[bmwmike]

I've been trying different stuff in safe areas with my car to see if the DTC/DSC electronics functions just like with the regular rear end. I'm not sure yet and have no conclusion. I need more testing and I’ve asked someone to verify the non-Quaife responses with their 335. However, the Quaife introduces some new abnormalities.

In all my comparisons I have left the DTC and DSC on. I’m no expert in this regard and the observations that I state are ones that stand out in my mind.

With the old setup I could push the car hard in the rain or in the snow and the rear end would swing out and stay out from a zero to 50 km/hr acceleration. With the new Quaife setup, the car will swing from side to side in the rain as the torque switches from side to side. I think the Quaife may cause a more unstable car in this situation, but i have no proof. With the regular rear end, the swing out is a gradual predictable thing and you can control its intensity. The darting with the Quaife is sudden and most likely causes unpredictable and unstable shifts of weight with each swing. I haven't had any real experience driving with an LSD since all my cars have been the one-wheel wonders. With the Quaife in the wet, if I apply full throttle it swings back and forth but not more than probably 10 degrees each way.

In the dry, in both instances of acceleration, the car stays straight. I have not noticed if the car accelerates faster with the Quaife in the dry - I doubt it or if it does it's immeasurable by me. It does accelerate faster in the wet and that is obvious.

When you go around bends applying the gas hard with the Quaife you can feel the inner wheel spinning and this causes the car to slip sideways which is undesirable. With the old rear end the car seams to adhere to the limits (with the DTC/DSC computer helping out) and creates more confidence accelerating hard around bends. I've also noticed with the Quaife that sometimes the inner wheel will spin if you start off from zero with not much power and are turning say on to a road from a parking lot.

I tried applying full throttle in 1st gear doing a donut in a safe area and the car just swings around in circles like an F1 or CART victory donut. I have not tried this without the Quaife so I have no comparison. I do remember trying this in my E46 330i and the car computer prevents the car from swinging out.

As expected, there is a light clunk once in a while when shifting into 2nd and letting out the clutch with the Quaife. I suspect the old stock rear end has clutches that may take up the release of torque to the rear end whereas with the Quaife it's solid gears so you get the torque sent right through to the wheels with less loss.

If you drive real nice it feels that the Quaife makes the car more sure footed with an even distribution of power to the rear wheels. I have the weird, seat of the pants, feeling that there is more drag from the rear end - but it's just a feeling and there is no evidence and this contradicts what I said in the previous paragraph.

[2K5 325i]

Not a bad write up!

I'm very curious about the Quaife, and I'm wondering if my driving style would benefit from it, or if i should just go to higher-ration Open (like I have in my E46) or regular LSD, or like previously stated: Quiafe.

Good stuff my man,
-Chris

[pittyinSC]

So how much was it to install and would this affect my factory warranty probably would if something happened to the drive train

[bmwmike]

My installer installed it in 6.5 hours, but they have lots of experience doing this. I'm told that it can take from 6 to 8 hours depending on the experience of the installer and if complications arise. You'd have to apply your own local shop rate to that to get an idea for your cost.

[teknochild]

by the way whats the gearing on that thing?

[bmwmike]

Originally Posted by teknochild

by the way whats the gearing on that thing?

I don't know enough about this Quaife to answer that. Hopefully someone knows?? I'm also crossing my fingers that the Quaife can be adjusted to fix my issues and i'll hopefully find out Monday.

[teknochild]

Originally Posted by bmwmike

I don't know enough about this Quaife to answer that. Hopefully someone knows?? I'm also crossing my fingers that the Quaife can be adjusted to fix my issues and i'll hopefully find out Monday.

you put a new rear differential in without knowing the gearing?

[bmwmike]

Originally Posted by teknochild

you put a new rear differential in without knowing the gearing?

If you are talking about changing the speed from input into the Quaife to output from the Quaife it does not change the speed from what i understand. I'll add that I believe it does slightly change the speed of an inside or outside wheel relative to the other one in cornering or while aiding in obtaining traction.

[teknochild]

Originally Posted by bmwmike

If you are talking about changing the speed from input into the Quaife to output from the Quaife it does not change the speed from what i understand. I'll add that I believe it does slightly change the speed of an inside or outside wheel relative to the other one in cornering or while aiding in obtaining traction.

yea gearing, the one they took out was 3.08, i thought i heard that the LSD was was going to be something like 3.5, but that might have been the other one thats 3k

[Ghunger]

Originally Posted by teknochild

yea gearing, the one they took out was 3.08, i thought i heard that the LSD was was going to be something like 3.5, but that might have been the other one thats 3k

You do realize that swapping an open differential for a LSD doesn't require any change to the final gear ratio?. It basically just bolts into the gears that were connected to the open differential before. Take out old open diff. and gears, remove open diff, connect LSD, reinstall gears and LSD. I doubt his gear ratio changed at all, unless he specifically asked them for new gears.

[teknochild]

Originally Posted by Ghunger

You do realize that swapping an open differential for a LSD doesn't require any change to the final gear ratio?. It basically just bolts into the gears that were connected to the open differential before. Take out old open diff. and gears, remove open diff, connect LSD, reinstall gears and LSD. I doubt his gear ratio changed at all, unless he specifically asked them for new gears.

yea i just took a look, i was thinking it was a whole new unit

[kujo]

Mike,
When will you be having the Quaife adjusted, as ORB instructed ?
I'm curious to hear your opinions on the diff when it's set up properly.

kj

[bmwmike]

Originally Posted by kujo

Mike,
When will you be having the Quaife adjusted, as ORB instructed ?
I'm curious to hear your opinions on the diff when it's set up properly.

kj

I was told that this particular model I have can not be adjusted. It sounds like the Group buy one may well be adjustable or adjusted.

I've never driven an LSD car before so I’m told this is normal and the computer is reacting correctly and effectively to the best of its ability. What I need to do is learn a whole new way of driving and learn to take my car to the limit without over pushing it. Even if I do push it, as long as I leave the DTC and DSC on then I will be fine.
The car tracks real well and feels much more solid and safe with the Quaife if you drive normal to spirited. If you go all out then it acts like an LSD car on crack should. Even though the car fish tales or wags slightly with full throttle, I've realized it's a lot safer then your rear end swinging out into traffic and staying there. Since I’ve driven mostly in rain these last few days I have to say it's waaaaay quicker accelerating from any speed.

I was also told that I need to give it a few weeks to break in. After a couple thousand miles I will be changing the oil in the rear end.

[spesrf25]

So, the DTC and DSC are not disagreeable with the LSD?

[bmwmike]

Originally Posted by spesrf25

So, the DTC and DSC are not disagreeable with the LSD?

I've only had my Quaife in a few days, so time will tell. So far it is interacting and correcting in most situations unless I overpower it, then it tries its best. Birds has had theirs installed for a while with no problems I hear. I'm sure Turner M.P. has tested theirs too for a while.

[Nyulak]

After I modded the engine in my old 98 Crown Vic with FMS LSD, I managed to kill the traction control/abs computer with the additional power. Poor thing couldn't keep up with the added torque. Not likely to happen to the Bimmer, since it is a vastly better car and far more reliable than my CV (see it's dead in the driveway, lol).

[Evo8MRto335I]

price please?

Thanks!

Carlos

[kujo]

Originally Posted by Evo8MRto335I

price please?

Thanks!

Carlos

We dont' have an exact cost for the GB on the LSD yet.

kj

[stressdoc]

Hey Mike, give us some more info on how it works in DTC mode if you could. I seem to hit the DTC button by instinct now, right after seat belt is fastened, but before mucking with the tunes.

[bmwmike]

Well, I’ve had the Quaife in for almost 2 weeks now and I’m getting use to it, enjoying it and appreciating it.

It's been raining the whole time in Vancouver so I’ve only had wet road driving. I can accelerate a lot faster in the wet without seeing the traction control light, even around corners. I've learned to push it to the limit, just short of causing the rear end to get out and wag. I'm sure the performance in the snow would be just as amazing.

I haven't really taken DTC or DSC off. The car control electronics works fine. I've spoken to an M3 owner and he said his M3 rear end acts the same way as my car, so that's reassurance.

For those getting this LSD, and have never driven an LSD car before, I would give yourself time to adapt to the new way the car responds and feels.

I'll give this upgrade a two thumbs up.

[kujo]

Can't wait to get this in my car and hang the arse out......
DTC/DSC will be off in my car quite a bit.

After all my Audi's this'll take me back to my Mustang GT days back in high school...... ;-)

kj

[Inkidoo]

I will love to have an LSD on my 335i, however, I am so not willing to pay more than $2500 installed. I have been told, to install the LSD it might cost me around $1000, but it all depends on what the store is willing to charge you. It is a expensive upgrade. And I will definitely benefit you. Anyone knows about another LSD besides the one? Not the one they are selling for $2700, hell no.