Installed Quaiffe LSD, car pulls right under hard acceleration

[kdog26372]

Got LSD installed a month back. It's a blast around corners and ramps, pulls so much harder without the electronics cutting in. Only complaint is under hard acceleration from stop or even on highway if slightly wet out, the car will pull to the right pretty quickly. I was under the impression the LSD would help keep me straight, but quite the opposite is true. Any reason one tire would be getting so much more traction? Alignment? Tire pressure all the same. It is colder out and I'm on run flats which seem to take forever to warm up and get any grip. Only mod is Cobb stage 1 aggressive.

[xerox445]

Bushing Mis-alignment.

[Pete_vB]

Originally Posted by kdog26372

Got LSD installed a month back. It's a blast around corners and ramps, pulls so much harder without the electronics cutting in. Only complaint is under hard acceleration from stop or even on highway if slightly wet out, the car will pull to the right pretty quickly. I was under the impression the LSD would help keep me straight, but quite the opposite is true. Any reason one tire would be getting so much more traction? Alignment? Tire pressure all the same. It is colder out and I'm on run flats which seem to take forever to warm up and get any grip. Only mod is Cobb stage 1 aggressive.

Alignment? Corner weight?

A limited slip diff will absolutely make the back end squirm around more. Before when you were spinning only one tire you still had one rolling along normally to keep you straight. Now neither one is contributing to that cause, so you expect the rear to be lively. The only question is why is it always pulling to the right? It could be as simple as the crown in the road, but you'd expect a well aligned and corner weighted car to pull either direction depending on which side was getting more traction...

[akak1997]

Check:
Tire Pressure
Wheel bolts torque
Alignment
if you've aftermarket swaybar,namely Hotchkis, make sure the bushing brackets are torqued to spec and the brackets are lined up correctly (slotted hole sucks)

I just got a kick ass deal for a used Quafie and I just got it installed last Friday. My car used to follow every single grove there is on the road, probably because of my -ve camber or alignment overall. After the LSD, the car just drives dead on straight even on roads where the car used follow the groves (there are many on my daily commute). WAY more stable than before. So if you're pulling, it's very likely it's one or combination of the things I mention above and not because of the LSD.
However, if whoever did the install messed up, like one side's seal wasn't seating correctly and it's catching the drive shaft, then maybe it's the LSD. But that probably will cause the car to pull to one side almost all the time.

[duvinclunk]

Out of curiosity, what did it cost including install? (if you don't me asking...)

[Mitch1er]

Originally Posted by akak1997

Check:
Tire Pressure
Wheel bolts torque
Alignment
if you've aftermarket swaybar,namely Hotchkis, make sure the bushing brackets are torqued to spec and the brackets are lined up correctly (slotted hole sucks)

I just got a kick ass deal for a used Quafie and I just got it installed last Friday. My car used to follow every single grove there is on the road, probably because of my -ve camber or alignment overall. After the LSD, the car just drives dead on straight even on roads where the car used follow the groves (there are many on my daily commute). WAY more stable than before. So if you're pulling, it's very likely it's one or combination of the things I mention above and not because of the LSD.
However, if whoever did the install messed up, like one side's seal wasn't seating correctly and it's catching the drive shaft, then maybe it's the LSD. But that probably will cause the car to pull to one side almost all the time.

Glad to hear that your enjoying your new LSD, Herbert. inspect the differential to make sure everything is sitted properly. Do you hear any abnormal noises when accelerating?

[kdog26372]

It was $900 to install at BMW dealer. Car doesn't pull or drift to a side unless heavy acceleration. I am going to get alignment checked though. I also switched back to v301 maps as the v203 map was very torque heavy under the slightest pedal pressure. Loved it, but with cold weather and snow on the way, a less touchy throttle should keep me out of trouble once snow tires put on.

[xerox445]

When is the last time you saw a drag car go straight down the track?

Once again, I feel like I am talking to the wall around here...Now that you are putting the power down...your sub-frame bushings are getting torqued more. Its changing the way the rear suspension is reacting to the road, and considering the multi-link design is already over-constrained, its loading one side up more then the other.

Now that your putting power down more equally, the car is going to also have more torque steer.

I got the powerflex inserts and don't have an issue now.

[kdog26372]

What are the power flex inserts? Your response does make sense as I am getting traction on 1 tire, which is what the LSD is supposed to do, put power to the tire with the most traction, if the flex insert evens it out that would be ideal.

[xerox445]

Originally Posted by kdog26372

What are the power flex inserts? Your response does make sense as I am getting traction on 1 tire, which is what the LSD is supposed to do, put power to the tire with the most traction, if the flex insert evens it out that would be ideal.

Your on the right track, not exactly but whatever. You have to imagine now that the power is being split more equally between both wheels, the whole sub-frame and car itself is going to want to "twist" the opposite way of the drive shaft rotation...Anyway Here is the link.

http://store.powerflexusa.com/bmw-e8...ngs-p1203.aspx



You want number 19 and 20. The SKU for the for auto's is on the first page, the manual set it on the second.

PFR5-419 and PFR5-421 are inserts to be used ONLY with the original bushings (location 19 and 20)
PFR5-420 and PFR5-422 are complete bushings and COMPLETELY replace the original bushings (location 19 and 20)
PFR5-421 Insert fits all models up to 07/2005, then Automatic models only from 07/2005+
PFR5-423 Insert fits manual models 07/2005+

[kdog26372]

Ok cool thanks.

[Dackelone]

I would have your alignment checked. I suspect your car's rear axle is not pointed straight ahead. In other words the rear tires are not pointing truely straight ahead but off in one side(angle). Its known as 'crabbing", like teh way crabs walk. Any alignment shop can check this for you and adjust the toe front and rear.

Perhaps it is your rear subframe bushings. You did not install 1M/M3 sub frame bushings when you had the LSD done?

The power flex inserts do the same thing as the harder M3 bushings... stiffen the rear suspension up and keep everything pointed in the right direction.

[IGoFast1589]

It only pulls when you are on the gas and in low gears either from a low speed roll or a stop? Sounds like torque steer to me also.

Just another thing for you to think about, when I used to load up my old STi with lots of stuff in the trunk and back seats where the rear would sag down a bit it would cause my alignment to toe out a bit in the rear making it want to change directions with even the slightest steering input. Doesn't sound like your situation, but it's something to think about.

[Dackelone]

One other thing it could be is the belts inside the tires being off/starting to sepperate. Try switching your rear tires L to R - and take it for a spin. See IF the car pulls the other direction. Only do this as a test, bc tires are unidirection in most cases.

[xerox445]

Originally Posted by IGoFast1589

It only pulls when you are on the gas and in low gears either from a low speed roll or a stop? Sounds like torque steer to me also.

Just another thing for you to think about, when I used to load up my old STi with lots of stuff in the trunk and back seats where the rear would sag down a bit it would cause my alignment to toe out a bit in the rear making it want to change directions with even the slightest steering input. Doesn't sound like your situation, but it's something to think about.

Same thing happened with my sti. I also remember with r-comps on, you could feel the entire chassis flex coming out of a turn in 2nd gear on boost. heh.

[GeeRam]

I think the OP needs to be more specific about what he means by pulling to the right...?

If he means under hard acceleration from a standstill, he has to wind on a touch of opposite steering lock, then this is normal with a LSD/ATB diff installed compared to an open diff, due to the torque reaction from the engine going to both rear wheels........as mentioned by a few other posters.

[SSIMPS]

my car pulled a bit after getting the Quaife. I got m3 subframe bushings and its all good now

[kdog26372]

Thanks for everyone's input. Getting winter tires on this Friday and having car aligned. But it would seem the bushing or bushing inserts will take care of most of the issues. Just wish I would have done this at the same time as LSD install. Probably just wait till Spring. Already switched to more linear Cobb maps and that helps quite a bit, just seems to be down on power with the newest Cobb map though.