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-   -   Go LSD or stay stock? (http://forum.e46fanatics.com/showthread.php?t=913235)

mrbcc 04-02-2012 03:30 PM

Go LSD or stay stock?
 
Hey all,

My differential pinion bearing is whining at 10+MPH. Took it in and the local shop (great guys, btw) and they quoted me a used diff replacement ("low mileage", 6mo warranty) diff "green-seal" improvement, boot seal replacement, general cleanup, fluid replacement, etc for about $985 (The diff was about $385, other parts about $150).

Asked if I brought in a new LSD and he quoted me 4 hours (~$100). thinking about $1700-2000k for the LSD diff...

So $2100-2400 for the LSD or $1000 for used, stock???

should I bite the bullet? Is the LSD that much of an improvement? what would you guys do?

brett

Jim Murphy 04-02-2012 03:52 PM

Quote:

Originally Posted by mrbcc (Post 14251958)
Hey all,

My differential pinion bearing is whining at 10+MPH. Took it in and the local shop (great guys, btw) and they quoted me a used diff replacement ("low mileage", 6mo warranty) diff "green-seal" improvement, boot seal replacement, general cleanup, fluid replacement, etc for about $985 (The diff was about $385, other parts about $150).

Asked if I brought in a new LSD and he quoted me 4 hours (~$100). thinking about $1700-2000k for the LSD diff...

So $2100-2400 for the LSD or $1000 for used, stock???

should I bite the bullet? Is the LSD that much of an improvement? what would you guys do?

brett

ONLY IF you have increased HP significantly and are experiencing quickly wearing RR tires and/or power cornering less than you like (one squeeling tire).

HTH,
Jim

DHK 04-02-2012 03:57 PM

Little disclaimer I have never driven a car with an LSD.

But in theory an LSD is really only useful in situations where you experience limited grip. So to me for an everyday driving car with traction control, I don't see the usefulness of an investment like this.

mrbcc 04-02-2012 03:58 PM

Quote:

Originally Posted by Jim Murphy (Post 14252032)
ONLY IF you have increased HP significantly and are experiencing quickly wearing RR tires and/or power cornering less than you like (one squeeling tire).

HTH,
Jim

Jim, no current HP gains. I'm mainly a have fun-on-the-street guy with dreams of track time in the future. I read about great improvements in response around the corners, improvements in deceleration handling etc... Would love to be able to turn off the TC and have more control...

jcns 04-02-2012 04:15 PM

Quote:

Originally Posted by DHK (Post 14252052)
Little disclaimer I have never driven a car with an LSD.

But in theory an LSD is really only useful in situations where you experience limited grip. So to me for an everyday driving car with traction control, I don't see the usefulness of an investment like this.

not entirely true.
Once you drive a car with LSD, you will not be crazy about cars without it.
If you are cornering (even on dry roads), and your speed causes the inside wheel to lift, the TC will kick in and slow you down until TC/ECU finds it safe to resume forward acceleration.
Same scenario, with LSD, turn TC off, inside wheel lifts, power goes to the outside wheel and you can keep forward acceleration.

328ci906 04-02-2012 05:09 PM

I wouldn't bother with an LSD. And honestly, you should be able to get a replacement diff for cheaper from a junkyard or even eBay. Shop around, maybe someone else will do this job for cheaper, you never know.

Alex323Ci 04-02-2012 05:28 PM

Quote:

Originally Posted by mrbcc (Post 14252055)
Jim, no current HP gains. I'm mainly a have fun-on-the-street guy with dreams of track time in the future. I read about great improvements in response around the corners, improvements in deceleration handling etc... Would love to be able to turn off the TC and have more control...

yes there are other gains as you mentioned with a LSD. people without or those that have never done just don't understand.

if you don't go with a LS diff then i would atleast suggest going with a lowered gear diff for some gains in acceleration.

i agree with the above post that you should be able to get a used diff installed for less than that quote. $700 would be the max i'd tell anyone to pay with the cost of used diff from an indy.
used diff for $200-$300 and DIY. :thumbup:

Alex323Ci 04-02-2012 05:29 PM

also, are you sure your pinion bearing is going out? have you checked your fluid and or replaced recently?

shanneba 04-02-2012 05:31 PM

Quote:

Originally Posted by mrbcc (Post 14251958)
Hey all,

should I bite the bullet? Is the LSD that much of an improvement? what would you guys do?

brett

I had a Quaife limited slip installed, that is what I would do!!

If you run AutoX, you will have inside rear wheel slip with a 330i/Ci and DSC off.
Even for a daily driver with DSC on, it will intervene less often with a limited slip.
I hated the ECU cutting power when DSC detected wheel spin. I get much much less of that now.

antonmn 04-02-2012 05:33 PM

After having a whole bunch of e30s and e36s with LSD, I find the e46 to be kind of depressing without it. Yeah, the brakes vector the torque around, but it just doesn't feel the same. If the prices were closer, I'd go for it.

How about tacking the labor yourself? Then you'd be all sorted.

Mango 04-02-2012 05:34 PM

My 3.38 (bought used from a forum member--forgot who lol) whines like a B***h at freeway speeds. Brand new fluid in it too and it had about 100k on it when I got it (same mileage as my car as coincidence) and now has 122k or around there. From the research I've done (including contacting Dan @ DiffsOnline.com, it seems that SOME BMW diffs whine, SOME don't. Anybody have a quiet 3.38 on their E46 330? I'm almost certain my butyl tape is in tact too. The indy I had do it (I don't have access to a lift and jackstands scare me) said he didn't drop the driveshaft which means the tape wasn't touched.. which means my diff truly whines.

Or I could put back my silent 2.93... :(

BeMyWhip 04-02-2012 05:35 PM

are you repairing your diff? instead of all that work, why dont you hunt down a used stock diff and just pay the install fee like if you were installing a posi???
maybe get a zhp 3.64:1

lab rat 04-02-2012 05:43 PM

I think it's overkill on a car with stock power output. Here is my experience:
stock 325 with 3.15 diff - no problems with traction
stock 325 with 3.46 diff - no problems with traction
supercharged 325 with 3.15 diff - still no problems with open diff. Turned the DSC off for spirited driving.
supercharged 330 with 3.46 diff - I'm glad I got the Quaife, even with the LSD it's tricky to get some traction.

My vote goes to used diff ($200) and DIY, it's pretty easy swap as long as you stay with the same input flange (I believe the 3.38 from a 330 automatic does).

lab rat 04-02-2012 05:44 PM

Quote:

Originally Posted by BeMyWhip (Post 14252356)
are you repairing your diff? instead of all that work, why dont you hunt down a used stock diff and just pay the install fee like if you were installing a posi???
maybe get a zhp 3.64:1

3.64 is a bit too much if you have a 5 speed

Alex323Ci 04-02-2012 05:46 PM

Quote:

Originally Posted by lab rat (Post 14252389)
ZHP is 3.07

yes in the manual.
but the automatic ZHP gets the 3.64

TX78666 04-02-2012 05:49 PM

My wife was at the track this weekend. She is ridiculously fast. I don't know what her trick is. She just keeps getting better and better.

Actually, I do know her trick. She learns the track, before worrying about going fast. I'm just not patient enough for that. I should learn from her.

Anyway...

This weekend, as she was passing everyone, a couple of instructors commented to their students about how fast she was. One of the students came and found her, to tell her about it. He also said "you were smoking your tires through those corners!"

I told her she needed a limited slip diff, and explained why.

"Nah" she said, "I can still see a lot more places where I can pick up more speed."

So, take that for whatever little it is worth. I think she might have liked hearing that she was putting on a show, as she left people behind. :-)

Alex323Ci 04-02-2012 05:51 PM

Quote:

Originally Posted by lab rat (Post 14252384)
I think it's overkill on a car with stock power output. Here is my experience:
stock 325 with 3.15 diff - no problems with traction
stock 325 with 3.46 diff - no problems with traction
supercharged 325 with 3.15 diff - still no problems with open diff. Turned the DSC off for spirited driving.
supercharged 330 with 3.46 diff - I'm glad I got the Quaife, even with the LSD it's tricky to get some traction.

:banghead::banghead::banghead::banghead::banghead:
why does everyone always insist on thinking this is for take-off traction. a LSD is not only used for take-offs. it's for traction in and out of every turn one makes and also on decel. a LSD is also about handling.

TX78666 04-02-2012 05:53 PM

Quote:

Originally Posted by Alex323Ci (Post 14252424)
:banghead::banghead::banghead::banghead::banghead:
why does everyone always insist on thinking this is for take-off traction. a LSD is not only used for take-offs. it's for traction in and out of every turn one makes and also on decel. a LSD is also about handling.

Yep.

jcns 04-02-2012 05:57 PM

Quote:

Originally Posted by Alex323Ci (Post 14252424)
:banghead::banghead::banghead::banghead::banghead:
why does everyone always insist on thinking this is for take-off traction. a LSD is not only used for take-offs. it's for traction in and out of every turn one makes and also on decel. a LSD is also about handling.

because some people live "1/4 mile at a time".

I agree with you. LSD is for cornering speed (in, middle and out of). Those who just don't get it will never appreciate what a LSD can do.
Even F1 during the pre spec ECU had LSD/active diff.

lab rat 04-02-2012 06:04 PM

Quote:

Originally Posted by jcns (Post 14252466)
because some people live "1/4 mile at a time".

Heh, good one. While I never said anything about take-off traction in my post I will admit that since I don't track my car I have not found the open diff limitations yet.


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