Rear Diff Options - Power Oversteer Found Here
Evolved Member
Joined: Jul 2003
Posts: 638
Likes: 7
As to the why's, check TRE's website referring specifically to clutch dumps etc. but also to a larger bearing and less run-out.
http://www.teamrip.com/HD_SIDE_COVER_UPGRADE.html
http://www.teamrip.com/HD_SIDE_COVER_UPGRADE.html
It's not overkill. The pinion driving the ring gear under extreme loads (clutch dump during drag racing) causes the ring gear and pinion to try to separate. That pushes the diff case apart and puts a TREMENDOUS load on said bearing. John makes a NEW backing plate that allows the use of a MUCH larger bearing to take this abuse.
My bearings on my stock diff after 6 passes down the strip was BEAT. I don't know what the two previous owners did, but I thought I was pretty nice to it. John says it's a weak point and he sees the wear on these units on drag raced cars quite often. His solution was this and I love it. The last thing I want is to be calling a flat bed tow service to tow my car from the race track back to my garage because I puked my drivetrain parts at the track.
My bearings on my stock diff after 6 passes down the strip was BEAT. I don't know what the two previous owners did, but I thought I was pretty nice to it. John says it's a weak point and he sees the wear on these units on drag raced cars quite often. His solution was this and I love it. The last thing I want is to be calling a flat bed tow service to tow my car from the race track back to my garage because I puked my drivetrain parts at the track.
It's not overkill. The pinion driving the ring gear under extreme loads (clutch dump during drag racing) causes the ring gear and pinion to try to separate. That pushes the diff case apart and puts a TREMENDOUS load on said bearing. John makes a NEW backing plate that allows the use of a MUCH larger bearing to take this abuse.
My bearings on my stock diff after 6 passes down the strip was BEAT. I don't know what the two previous owners did, but I thought I was pretty nice to it. John says it's a weak point and he sees the wear on these units on drag raced cars quite often. His solution was this and I love it. The last thing I want is to be calling a flat bed tow service to tow my car from the race track back to my garage because I puked my drivetrain parts at the track.
My bearings on my stock diff after 6 passes down the strip was BEAT. I don't know what the two previous owners did, but I thought I was pretty nice to it. John says it's a weak point and he sees the wear on these units on drag raced cars quite often. His solution was this and I love it. The last thing I want is to be calling a flat bed tow service to tow my car from the race track back to my garage because I puked my drivetrain parts at the track.
Man, I think I'm losing the contest for TRE #1 Fanboy. I better start posting more. Just wait till you see what super-secret new trick he has in store for my transmission. He won't even tell ME, but Jon assures me I will love it. I'm so excited, what could it be!?? 
(not being sarcastic - totally serious here)
(not being sarcastic - totally serious here)
Last edited by EVOlutionary; Nov 6, 2012 at 06:57 AM.
Newbie
Joined: Jun 2008
Posts: 27
Likes: 0
From: San Francisco, CA
I wanted to add that I had the Weir Performance 12 plate upgrade installed into my 2003 Evo. I have a Robispec AST coilover 8k/9k set up with the stock anti-roll bars for reference. It really made a difference. I'm no 'Evonils' (really cool power steering vids on youtube) going around the track now but in the rain if I get belligerent the rear will step out under power when before it would do so only when I modulated the throttle a lot at the traction limit. The cars character is definitely improved. I've done two track days since the install, and I'm looking forward to the next one a lot.
Has anyone gotten a JDM 8/9 RS rear end and just replaced their stock US one? These cars are old enough overseas that it shouldn't be that hard to get one if you had the connections.
Has anyone tried the Weir 16 plate diff upgrade? What are the upsides/downsides vs the 12 plate? On their website they state: "Note, this kit is for serious performance use only and is not intended for your daily driver."
Does this mean it's unsafe to use on anything other than a road course, or that the noise is increased even over the 12 plate? I have read that the 12 plate 'chatters'...
Does this mean it's unsafe to use on anything other than a road course, or that the noise is increased even over the 12 plate? I have read that the 12 plate 'chatters'...
agreed. i can't imagine a reason for more than 12 plates other than for a "hey! look! we fit more plates!" kinda thing.
personally, i plan to do Shep's 8-plate setup. no reason for me to do more than that.
I dont know at which point having more plates is overkill. As with most things, I would imagine there is a point of diminishing returns past a certain amount. Its sort of like the hand held razors, what are they up to like 5 blades? Pretty soon it wont be a razorblade but rather a hand held strip of a dozen blades.