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1-Way vs 1.5-Way Rear Differentials

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Old Oct 17, 2018, 01:44 PM
  #76  
kaj
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Originally Posted by bee-raddd
You seem very undersprung Kaj if your 9k front 10k rear. have u tried cranking it right up to like 14kf 16kr? might solve your inside tire lifting at least. Ive just gone 16kf 20kr on mine. i think dallas runs even more
Honestly, the car has always worked well. My lap times are pretty decent, considering my skill level, and I'm not too hard on tires, really. The most popular rates seem to be 10kF and 12kR, I'm not too far from that. I think I'd like to try the traditional 2k difference between F/R, though. I started out 8/10, then to 9/10 to try and decrease the roll I was getting when I try AX events. Or so I THOUGHT but turns out I was sold the wrong springs LOL. I'm currently at 10/10 which possibly explains why the car drives like *** after the spring swap
Old Oct 17, 2018, 01:46 PM
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1-Way vs 1.5-Way Rear Differentials-x9duvcu.jpg
Old Oct 17, 2018, 01:50 PM
  #78  
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I'm waiting to hear from AST as to where my valving is. I'll only run as stiff as allowed, until they need a rebuild. Then I'll have the valving redone (Or start over with a fresh set of Ohlins).
Old Oct 17, 2018, 03:26 PM
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Originally Posted by Dallas J

I second the above! hahaha
Old Oct 17, 2018, 04:40 PM
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Originally Posted by bee-raddd
I second the above! hahaha
Old Oct 18, 2018, 12:22 PM
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FYI, ordered the 55/3 OSG. OSG let me know that's probably too aggressive on the accel side, due to the OSG's ability to lock up "more efficiently" than the Cusco. Not sure how true that is, but we'll see. If it's "too much" for the car, all that really means is I'll need to get on the throttle more progressively.
Old Oct 18, 2018, 12:34 PM
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Nice! I really want to go the OSG route, but dang.. they are so pricey. Worth it I'm sure, though. Maybe it will be my next big investment.
Old Oct 18, 2018, 12:36 PM
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yea, it's an additional 150 for a custom setup like i'm doing.. but rarely do you have to pay msrp on them...
Old Oct 18, 2018, 02:07 PM
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Originally Posted by kaj
Honestly, the car has always worked well. My lap times are pretty decent, considering my skill level, and I'm not too hard on tires, really. The most popular rates seem to be 10kF and 12kR, I'm not too far from that. I think I'd like to try the traditional 2k difference between F/R, though. I started out 8/10, then to 9/10 to try and decrease the roll I was getting when I try AX events. Or so I THOUGHT but turns out I was sold the wrong springs LOL. I'm currently at 10/10 which possibly explains why the car drives like *** after the spring swap
i ran the opposite 12k/F and 10k/R on my car and I liked the way it handled.
Old Oct 18, 2018, 02:30 PM
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still looking for help in thinking about this - with too much ramp angle, in mild throttle, steady state, etc. if the wheels are continuously traveling in a large arc and need wheel differentiation, would any amount of mild throttle + a high ramp angle = understeer? OR will the mild throttle try to shift the torque to the outside wheel, "helping" in steady state, or will they simply try to lock together and create understeer?

i think they will create understeer - so high cam angle (aggressive) pro - power oversteer on high torque, con, light-power understeer everywhere else?

This is really some black magic ****. I guess too much ramp will create too much lock on part throttle, meaning understeer, which is the opposite of what I'd want - on part throttle I'd like want the diff open, so they aren't trying to lock the wheels together. Only on full-on accel would I really want the diff locked.

Last edited by kyoo; Oct 18, 2018 at 04:02 PM.
Old Oct 18, 2018, 04:01 PM
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Hard to say until you drive it.
Old Oct 18, 2018, 04:09 PM
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agreed. i THINK you'd almost want it open everywhere but full accel, which then would mean low cam angles, which seems counter to everything everyone does for an "aggressive" diff
Old Oct 18, 2018, 04:13 PM
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You want it progressive, not all at WOT or nothing. It's something you'll have to test.
Old Oct 18, 2018, 04:54 PM
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right, so that's in part determined by the cam angles - lower the number, the more progressive it will be. in the case of the cam angle then, i'd want something lower, not higher.

after speaking with them on the phone again, im going to give some variation of their 1.5 way diff a try (38 accel/25 decel).

what we are essentially wanting is open on turn-in, very mild on mild throttle, and close to full lock on WOT corner exit. they're adamant that even their 1.5-way diff will essentially be open on turn-in/coasting/light braking scenarios, even trail braking. on the steady state side, we don't want the wheels to lock at all IMO - that will just create drag between the inner and outer wheel. Then, when we put the hammer down, we want powa oversteer!! or just good lockup to help corner exit.

I'll give it a shot, and if it's too pushy/not doing enough, I can get it re-adjusted for my needs.
Old Oct 18, 2018, 08:40 PM
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Keep track of how light the inside rear is. Off the ground and any lock with throttle is oversteer (corner exit). Nearly equal weight across the axle and any lock is understeer (corner entry).


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