Author Topic: LSD/DIFF questions (Read 4249 times)

jakeb · « **on:** August 11, 2006, 03:54:33 PM »

I am debating getting an LSD for my 318is. As it would really help when autocrossing as well as for the winter months that I will be driving it here in Michigan.

Should I just go with a replacement 4.10 LSD or a 3.91 LSD... I have a line on a small case 3.91

I like the accel with the 4.10 but it would be nice to be able to get to 60mph in 2nd with the 3.91 and the lower revs...better mpg on the highway(or in theory)

What do you all suggest?

My 318is is pretty much bone stock right now with 160k on it. I plan to keep it for a long time. It is getting a respray at the end of the week and some suspension upgrades in time.

Jake

2002maniac · « **Reply #1 on:** August 11, 2006, 04:47:53 PM »

It's up to you. Dino has a 3.91 and likes it alot. I love my 4.10 w/undersized tires.

jakeb · « **Reply #2 on:** August 11, 2006, 05:27:30 PM »

What size tires are you running? I am thinking about getting some new tires actually. What would you suggest running? I was thinking some Falkin 615s or whatever they are called now. I am running stock 14" basketweaves now and I have a set of snows on bottlecaps.

So maybe 4.10 with different tires and a chip(which is planned soon....93 octane mark D)

anyone know the rev limit on the mark d chip? 7100?

Jake

dino245 · « **Reply #3 on:** August 11, 2006, 05:37:59 PM »

I am running the 3.91 and the stock 14" tires and love the diff. I am also putting out mor Hp's and will be producing more as time goes by. If you have a line on the 3.91 do it.

jakeb · « **Reply #4 on:** August 13, 2006, 07:36:24 AM »

What are the advantages to the 3.91? and disadvantages for that matter?

jake

silverblades181 · « **Reply #5 on:** August 13, 2006, 05:23:56 PM »

well you get to keep the gear longer so you dont have to shift as often but the power in the M42 is at the high end and you get there slower so I don't the advantage. You also get a theoretical higher top speed (I say theoritical because I doubt you'll get there)

Deutschbag · « **Reply #6 on:** August 17, 2006, 02:19:50 PM »

How do you tell if you have an LSD in your car stock? I'm pretty sure I don't, but still, I'd like to know for sure.

bmwman91 · « **Reply #7 on:** August 17, 2006, 02:22:14 PM »

Look on the metal part # tag on the diff. If the number begins with an S then it is an LSD.

jakeb · « **Reply #8 on:** August 17, 2006, 02:49:22 PM »

or jack up the rear end...turn one wheel...if the other turns the same direction you have an LSD. Or just take a hard turn and see if they both grab...or if one wheel spins

It is amaseing how much LSD helps.. I have it in my 2002 now...and man it is nice for coming out of a turn

jake

Deutschbag · « **Reply #9 on:** August 17, 2006, 05:50:19 PM »

Where on the case is the part number tag? I went under there and it's kinda covered in grime, so I need to know where to start washing the crap off to see.

Eurospec · « **Reply #10 on:** August 17, 2006, 05:53:49 PM »

Should be to the right of the speed sensor. It's marked vertically as you're looking from the rear.

///Motorsport · « **Reply #11 on:** August 17, 2006, 06:05:09 PM »

im scared to put the LSD im getting on my car. i love driving a bmw with a LSD like nothign else, and no matter hwat im doing it for the pure fun, but when im mobbin pretty fast i already get the back to step out and itll be freaky when it goes more.... i guess itll be more predictable and controllable but still..

jakeb · « **Reply #12 on:** August 17, 2006, 06:31:27 PM »

The LSD should stop it from sliding out...and if you keep in it it will pull back.

Thats how it was with my e30 m3...but that had a little extra power

silverblades181 · « **Reply #13 on:** August 17, 2006, 07:31:16 PM »

Anyone ever tried putting a higher gearing? Like a 4.27 LSD from an auto convertible or a 4.45 LSD from an auto 318ti??

Author Topic: LSD/DIFF questions (Read 4249 times)

Deutschbag

Deutschbag

///Motorsport