Have you noticed any changes in over/understeer while coming out of corners?
after-market limited slip differential
- Thread starter decio
- Start date
doofus4000
Active member
Im very intrested in this..I too have the 3.0si..how many hours did it take to get your lsd fitted? I would love to buy one but I am afraid of the labour costs being excessively time consumive and therfore high to install. Anyone in the U.K. fitted an lsd to their Z4?
doofus4000
Active member
Taz x said:
no mate - this is what stops our car being any good at it..at the moment say for instance when you are at a junction and you turn left or right and floor it, 9 times out of 10 the inside wheel spins up as the differential is of the open type which more or less leads to most of the power going to the wheel with least grip (the inside wheel). The odd time from a standstill you can get the car to go out. A limted slip differential locks the two output shafts going to the back wheels from the diff when it detects slip so when at the junction again for example you would nicely sweep outwards in drifting type manner as you say. So technically you are not wasting the power by spinning up at that inside wheel with no grip - the outside wheel with most grip gets some of that power giving you overall better traction. So its gives you more grip due to wasting less power or makes it a doddle to get the arse out of the car. The open differential thats in our 3.0si together with the all the dsc crap is useless compared to say one with a lsd for 'drifting' purposes - dsc for safety and lsd for drivers
Yes, oversteer occurs in first stage while banding the corner. For example left corner, before entering the corner i put in third gear and squeeze the throttle a little bit achieving 4000 rev and steer to the left while increasing revolutions. In that moment oversteer begins, the tail starts to drift. All that is needed to exit the corner is to steer to counter side (right) and play with gas pedal waiting for zed's nose to get steady on desired course and than release the steering wheel. in that moment with quaife i even apply more power, and that is it more or less.Incompatible said:
doofus4000
Active member
decio said:
on a scale of 1-10, how much would you recommend this type of mod? are you a daily driver and just want that little bit extra when you get that urge to give it some beans?
well doofus4000, the common opinion is that the clutch type such is in M model are more suited for drifting and the gear type such is quaife and torzen are more suited for drag race it means that quaife gives the best of it self in hard starts and it really is it is a hard kick in your back when you release the clutch pedal and apply a hugh amount of throttle! But as I already explained it suits myself very well even for drifting as I am weekend driver and i don't go on track oftenly and quaife was best product for me. Like I said it is maintenance free, you instal it and forget about it. In normal way of driving it acts like an open diff and when you turn off DSC and turn on Sport mode you can see the real difference. But one thing on which i have to comply is that Mr. Bird told me that the mounting process is not a big deal, but in reality it was not like that. My mechanic which is my friend and a certified bmw and only bmw mechanic told me that BMW don't allow to any body to dismount their differentials. In bmw tis you don't have any diagram of how to open a bmw's differential. He was forced to order specula tools to pull out the bearings because they'r the only problem in this all story...you have to pull them out but not damage them. Any way he manage to install quaife and for now everything is working fine. Don't ask me how much I gave him for the installation! Cheersdoofus4000 said:
decio said:First of all merry christmas to you and all z4-forum friends! Regarding quaife diff...so far so good! I must say that I am still wide awake while driving my zed! I am aware that LSD now is an alien object in my car, but it's working smoothly, activates when it is really needed and at that moment works quietly. I'll wait to pass at least 1000 km, and than i'll change diff oil (it is an opinion of my mechanic whom installed it). I also contacted a friend of mine who's working at Castrol, he will perform a thorough check of my old oil to see if there is any kind of wear or some other changes which indicate that something it wrong. After that I'll close that chapter and once for all and continue to enjoy my beautiful car!Incompatible said:
Merry christmas to everyone dear zed-mates-
. I was also thinking of analyzing oil samples. From my working experience I know that you should compare these results with that of previous oil samples. Also in order to draw a conclusion you should check If your results are within the limits published from BMW. As far as I know there isn't such data available.. 
decio said:
I am also very interested by adding a LSD. My previous car, a Z3 2.8 had a 25% LSD and it was very fun on small turning road!
Your return on the Quaife LSD is very encouraging.
I would like to do the same modification but I have to find who is able to do this sort of job in France. Will not be easy to find a good mechanics.
On the french Z4 club, I have found nobody with such modification. That's why it is interesting to have a look on other forum from other my native one.
After several month using your Z4, are your still enjoyed with the Quaife LSD?
If you get a higher ratio you'll go faster through the gears, so you'll be quicker, but gears are shorter too.
That means that for example if you can now reach 65mph in 2nd and with the new gearset you may reach only 60mph in 2nd, you'll be quicker until the 60mph mark, then you must shift, and between that 60mph and 65mph the old gearset is quicker, but then the old gearset must shift and the new gearset is quicker again. But overall a higher or shorter gearset will accelerate more quickly.
Highway mpg will get worse though.
You can get a quaife (or other brands) lsd's for the automatic diff (ratio 1:3.46), but you'll need an automatic diff. If you buy an lsd you just get the inner core, and you have to use the crown gear, casing etc from the old diff, so you'll need a complete automatic donor diff.
An lsd for a manual (1:3.07 or 1:3.23 for the facelift) wont fit the automatic ratio, so you have to make that choice before you buy the lsd.
That means that for example if you can now reach 65mph in 2nd and with the new gearset you may reach only 60mph in 2nd, you'll be quicker until the 60mph mark, then you must shift, and between that 60mph and 65mph the old gearset is quicker, but then the old gearset must shift and the new gearset is quicker again. But overall a higher or shorter gearset will accelerate more quickly.
Highway mpg will get worse though.
You can get a quaife (or other brands) lsd's for the automatic diff (ratio 1:3.46), but you'll need an automatic diff. If you buy an lsd you just get the inner core, and you have to use the crown gear, casing etc from the old diff, so you'll need a complete automatic donor diff.
An lsd for a manual (1:3.07 or 1:3.23 for the facelift) wont fit the automatic ratio, so you have to make that choice before you buy the lsd.