M50 with S50 cams and G250 with S3.73 will this be a good set up?

[Wh33lhop]

15" or 16" wheels makes no difference in the gearing. It's the rolling diameter of the tires that matters.

[agent]

True. A 205/50-16 setup has almost the exact same rolling diameter (0.3% difference) as a stock weave on 195/65-14s.

[emmanuel.dlc]

Do you know which cars had the lsd 3.25??

e28's have 3.25lsd medium case ready to swap.

[Nick_S]

OP you should re-edit your original post with the original question. Threads like this are what helped me figure out my setup when searching around.

[rickston69]

I'm running a large case 3.46 LSD in my M52 swapped e30 318is with the stock 14" wheels and tires. For a brief period I left the original small case 4.10 LSD with the new engine and it was horrible. It was wicked as hell and it could spin the rear tires through the first 3 gears. As much "fun" as it was to play with, the lower 4.10 gear ratio caused it to turn about 4500 RPMs at 70 on the highway. The diff probably would not have held up for very long at all. With the higher 3.46 gear ratio it now turns about 3500 at 70 but since I drive it in town between 45-55 mph, it is turning ~2500/~2900 RPMs. Much more enjoyable, it gets down the street like a scalded cat, and it still has great pull in every gear too! If your daily driving is mostly highway, something even higher than a 3.46 would probably be better for gas mpg.

[emmanuel.dlc]

I'm running a large case 3.46 LSD in my M52 swapped e30 318is with the stock 14" wheels and tires. For a brief period I left the original small case 4.10 LSD with the new engine and it was horrible. It was wicked as hell and it could spin the rear tires through the first 3 gears. As much "fun" as it was to play with, the lower 4.10 gear ratio caused it to turn about 4500 RPMs at 70 on the highway. The diff probably would not have held up for very long at all. With the higher 3.46 gear ratio it now turns about 3500 at 70 but since I drive it in town between 45-55 mph, it is turning ~2500/~2900 RPMs. Much more enjoyable, it gets down the street like a scalded cat, and it still has great pull in every gear too! If your daily driving is mostly highway, something even higher than a 3.46 would probably be better for gas mpg.

which tranny? stock 318i? or the zf from the m52?

[ArtClassShank]

I'm running a large case 3.46 LSD in my M52 swapped e30 318is with the stock 14" wheels and tires. For a brief period I left the original small case 4.10 LSD with the new engine and it was horrible. It was wicked as hell and it could spin the rear tires through the first 3 gears. As much "fun" as it was to play with, the lower 4.10 gear ratio caused it to turn about 4500 RPMs at 70 on the highway. The diff probably would not have held up for very long at all. With the higher 3.46 gear ratio it now turns about 3500 at 70 but since I drive it in town between 45-55 mph, it is turning ~2500/~2900 RPMs. Much more enjoyable, it gets down the street like a scalded cat, and it still has great pull in every gear too! If your daily driving is mostly highway, something even higher than a 3.46 would probably be better for gas mpg.

Is it really that much harder on a diff to have a 4.10?

[techno550]

with the 3.73 and stock size E30 tires, you will have a top speed of 130mph assuming a 7k rpm redline.
70mph cruise will be 3750 rpm.

really depends on what you can tolerate. This is almost identical RPM/speed wise to a 3.91 on an E36, and I had that as my daily for a year or so. Wasn't too bad as I had a relatively quiet exhaust.

[rickston69]

which tranny? stock 318i? or the zf from the m52?

ZF that was mated to the M52. I don't think the 5spd from the M42 would work or was just not recommended ~ I forget. :-/

[rickston69]

Is it really that much harder on a diff to have a 4.10?

My mechanic said the small diff would probably not have held up long with the bigger engine. Who knows how long it would have taken? I wasn't abusing the car every time I drove it although I had some fun with it. ;) I assume for racing the guys are using the small case 4.10 diffs. I am really glad to have the 3.46 in its place though. :)

[emmanuel.dlc]

ZF that was mated to the M52. I don't think the 5spd from the M42 would work or was just not recommended ~ I forget. :-/

not recommended but it works, i will math your ratio out, i want to run 4.10 with my b28 but with g260

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[rickston69]

not recommended but it works, i will math your ratio out, i want to run 4.10 with my b28 but with g260

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Cool ~ I'd be curious to see just how different it is from the 3.46 in it now.

[emmanuel.dlc]

well, here is the calc:

ZF320/3.46 vs. G260/4.10 both with 225/45/16 and 7,000 limiter:


zf

1- 34.4
2- 57.9
3- 86.9
4- 116.4
5- 144.3

g260

1- 31.8
2- 55.4
3- 87.0
4- 121.8
5- 150.3

very close, the g260 a bit more long on the latest 2 gears but its very comparative. it must be a blast to drive, i liked the 3.73 with the g260 now i want the 4.10 :D

[ArtClassShank]

http://www.endtuning.com/gearratios.html

This site is a good resource for playing around with ratios. I use it all the time.

[emmanuel.dlc]

i use this one:

http://members.dodo.com.au/~wawawa/revs.htm

its tailored for e30/e36 with the ratios already dialed in, nice tool!