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View Full Version : My DIFF.. BLEW.. looking to get 4.45 diff


Mr.///Matt
11-10-2008, 07:45 AM
http://cgi.ebay.com/ebaymotors/BMW-E36-E30-LIMITED-SLIP-DIFFERENTIAL-4-45-Gear-Ratio_W0QQcmdZViewItemQQ_trkparmsZ72Q3a570Q7c66Q3a 2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2 ec0Q2em14QQhashZitem190265052816QQitemZ19026505281 6QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories


i know that the gear ratio is high. any idea on how what the top speed will be?!

Bruce
11-10-2008, 08:06 AM
Assuming 245/40 17 tires....7000 rpms in 5th = 116 mph. 70 mhp in 5th gives you 4250 rpms. 1st gear will basically be unuseable.

Besides, the E36 318 used a small case diff (168) versus the medium case diff (188) the 6 cylinder cars use.

willysully
11-10-2008, 08:29 AM
If you are going to go over 4.00 I would get a 4.11 0r 4.10 wichever is most redily available.

Mr.///Matt
11-10-2008, 08:46 AM
holy cr@p nevermind then... how bout a 3.91lsd... im guessing that should give a bit more off the line you know for that pulling feeling.

Bruce
11-10-2008, 10:21 AM
I wouldn't go higher than a 3.64 or maybe a 3.73 on a street car.

Mr.///Matt
11-10-2008, 04:53 PM
what car can i get the diff out of..

rrsperry
11-11-2008, 04:21 AM
None. You have to build it. The only other ratio offered in the E36 M3 was a 3.38, out of the automatic M3 sedans. I have it installed in my 5 speed car and it's great. Dan at diffsonline builds and sells a lot of ratios, but like was said, you don't want to go higher than a 3.46:1 in a 5 speed car.

A rebuilt diff with 40% lockup lsd unit was about $1600 last I looked.

Bruce
11-11-2008, 04:58 AM
None. You have to build it. The only other ratio offered in the E36 M3 was a 3.38, out of the automatic M3 sedans. I have it installed in my 5 speed car and it's great. Dan at diffsonline builds and sells a lot of ratios, but like was said, you don't want to go higher than a 3.46:1 in a 5 speed car.

A rebuilt diff with 40% lockup lsd unit was about $1600 last I looked.

Other E36 diffs will work....or you could have E30 ratios put into an E36 diff case.

Mr.///Matt
11-13-2008, 06:23 AM
^ how much would that cost to change

Bruce
11-13-2008, 06:33 AM
Sounds like your best bet is to contact a BMW diff rebuilder. Diffsonline, Koala Motorsport, Blanton, Metrix Motorsport, etc.

PhilipWOT
11-17-2008, 05:10 PM
I want a taller diff. More mph's on the highway baby! (I think I have a 3.15?)

e36m34life
11-20-2008, 06:27 PM
I want a taller diff. More mph's on the highway baby! (I think I have a 3.15?)

The negative aspects of taller gear ratios outweigh the positive.......by a lot.

Don't go GM on us now! :rofl: :p

dinanm3atl
11-21-2008, 09:03 AM
A 4.45 gear?!?!?! Wowsers!

Mufflerman
11-23-2008, 06:11 PM
This is educational, I was not aware that the auto cars had shorter ratios, I assume that an automatic rear end is a direct swap for a 5 speed car? Did it change the speedo much? And lastly, it has the same limited slip as the 3 pedal car?

FenderBender
11-23-2008, 07:37 PM
The negative aspects of taller gear ratios outweigh the positive.......by a lot.

Don't go GM on us now! :rofl: :p

Hey now, let's not go below the balls, they're not broke yet......

Bruce
11-24-2008, 05:07 AM
This is educational, I was not aware that the auto cars had shorter ratios, I assume that an automatic rear end is a direct swap for a 5 speed car? Did it change the speedo much? And lastly, it has the same limited slip as the 3 pedal car?

Yes it should be a direct swap, but they don't necessarily have a LSD.

rrsperry
11-30-2008, 07:15 PM
Direct? depends on the year of the car it's going into. To put it in a 95 you either have to change the input flange or the driveshaft. The speedo is not affected at all. It has a specific speed sensor, provided you keep the tire about the same diameter.

Mr.///Matt
12-03-2008, 01:33 PM
hey guys what if i got a 3.15 diff on my s52 ... any idea .. has any one done it.. or how bout a 3.91 lsd... 250.00 off ebay,..

3.62 pazi came from an e46 m3... will that fit in the e36.

Bruce
12-03-2008, 02:13 PM
for E30 S52? street car? track car? dual duty? for a street car a 3.15 or 3.23 or even a 3.38 would be ideal. Track car I would say 3.46, 3.64 or 3.73.

Mr.///Matt
12-03-2008, 02:17 PM
no no.... this is for my e36 m3.

rrsperry
12-03-2008, 02:56 PM
3.15 why? Just see if you can find a 3.23 or a 3.38 and be done with it.

Mr.///Matt
12-03-2008, 03:02 PM
3.15 why? Just see if you can find a 3.23 or a 3.38 and be done with it.

lol... true.. im just wondering what i can do... and i guessing 3.91 is to high...

e30e
12-03-2008, 03:44 PM
Yes a 3.91 is too high unless you never go faster than 70 mph and love the buzzing sound of an engine. 3.23 is what 96+ on had.

Mr.///Matt
12-04-2008, 07:32 AM
yeah i know that.. thats what i have right now.. till it blew.. im just looking for something with more kick.. loll.. i dont want to spend money on a new diff. i just want one from maybe a different model bmw. with a higher ratio