3.73. That is, at least if you're making the power of an S50.

Best all around gearing would be the 3.25. Can't comment on the 3.46 since I have no experience with it.

[mazur]

traction is really that much of a problem for you guys? hmm, s52 must put out alot more power then s50, i cant break my 235's loose unless i try.

Mine is an S50 ;)

I think the main reason I spin so easy is because of my LTW flywheel. I have a 10 pounder.

[guibo09]

Just to let you guys know, you're slowing yourself down with the 3.73. It may feel fast, but what's the point when it isn't?

I know it doesn't sound intuitive, but a 2.93 will make your car a lot quicker than with a 3.73. That is, at least if you're making the power of an S50.

Best all around gearing would be the 3.25. Can't comment on the 3.46 since I have no experience with it.

i dont agree. the only disadvantage of shorting gearing is the extra time spent shifting. however, differences are pretty small here (10-15%) so in most cases, you wont require the extra shift anyway, therefore you will be faster if you can put the traction down.

things like 0-60 times take a hit when you go to shorter gearing cuz you're forced to shift to 3rd for 60mph. but otherwise, shorter gearing is better off unless you're going for top speed.

[1990m3]

Just to let you guys know, you're slowing yourself down with the 3.73. It may feel fast, but what's the point when it isn't?

I know it doesn't sound intuitive, but a 2.93 will make your car a lot quicker than with a 3.73. That is, at least if you're making the power of an S50.

Best all around gearing would be the 3.25. Can't comment on the 3.46 since I have no experience with it.

My car sees a 5mph difference in speed on the long straights of road america when I use a 3.46 v 3.25. I like the 3.25 but it does feel a little slower. Tire size has a lot to do with it as well...I haven't used the 3.25 on any of the shorter tracks yet

[mazur]

i dont agree. the only disadvantage of shorting gearing is the extra time spent shifting. however, differences are pretty small here (10-15%) so in most cases, you wont require the extra shift anyway, therefore you will be faster if you can put the traction down.

things like 0-60 times take a hit when you go to shorter gearing cuz you're forced to shift to 3rd for 60mph. but otherwise, shorter gearing is better off unless you're going for top speed.

The problem of shifting too often is evident with this that particular gearing. I'm no slow shifter by any means, in fact havn't seen anyone else shift faster, but the short amount of time spent in each gear slows down your overall acceleration. I doubt a sequential shifter would even negate the problem.

Some real world scenarios:

Race my friend multiple times in his stock E36 M3 w/ a 3.73. Barely pull on him and am disappointed. With the 2.93 I blow his doors off.

Race my friends untuned M20 at 6psi w/ the 3.73 and get beat as he walks on me. With the 2.93 I blow his doors off, and by now he's engine dyno tuned at 7psi.

I have more of those scenarios, but that's a taste. Again, my belief is that the more power you make, the more rediculously short gearing hurts you...and 3.73 on a ZF is rediculously short. I'm not saying my 2.93 is the best ratio, but I know it's better than a 3.73 hooked up to the ZF :-)

I also believe that more time spent in the powerband is beneficial. Imagine a 2000hp standard car with the same short gearing and let's imagine it has all the traction it needs. You'd be shifting every second. But with taller gearing your powerband would be able to spread its legs and be usable.


Make sense? It does to me... obviously

[guibo09]

The problem of shifting too often is evident with this that particular gearing. I'm no slow shifter by any means, in fact havn't seen anyone else shift faster, but the short amount of time spent in each gear slows down your overall acceleration. I doubt a sequential shifter would even negate the problem.

Some real world scenarios:

Race my friend multiple times in his stock E36 M3 w/ a 3.73. Barely pull on him and am disappointed. With the 2.93 I blow his doors off.

Race my friends untuned M20 at 6psi w/ the 3.73 and get beat as he walks on me. With the 2.93 I blow his doors off, and by now he's engine dyno tuned at 7psi.

I have more of those scenarios, but that's a taste. Again, my belief is that the more power you make, the more rediculously short gearing hurts you...and 3.73 on a ZF is rediculously short. I'm not saying my 2.93 is the best ratio, but I know it's better than a 3.73 hooked up to the ZF :-)

I also believe that more time spent in the powerband is beneficial. Imagine a 2000hp standard car with the same short gearing and let's imagine it has all the traction it needs. You'd be shifting every second. But with taller gearing your powerband would be able to spread its legs and be usable.


Make sense? It does to me... obviously

i think you have to differentiate between close gear ratios and a short final drive. it dont matter what rear end ratio you have, if you shift at 7000 rpm in first gear, you will always fall back at the same exact rpm in second gear. therefore, you will always rev through the same rpm range and use the same power band.

you are completely right if your car makes, say, a constant 200hp between 4000rpm and 7000rpm. the ideal gear box would allow you to always fall back to 4000 at each shift, falling back to 5000 would waste some good power band.

unfortunately, we dont really have the luxury of playing with the gear ratios since it's quite expensive to get a custom gear set.

when only changing the final drive, all you do is multiply the amount of torque at the wheels in each specific gear. HOWEVER, you spend less time in each gear and your end speed of each gear is lower.

so the outcome of a race between two equal cars with only different final drives would depend entirely on the end point of the race. if both cars finish in 4th gear (say a 1/4 mile), then they will have the same number of shifts and the shorter final drive car will win.

basically the race will go like so: shorter leads until 1st shift, gets passed by longer, shorter catches back and passes longer before 2nd shift where longer takes the lead again. this keeps going until 4th, where shorter will take the lead and win, unless he has to shift to 5th. but unless you are making 300whp, that should not be a worry.

basically, you are giving up top speed to increase torque at the wheels throughout the acceleration.

[e30polak]

Mazur, with the power you're putting down, I think you would love the 3.25 IMO. And yes a 3.73 with the ZF trans is too short.

Like I've said before, 3.46 is the perfect STREET gear. A 2.93 might be more fun then the 3.46 in first and second only, because they would essentially be longer. However, 1st and 2nd in our swap cars is fast with almost any ratio, therefore I wanted to shorten 3rd and 4th to get into peak powerband quicker!

Several people have driven my car before and after, and it truly pulls way better! As far as top speed is concerned, this is not a track car. I am going to auto x it when I get the funds for tires. I also run the twities in it quite a bit, so for me it is perfect.

Concerning highway revs, well I had to give up something. When I get the money I will be upgrading to the 6 speed to get a nice overdrive gear!

[z31maniac]

Your gearing is closer to a ZF with a 3.25, a 260 with 4.10s is almost the same I believe.

Interesting. It looks like I may end up with an S52 now instead of an M52 and it will be hooked up to a Getrag 260 and I have a 4.10.

Although I'll most likely go back to a 3.73. I want to be close to 60 in 2nd gear because most of our Auto-x tracks are long, fast layouts.

[z31maniac]

i think you have to differentiate between close gear ratios and a short final drive. it dont matter what rear end ratio you have, if you shift at 7000 rpm in first gear, you will always fall back at the same exact rpm in second gear. therefore, you will always rev through the same rpm range and use the same power band.

you are completely right if your car makes, say, a constant 200hp between 4000rpm and 7000rpm. the ideal gear box would allow you to always fall back to 4000 at each shift, falling back to 5000 would waste some good power band.

unfortunately, we dont really have the luxury of playing with the gear ratios since it's quite expensive to get a custom gear set.

when only changing the final drive, all you do is multiply the amount of torque at the wheels in each specific gear. HOWEVER, you spend less time in each gear and your end speed of each gear is lower.

so the outcome of a race between two equal cars with only different final drives would depend entirely on the end point of the race. if both cars finish in 4th gear (say a 1/4 mile), then they will have the same number of shifts and the shorter final drive car will win.

basically the race will go like so: shorter leads until 1st shift, gets passed by longer, shorter catches back and passes longer before 2nd shift where longer takes the lead again. this keeps going until 4th, where shorter will take the lead and win, unless he has to shift to 5th. but unless you are making 300whp, that should not be a worry.

basically, you are giving up top speed to increase torque at the wheels throughout the acceleration.

He's right, I noticed my R6 was faster when I backed down from over aggressive gearing.

Not to mention, how many drag racers use Powerglide's? 2 speeds, to keep the engine in the power band and reduce shifts.

[guibo09]

He's right, I noticed my R6 was faster when I backed down from over aggressive gearing.

Not to mention, how many drag racers use Powerglide's? 2 speeds, to keep the engine in the power band and reduce shifts.

again you are confusing tranny gear ratios and final drive ratio.

and if you read what i wrote more carefully, i said the shorter final drive is only faster if you're not forced into the extra shift.

on most cars, within reasonable gearing and HP numbers, you will always finish the quarter mile in 4th. so both cars have to shift 3 times, same wasted shift time, shorter final drive is faster.

[e30polak]

again you are confusing tranny gear ratios and final drive ratio.

and if you read what i wrote more carefully, i said the shorter final drive is only faster if you're not forced into the extra shift.

on most cars, within reasonable gearing and HP numbers, you will always finish the quarter mile in 4th. so both cars have to shift 3 times, same wasted shift time, shorter final drive is faster.

So true. :up:

[z31maniac]

again you are confusing tranny gear ratios and final drive ratio.

and if you read what i wrote more carefully, i said the shorter final drive is only faster if you're not forced into the extra shift.

on most cars, within reasonable gearing and HP numbers, you will always finish the quarter mile in 4th. so both cars have to shift 3 times, same wasted shift time, shorter final drive is faster.

Yes, you are right.

But in the real world shifting (and traction) have to be taken into account.