Diff nightmare ?
02-11-2005, 06:50 PM
#21
Registered User
Join Date: Dec 2003
Location: Calgary, Alberta, Canada
Posts: 725
Likes: 0
Received 1 Like
on
1 Post
The 240SX rear differential is Nissan's R200 rear diff. This is a design that has been around forever and proven itself to be a bomb proof diff. Variations have ended up in 240's, 300's (not the turbo - that got the R230, which could very well be the most ridiculous and overbuilt diff ever), loads of Infinity's, and the 350Z. The C200 I believe is the solid axle version of this design. The 240 gear ratio is 4.08. The 300ZX got a 3.77 (I think), the 350Z is 3.54. Nismo did make a 4.6 rear end set for it.
The majority of 240SXs in the US have open differentials (no LSD). Those that did get an LSD, Nissan used a Viscous LSD, which is basically a sealed silicon chamber in the LSD. When one wheel starts to spin, the silicon heats up and locks the diff. This has proven to have a limited service life. The sealed units just wear out and the LSD reverts to behaving like an open diff. There are lots of aftermarket companies that make replacement mechanical LSDs. Just drop it into the diff housing and away you go. For those in Canada, ALL 240SXs '91 and newer got a VLSD installed from the factory (due to our lousy weather). The 350Z is still using the VLSD, which in my opinion sucks. We may have gotten an undersized diff in our cars, but at least we got a real Torsen unit.
How do I know all this? I've also got an '89 240 and I dropped out my old open diff for a '92 LSD donor. So I had to research this quite a bit on all the 240 forums.
Something else that is interesting: the LSD diffs had way larger diff fluid reservoirs on them. If you can get a genuine LSD, you'll have about 50% more fluid capacity. Here's a link I set up comparing my old open diff with my newer LSD diff.
http://members.shaw.ca/chrissa/240SX_diffs.html
Ohh, and with the sudden popularity of 240s again with all this drifting, the LSD rear ends are becoming very scarce.
You know, I took a short break from s2ki for a while (been hanging out on thumpertalk.com figuring out my new CRF250R), so I missed a few of the first posts about this type of swap. But this idea has always been in the back of my mind as well. My old 240 open diff is still sitting on the floor of my garage and it often reminded me that this was probably the type of diff our cars should have got. Hell, the 140 HP 240SX got it.
Chris.
The majority of 240SXs in the US have open differentials (no LSD). Those that did get an LSD, Nissan used a Viscous LSD, which is basically a sealed silicon chamber in the LSD. When one wheel starts to spin, the silicon heats up and locks the diff. This has proven to have a limited service life. The sealed units just wear out and the LSD reverts to behaving like an open diff. There are lots of aftermarket companies that make replacement mechanical LSDs. Just drop it into the diff housing and away you go. For those in Canada, ALL 240SXs '91 and newer got a VLSD installed from the factory (due to our lousy weather). The 350Z is still using the VLSD, which in my opinion sucks. We may have gotten an undersized diff in our cars, but at least we got a real Torsen unit.
How do I know all this? I've also got an '89 240 and I dropped out my old open diff for a '92 LSD donor. So I had to research this quite a bit on all the 240 forums.
Something else that is interesting: the LSD diffs had way larger diff fluid reservoirs on them. If you can get a genuine LSD, you'll have about 50% more fluid capacity. Here's a link I set up comparing my old open diff with my newer LSD diff.
http://members.shaw.ca/chrissa/240SX_diffs.html
Ohh, and with the sudden popularity of 240s again with all this drifting, the LSD rear ends are becoming very scarce.
You know, I took a short break from s2ki for a while (been hanging out on thumpertalk.com figuring out my new CRF250R), so I missed a few of the first posts about this type of swap. But this idea has always been in the back of my mind as well. My old 240 open diff is still sitting on the floor of my garage and it often reminded me that this was probably the type of diff our cars should have got. Hell, the 140 HP 240SX got it.
Chris.
02-11-2005, 07:00 PM
#23
Registered User
Join Date: Feb 2002
Location: Virginia Beach, VA
Posts: 13,065
Likes: 0
Received 0 Likes
on
0 Posts
Another question... how far do we want to take this? As much as I want an invincible diff I can't help but wonder: Won't a truly bomb-proof diff just transfer the shock to something more expensive?
Where does it end?
Where does it end?
02-11-2005, 09:00 PM
#29
Registered User
Join Date: Nov 2004
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by yellowknockers' date='Feb 11 2005, 05:42 PM
Wonder if I can jump in and get feedback from you folks on the drivetrain set up I'm looking at longterm, would be for about a 400-500hp S2000 with no plans for drag use. Planned use would be mostly for street driving and the occasional track outing.
I already have the Comptech reinforced pumpkin, 4.77 gears and a Cusco RS LSD.
I'm probably going to add to that a Level 2 or 5 axle and driveshaft from The Driveshaft Shop.
I already have the Comptech reinforced pumpkin, 4.77 gears and a Cusco RS LSD.
I'm probably going to add to that a Level 2 or 5 axle and driveshaft from The Driveshaft Shop.
