[fbsm]

Originally Posted by Liquidpaper

Not really an issue. I was getting the rear end built and the builder asked if I wanted the ratio upgrade -- he recommended it as a lot of the 1 series guys did it. That and the gearing was just too long for my taste. On track, third gear put you at about 110 mph. That is too long for a 7000 RPM redline.

Here is the thing, is the M2 better? Yeah. Is it different enough to warrant getting rid of a perfectly good M240i (in your case) and getting that car? I don't really think so, but your mileage may vary.

I see your point about tracking the car and 3rd gear putting you over a ton......

The M2 is more of a want.....I do love the looks quite a bit better but the 240 clearly suits 99% of my driving better than the M2 would.....and the GF bitches enough about the suspension when I do the long hold of the DSC button.....If I bought the M2 I suspect she would never get in it....oh wait....that might be a feature.......hmmmmmm

In the end I dont think the M2 is worth the extra 15-20k after the desireable car markup.....

[Paisano]

Thanks for the reply Liquid, aggressive tyres btw. Your review has pretty much put me over the edge for buying the M Diff; only problem - super expensive (for a diff.) in Canada.

[Liquidpaper]

Originally Posted by Paisano

Thanks for the reply Liquid, aggressive tyres btw. Your review has pretty much put me over the edge for buying the M Diff; only problem - super expensive (for a diff.) in Canada.

Here is the thing -- relative to most upgrades that people do, it is expensive. But you aren't paying for some off the shelf software or some silicon boards or wiring or whatever. You're paying for a very, very complicated box of clutch plates, gears, bearings, etc. It's going to be expensive.

With respect to the tires, I run 200 TW tires all year round because I live in SoCal -- it never gets below 60 degrees and it doesn't rain too much (except this year). That and I upgraded to 255 tires because there are simply more options than at 245/35.

[XutvJet]

Liquid -

I'm with you on the 3.08 gearing. I feel it's a tad long. Perhaps with a tune, you can make up for the lack of torque multiplication with the 3.08 gear. I will note that while the M2 has a 3.46 gear, it's tires are a bit taller than the ones on the M235, therefore, the gearing on the M2 isn't as improved as your M235 running on what I assume to be stock height tires.

I totally respect your setup. From the looks of it, you're maximizing performance without compromising the motor. The 3.46 diff takes some load off the motor and the aftermarket catted DP let's the motor and turbo breath a bit better. You are not running a tune, right?

I'm thinking about running a very similar setup, but damn, a Diffsonline 3.46 gear with a Wavetrec is $3,400. Man.

[Liquidpaper]

Originally Posted by XutvJet

Liquid -

I'm with you on the 3.08 gearing. I feel it's a tad long. Perhaps with a tune, you can make up for the lack of torque multiplication with the 3.08 gear. I will note that while the M2 has a 3.46 gear, it's tires are a bit taller than the ones on the M235, therefore, the gearing on the M2 isn't as improved as your M235 running on what I assume to be stock height tires.

I totally respect your setup. From the looks of it, you're maximizing performance without compromising the motor. The 3.46 diff takes some load off the motor and the aftermarket catted DP let's the motor and turbo breath a bit better. You are not running a tune, right?

I'm thinking about running a very similar setup, but damn, a Diffsonline 3.46 gear with a Wavetrec is $3,400. Man.

Correct, the motor is on the stock tune. Also, my tire heights are very close to stock (255/35 x 4 is within 1% RD of stock height).

Yes, Diffsonline is expensive. Very expensive. However, you get what you pay for. My differential is as aggressive as one would have for a general use track-differential, but makes no noise or vibration. It's about the best you are going to get short of somehow reverse-engineering the MLSD into the car, which is probably impossible (and prohibitively expensive).

If you plan on keeping the car for a while (like me), its worth it. If you plan on getting rid of it at some point in the near-ish future, it is too expensive.

My goal with this is to get as much as I can out of the car without messing (generally) with the engine. I know that most tunes these days are relatively safe, but the most reliable motor (generally -- not including you 996 Porsche 3.8 IBS bearings) is a stock motor. That and I like the power of the car with this gearing -- its fast enough, but it doesn't want to murder you.

[XutvJet]

Agreed, I'd prefer to capitalize on what's already available and just make it more efficient for performance. What's interesting is that the F3X 3 and 4 series 6MT (same tranny as the M235) 6 cylinder cars come with 3.23s which I guess is because those cars run 1" taller tires. A 3.23 in the M235 6MT would essentially be the same gearing as the M2 6MT (3.46 ratio). I really wish someone could confirm that the 3.23 geared MPE LSD for the 3/4 series was a direct fit into the M235 because it's literally half the price of a Diffsonline unit with Wavetrac and a 3.23 or 3.46 gear. I'd be fine with the 3.23 gear set. I guess I'll look into that.

Otherwise, I think I may go with 3.46 with Wavetrac. I do plan on keeping the car a long while. I may keep the old diff and swap when it comes time to sell. I am annoyed that BMW got rid of the bolt-on axle arrangement. If it had that, I'd do the swap myself. BUT no, in BMW's desire to make things needlessly complex, they've now made it that you need $500+ in special tools to get the axles out of the pumpkin. Dumb.

[Liquidpaper]

Originally Posted by XutvJet

Agreed, I'd prefer to capitalize on what's already available and just make it more efficient for performance. What's interesting is that the F3X 3 and 4 series 6MT (same tranny as the M235) 6 cylinder cars come with 3.23s which I guess is because those cars run 1" taller tires. A 3.23 in the M235 6MT would essentially be the same gearing as the M2 6MT (3.46 ratio). I really wish someone could confirm that the 3.23 geared MPE LSD for the 3/4 series was a direct fit into the M235 because it's literally half the price of a Diffsonline unit with Wavetrac and a 3.23 or 3.46 gear. I'd be fine with the 3.23 gear set. I guess I'll look into that.

Otherwise, I think I may go with 3.46 with Wavetrac. I do plan on keeping the car a long while. I may keep the old diff and swap when it comes time to sell. I am annoyed that BMW got rid of the bolt-on axle arrangement. If it had that, I'd do the swap myself. BUT no, in BMW's desire to make things needlessly complex, they've now made it that you need $500+ in special tools to get the axles out of the pumpkin. Dumb.

I don't really know why the 3 series wouldn't fit -- so long as the splines line up, you should be good to go. Not sure though.

If you wanted a slightly less aggressive rear end, I think Dan can do a 3.23 ratio if you want.

[///CSL]

Originally Posted by fbsm

and there have been times when accellerating in a more spirited manner I can feel one wheel spin and the other get SOME power.....and I find myself wondering if I would have been better off (happier) with something more agressive

Can that be changed somehow to be more like in M2?

[bowhun2r]

How about auto cross? I can see where HPDE would really make a difference. Just wondering if the LSD makes a big difference during an autoX event.
Thanks

[rwalker]

Originally Posted by bowhun2r

How about auto cross? I can see where HPDE would really make a difference. Just wondering if the LSD makes a big difference during an autoX event.
Thanks

The effect of an LSD at autocross can be more dramatic than on a road course, because the turns are often much tighter.

[Liquidpaper]

Originally Posted by rwalker

The effect of an LSD at autocross can be more dramatic than on a road course, because the turns are often much tighter.

QFT. The very tight, low gear turns in autocross will be more likely to light up your outside tire (higher torque, more load on inside tire) than in most HPDE situations. Also, there is more of a need to "get out of the hole" in autocross, which a LSD is very good for.

[THEOS]

Can the MPE LSD for the M235i also be installed on the 228i? I just picked one up and would like to add an LSD.

[Liquidpaper]

Originally Posted by THEOS

Can the MPE LSD for the M235i also be installed on the 228i? I just picked one up and would like to add an LSD.

Depends. The rear end gearing on the M235i is 3.08 (either gear box). On the 228 it is 3.08 if you have the automatic, but 3.9 if you have the manual. If you try installing the MPLSD into the manual 228i, your gearing will be completely screwed up.

[OverRev]

Wow, very interesting thread. I just bought a M235i and took it to the track last weekend. I really want to get an Clutch type LSD and didn't be thing of upgrading the diff. gear ratio, seems like it's the way to go. May I ask Liquidpaper how can you manage to run 255 in the front w/o rubbing? What kinda offset on the front wheel? I am running 235/35/18 on 18x8 ET35 and it rubs a little I had to roll my fender, since I couldn't adjust the front camber... u have camber plate?

[Liquidpaper]

Originally Posted by OverRev

Wow, very interesting thread. I just bought a M235i and took it to the track last weekend. I really want to get an Clutch type LSD and didn't be thing of upgrading the diff. gear ratio, seems like it's the way to go. May I ask Liquidpaper how can you manage to run 255 in the front w/o rubbing? What kinda offset on the front wheel? I am running 235/35/18 on 18x8 ET35 and it rubs a little I had to roll my fender, since I couldn't adjust the front camber... u have camber plate?

My fronts are 18x8.5 ET 38 and I have camber plates with about -2.5 degrees of camber dialed in. Also have my front fenders rolled just for some extra clearance.

[mazerrackham]

Originally Posted by Liquidpaper

My fronts are 18x8.5 ET 38 and I have camber plates with about -2.5 degrees of camber dialed in. Also have my front fenders rolled just for some extra clearance.

Are you running spacers at all? Do you have the M3 LCAs/tension struts? I'd really like to go with the same square setup of 255s all around.

[Liquidpaper]

Originally Posted by mazerrackham

Are you running spacers at all? Do you have the M3 LCAs/tension struts? I'd really like to go with the same square setup of 255s all around.

No, just camber plates. My wheel sizes are the same, but I moved to an ET 45 wheel in the rear (fits better). My alignment settings right now are -2.45 in the front and -2.25 in the rear, with some street appropriate toe in both the front and rear.

[230iZTR]

Originally Posted by Liquidpaper

Depends. The rear end gearing on the M235i is 3.08 (either gear box). On the 228 it is 3.08 if you have the automatic

So it would bolt right up? My parts department guy keeps trying to tell me its not compatible because his computer said so after he put in the VIN <eye roll>