Autocross alignment specs? [Archive] - MX5 Miata Atlanta Owners Club

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JDM88
08-12-2008, 10:38 AM
My alignment seems to be a bit out of kilter since I've put the flyin miata springs and bilstein's on, it looks like it's got more negative camber than the tower of Pisa. What do the autox'ers on here run?

I noticed I had some harsh understeer this last event, I think that might be due to disconnecting the rear sway bar to see how it felt. I think I'll either be putting that back on or buying a bigger new one before the alignment.

Tinman88
08-12-2008, 07:00 PM
What spring rates are you running? The CSP NC is on 400#/300# IIRC, and is waaaay undersprung, but it's also a lot heavier--NAs in STS2 typically run about 700/450. Big front bar and no rear bar and it's VERY neutral, just upsets easily in quick transitions.

I believe when I got it aligned I got something like -2.5*F/-3.0*R camber, as much caster as possible in the front, and a bit of toe out in the front (maybe 1/8" or 1/4" total), none in the rear.

Jack-MX5ATLanta.com
08-12-2008, 07:58 PM
According to their website they're 318 front, 233 rear and they're paired with some Bilstein HD's from the advice of fatcatmotorsports. It's a street and autox setup. I'm currently running without the rear bar but I don't think the rates are high enough in the rear to compensate for the lack of it.

Body Roll isn't really an issue any more, and it remains very steady through corners, it's just when it comes time to dive in and turn it likes to push rather than rotate.

Tinman88
08-12-2008, 08:08 PM
If roll is controlled and it's neutral through corners, you may just be coming into the corners too hot.

"In slow, out fast."

Jack-MX5ATLanta.com
08-12-2008, 08:17 PM
I don't think this was the case where it was hurting the most on the decreasing radius sweeper. I was taking it really wide waiting for the point to turn in, not going particularly fast, and it just kept on going. Should I be more gradual on the throttle? I wouldn't have thought with the power of a 1.8 it would be too much of an issue.

Jack-MX5ATLanta.com
08-12-2008, 08:20 PM
I could do with letting some of the more experienced auto'xers having a run in my car and seeing if its a balance issue or just me. I know for sure there are a few seconds to be cut from my times. I just need to figure out where I'm going wrong. Most likely too fast in the wrong places.

amaff
08-13-2008, 09:44 AM
what run group were you in? I ran in the 1st heat aka the street sweeper heat and all I had was understeer, everywhere. It didn't even dawn on me what the problem was (not really the car, but how I was driving on dirty pavement) until the 4th run group where I ran TO and had a TON more grip just from the course being clean. The front end was biting, and the rear was dancing right where I needed it. I shaved a full second on my 1st TO run in the miata from my fastest time in the morning.


To answer the original question (though I know I posted this on here at some point)
Front
Camber: -2.5
Caster: 4.5-ish
Toe: 1/8" out total

Rear
Camber: -2.0
Toe: 1/16" in total.

Jack-MX5ATLanta.com
08-13-2008, 09:53 AM
I was in the 3rd run group. It could have just been that corner and the general speeds involved. When I was working it I noticed alot of people having issues tackling it. What kind of a balance does that setup give you?

amaff
08-13-2008, 10:40 AM
That combined with the suspension I'm running is very neutral in sweepers, slaloms ALMOST as good as a CRX (puller instead of pusher...), but gives just enough throttle on oversteer (or throttle off oversteer, whichever you perfer)

matthew
08-13-2008, 10:47 AM
On my CSP miata I was running 450F/300R but would have liked something a little stiffer. No rear swaybar.

On mine....

FRONT
camber: -2.0
caster: 4.X (cant remember)
tow: +1/16

REAR
camber: -2.5
tow: -1/16

Roadster
08-13-2008, 10:53 PM
Glad to see you found the forums, Matt.

Did you pick up another Miata?

matthew
08-15-2008, 01:41 PM
Glad to see you found the forums, Matt.

Did you pick up another Miata?


someone buy my subaru please. haha

mustangtomiata
08-25-2008, 04:54 PM
Honestly, it could have been a little bit of both. You could have been over driving but your car also could have just been pushing. amaff was saying there was dirty pavement and that could have been a big factor in your understeer but as far as driving goes be smooth and don't try and go balls to the wall first time out, drive agressively but not 10/10ths and slowly build your speed. Then you will notice when your start over driving. Also coming up to the sweeper was there any braking or was it just an off throttle turn?