[TSM330i]

I finally got my LSD from Dan at Diffsonline installed. I got 3-disc, 40% carrier with 3.38 rear gears. Everything was new including the diff. I sent mine back for a core. They offer 3.64, but I think this is too high based on my experience with the 3.38 (stock is 3.15).

First off – oversteer is possible with these cars! Yes, it is possible and you can balance the car mid-corner much easier than with the open diff. This is the main reason I got the LSD (the balance part).
Second - It makes the car more drivable and quicker coming out of corners. You can get on the gas earlier coming out of the corner and not worry about burning off the inside tire. Also, pulling out from a stop while turning (at a T-intersection) is better as well. The traction control doesn’t kick in and slow you down as you’re trying to get out of someone’s way.
Third – acceleration is a bit stronger than stock. 60mph is achieved right at the top of second gear or perfect timing if you want 0-60 (this may vary slightly based on the diameter of your tires – I’m running 265/35-18). Roll-on in top gear or 5th is much better and speed is picked up rapidly. 4th gear seems more like a power gear as things happen much quicker and speed builds very well. At 80mph the tach is ready exactly 3,000rpm. At 60mph, it’s about 2,400rpm.
Fourth – by increasing gearing by 7%, I haven’t seen any difference in fuel mileage. This is a good thing for sure and a nice bonus.
Fifth – I went with Diffsonline after noticing may top race teams using them. I spoke to the Bimmerworld team at the 12 hours of Summit and they had nothing but high praise about the quality of their products. This sealed the deal for me.

Overall – I’m very happy with this modification. I’ve been driving around with it for over 1 week and am really getting more and more used to it. It is an expensive mod no doubt, but for driver involvement it’s something you feel all the time and it really affects the car in a good way. It makes the car much more of a true sports car being able to adjust it mid-turn and to drive harder without worrying about spinning the inside tire. In two weeks, I’ll have feedback from the track (NJMP). I have my Stoptech’s on for this track session as well so more feedback will be available.

Stay tuned….

[MMAJNKE]

how much did the lsd run you installed

[TSM330i]

Originally Posted by second_2_nun

how much did the lsd run you installed

$3300 for the Diff, install was 2.5 hours (so $200).

[Synergy]

now update your sig

[Pyrat 2]

Welcome to the club. I had mine built by Performance Gearing. I too went for the 3.38. I really wanted a 3.46 but that gearset was not available. Did he add a drain plug so you can swap out the fluid easier?

[TSM330i]

Originally Posted by HeelToe

Welcome to the club. I had mine built by Performance Gearing. I too went for the 3.38. I really wanted a 3.46 but that gearset was not available. Did he add a drain plug so you can swap out the fluid easier?

No drain plug. I'm not sure how often I'm going to have to change the gear fluid. It shouldn't get that hot on the short track sessions I run.

Thanks and yes, I wanted 3.46 as well. I really think the 3.38s work well and are definitely worth it.

You and I have VERY similar taste. Nice wheels!

[mike-y]

so you are saying 6th gear at 80mph is 3000rpm? sounds pretty nice.

btw, what size front tires do you have?

[TSM330i]

Originally Posted by mike-y

so you are saying 6th gear at 80mph is 3000rpm? sounds pretty nice.

btw, what size front tires do you have?

In my post: 265/35-18 rears and yes, 3,000 exactly at 80mph.

[J.]

Seeing this thread I feel that most ADVAN RS owners all buy LSD!!

Jon

[Pyrat 2]

Originally Posted by J.

Seeing this thread I feel that most ADVAN RS owners all buy LSD!!

Jon

Next question is why?

My guess is we're looking for real performance benefits. 18 inch Advans are 19ish pounds compared to 26 or 27 for OEM wheels. AND they look sic IMO. This lighter weight will increase performance (and responsiveness) as will the LSD with an increased final drive ratio.

I see a lot of other nice looking wheels and mods on this forum but most are more for show and actually decrease the performance (19 inch 25 pound wheels come to mind compared to 18 inch 25 pound wheels).

[TSM330i]

Originally Posted by HeelToe

Next question is why?

My guess is we're looking for real performance benefits. 18 inch Advans are 19ish pounds compared to 26 or 27 for OEM wheels. AND they look sic IMO. This lighter weight will increase performance (and responsiveness) as will the LSD with an increased final drive ratio.

I see a lot of other nice looking wheels and mods on this forum but most are more for show and actually decrease the performance (19 inch 25 pound wheels come to mind compared to 18 inch 25 pound wheels).

Ding, ding, ding - we have a winner!

[mike-y]

Originally Posted by AW325xi

In my post: 265/35-18 rears and yes, 3,000 exactly at 80mph.

thx, though I asked about the fronts.. but it may be moot, I can't seem to find out where the e90 gets it speed signal from, the front wheels, rear wheels, or from the diff?

[TSM330i]

Originally Posted by mike-y

thx, though I asked about the fronts.. but it may be moot, I can't seem to find out where the e90 gets it speed signal from, the front wheels, rear wheels, or from the diff?

Ah, definitely wheel sensor, but not sure which one. I'm running 245/35 up front.