View Full Version : 3.46 LSD 1 day impressions
bluetree211
12-07-2004, 09:46 AM
WOW :yikes:
I finished the install on sunday, it went pretty well except the diff came with 323 flanges so I was a little worried about getting the pinion nut torqued correctly when swapping the input flange (drive flanges are cake)
The difference is amazing, I can accelerate HARD out of corners with very little wheelspin with no DSC, and even with DSC on it hardly complains. Clutch "chatter" (sounds and feels like a concrete block dragging behind the car) was bad at first but its almost unnoticeable now, and that only happens during sharp low speed corners.
The more aggressive ratio makes the car seem a little faster, but honestly I didn't get the diff for the 3.46, I got it for the limited slip. RPMs are much higher (around 3700 at 80mph) so I honestly would not do this if it was just an open diff. I wonder how the increased torque multiplication would behave in an open diff in 1st or 2nd gear.
Cant wait to try this out during the winter and autocross next year :thumbup:
Congrats! Wish I had the money for an LSD :( . It's a Kaaz unit correct? How much did everything run you? Enjoy it :thumbup:
bluetree211
12-07-2004, 09:56 AM
It's a Kaaz unit correct? How much did everything run you? Enjoy it :thumbup:
Yeah its kaaz, got it from someone for $1200 used. I think the internals alone are normally $1200 plus $300 or so for a carrier, then having them assembled so you could probably get one for $1700 or so with new internals (unless you can assemble it yourself, involves opening the case and shimming the bearings)
Wow... do they only offer 3.46:1?
I had never heard of these guys before this thread.
wag-zhp
12-07-2004, 10:08 AM
Sweet! I'm jealous. I sure do wish limited slip were an orderable option...
Say, does anything have to be done to correct the speedometer when swapping final drive ratios on the E46?
bluetree211
12-07-2004, 10:19 AM
Wow... do they only offer 3.46:1?
Yeah the kaaz internals only fit in the 3.46 carrier
Sweet! I'm jealous. I sure do wish limited slip were an orderable option...
Say, does anything have to be done to correct the speedometer when swapping final drive ratios on the E46?
the ZHP package should have included an LSD...
I'm pretty sure the speedo gets its reading from the DSC sensor on the wheel, so no change is necessary. If I'm wrong, let me know ASAP :rofl:
Yeah its kaaz, got it from someone for $1200 used. I think the internals alone are normally $1200 plus $300 or so for a carrier, then having them assembled so you could probably get one for $1700 or so with new internals (unless you can assemble it yourself, involves opening the case and shimming the bearings)
yeah, I've been keeping my eye on the kaaz units, lots of people are pleased with them (other than the noise, which people say goes away after warm up). Although the m3 lsd would be a nice option as well, the 3.62 is a little too much for my 5-speed. The zhp/6-speed tranny combo comes to mind, but that's just digging a big rabbit hole. Although my neighbor is selling his e46 m3 rear calipers, the 3.62 would be perfect. Once again, rabbit hole :( . Do keep us updated with more mileage though.
bluetree211
12-07-2004, 10:33 AM
...Although the m3 lsd would be a nice option as well, the 3.62 is a little too much for my 5-speed. The zhp/6-speed tranny combo comes to mind, but that's just digging a big rabbit hole...
yeah, I have the 5 speed too, car-part.com doesn't show any available 6 speeds yet, but I'd expect to pay almost $2000 for what amounts to be an added 6th gear for lower gas mileage.
What type of lsd is the m3 differential?
yeah, I have the 5 speed too, car-part.com doesn't show any available 6 speeds yet, but I'd expect to pay almost $2000 for what amounts to be an added 6th gear for lower gas mileage.
What type of lsd is the m3 differential?
http://www.unofficialbmw.com/images/e46m3-2.jpg
Moderato
12-08-2004, 08:16 AM
Sounds like the E90 M3 is going to be sweet.
bluetree211
12-08-2004, 01:49 PM
Sounds like the E90 M3 is going to be sweet.
I believe that m-diff is the one already on the e46 M3
I'm not sure what make the m-diff unique, compared to the kaaz diff, except that kaaz puts friction plates on both sides of the pinion gears. I dont know what the "traditional viscous coupling" is that they mentioned...
Moderato
12-08-2004, 02:30 PM
Sounds like the E90 M3 is going to be sweet.
:slap: :ouch:
KrisL
05-09-2007, 07:24 PM
Bluetree,
What are your 2.5 year impressions?
I'm thinking of a 3.46 LSD and the Kaaz is the least expensive...
Is it only noisy when it's cold AND you've got a wheel slipping?
bluetree211
05-10-2007, 11:38 AM
Bluetree,
What are your 2.5 year impressions?
I'm thinking of a 3.46 LSD and the Kaaz is the least expensive...
Is it only noisy when it's cold AND you've got a wheel slipping?
Fun while it lasted...
The diff locked up on the highway last october, sheering off the pinion nut and leaving a puddle of oil in the breakdown lane where I managed to pull off. I was afraid of transmission/driveshaft damage but everything ended up fine, the tow truck had to *drag* the car onto the bed because the rear wheels were still locked.
I have the stock 2.93 diff on again, and honestly the gearing difference was not huge but the cornering acceleration will be missed. I'm planning to put another LSD in the car next year, but I'll be having a custom built 3.15 put in instead. Until then I'll be saving up, its approximately $4500 from someplace like diffsonline.
Kaaz:
Always noisy, not just when cold, mostly around slow, tight corners. Sounds like you are dragging a concrete block on the pavement behind you. Oil changes are fairly easy, I did them every 5k or so but you're supposed to do 3k which is pretty often and sometimes a pain. They help alot with the noise. In a straight line there is no extra noise.
3.46:
I was getting about 4-5 mpg less with the 3.46 vs. the 2.93. I have a 5-speed which made my "cruising" gear really more like a 4th gear; annoying at first but I got used to it.
Acceleration-wise the 3.46 is slightly faster off the line but you may shift/redline more often depending on the track/autocross setup. Really helped 2nd gear out the most (made 1st gear go by too fast.)
Top speed is affected as well, I never ran into that as I only made ~120mph on the long straight at Tremblant (getting close to 7k redline though.) Watkins glen has a higher-speed straight I believe so you would stop accelerating. This may be irrelevant for you however.
KrisL
05-10-2007, 11:49 AM
Wow, good info. Looks like I'll stay away from Kaaz.
Yeah, I've got a 6 speed, so I'd still be OK cruising. I populated this spreadsheet.. stock zhp on the left (3.07), 3.46 on the right:
http://www.linquist.net/temp/gearcalc-zhp.xls
Ugh, $4k is a lot.
Moderato
05-10-2007, 02:30 PM
Fun while it lasted...
The diff locked up on the highway last october, sheering off the pinion nut and leaving a puddle of oil in the breakdown lane where I managed to pull off. I was afraid of transmission/driveshaft damage but everything ended up fine, the tow truck had to *drag* the car onto the bed because the rear wheels were still locked.
I have the stock 2.93 diff on again, and honestly the gearing difference was not huge but the cornering acceleration will be missed. I'm planning to put another LSD in the car next year, but I'll be having a custom built 3.15 put in instead. Until then I'll be saving up, its approximately $4500 from someplace like diffsonline.
Kaaz:
Always noisy, not just when cold, mostly around slow, tight corners. Sounds like you are dragging a concrete block on the pavement behind you. Oil changes are fairly easy, I did them every 5k or so but you're supposed to do 3k which is pretty often and sometimes a pain. They help alot with the noise. In a straight line there is no extra noise.
3.46:
I was getting about 4-5 mpg less with the 3.46 vs. the 2.93. I have a 5-speed which made my "cruising" gear really more like a 4th gear; annoying at first but I got used to it.
Acceleration-wise the 3.46 is slightly faster off the line but you may shift/redline more often depending on the track/autocross setup. Really helped 2nd gear out the most (made 1st gear go by too fast.)
Top speed is affected as well, I never ran into that as I only made ~120mph on the long straight at Tremblant (getting close to 7k redline though.) Watkins glen has a higher-speed straight I believe so you would stop accelerating. This may be irrelevant for you however.Good review. I suppose from reading this that you're better off doing this if you have the 6sp. Perhaps the 3.37 (IIRC) would be a slightly better up grade then the 3.46 then. Do you really think it's worth the cost to go from 2.93 to 3.15 though?
The diff locked up on the highway last october, sheering off the pinion nut and leaving a puddle of oil in the breakdown lane where I managed to pull off.
:wow:
:(
Nick325xiT 5spd
05-11-2007, 02:21 AM
Good review. I suppose from reading this that you're better off doing this if you have the 6sp. Perhaps the 3.37 (IIRC) would be a slightly better up grade then the 3.46 then. Do you really think it's worth the cost to go from 2.93 to 3.15 though?
I was getting 28+ MPG on the highway in the 323 with a 3.64. (Back when the car had plates.)
My diffsonline diff is dead silent, a thousand times nicer on the street than the E46 M3 diff, and really only discernable from an open diff when I'm standing on it out of a corner.
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