Rear Diff Options - Power Oversteer Found Here
Actually, it isn't like returning it to stock operation. When I removed my diff, two steel plates and two friction plates were side by side, effectively reducing the grip by 50%. That's the way all USDM evos came from the factory. According to the manual, the diff should be set up to have a steel plate between the two friction plates.
Do you realize what your saying? You're talking about custom work that no dealership does, of course it's going to be no comparison between the TRE diff and stock diff, regardless of plate orientation.
I'm simply talking about assembling the diff to specifications, in the manual, that double the friction.
I, in no way, implied that this is as good as or better than their modification.
From my experience, I know that correcting the order of the plates made a world of difference. On street tires, I don't think I would want more lock than what it has now with the plates corrected. I think it would produce too much oversteer, under power. If I was running extremely soft compound tires, I think I would kick it up a notch with the TRE diff and upgrade to the HD parts as well due to the increased force from the tires.
Now at WOT, exiting a turn, when I shift I don't have to correct the steering angle as much, as the rear is already trailing nicely. Its perfect.
You can go overkill as much as you want, it doesn't always make something better.
Do you realize what your saying? You're talking about custom work that no dealership does, of course it's going to be no comparison between the TRE diff and stock diff, regardless of plate orientation.
I'm simply talking about assembling the diff to specifications, in the manual, that double the friction.
I, in no way, implied that this is as good as or better than their modification.
From my experience, I know that correcting the order of the plates made a world of difference. On street tires, I don't think I would want more lock than what it has now with the plates corrected. I think it would produce too much oversteer, under power. If I was running extremely soft compound tires, I think I would kick it up a notch with the TRE diff and upgrade to the HD parts as well due to the increased force from the tires.
Now at WOT, exiting a turn, when I shift I don't have to correct the steering angle as much, as the rear is already trailing nicely. Its perfect.
You can go overkill as much as you want, it doesn't always make something better.
My issue with it donig this was that I felt like the rear end was kicking out too easily. Turn in was still not where I wanted it. I then installed a tanabe front sway bar and then took it out at the same track. I found with my new setup and the front sway bar turn in greatly improved. Before I was going through the s turn at turn 11 at T-hill off throttle, now I found I could go in on the throttle and at a higher rpm in 3 rd gear.
Its all setup dependant, imo. Dont be afraid of the oversteer. If you still find that your not warming up the front tires as quickly as you need, or you now see yourself with too much oversteer, then a fsb might be of benefit. installing an aftermarket one on my evo made a awesome improvement at the track.
I thought before I had maxed out my robispec/kyb combo, but I now found a faster setup that I need to get used to again.
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Joined: Jun 2011
Posts: 3
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From: California
When the plates are installed correctly, you will definitely have to change the LSD fluid at 15k or less, depending on how you drive your car, no different than a upgraded/modified diff. I'm guessing they didn't set it up this way because of service intervals, and noise. Which it isn't really noisy, BTW.
I truly think they set it up this way to reduce customer complaints.
I truly think they set it up this way to reduce customer complaints.
I am glad to see that this info has finally been posted on the forums. The LSD itself was not set up incorrectly from the factory, it was done this way on purpose. As EVO8emUp said above the clutches were arranged this way to eliminate any clutch chatter (noise) from the LSD. It would cost Mitsubishi a fortune in warranty repairs for customers who complain about differential noise. Also, this is not done only by Mitsubishi, other OEMs do the same thing to reduce the noise from clutch type LSD units. This is a big reason a lot of OEMs have gone to Torsen style LSD units in IRS applications, which are nearly silent.
The 8 plate LSD mod, as some people call it, can easily be done by someone who has mechanical skill following the service manual in their garage at home. It’s great info for people who want a better locking LSD without having to spend a bunch of $$. One thing that is important to note that I am not sure if the service manual covers clearly; The OEM LSD unit is a 1 way unit. It is important that the pressure rings or cams are installed exactly as they came out of the LSD. If you get them reversed your LSD will lock on deceleration and not on acceleration, as it should.
I am glad to see that this info has finally been posted on the forums. The LSD itself was not set up incorrectly from the factory, it was done this way on purpose. As EVO8emUp said above the clutches were arranged this way to eliminate any clutch chatter (noise) from the LSD. It would cost Mitsubishi a fortune in warranty repairs for customers who complain about differential noise. Also, this is not done only by Mitsubishi, other OEMs do the same thing to reduce the noise from clutch type LSD units. This is a big reason a lot of OEMs have gone to Torsen style LSD units in IRS applications, which are nearly silent.
The 8 plate LSD mod, as some people call it, can easily be done by someone who has mechanical skill following the service manual in their garage at home. It’s great info for people who want a better locking LSD without having to spend a bunch of $$. One thing that is important to note that I am not sure if the service manual covers clearly; The OEM LSD unit is a 1 way unit. It is important that the pressure rings or cams are installed exactly as they came out of the LSD. If you get them reversed your LSD will lock on deceleration and not on acceleration, as it should.
The 8 plate LSD mod, as some people call it, can easily be done by someone who has mechanical skill following the service manual in their garage at home. It’s great info for people who want a better locking LSD without having to spend a bunch of $$. One thing that is important to note that I am not sure if the service manual covers clearly; The OEM LSD unit is a 1 way unit. It is important that the pressure rings or cams are installed exactly as they came out of the LSD. If you get them reversed your LSD will lock on deceleration and not on acceleration, as it should.
Yeah, thats correct. Best time Ive found to call was tues-fri 11-2 pacific (2 -5 his time). He tends to work late and not early, and doesnt work mondays either.
He might be a little difficult to get a hold of, but its not impossible and he WILL take care of you.
He might be a little difficult to get a hold of, but its not impossible and he WILL take care of you.
Took a while posting this - don't have a ton to say though:
Did an autocross school a few weekends ago - car rotates a LOT on throttle, i really have to modulate if I'm looking for a fast time. car can also rotate a lot on braking/turning. i know a lot probably has to do with weight shifting etc but i don't think my car rotated the way it did off throttle before the rear diff. car felt very good overall. all i want now are coilovers and better tires lol.
Set up:
- Cusco 1.5 way Type RS with TRE's HD Side cover and other goodies, reshimmed, shot peened, sight glass etc etc by Jon
- ACD Reflash by Gruppe-S
- GTWorx Springs and Bilstein HD struts
- WL RCA, Bumpsteer kit, FCA bushings and RTA bushings
- Stock sway bars
ps.....
https://www.evolutionm.net/forums/sa...-hd-il-mo.html
lol
Did an autocross school a few weekends ago - car rotates a LOT on throttle, i really have to modulate if I'm looking for a fast time. car can also rotate a lot on braking/turning. i know a lot probably has to do with weight shifting etc but i don't think my car rotated the way it did off throttle before the rear diff. car felt very good overall. all i want now are coilovers and better tires lol.
Set up:
- Cusco 1.5 way Type RS with TRE's HD Side cover and other goodies, reshimmed, shot peened, sight glass etc etc by Jon
- ACD Reflash by Gruppe-S
- GTWorx Springs and Bilstein HD struts
- WL RCA, Bumpsteer kit, FCA bushings and RTA bushings
- Stock sway bars
ps.....
https://www.evolutionm.net/forums/sa...-hd-il-mo.html
lol
i take both your opinions with high regard - but i'd like to ask why? i've heard of many people who have modded their rear diffs and actually went back to stock sway bars.. and some who still do - while running coilovers.
Swaybars are one of several ways to balance the car. If you add the rear diff and your car is handles how you want it to steady state in corners then you don't need to mess with the rear bar. If in big sweepers the car pushes a lot then you may want to add more rear bar. If in big sweepers the car keeps wanting to come around on you then you may want less bar, less toe out, etc. . .
Swaybars are one of several ways to balance the car. If you add the rear diff and your car is handles how you want it to steady state in corners then you don't need to mess with the rear bar. If in big sweepers the car pushes a lot then you may want to add more rear bar. If in big sweepers the car keeps wanting to come around on you then you may want less bar, less toe out, etc. . .
When I put the diff in my car with an 8k/10k setup, whiteline FSB, and Hotchkiss RSB on full soft I was having a little too much oversteer. It was progressive but a little to aggressive to drive hard with full confidence on course. Both lift and throttle oversteer had the back end moving a lot but it was still pretty easy to catch.
I changed to a 12k/16k setup with the stock RSB, so 50/60% stiffer in spring but 10% softer in RSB. The overall balance mid corner is about the same, slight oversteer (More like a high rear slip angle) but now that I'm not lifting the inside rear I don't have nearly as much lift oversteer and throttle oversteer is very composed.
Although, in the wet its a completely different story. There Id just recommend disconnecting the RSB cause was all sideways action driving at full lock this last weekend.
I changed to a 12k/16k setup with the stock RSB, so 50/60% stiffer in spring but 10% softer in RSB. The overall balance mid corner is about the same, slight oversteer (More like a high rear slip angle) but now that I'm not lifting the inside rear I don't have nearly as much lift oversteer and throttle oversteer is very composed.
Although, in the wet its a completely different story. There Id just recommend disconnecting the RSB cause was all sideways action driving at full lock this last weekend.
When I put the diff in my car with an 8k/10k setup, whiteline FSB, and Hotchkiss RSB on full soft I was having a little too much oversteer. It was progressive but a little to aggressive to drive hard with full confidence on course. Both lift and throttle oversteer had the back end moving a lot but it was still pretty easy to catch.
I changed to a 12k/16k setup with the stock RSB, so 50/60% stiffer in spring but 10% softer in RSB. The overall balance mid corner is about the same, slight oversteer (More like a high rear slip angle) but now that I'm not lifting the inside rear I don't have nearly as much lift oversteer and throttle oversteer is very composed.
Although, in the wet its a completely different story. There Id just recommend disconnecting the RSB cause was all sideways action driving at full lock this last weekend.
I changed to a 12k/16k setup with the stock RSB, so 50/60% stiffer in spring but 10% softer in RSB. The overall balance mid corner is about the same, slight oversteer (More like a high rear slip angle) but now that I'm not lifting the inside rear I don't have nearly as much lift oversteer and throttle oversteer is very composed.
Although, in the wet its a completely different story. There Id just recommend disconnecting the RSB cause was all sideways action driving at full lock this last weekend.
I'm really happy I went through the effort of replacing the FSB. The evo's non-existent camber curve really calls for more roll resistance and I noticed a pretty big difference in front bite though this was before coilovers.