i have some questions about the diff alpina used on the B6.

did they used the regular E21 LSD diff? i know they added the drive cover with fins to cool it. but appart from that its a regular diff?

The B6 used a 3.91:1 LSD with 30Nm or 25%, and not the 3.45:1 final ratio like the 323i.

up to how much hp and torque its ok to use that diff. i read that some people say that they blew their diff with some turbo M20.

From what I read, abouut 400hp, maybe 300tq, it all depends on how you drive it and how well you take care of it. I'm sure they can handle more, but the tq is what will kill the diff. The E21 diffs are pretty stout.

up to how much hp and torque its ok to use that diff. i read that some people say that they blew their diff with some turbo M20.

Do you have some big plans?

Blitzed310

are you sure they used only 3.91 diff ?

No I am not 100% sure as I do not own own, havnt checked every B6 to see, but from research and from people who own them is where I got my info from. Im sure they didnt come with the 3.45:1 LSD like the 323i, and C1 did.

Guess I was right. http://www.bmwe21.net/e21/alpina/

just aask Brent, he has an Alpina B6

From what I was told it was a non LSD diff. Mine had a LSD added in 1993.
BTW The B6 is on e-bay right now!!!

Do you have some big plans?

im doing some research for a M30B35 swap. with some tune ups, it should be giving way over 250hp easily.

so far i dont have a simple alternative to the original E21 diff. so i wanted to know how much hp and tq it would handle.

is there any "simple" alternative to the E21 diff?

Hi

The b6 diff was just the e21 diff with a larger casing, on my e21 it used to eat diffswith 250HP untill the rear diff was upgraded to an e12 one.

Jason

what modifications you made to fit the E12 diff?

I have some big plans, and from what I heard from Pete aka Redmist,
there is some AUDI diff that will bolt in, can be had cheaply and can handle up to 600 HP.

Pete - aka Redmist knows all the details on this swap. He is on Tricord's site

later,
J

nice tip, thx mate.

I don't think it bolts right in, but does fit with min. mods, and the CV flanges are likely the same dia or should swap easily to the correct ones.

which diff? the audi one, or the E12??

You can always have the diff sent out to be rebuilt. New clutches, bearings and seals, you can even up the LSD or amount of clutches, get the gears REM polished to keep friction and temps down. If the car is off the road now you can send the diff in and not have to cover a core charge on the rebuild. Also we will warrentee the diff after the rebuild.

Good luck with your project!

You can always have the diff sent out to be rebuilt. New clutches, bearings and seals, you can even up the LSD or amount of clutches, get the gears REM polished to keep friction and temps down. If the car is off the road now you can send the diff in and not have to cover a core charge on the rebuild. Also we will warrentee the diff after the rebuild.

Good luck with your project!

John,
I know you are around my area. However, I know a guy with an e30 who
brought his car, and his mother's car to your place.
He told me you guys are very expensive.
He was not too happy of a customer.

Just a curiosity What would it cost for you to rebuild an Audi or BMW dif?
This diff could be the standard 320 is one or a e21 323i one.. for example.
Do you warrenty it for a certain period of time - or to handle a certain amount of HP/TQ?

I'd recommend calling Dan on Monday, he'll be able to give you exact details including pricing. All the differential work is through Diffsonline, we just happen to share space.


John,
I know you are around my area. However, I know a guy with an e30 who
brought his car, and his mother's car to your place.
He told me you guys are very expensive.
He was not too happy of a customer.

Just a curiosity What would it cost for you to rebuild an Audi or BMW dif?
This diff could be the standard 320 is one or a e21 323i one.. for example.
Do you warrenty it for a certain period of time - or to handle a certain amount of HP/TQ?

I'd recommend calling Dan on Monday, he'll be able to give you exact details including pricing. All the differential work is through Diffsonline, we just happen to share space.

You guys are right down the street from my house, I will stop by.

later,
J

Ive heard nothing but good things about BPG and diffsonline. I too am curious to know how much a 320is diff would cost to rebuild. I just need to get the damn thing off the car.

J, i would love to hear any detail you cand find.

Ive heard nothing but good things about BPG and diffsonline. I too am curious to know how much a 320is diff would cost to rebuild. I just need to get the damn thing off the car.

I know this kid who has built e30. He live is MA, and he runs 18s on it, and I have know him for a least a few years. He and his mother took both of their cars to BPG, and he had a extreemely bad experience with them. I would rather not go into it..as its not my car or story ..but basically it was an expensive time consuming process and the result was not to their satisfaction.

As for the cost to rebuild a diff, I will check out and report back to you all.

I blew up one of my 3.90 LSD's at Lime Rock in early 05' and am also interested in having that rebuilt. I'm chiming in to hear the answer! :D

I know this kid who has built e30. He live is MA, and he runs 18s on it, and I have know him for a least a few years. He and his mother took both of their cars to BPG, and he had a extreemely bad experience with them. I would rather not go into it..as its not my car or story ..but basically it was an expensive time consuming process and the result was not to their satisfaction.

As for the cost to rebuild a diff, I will check out and report back to you all.

Ok. I called them and spoke to Dan, they are the same company as BPG.
For the cost its 1125 for either the 3.9 320is diff, or the e21 323i 3.45 diff.
This process takes a week, is warrentied for 3 years, and includes all new bearings and seals. Dan said after its rebuilt the diff should have a 40 percent lock.

So, the good news is that they are literally right down the street. So if you guys need me to drop a diff off to them I can.
The bad news is that I have heard some stuff about BPG that was not good at all. So ..caveat emptor.

Since my diff is still on my 323i, I am going to hold off right now.

later,
J

did you ask them about the Hp and Tq they warrenty?

did you ask them about the Hp and Tq they warrenty?

Yeah..Its not rated for anything more than stock.

Ok. I called them and spoke to Dan, they are the same company as BPG.
For the cost its 1125 for either the 3.9 320is diff, or the e21 323i 3.45 diff.
This process takes a week, is warrentied for 3 years, and includes all new bearings and seals. Dan said after its rebuilt the diff should have a 40 percent lock.

So, the good news is that they are literally right down the street. So if you guys need me to drop a diff off to them I can.
The bad news is that I have heard some stuff about BPG that was not good at all. So ..caveat emptor.

Actually I said it is the same building but 2 distinct companies, different pricing structures and the only similarity is the address. Just want to set the story straight. Staffed by different people.
3 year warranty on the rebuild, on parts and workmanship supplied by Diffsonline.
Just wanted to clear things up.
Not trying to start a pissing match either.

There are stronger lsd carriers out there, but what fails more are the gearsets. The only way to make the gears themselves stronger are with cryo treating and polishing.

Actually I said it is the same building but 2 distinct companies, different pricing structures and the only similarity is the address. Just want to set the story straight. Staffed by different people.
3 year warranty on the rebuild, on parts and workmanship supplied by Diffsonline.
Just wanted to clear things up.

Dan your website and signature list both places.
This is directly from your Diffsonline website:

"We are your Bavarian Performance specialists. Give us a call to learn how else we can improve the performance of your BMW."
http://www.diffsonline.com/images/misc/bpg.jpg

I've been using one of Dan's diffs (3.64LSD w/40% lockup) for almost a year now and I love it. Good stuff!

Jay