SilviaVsSupra

Hey all. I changed my setup quite a bit during the off-season. Hoping some knowledgeable people can chime in on a good place to start as far as settings.
Here's the setup:

Street driven to AutoX only. No HPDE's or track days as of now.
03 Evo 8 non-AYC
275 slicks (c71)
Camber/Caster Plates
10/12k Springs on AST 4100's
Bigger RSB
Adj. FSB bracket
Roll Center Kit

I am looking for some settings to start with on the following:
Ride height F&R
Camber F&R
Sway bar settings F&R

Dallas J

iTrader: (1)

The C71s are a pretty poor tire to run IMO. You're actually probably better off on some Rivals or RE71s. C71 heat cycles out pretty quick and at that point, they just arent any good (I have run them and pretty much every other AutoX tire). For reference, I see 1.3g on Hoosier A6s and 1.2g on RE71r's logged via RCP3 and Solostorm.

Camber probably suited for around 4deg with your setup, ride height I would just get to around 25.5-26" measured ground to fender up front and 0.5" lower in the rear. Thats assuming a 25.3" tire. You can go lower but CG starts doing interesting things and you can quickly run into the hop issues a lot of us have chased our tails on.

Id just set your from bar to stiff considering your rates, then back to full stiff. Hows that feel and look? Lifting a tire just a little bit or a lot? If a lot, soften bar. If you need more rotation, increase rear tire pressure or rear spring rate.

Overall though, its a solid setup you got there for a street/AX car.

SilviaVsSupra

Dallas, I appreciate your input, very helpful. I do have a follow-up question though.
4 degrees of camber!?
Surprised to hear that much, I expected 3ish. Whats the reasoning?

Dallas J

iTrader: (1)

Yeah, evos need quite a bit of camber especially when lowered. Evo geometry goes in to camber loss pretty quickly because we have a very shallow slider axis angle and control arms go inverted almost as soon as you lower the car. So in roll you're battling tire roll, chassis roll, and camber loss. The fastest ASP guys are running more like -4.5deg of camber.

Even with my corrected geometry and roll stiffness, I still run over 3 deg and have 7.5deg of caster. You can run down in the -3deg range but you'll definitely be working mostly on that outside edge of the tire.

LetsGetThisDone

iTrader: (1)

Yeah, about 6.5* of caster, I run 3 to 3.2* camber with just NT01's. Slicks need more for sure, and you don't have any parts that add caster, so that doesn't help.

I would highly recommend getting with Dallas on some parts to add caster. The rear pivot for the LCA, and coilover top hats at minimum.

SilviaVsSupra

Ok, current alignment:

Camber 3.9*f & 2.9*r
Toe in 1/16" F&R (course is a small kart track this weekend so hoping this will help)
RSB full stiff
FSB bracket 115%

Car feels really good so far, cant wait to see how it does on course this weekend.
I do need to reevaluate tire temps now, was thinking to start around 34 cold. Thoughts?

SilviaVsSupra

No runs, sunny skies turned to hurricane within 15min.. Good ole FL... (anybody remember that Sebring race a couple years ago?).. Anyways, I will update after next event a few weeks away..

Got plenty more work to do with the car;

ABS computer is fried, I guess.. No codes but light is on. Actually no communication at all from the ABS computer, even had the dealer try.. Guess it doesn't matter for competition, I prefer it not interfere but I feel the need to fix or delete it now..

Also have a Weir plate kit and trying to get a front diff as well.

Both kind of messy jobs so I have to decide if now is the right time window...

Butt Dyno

iTrader: (10)

Why 2.9 in the rear? That seems like a lot especially with relatively soft springs.

SilviaVsSupra

Pretty sure that was a typo, 1.9* sounds more like it.. I maxed out the camber on the stock hardware but I don't think they offer THAT much.. can double check.. I want to get a laser alignment done once I get things more or less finalized.

SilviaVsSupra

Ok guys, finally got some AutoX runs in this past weekend. I will try to upload a video but I have some questions.

Tires - struggling to keep my fronts happy. started 38 cold/42 hot, still rolling over the edge a bit too much and one side especially getting too hot on this course. Rears seem ok @ 34c/36h (I verified, running 2.9* camber in the rear. Idk if this is too much, they're a bit cold on the outside but wear on the shoulder is spot on)

Understeer - cannot power out of turns. I am on a open front diff, surely is the main issue. looking to upgrade, Wavetrac seems to be the consensus. Wondering about how much better than the RS it would be, the RS is a fraction of the cost.

Bouncing - Car gets unsettled a bit too easily, causing power delivery to become unsmooth, makes a significant warbling effect. Video I will upload demonstrates this better than my trying to articulate it. Thinking this is the stock motor/trans mounts. Can somebody confirm?


Other than that, car feels great.
Has come a long way since I bought it from a drag racer.

Thanks for the help so far, and for any additional help you guys can offer.

CaptainSquirts

iTrader: (3)

We're kinda setup the same.

My setup is the following...
FA510's 10k front 12.5k rear.
24mm whiteline rsb middle setting.
-3.5 front and -1.5 rear.
Front sway bar cusco bracket set at the stiffest setting.
Roll center kit front
Caster plates up front and super pro duroball offset bushing.

So I need to be at least 42 hot to not roll over on the triangle indicator, even with -3.5 up front. I had bouncing in my rear and I had to decrease the rebound on that end for the bouncing/pogoing to stop. Also if you haven't already, restack the rear diff, that has helped with powering out of corners.

Also you probably have too little spring rate for those tires. They're going to grip harder thus more body roll which = more camber loss.(I think thats how it works).

Dallas J

iTrader: (1)

Just some thoughts from your comments,

If your fronts are overheating and rears aren't then you have to do something to get the rears to do more work. That typically means adding more rear stiffness to take a greater portion of the total weight transfer. Of course you'll never get even heat with the weight distribution and fronts doing steering work, but sounds like the rear can do more work.

Dont optimize rear tire pressure for grip unless you have too much rotation which sounds like you dont. How much front camber? Rear at 2.9 is quite a bit but not the end of the world. Lately ive been using the build up of OPR as an indicator if I need more or less rear camber, 2.1deg was not enough so I'll be increasing to 2.5ish.

10k/12k is still pretty soft for a sticky tire AX car, so theres only so much you can do with pressures. At a point you'll just have more chassis roll than camber.

Understeer out of corners is partially your front diff and possibly driver induced. Rolling into throttle smoother and earlier seems to make quite a bit of difference on the cars attitude on corner exit. Difference between RS and wavetrac is the wavetrac wont break and destroy your t-case. 1way clutch is better, but torsen is ok. Will cause high steering angle push off throttle. Clutch will be open off throttle and lock up better on throttle. Its not an insignificant improvement over the torsen but unfortunately the Mfactory 1way isnt available right now and the cusco is >2k.

Bouncing/Hopping is an evo issue thats tough to truly prevent. But a few things make it worse. Too low on factory geometry definitely makes things worse. The more grip you have the more itll try and hop. Its annoying, but it shouldn't happen on entry as much as on throttle exit. I've only gotten it on entry if front bar was too stiff (at least thats what my memory of that particular setup was different).

SilviaVsSupra

https://photos.app.goo.gl/UTvUya6HWwVAYxzQ8

SilviaVsSupra

Not sure the best way to upload videos but hopefully that link works out.

12-15 seconds in you get the bouncy warbling thing. It did it worse in earlier runs, I was able to control it somewhat by just keeping the car moving smoothly through that section.

29 & 35 seconds I am unable to put power down out of turns due to front end starting to lose grip.

SilviaVsSupra

The rear end was definitely not rotating much at this event, so ill remove some camber and raise the pressure a bit. See how that goes.

Is adding springs +2k F&R worth the while? I don't think I can safely do any more than that with my dampers as-is. If +2k isnt going to cut it, I'll plan for something more.

I do have a weir 12plate for the rear still waiting to go in, which should help with some off throttle rotation but I feel power understeer will still occur when the throttling out of the slow turns.
Jack's Trans has a few RS LSD's fora quarter of the price of a wavetrac, so I am leaning that way but hesitating because I dont want to short myself.