Rear Diff Options - Power Oversteer Found Here
Sep 12, 2017, 06:26 PM
#1174
In my brain box I was thinking the car would be able to put more power to the ground if dangling a wheel in the air but other than that I'm not sure what I was expecting. The car has low low miles so diff that was in the car was fresh meaning no issues with spinning one wheel. Maybe someone can explain how this diff is superior to a properly functioning OEM rear diff.
FROM POST 1
PROS:
- Power oversteer! Any of these rear diff options will allow the USDM CT9As to do 95% of what AYC can do, while being a simpler, lighter, and more reliable mechanical solution. Any of the aforementioned rear diffs will provide your car enough lockup to completely turn the car around in a tight corner. I've experienced first-hand power understeer before this mod and power oversteer afterwards, with enough capability to do a 180 if I keep my foot planted.
- With that comes the ability to get on the throttle sooner, as well as take a better line through corners for overall quicker times! The car WILL be faster. For anyone who's dealt with the frustration of waiting waiting waiting until they can get back on the throttle, this is absolutely the solution.
- You can set up your cars suspension for maximum grip rather than trying huge rear bars etc to "artificially" coax the car into oversteering and probably end up making the car slower
- Less wear on your front tires! This has been noticeable for a variety of the evo owners so please comment if you've noticed any (you should) - you can keep the steering wheel straight for longer and let the rear do the turning for your car.
- MORE FUN. Breaking the rear tires loose at will is always fun.
I do agree its fun but for me it's not really faster thru turns that didn't require oversteer to complete cleanly. For me I can't get in the throttle sooner .... in fact its the opposite unless you are talking about very low speed cone dodging on a parking lot. My primary use case is big track cold tire time attack.
Sep 12, 2017, 06:40 PM
#1175
i guess it's hard to really tell what it is. you sound like you're in a very low grip environment, and yes i will oversteer in snow making slow turns in second gear. most of us are racing on asphalt or concrete and for that this does as intended. if you're getting that much oversteer i guess i would say to either swap back to stock or change your setup to add more grip to the rear, either through bars or spring
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EVIL_EV0 (Sep 13, 2017)
Sep 13, 2017, 08:23 AM
#1176
EvoM Guru
iTrader: (1)
I run stock front and rear swaybars on my car. Maybe you should try that.
The diff will give you more drive out of corners. You just need to set the car up for it. You had the car setup for a diff that needed help from the suspension to get hte car to rotate. Now you have a diff that does that all by itself, in spades. So you need to rethink the chassis setup a bit.
The diff will give you more drive out of corners. You just need to set the car up for it. You had the car setup for a diff that needed help from the suspension to get hte car to rotate. Now you have a diff that does that all by itself, in spades. So you need to rethink the chassis setup a bit.
Sep 13, 2017, 11:21 AM
#1177
^ this. like i indicated in the first post, i'd do these mods first, then adjust the suspension for the evo to adjust balance accordingly. you can increase the grip of the rear, instead of past setups basically being a big fat bar to get the car to rotate, which is not ideal IMO. i'm still running a WL rear sway bar, on the middle setting at that, and not getting crazy power oversteer.
Sep 14, 2017, 10:26 AM
#1180
If you count that much on decel rotation the car is still set up like a FWD, kind of like it came from the factory. With an aggressive ACD remap and a max-lock diff you should need very little of that driving style ... it is capable of driving almost like a RWD car ... only that you can get on it much sooner and much harder.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
With standard front bar the rear was a bit lively in the rain. The bigger front bar cured that with no adverse effects in the dry.
BTW, with spherical bushings the tire wear with that set-up is spectacular in a good way - very even.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
With standard front bar the rear was a bit lively in the rain. The bigger front bar cured that with no adverse effects in the dry.
BTW, with spherical bushings the tire wear with that set-up is spectacular in a good way - very even.
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EVIL_EV0 (Sep 15, 2017)
Sep 14, 2017, 11:28 AM
#1181
If you count that much on decel rotation the car is still set up like a FWD, kind of like it came from the factory. With an aggressive ACD remap and a max-lock diff you should need very little of that driving style ... it is capable of driving almost like a RWD car ... only that you can get on it much sooner and much harder.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
With standard front bar the rear was a bit lively in the rain. The bigger front bar cured that with no adverse effects in the dry.
BTW, with spherical bushings the tire wear with that set-up is spectacular in a good way - very even.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
With standard front bar the rear was a bit lively in the rain. The bigger front bar cured that with no adverse effects in the dry.
BTW, with spherical bushings the tire wear with that set-up is spectacular in a good way - very even.
Sep 15, 2017, 11:00 AM
#1182
The most important ones are the rear inner bushing on the front LCA (use PSRS or Whiteline part or even Ralliart) and the rear trailing arm bushing (use spherical, Ralliart or urethane - my order of preference) and the rear link bushing that effects bump steer (Whiteline KCA 388).
Stock these bushings are all soft and when you put power on they deflect which causes toe-change and erratic handling, as well as tire wear.
Given that the Evo is an AWD car, under power the front wheels will move towards toe-in under power, setting it slightly towards toe-out will minimize tire wear. The rear, it is my understanding, tends to increase toe-in under suspension movement which the KCA 388 minimizes, especially when lowered. The spherical in the trailing arm keeps it buttoned down and from moving.
The less toe-change you get, the more predictable the handling and the less tire wear.
Regarding excessive oversteer with a Max-lock. Other than being soft in the rear it may also reflect the nose being too low compared to the rear. Some people like their Evo set up that the rear breaks loose at the limit - like a pendulum - to combat understeer but this strategy is in juxtaposition what you try to do with an aggressive rear diff.
Stock these bushings are all soft and when you put power on they deflect which causes toe-change and erratic handling, as well as tire wear.
Given that the Evo is an AWD car, under power the front wheels will move towards toe-in under power, setting it slightly towards toe-out will minimize tire wear. The rear, it is my understanding, tends to increase toe-in under suspension movement which the KCA 388 minimizes, especially when lowered. The spherical in the trailing arm keeps it buttoned down and from moving.
The less toe-change you get, the more predictable the handling and the less tire wear.
Regarding excessive oversteer with a Max-lock. Other than being soft in the rear it may also reflect the nose being too low compared to the rear. Some people like their Evo set up that the rear breaks loose at the limit - like a pendulum - to combat understeer but this strategy is in juxtaposition what you try to do with an aggressive rear diff.
Sep 15, 2017, 03:30 PM
#1184
If you count that much on decel rotation the car is still set up like a FWD, kind of like it came from the factory. With an aggressive ACD remap and a max-lock diff you should need very little of that driving style ... it is capable of driving almost like a RWD car ... only that you can get on it much sooner and much harder.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
FWIW, for a fast road set-up, standard rear bar with bigger front bar and aggressive ACD remap in combination with max-lock diff works for me. Slight toe-out in front and 0 toe in rear with -2.5 camber front and -1.25 rear. Stock Bilstein w/ Robispec springs.
As for the suspension settings, those are, of course, subjective, so it's hard to compare.