m50 project with getrag 260 tranny 2.93 vs 3.25

[1991318is]

Hi, i'm almost done in collecting parts for my m50 project. I decided to use a Getrag 260 tranny but not to shure wich diff to use. I would rather use my 2.93 diff since i have it. But i'm a bit consern on not choosing the perfect diff ratio for my setup. My m50 will have minor performance upgrades but nothing to crazy. Wich one would you recomand??? I do love acceleration specially in 4th and 5th gear and a nice top speed but i do not like spining out on 2nd and 3rd. I would also like to hear from people that have done the 1/4 mile with the m50 engine, what where the results and wich diff where you using. Any experiments with using different diff's??
Thanks

[Jarvis]

use a 3.73 with the Getrag 260. Or 3.45-3.64ish if you want really relaxed highway cruising or plan on putting out a lot of power with FI. Or use a 3.91 or 4.10 for maximum acceleration at lower speeds (sacrificing top speed and comfort on the highway). A 2.93 will make the gears way too long for a smallish motor that likes to rev. 3.25 is a stretch too for a lightly modded n/a M50 with a 260 tranny.

[Stu]

I'd use a 3.73 or 3.91 if you can find one. I use a 3.73 in mine and I think it's perfect...it's what BMW used to gear the 2.5 M20.

[ed94r]

Ditto on the 3.73. A great all around gear.

[1991318is]

Thanks everyone, what is the top speed with a 3.73? How is it on 1st and 2nd gear? What is the approx time in 0-60mph acceleration? To be honnest i feel more confident using this ratio. I got a bit confused on the DOHC topic since the 2.93 and 3.25 where mentionned often. Can i use my driveshaft of my 318is m42 with this setup, i noticed that it's ajustable, look's like you can extend it or make it shorter, i'm not shure.

[Stu]

Thanks everyone, what is the top speed with a 3.73? How is it on 1st and 2nd gear? What is the approx time in 0-60mph acceleration? To be honnest i feel more confident using this ratio. I got a bit confused on the DOHC topic since the 2.93 and 3.25 where mentionned often. Can i use my driveshaft of my 318is m42 with this setup, i noticed that it's ajustable, look's like you can extend it or make it shorter, i'm not shure.

1st gear will pull about 30mph at 7000, 2nd about 60mph. You will not be able to use your 318 driveshaft, it's too long, you need an E30 325 driveshaft from a stick-shift car. 2.93 and 3.25 are common rear gears used when you also use the E36 transmission which is not overdriven. My 3.0 pulls to 6700 rpm in 5th and won't pull any farther, ~159mph. 2.5 M50/E30's do about 140mph, which is more than enough.

[1991318is]

Thanks everyone, what is the top speed with a 3.73? How is it on 1st and 2nd gear? What is the approx time in 0-60mph acceleration? To be honnest i feel more confident using this ratio. I got a bit confused on the DOHC topic since the 2.93 and 3.25 where mentionned often. Can i use my driveshaft of my 318is m42 with this setup, i noticed that it's ajustable, look's like you can extend it or make it shorter, i'm not shure.

1st gear will pull about 30mph at 7000, 2nd about 60mph. You will not be able to use your 318 driveshaft, it's too long, you need an E30 325 driveshaft from a stick-shift car. 2.93 and 3.25 are common rear gears used when you also use the E36 transmission which is not overdriven. My 3.0 pulls to 6700 rpm in 5th and won't pull any farther, ~159mph. 2.5 M50/E30's do about 140mph, which is more than enough.

Thank you for your help it was greatlly apreciated. One more question for the shifter linkage. I know that many use the Z3 1.9 shifter as a short shift. I have with me a picture that compares lenghts of different BMW shifters between: Z4-2.5, Z4-3.0, Z3-M, Z3-2.8/3.0 and Z3-1.9. My question is wich one would you recomand with the getrag260 and do i need to use the complete shifter linkage. I wish i could post the picture but i dont know how to do it.

[Stu]

Thanks everyone, what is the top speed with a 3.73? How is it on 1st and 2nd gear? What is the approx time in 0-60mph acceleration? To be honnest i feel more confident using this ratio. I got a bit confused on the DOHC topic since the 2.93 and 3.25 where mentionned often. Can i use my driveshaft of my 318is m42 with this setup, i noticed that it's ajustable, look's like you can extend it or make it shorter, i'm not shure.

1st gear will pull about 30mph at 7000, 2nd about 60mph. You will not be able to use your 318 driveshaft, it's too long, you need an E30 325 driveshaft from a stick-shift car. 2.93 and 3.25 are common rear gears used when you also use the E36 transmission which is not overdriven. My 3.0 pulls to 6700 rpm in 5th and won't pull any farther, ~159mph. 2.5 M50/E30's do about 140mph, which is more than enough.

Thank you for your help it was greatlly apreciated. One more question for the shifter linkage. I know that many use the Z3 1.9 shifter as a short shift. I have with me a picture that compares lenghts of different BMW shifters between: Z4-2.5, Z4-3.0, Z3-M, Z3-2.8/3.0 and Z3-1.9. My question is wich one would you recomand with th\e getrag260 and do i need to use the complete shifter linkage. I wish i could post the picture but i dont know how to do it.

I have that pic too. I use the Z3 4cyl lever in my car, have had it in there for about 3 yrs, zero complaints. I absolutely love the shift pattern, am always confident on gear selection regardless of conditions....some may like the other levers, there may be one with a better 'feel'....but i'd say you'd be fine with anything other than the stock E30 lever. However, I drove a friends 318is with an Mcoupe S54 lever, and I thought the pattern was way too closely spaced and lacked smooth gear engagement.

-stu
3 sheets to tha wind

[lordofmpower]

Thanks everyone, what is the top speed with a 3.73? How is it on 1st and 2nd gear? What is the approx time in 0-60mph acceleration? To be honnest i feel more confident using this ratio. I got a bit confused on the DOHC topic since the 2.93 and 3.25 where mentionned often. Can i use my driveshaft of my 318is m42 with this setup, i noticed that it's ajustable, look's like you can extend it or make it shorter, i'm not shure.

1st gear will pull about 30mph at 7000, 2nd about 60mph. You will not be able to use your 318 driveshaft, it's too long, you need an E30 325 driveshaft from a stick-shift car. 2.93 and 3.25 are common rear gears used when you also use the E36 transmission which is not overdriven. My 3.0 pulls to 6700 rpm in 5th and won't pull any farther, ~159mph. 2.5 M50/E30's do about 140mph, which is more than enough.

Thank you for your help it was greatlly apreciated. One more question for the shifter linkage. I know that many use the Z3 1.9 shifter as a short shift. I have with me a picture that compares lenghts of different BMW shifters between: Z4-2.5, Z4-3.0, Z3-M, Z3-2.8/3.0 and Z3-1.9. My question is wich one would you recomand with th\e getrag260 and do i need to use the complete shifter linkage. I wish i could post the picture but i dont know how to do it.

I have that pic too. I use the Z3 4cyl lever in my car, have had it in there for about 3 yrs, zero complaints. I absolutely love the shift pattern, am always confident on gear selection regardless of conditions....some may like the other levers, there may be one with a better 'feel'....but i'd say you'd be fine with anything other than the stock E30 lever. However, I drove a friends 318is with an Mcoupe S54 lever, and I thought the pattern was way too closely spaced and lacked smooth gear engagement.

-stu
3 sheets to tha wind

Are you talking shit about my shifter Stu? :evil:

well I have a new one in the works but shhh not until it done. :twisted:

[Addissimo]

Definately dont use a 2.93... Ask me how I know....

[Stu]

I'm considering going to a 4.10 in my car. I have an available trade of my 3.73 for a 4.10...i'm weighing the advantages/disadvantages.

pros:
-After driving his car with the 4.10 (one of dads 2.8i M20's)..it really hauls through the gears. Redline 1st, get second gear nicely and the car is OUT..
-I feel the 4.10 would be beneficial at the track I run at. The back section of the track is tight and I found myself falling below the powerband in 3rd, with the 3.73.

cons:
-higher revs on the highway
-MPG
-shifting more often

Can't decide. I may wait for one more track day with the 3.73 to make a decision.