Tre Rear Differential Upgrade Service
Jul 14, 2009, 07:13 PM
#332
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As I said, after the TRE rebuild, I had to completely rebalance the car to get it to not be too loose. Nobody with the stock rear diff has that problem, to my knowledge.
Mike
Jul 14, 2009, 07:14 PM
#333
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I don't think ANYONE running Jons rear diff is unhappy. 
It's those looking to get a hold of Jon at TRE that are unhappy.
I hope he gets back to work soon, I want him to do my trans.
It's those looking to get a hold of Jon at TRE that are unhappy.
I hope he gets back to work soon, I want him to do my trans.
Jul 15, 2009, 01:29 PM
#336
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That's because you went from FWD to AWD. When you have a rear wheel off the ground under corning (and you do, with the big sway bar), and you have the stock rear diff with more than one year of racing on it, you are in FWD mode. The rear diff clutch plates are worn to the point where it's basically an open diff, so as soon as a rear wheel lifts, there is no power to the rear at all, hence understeer on corner exit as in any FWD car.
As I said, after the TRE rebuild, I had to completely rebalance the car to get it to not be too loose. Nobody with the stock rear diff has that problem, to my knowledge.
Mike
As I said, after the TRE rebuild, I had to completely rebalance the car to get it to not be too loose. Nobody with the stock rear diff has that problem, to my knowledge.
Mike
Jul 15, 2009, 02:38 PM
#337
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Rear Sway question..thanks!
Thanks to all the replies re: the rear sway...
I will have the same set up with the diff and the ACD flash as well
Thanks Mike,
From others that I've spoke to, 27mm is too big as you said. I'm going to try the 24 mm whiteline adjustable
I have the robispec Group N's which I bought slightly used, so my the rates on these are a bit higher than the CS. (10K-12K I suspect...robi's secrect sauce) so I'm thinking the 24mm will do just fine. I previously ran the same set up as you (robi clubs and a 27mm but w/o the diff)
Trying to get robi to come out to the local track here outside of Pittsburgh (BeaveRun) on a test-and-tune day the end of August/Early Sept. to dial the set up. Diff/ACD/GroupN's and a 2700 lb. race car....lots of changes at once so time to call in the professionals
Use the rear bar to balance the car. With that low of spring rate on a racing application I will guess you will probably want the big bar. Just got back from Mid Ohio and I was running very high rear rates and a bar set on full stiff and the TRE rear diff and the GruppeS reflashed ACD controller and a big rear wing and it felt very neutral on mid corner with just a hint of rotation upon on-power corner exit. . .
EVOlutionary
EVOlutionary
Do not use a 27mm bar with the TRE diff, unless you have really unusual spring rates. I have the 25mm Perrin adjustable, and when I installed the TRE diff the car got so loose that I've spent a year trying to make it neutral. (This is a tribute to the way the TRE rebuild sends power to the rear wheels, not a complaint.)
Anyway, I have now finally got the car neutral again, after increasing the spring rates in the front and setting the 25mm bar to its softest setting (170% of stock) and increasing the rear camber to -2.25. I'm at 14K/16K spring rates F/R by the way. I'm thinking of going back to the stock rear bar, because I'm still getting rear wheel lift until corner exit, and it may be limiting how soon I can go to full throttle.
Mike
Anyway, I have now finally got the car neutral again, after increasing the spring rates in the front and setting the 25mm bar to its softest setting (170% of stock) and increasing the rear camber to -2.25. I'm at 14K/16K spring rates F/R by the way. I'm thinking of going back to the stock rear bar, because I'm still getting rear wheel lift until corner exit, and it may be limiting how soon I can go to full throttle.
Mike
From others that I've spoke to, 27mm is too big as you said. I'm going to try the 24 mm whiteline adjustable
I have the TRE rear diff and the 27mm rear bar, I am not sure what my spring rate is (I have RobiSpec K&W clubsport) with the stock rear spoiler and I love it. The car is great in low and mid speed corners. I have not had a chance to try high speed corners.
Hope this helps
Hope this helps
Trying to get robi to come out to the local track here outside of Pittsburgh (BeaveRun) on a test-and-tune day the end of August/Early Sept. to dial the set up. Diff/ACD/GroupN's and a 2700 lb. race car....lots of changes at once so time to call in the professionals
Jul 15, 2009, 06:48 PM
#340
Thanks to all the replies re: the rear sway...
I will have the same set up with the diff and the ACD flash as well
Thanks Mike,
From others that I've spoke to, 27mm is too big as you said. I'm going to try the 24 mm whiteline adjustable
I have the robispec Group N's which I bought slightly used, so my the rates on these are a bit higher than the CS. (10K-12K I suspect...robi's secrect sauce) so I'm thinking the 24mm will do just fine. I previously ran the same set up as you (robi clubs and a 27mm but w/o the diff)
Trying to get robi to come out to the local track here outside of Pittsburgh (BeaveRun) on a test-and-tune day the end of August/Early Sept. to dial the set up. Diff/ACD/GroupN's and a 2700 lb. race car....lots of changes at once so time to call in the professionals
I will have the same set up with the diff and the ACD flash as well
Thanks Mike,
From others that I've spoke to, 27mm is too big as you said. I'm going to try the 24 mm whiteline adjustable
I have the robispec Group N's which I bought slightly used, so my the rates on these are a bit higher than the CS. (10K-12K I suspect...robi's secrect sauce) so I'm thinking the 24mm will do just fine. I previously ran the same set up as you (robi clubs and a 27mm but w/o the diff)
Trying to get robi to come out to the local track here outside of Pittsburgh (BeaveRun) on a test-and-tune day the end of August/Early Sept. to dial the set up. Diff/ACD/GroupN's and a 2700 lb. race car....lots of changes at once so time to call in the professionals
http://www.youtube.com/watch?v=BYhQvbmfhBY
Jul 15, 2009, 07:24 PM
#341
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Which part of the corner is the car not loose enough? on entry or exit? From that video, it looks like your hands were moving for opposite lock on exits but perfectly stable on entry and mid corner.
I'm hoping that the rear diff is gonna balance things out on exit only.
-heeltoer
PS. one of those corners remind of the nordshleife, awesome!
I'm hoping that the rear diff is gonna balance things out on exit only.
-heeltoer
PS. one of those corners remind of the nordshleife, awesome!
Maybe it depends on driving style, but I've done everything I can to my Evo to make it looser and it's never loose enough for me, including the TRE diff and a 27mm bar. This is with a TRE diff, 27 mm bar, rear toe out, high rear spring rates, etc:
http://www.youtube.com/watch?v=BYhQvbmfhBY
http://www.youtube.com/watch?v=BYhQvbmfhBY
Jul 15, 2009, 07:38 PM
#342
Which part of the corner is the car not loose enough? on entry or exit? From that video, it looks like your hands were moving for opposite lock on exits but perfectly stable on entry and mid corner.
I'm hoping that the rear diff is gonna balance things out on exit only.
-heeltoer
PS. one of those corners remind of the nordshleife, awesome!
I'm hoping that the rear diff is gonna balance things out on exit only.
-heeltoer
PS. one of those corners remind of the nordshleife, awesome!
Jul 16, 2009, 06:22 AM
#343
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Maybe it depends on driving style, but I've done everything I can to my Evo to make it looser and it's never loose enough for me, including the TRE diff and a 27mm bar. This is with a TRE diff, 27 mm bar, rear toe out, high rear spring rates, etc:
http://www.youtube.com/watch?v=BYhQvbmfhBY
http://www.youtube.com/watch?v=BYhQvbmfhBY
https://www.evolutionm.net/forums/ev...available.html
Good luck to you!
