LSD on a zhp

[antcamp]

Who has had experience they can comment from driving a zhp with an lsd? To be honest I know a lot of people are doing the m3 rear swap, but to me buying a used rear from an m3 that has had hard miles is not worth the risk. Im looking to upgrade with quaife, os giken, or kaaz. Not sure which one to get. I can do the work myself just need to get some opinions.




OR WELD SPIDER GEARS!!!

[328ioc]

I personally dont have experience. But a friend of mine has a wavetrac in his worked 335 and he swears by it.

Sent from my DROID RAZR using Tapatalk 2

[BRGcoopahS]

When I first read the title I thought it was about driving a ZHP on LSD.

[zhp43867]

Sna77 has one.

Be careful which aftermarket unit you go with. Some need frequent rebuilds, some make noises, some can cause skiddish behavior, etc.

The best LSD would be one you don't notice in 75% of your driving.

[antcamp]

When I first read the title I thought it was about driving a ZHP on LSD.
yes..... everyone should drive their zhp on LSD.

[zhp43867]

I am going to get a setup on my ZHP this summer I hope.

M3 rear end with a 3.15 clutched rebuild, or a 3.23 in my original casing from diffsonline or performance gearing.

[antcamp]

I am going to get a setup on my ZHP this summer I hope.

M3 rear end with a 3.15 clutched rebuild, or a 3.23 in my original casing from diffsonline or performance gearing.
so youre seroiusly going to spend like 3-4 grand for a rear diff?

[antcamp]

so youre seroiusly going to spend like 3-4 grand for a rear diff?

that was diffsonline rough quote, i just saw performance gearing. their pricing isnt bad

[Vas]

I am most likely will just swap in an m3 rear end

[derbo]

I want to do a performance gearing rear end diff hopefully in the summer. My front differential mount is starting to go, so I might as well replace the 3.07 with a 3.46 with an agressive street/track setup recommended by Jim.

aggressive street/driver's schools : 40% static lock (for maximum inside
wheel spin control, without generating understeer) and 30/50 ramp angles for
the most aggressive dynamic lock during acceleration (40% to 100%), yet
modest dynamic lock during deceleration (40% to 60%)

[Johal E32]

I think M3 rear end is the way to go. 3.64 rear end will really wake up the zhp

It is up to you though, otherwise, diffsonline is a good place from what I hear.

[mr hish]

How much would a non m3 LSD cost??

[Johal E32]

http://diffsonline.com/product/customdiff2.shtml

[derbo]

www.performancegearing.com

[JKO_ZHP]

DID SOMEBODY SAY LSD??? :D :party
Jk. But I have something for you all.
Stare at the center of the GIF below for exactly 1 minute, then look around the room you're in.
Here ya go fellas:
http://25.media.tumblr.com/tumblr_m1r0wq4XT51r2kjgmo2_500.gif

What you just experienced was the effects of LSD.

Sorry for thread hijack.

[Rovert]

I guess you just need an LSD if you frequent rear end slippage or you track a lot. It's not comfortable slipping with an open diff compared to driving an M3. But other than sliding sometimes in a street application I don't see a major need for the expense of 1/3 worth of our vehicle. But if it's not about money and all about just having something more race inspired..no amount of persuasion will make you not do it. LOL.

[derbo]

I guess you just need an LSD if you frequent rear end slippage or you track a lot. It's not comfortable slipping with an open diff compared to driving an M3. But other than sliding sometimes in a street application I don't see a major need for the expense of 1/3 worth of our vehicle. But if it's not about money and all about just having something more race inspired..no amount of persuasion will make you not do it. LOL.


the latter for me :)

[Rovert]

Haha...and the smug grin on your face when you exit a corner under hard throttle oversteer holding a beautiful off-angle while slowly rotating the chassis into a straight line to rocket through the straight away. With an open diff...there would have been a little subframe stress on the recovery and all the points you gathered for style at apex would have disappeared when the back end smacks back into line and jerks the car back straight. LOL

[derbo]

Haha...and the smug grin on your face when you exit a corner under hard throttle oversteer holding a beautiful off-angle while slowly rotating the chassis into a straight line to rocket through the straight away. With an open diff...there would have been a little subframe stress on the recovery and all the points you gathered for style at apex would have disappeared when the back end smacks back into line and jerks the car back straight. LOL

At Buttonwillow CW13 configuration, turn 2 is a heavy 2nd corner off camber hairpin. I lose precious time there when I have to get on the gas slower due to the risk of burning up the inside tire cause of the open diff. I think the major benefit of a rear differential is that you can change the gear ratio higher as well as get a limited slip. IMO all BMWs "performance packages" should have LSD.

While the 3.64 is probably the most optimal for performance (18% increase in acceleration from the 3.07), I think the 3.46 is the most drivable and most compromised. After all this is what the performance package is all about. Compromising some racing performance to gain more drivability on the streets is what I believe the ZHP was meant to do. :) Though, I might be thinking of an M3 now ;)

[mr hish]

Woooow fun doesn't come cheap :p

[Jlastor]

I have an M3 rear end. I would not change it for anything in this world! The 3.62 gear is not to short. All gears feel just right while driving around. Sixth gear at 65mph I at around 2,700rpm. Remember M3's have almost the same gear ratios on their 6sp, and they even go up to 4.10 on the rear end.

LSD should have come standard on the zhp. While must will never use the benefits of it, it is nice to have it when you want to. I probably run once a year on the track (never drag), but I do like having fun on the streets once in a while.

I'd say if you can afford it, go for it! Even with a M3 rear end you are looking to close to $2k.

[Ryans323i]

DID SOMEBODY SAY LSD??? :D :party
Jk. But I have something for you all.
Stare at the center of the GIF below for exactly 1 minute, then look around the room you're in.
Here ya go fellas:
http://25.media.tumblr.com/tumblr_m1r0wq4XT51r2kjgmo2_500.gif

What you just experienced was the effects of LSD.

Sorry for thread hijack.

Kinda close.

[Vas]

So when doing an m3 diff swap, is it worth swapping over the complete rear end or just getting the necessary items and doing it that way ?

[derbo]

So when doing an m3 diff swap, is it worth swapping over the complete rear end or just getting the necessary items and doing it that way ?

It's probably easier just the whole rear end. You already need the whole rear subframe, rear sway bar, diff, m3 axle as the main larger components..

[webster]

Eh it sounds great in theory but i think i would forego all that expense and just get an M3...

[Jlastor]

So when doing an m3 diff swap, is it worth swapping over the complete rear end or just getting the necessary items and doing it that way ?

just the necessary; driveshaft, diff, carrier, and sway bar. But I would also recommend replacing all the mounts on the carrier since they a prone to wear and it is obviously easier to do before installation, and the diff fluid.

No suspension components need to be changed. If you know what you are doing it is possible to do it in a single day (entire day).

[BRGcoopahS]

I think M3 rear end is the way to go. 3.64 rear end will really wake up the zhp

It is up to you though, otherwise, diffsonline is a good place from what I hear.

Wouldn't putting in an M3 LSD totally screw with the gearing of the car? I heard somewhere the car would be revving higher at any speed and ruin gas mileage.

[Hermes]

if you are thinking of driving a car with a LSD then gas mileage should not even be a thought in your mind

[Rovert]

Burn burn burn that rubba!!!

[Hornung418]

M3 rear end with a 3.15 clutched rebuild.
This.

if you are thinking of driving a car with a LSD then gas mileage should not even be a thought in your mind
And This.

The 3.15 Ring and Pinion from an e39 M5 will fit the M3 rear end (210mm) and will keep your power band relatively close to the stock setting. For a car with 1200 less RPM capability with roughly the same transmission ratios, there is no need to keep the M3 ratio of 3.62:1. Any and all available power runs out too quickly without that extra 1200rpm to wring out.

Best of luck with the mod. I've got my sights set on a complete rear (diff, subframe, trailing arms, swaybar, calilpers and rear axles) for $1200 shipped. Just waiting for next year to come rolling in. Should have saved enough cash to overhaul the rear. Been driving far too long on the rear end clunk of death.

[az3579]

if you are thinking of driving a car with a LSD then gas mileage should not even be a thought in your mind

I disagree.
I daily drive my car the vast majority of the time, but I also do 4 track events and 1-2 autocross events per month from March to November. That's a lot of performance driving, and every single one of those driving events I wished I had an LSD. Every. Single. One.

At the same time, I LOVE the amount of revs on the highway with the 3.07. My old car did 3k RPM at 70, which is bad for gas mileage. Considering I drive 33k or so a year on average, you can imagine that most of those are highway miles, meaning gas mileage = very important.

So gas mileage probably won't be important for most of the people here, but it most definitely is to me. If it didn't matter, I'd have an M3. This car is no powerhouse, and having a shorter-geared diff isn't going to make the car a significant amount faster, unless milliseconds and the butt dyno are important to you. For me, if I want the power, I'll just downshift, which is actually more fun to me than the acceleration itself (listening to a perfectly executed downshift is orgasmic with this exhaust). That pretty much nets you the same result, only you don't have to shift as quickly.

[antcamp]

haha performance gearing has a 4.56 available....could you imagine?

[BRGcoopahS]

if you are thinking of driving a car with a LSD then gas mileage should not even be a thought in your mind

Why? My mini has one and so did my 944. Are you trying to say I'll drive the car hard?

[terraphantm]

Wouldn't putting in an M3 LSD totally screw with the gearing of the car? I heard somewhere the car would be revving higher at any speed and ruin gas mileage.

It would be revving higher. Gas mileage would probably be comparable to to a 5-speed 330

Performance benefit would be worth it I think. IMO Euro cars come geared too tall -- I really see no reason one needs to be able to hit 100mph in 3rd gear (and nearly 200 in 6th)

[Hermes]

I disagree.
I daily drive my car the vast majority of the time, but I also do 4 track events and 1-2 autocross events per month from March to November. That's a lot of performance driving, and every single one of those driving events I wished I had an LSD. Every. Single. One.

At the same time, I LOVE the amount of revs on the highway with the 3.07. My old car did 3k RPM at 70, which is bad for gas mileage. Considering I drive 33k or so a year on average, you can imagine that most of those are highway miles, meaning gas mileage = very important.

So gas mileage probably won't be important for most of the people here, but it most definitely is to me. If it didn't matter, I'd have an M3. This car is no powerhouse, and having a shorter-geared diff isn't going to make the car a significant amount faster, unless milliseconds and the butt dyno are important to you. For me, if I want the power, I'll just downshift, which is actually more fun to me than the acceleration itself (listening to a perfectly executed downshift is orgasmic with this exhaust). That pretty much nets you the same result, only you don't have to shift as quickly.


Why? My mini has one and so did my 944. Are you trying to say I'll drive the car hard?

that's not exactly what I meant by my comment... what I was trying to say is on this thread specifically related to converting our open diff cars to LSD that if somebody is willing to spend the money on the conversion, the change in their gas bill should not come in to play due to the much greater cost of the conversion itself.

[sna77]

I have the Diffsonline LSD. With a 3.73 dif. LOVE IT.
http://www.diffsonline.com/

[M0nk3y]

Regarding LSD - Drive a car with one and you will quickly see the benefits of having it. It's totally worth the cost.

3.73 IMO would be perfect. Given that I have a 3.64, I would love to have a 3.73.

Like others said, there is no need to hit 100+ in 3rd gear. Hell, on the track I was topping 4th at 135. It's totally not needed.

With that being said, 3.64 1st gear is stupid short. And if you go to a 3.73 or anything else 1st gear will basically become useless.

[Hornung418]

M3 has a 3.62...

ZHP Auto has a 3.64.

From a GS3, this was sent.

[johnrando]

I thought non-ZHP Auto's had a 3.64 but it was show (just recently) that the ZHPs got a 3.38 (or something like that).

[M0nk3y]

M3 has a 3.62...

ZHP Auto has a 3.64.

From a GS3, this was sent.

Close enough....

[Hornung418]

I thought non-ZHP Auto's had a 3.64 but it was show (just recently) that the ZHPs got a 3.38 (or something like that).

That's the auto verts.

From a GS3, this was sent.

[johnrando]

That's the auto verts.

From a GS3, this was sent.

Yes, I wasn't very clear, auto vert zhps got 3.38. I thought other auto zhps got the 3.38 too. I know auto non zhps got the 3.62. Is that right?

[alexandre]

Auto ZHP sedan/coupe have 3.64. Auto ZHP verts have 3.38. Manual ZHP sedan/vert/coupe have 3.07. Dunno about the rest :biggrin

[Hornung418]

Auto ZHP sedan/coupe have 3.64. Auto ZHP verts have 3.38. Manual ZHP sedan/vert/coupe have 3.07. Dunno about the rest :biggrin
This is correct.

Non ZHP 330 received a 2.93. This is what is currently in my car.

[Johal E32]

This is correct.

Non ZHP 330 received a 2.93. This is what is currently in my car.

you have a 5 speed w/ a 2.93??

How do you like it? Does the car still accelerate quickly?

My 3.46 diff is really best suited with a 6 speed tranny.. lol

[johnrando]

Thanks for the clarifications.

[Hornung418]

you have a 5 speed w/ a 2.93??

How do you like it? Does the car still accelerate quickly?

My 3.46 diff is really best suited with a 6 speed tranny.. lol
Standard equipment, bud. BMW thought it was quick enough. It accelerates fine, but I want a 3.15 LSD.

[Hermes]

the 2002 and the E21 are currently running 3.91 open diffs (stock), I would love a 4.05 LSD for both

[UdubBadger]

Whoops did I read the thread title wrong?

6552

[Vas]

Time to source an m3 rear end. Open diff blows.

[webster]

damn if only i had $7k to drop into the parts and labor for a custom LSD...hmm....

[LivesNearCostco]

I ran into the same problem at Buttonwillow... it felt like a rear wheel (probably right rear, the inside) was hopping as I tried to accelerate out of it in 2nd gear. (Not sure if it happened if I stayed in 3rd gear.) Last month in an AutoX same thing happened in a left turn accelerating out of a chicane in 2nd gear.

I have single-adjustable rear shocks. Anyone know if adjusting rear rebound can reduce this rear wheel hop, or is the only answer to be more careful on the throttle or get a LSD?


At Buttonwillow CW13 configuration, turn 2 is a heavy 2nd corner off camber hairpin. I lose precious time there when I have to get on the gas slower due to the risk of burning up the inside tire cause of the open diff. I think the major benefit of a rear differential is that you can change the gear ratio higher as well as get a limited slip. IMO all BMWs "performance packages" should have LSD.

[danewilson77]

Whoops did I read the thread title wrong?

6552

LMAO

[UdubBadger]

glad someone is willing to put up with my shenanigans

[Vas]

You can try to crank up the dampening on the shocks however the only correct solution is to get an LSD.

I hated the open diff on a wet skidpad.

[M0nk3y]

I ran into the same problem at Buttonwillow... it felt like a rear wheel (probably right rear, the inside) was hopping as I tried to accelerate out of it in 2nd gear. (Not sure if it happened if I stayed in 3rd gear.) Last month in an AutoX same thing happened in a left turn accelerating out of a chicane in 2nd gear.

I have single-adjustable rear shocks. Anyone know if adjusting rear rebound can reduce this rear wheel hop, or is the only answer to be more careful on the throttle or get a LSD?

Adjusting rebound will not solve the issue.

Rebound deals with the sprung weight. You need to adjust compression to deal with unsprung weight, as this is what actually keeps the wheel forced down onto the road.

AKA - You need dual adjustable shocks. Even with that, you will probably encounter the same issue.

[Sockethead]

yep I had that same problem at Beaver Run... I think it was turn 10...that uphill turn before the strait: 3rd gear was too high and 2nd spun the inside rear tire. Very frustrating

[LivesNearCostco]

So I need dual-adjustable shocks and a LSD!

[derbo]

So I need dual-adjustable shocks and a LSD!

LIKE!

[wertyu78]

M3 Rear end swap coming soon for this guy!

[Vas]

Are you buying a complete rear end or just putting the parts together?

Also has anybody successfully run m3 rear wheel speed sensors on the zhp?