04-01-2017, 01:28 PM | #1 |
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
Location: NY
Posts: 17,475
|
E46 LSD options
I'm trying to pick an LSD for my car. I'm leaning toward the MFactory helical, but I'm just not excited about it. I like the idea of quiet and low-maintenance, but am wondering how often I'm going to end up spinning one wheel anyway (I did get a stiffer rear bar...) If I could find a quiet clutch type I could be convinced to jump to that instead.
Nick, didn't you have a diffsonline diff? Was it noisy? Did you like it? Options thus far: MFactory helical / torsen: MFactory highly recommends for a street driven car. They downplay the odds of spinning one wheel and say you'll love it. MFactory 1.0 or 1.5 way: MFactory says they're noisy and not recommended for street Wavetrac: A helical that supposedly prevents wheel spin during lift. Sounds ideal in theory... but JV heard bad things about them diffsonline: Their site tells me very little OS Gilken: double the price and require more frequent oil changes. Last edited by rumatt; 04-01-2017 at 01:46 PM. |
04-01-2017, 01:43 PM | #2 | |
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
Location: NY
Posts: 17,475
|
I just noticed that diffsonline sells clutch-type as well as helical and wavetrac. I emailed him to ask his opinion on all of them.
EDIT: Got this reply right away from dan. Not particularly informative (?) Quote:
Last edited by rumatt; 04-01-2017 at 01:59 PM. |
|
04-01-2017, 02:13 PM | #3 |
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
Location: NY
Posts: 17,475
|
|
04-01-2017, 02:31 PM | #4 |
Relic
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 12,490
|
I have two diffsonline units. One of them I bought used, and it slightly whines (it may have had the input flange swapped, which can cause pinion whine if it's done wrong). The one I bought new is in the race car and it's been great.
We just installed a (used) wavetrac unit in Mike's E90, but haven't driven it yet. It does spin both wheels in the same direction on the lift, but I can't speak to how it behaves in reality. OS Giken has been incredibly unreliable in E46 applications. Failure after failure after failure is what I hear. I would not consider it. The upshot of helical is that it gives you a basically completely clean steering response. Clutched diffs will be a lot more likely to impact steering in some way. Helical diffs also basically don't wear out, which has some virtues. Personally, I really like the way that the 30/90 diffsonline units drive. On a street car, this is less of a factor though. I wouldn't have done the E36 diff if it hadn't been fairly cheap.
__________________
2011 M3 2006 Sierra 2500HD 4WD LBZ/Allison 2004 X5 3.0i 6MT 1995 M3 S50B32 1990 325is 1989 M3 S54B32 Hers: 1989 325iX 1996 911 Turbo |
04-01-2017, 02:41 PM | #5 | ||
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
Location: NY
Posts: 17,475
|
Quote:
Quote:
He doesn't allow anyone else to install his diff internals. |
||
04-01-2017, 02:49 PM | #6 |
lawn boy
Join Date: Oct 2003
Carmudgeonly Ride: e46m3, f25x3,C5 Z06, C4 Vette, 06 CTD Ram, and a trailer
Location: Maryland
Posts: 14,029
|
Where is the option to just do whatever JV says?
I had a helical in the front of a Jeep for years, never even knew it was there. That said, I can't imagine noise would ever be an issue for you on any diff. It's not like this is some quiet new luxury car. |
04-01-2017, 02:59 PM | #7 | |
Mugwump
Join Date: Oct 2003
Carmudgeonly Ride: E46 330i, Chevy Colorado, Tesla Model 3
Location: NY
Posts: 17,475
|
He told me I had to pick.
Quote:
|
|
04-01-2017, 03:16 PM | #8 |
lawn boy
Join Date: Oct 2003
Carmudgeonly Ride: e46m3, f25x3,C5 Z06, C4 Vette, 06 CTD Ram, and a trailer
Location: Maryland
Posts: 14,029
|
Well, I'd do a clutch type and live with the noise. If you want quiet and maintenance free, get a helical.
|
04-01-2017, 03:51 PM | #9 |
No more BMWs
Join Date: Apr 2005
Carmudgeonly Ride: Ram, MS3, CX-5, RX-8
Location: Glenwood, MD
Posts: 14,753
|
OS Giken is discontinued. They had to spec an undersized unit for the E46 because the case is so narrow. That ended up being a bad idea.
Jim Blanton (Performance Gearing) and Dan ( Diffsonline) will sell LSDs but only Jim will let you do the install and setup. I have dealt with Jim a lot and he is very quick and reliable. I've bought parts from Dan (crush sleeves and a set of gears way back) and he's fine too. Here is the deal. I would not put a helical in my car for the street. I thought the wavetrac would be a "best of both worlds" thing but what I'm hearing is they aren't great. They end up acting like an open diff in about the same conditions as a helical. The clutch type diffs should never make pinion or gear noise. That is purely setup error. Going down the road straight or around turns at speed you will never hear it. Clutch type diffs will make noise in tight parking lot maneuvers at low speeds. First, you'll hear the inside tire skidding as the clutch plates are trying to equalize the speed of the rear tires. Second, you may sometimes hear the clutches clunk a bit. Both of these noises can be minimized but not eliminated if you want the LSD to actually work. Clutch noise gets worse the more static preload the diff has. I had Jim build my diff with 90lb-ft of preload and I run Redline shockproof oil with no additive... super thick gear oil. The MFactory diffs will have much less preload than that. I'll also put some friction modifier in the fluid to reduce the clutch noise and we'll run Redline 75/90 standard fluid which is thinner. I'm happy to put a Blanton diff in there, but it's double the price of the MFactory unit and I don't think you'd be any more happy with it than the MFactory. The MFactory set up as a 1.0-way diff should be similar to Nick's 30/90 ramp diff. A 30 degree ramp on acceleration and a 90 degree ramp (it's probably like 85 degrees in reality) means it'll lock up very hard on acceleration and be almost entirely open on decel, which is great for a street car or autocross car. |
04-01-2017, 05:06 PM | #10 |
lawn boy
Join Date: Oct 2003
Carmudgeonly Ride: e46m3, f25x3,C5 Z06, C4 Vette, 06 CTD Ram, and a trailer
Location: Maryland
Posts: 14,029
|
Yup, I've had clutch diff's in many cars, no reason not to go that route imo.
|
Bookmarks |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
vehicle options I'd like to see | wdc330i | Car Talk | 23 | 06-10-2008 08:40 PM |