jlwdvm

Time for my first autocross with my complete Strano package on my 2011 gt: Koni yellows, Steeda sport springs, adjustable sway bars, etc. When taking a hard sharp corner with the shocks on 3 turns out and the bars in the middle hole the car seems neutral to a little loose if I get onto the gas harder (BAMA tune). I adjusted the toe to zero and I can adjust the camber with my Steeda HD camber plates. What should I set my camber too, shock settings, bars? Any thoughts?

darksky1984

A lot of guys like to run as much front camber as possible. If you can get around -3 degrees that would be optimal. I adjust my yellows with 2 full turns up front and 1.5 turns in the back. I'm not sure about the sway bar settings though. Good luck.

Norm Peterson

I'd leave the bars where they are, at least for now. I didn't think Konis had 3 full turns of adjustment, but anyway I'd suggest setting the rear shocks half a turn or so softer than the struts

Do you know where your cambers are at now?

For better throttle modulation at the smallish throttle openings you'll see at autocross cornering speeds, you may well be better off getting some of the throttle response from that tuned out.

What you want at autocross and to a lesser extent out on the big tracks is pretty much opposite to what the drag racers and street racers/racer wanna-be's want. They want response that is at least as fast as they can move their foot down, but at autocross you want the initial response to be slower so that it doesn't get ahead of you and put you into the beginning of wheelspin.


Norm


Norm

Whiskey11

I run my Strano bars at full stiff in front and the middle position in the rear. Watts link is in the 2nd from bottom hole. I use D-specs for dampers though. Front camber is -1.7 degrees with no toe and +7.5 degrees of caster.

The car feels pretty neutral in steady state and maybe just a touch of oversteer. Usually any throttle input more than already being used results in the rear end coming loose and the only appreciable understeer comes from braking too hard or from overcooking the corner entry. I'm also on different tires at 245/45/18 star specs at 31 psi front and 32 psi rear.

I'm not sure how that set up will work with different tires and dampers though.

safetyfastgt

Whiskey, is that the cold pressure your running at autocross? Seems low since lower than stock pressure? Do you adjust that between runs? Thanks for helping us autocross newbies.

Norm Peterson

The best advice I can give here is don't trap yourself into over-thinking your setup. First fix the loose nut behind the steering wheel, as one of the sayings to auto-X newbies goes (flame not intended). You may also hear "seat time, tires/wheels, everything else".

Take the organizers up on any instructed course walks and/or ride-alongs.

The biggest early gains come from learning how to drive the car at that intensity and with the necessary accuracy. Once you get out there the first time, you'll forget all about your setup, guaranteed.

Keep in mind that Whisky's car and mine are 4.6L cars with about a hundred HP and at least 50 ft-lbs less to work with, so you probably wouldn't want a setup that's as "loose" as what either of us could work with.

But FWIW, I'm running -1.8° camber, Sam's 35/22 mm bars mid-firm front/full firm rear. Konis at about +1.5 turns front, +1 or just a tiny bit more out back for autocross or track, and 255/45 Goodyear Asymmetrics on 18x9.5" wheels (not as grippy as Whiskey's but pretty good as true street tires go). One of the last autocrosses, I ran 35f/31r which are my normal street pressures (cold). Lower rear tire pressure seems to provide a little extra margin between being stuck down at a small to moderate slip angle while cornering and getting too loose when you add throttle.

When I was seriously autocrossing, I'd always set hot pressures, because that's what you're measuring in between runs (and that's what the tire behavior out on course is going to be based on). On a hot day, it's entirely possible for pressures to sneak up by 3 psi or more in a single run.

Short of marking the shoulders of your tires with shoe polish (to see how far you're rolling over around the tire shoulders) or getting involved with some sort of thermal probe (way past what you need to be cluttering your mind with at this stage), just observe how far the scuffing goes around the shoulder and adjust based on that. There may be some indicators molded into the tire to help guide you here, or you can get somebody with experience to take a look.


Norm

Whiskey11

Sorry I should have specified that is "hot" (if you can call it that) pressure. Measured after the run off, and after parking in the grid and after shutting off the camera, bsing a little, then checking so maybe warm is more accurate.

Those pressures are based off of the scuffing on the shoulder and it is spot on the end of the shoulder blocks. The rears could probably drop a PSI but the extra rotation doesn't hurt.

What boggles my mind is several other competitors on the same tires run much higher in lighter vehicles. My buddy in his evo says to watch the scuffing, everyone else I have talked to said the scuffing is usually spot on for pressures but they then say street tires need to be up higher than r comps?? I dunno, as Norm said, I have other things to worry about then why the pressure is so low. Chances are I am not driving hard enough. Considering that my, probably not super accurate, accelerometer on my Droid Razr says that I pulled over 1.1 G on most corners and peaked at basically 1.2 G at the last event, I am not sure how much more I can drive the tires though...

I should also note I am running Sam's 25mm rear bar not the 22mm

darksky1984

I don't know if you have it but BAMA makes an auto-x tune that provides more HP in the mid-range RPM's. It's not as powerful as their race tune but better than stock.

safetyfastgt

Just so I'm clear, Norm, do you bleed off pressure between runs to maintain your cold pressure? I had my pressures set at factory starting out a couple of weeks ago. When I checked them hot, the pressure was in the low 40s. I used shoe polish, but I wasn't getting over onto the polish. I've heard that trick doesn't work so well with modern tires and their stiff sidewalls.

darksky1984

You want to keep your tires at your hot pressure. The goal is to stay at that goal pressure and bleed it off when it goes up between runs. Also a good thing to do is spray the tires with water to keep them from getting too greasy. Also low 40's seems really high for street tires. I run 38 psi in the front and 36 psi in the rear.