Ideal rear gear for my setup?
3.9 is a regular. I honestly dont think it's bigger or stronger, I just dont think many people drag race on MSM torsens, and the ones that do are mostly stock or bolt ons so they're not making any sort of significant power. just speculation tho
I can tell you 6 sp + 3.9 sucks on the street.
3.6 is noticeably better.
My old 5 sp + 3.9 was wonderful on the street. I miss it dearly.
Its gears 1-4 are similar to a 6sp + 3.3.
The roadstermiata 3.3 group buy is dead.
3.6 is noticeably better.
My old 5 sp + 3.9 was wonderful on the street. I miss it dearly.
Its gears 1-4 are similar to a 6sp + 3.3.
The roadstermiata 3.3 group buy is dead.
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
I grenaded my 4.1 torsen at around 220whp, 190lb/ft. But according to my logs I was nowhere near peak power when it blew. Probably more in the 170-180 in first. Leafy did the same with a lot more power. I was on relatively sticky tires on one of the best drag strips on the east coast. So there was a ton of grip. Wheelhop killed it, I doubt it was power.
Thread Starter
Elite Member
iTrader: (16)
Joined: Aug 2007
Posts: 9,406
Total Cats: 559
From: Houston, TX
The S2000 guys have mods they do to the diffs to handle their big turbo motors. Billet caps, preloaded caps, etc. Search Puddymod.
cap straps

solid crush collar

plus nicer hardware, cryo, REM, bla bla bla.
cap straps

solid crush collar
plus nicer hardware, cryo, REM, bla bla bla.
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
<p>Revisiting this because I think there was false information posted above. The MSM diff is a Torsen, just called something different. Bosch sold the Torsen name so they had to call it the Bosch torque sensing limited-slip rear differential. The rest of the miata line up switched to the TF in 03 but the MSM didn't.</p><p>Which LSD in an MSM [Archive] - MX-5 Miata Forum</p><p>http://forum.miata.net/vb/showthread.php?t=508115</p><p>http://www.s2ki.com/s2000/topic/7755...-differential/</p>






