Basic FS autocross setup questions

[Laserbrain]

I'm going to my first autocross in more than 10 years. Last time I autocrossed regularly was in a 1999 Miata without even ABS, never mind traction control, stability control, multiple drive modes (sport, track, etc), and of course, nowhere near the amount of power the Mustang has.

It's a 2019 GT with 6 speed manual and PP2. 305 tires all around. 305/30ZR-19 Falken Azenis FK510. I know they're not ideal, but I wasn't thinking about autocross when I got them.

All stock (but I no longer have the Cup2's) so I'll be in FS.

Where should I start with tire pressures?

What do I do with driving modes?

I have a vague recollection from ~2007 of drivers putting "trac off!" notes on their steering wheel to remind them to turn off traction control because leaving it on would kill their laptime.

It's raining, so today I'm going to try to turn these CS magnets into FS

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[Gearz]

Welcome back! I think you'll find your GT is like a heavy Miata with power. It should be well balanced, but she's a big gal.

Start with your tires at 36-40 PSI and drop based on how the shoulder wear rollover looks. Try not to really crank the fronts if you've got understeer, just enter the corner slower if you're getting that.

Unless your car has Magnaride shocks, the modes won't change much other than the throttle mapping, but run it in Track anyhow. If you do have Magnaride, run it in Track.

Hold up on the traction control switch for 7 seconds to get "Advance-Trac Off". If you just hit it for a sec and let go it'll show it as off but it's not really off. You have to do the 7-second wait to turn it all-the-way off.

First time coming back at least you'll know the basics but the key is looking ahead. It can take some time to be able to see the course instead of a ton of cones. When you walk the course try to pick out the key cones that define the turn and just look for those. Walk with an experienced person and ask them to point them out. Don't commit to the gas until you see the exit of the corner AND the entry to the next one, then start looking for the exit. Look ahead - that's always the key. Have fun!

 

[Laserbrain]

Thanks for the thoughtful response.
It's so much bigger than the Miata!

It's a PP2, so it has MagneRide, "Unique Track Inspired Springs and Sway Bar", and wider tires and wheels.

Hold up on the traction control switch for 7 seconds to get "Advance-Trac Off". If you just hit it for a sec and let go it'll show it as off but it's not really off. You have to do the 7-second wait to turn it all-the-way off.

Ok, yes, this is what I'm looking for. This would explain the "Trac Off!" note taped to the steering wheel I remember from years ago.

Turning off Advance-Trac here means stability control, traction control, or both?

TBH, I've never driven the car with Advance-trac off. I guess an Autocross is the place to try it.

 

[Dana Pants]

There is a connector to nowhere next to the airbox. Unplug it to turn off the Nannies.

 

[Gearz]

Turning of the Advance-Trac quickly (quick toggle the switch) will turn off traction control (you can spin the rear tires) but not the stability control (nannies will apply brakes and cut throttle when they get scared). Turning off the Advance-Trac "all the way" (hold the switch and repeat saying "I really f'ing mean it - turn it ALL off) will turn off everything and you have a full analog car, except for the digital throttle and electric power steering, but it'll do what you want for better or for worse and the computer will point and laugh if it goes sideways.

Advance-Trac has saved me on the street when I was being extra stupid but in autox or on the track I want it all off. There's nothing worse than pressing the gas through the floor and the computer cuts the throttle on you. I hate it. HATE IT!!!

 

[Laserbrain]

Excelent explanation, thanks.

When I put the car in Track mode (and change nothing else), I see the Advance-trac icon on the dash. What does that indicate?

I think I'll keep Advance-trac on for the first run. To make sure I can find my way around the course and get a feel for the width of the car.

 

[Gearz]

In track mode the Advance-Trac nannies are a little less nervous than in normal mode so they won't cut in quite as soon. They're still very annoying and on a race track they'll make your rear brakes unhappy if you're pushing hard. I had a Subie STI that I forgot to turn everything off and after a couple of laps I was wondering why the rear brakes were smelly.

There's probably better info out there that explains exactly what each mode does and how it affects the settings. I just always turn everything of in everything I race, but I've been doing it for a while (I'm only a little younger than the first Mustangs).

At some point you'll want to put a "fast guy/gal" in your car and get a sense of what it'll really do. That will help you understand where the limits are.

Have fun!

 

[mavisky]

Excelent explanation, thanks.

When I put the car in Track mode (and change nothing else), I see the Advance-trac icon on the dash. What does that indicate?

I think I'll keep Advance-trac on for the first run. To make sure I can find my way around the course and get a feel for the width of the car.

Track mode should have you set to traction control off but stability control in it's most relaxed mode. I ran this mode for the first year or so of coming back to autocross. 9 times out of 10 if the system was intervening, I had already made a big enough mistake that it wasn't going to be my fastest run anyway. It's a nice safety net to get accustomed to the car and it's dynamics. Once you're comfortable you can disable the system fully so that you can drive the car without any intervention.

Be wary though that the S550 chassis doesn't have much in the way of intuitive countersteer on it's own. This isn't like a Miata where in a small slide it will self-steer to help you counter the rotation. You have to forcefully and quickly input countersteer to catch the slide. Once you get used to this though you can really push the car.

 

[petronix]

I’d recommend against unplugging the “Dyno plug”. It is suspected that this also disables ABS brakes, which may not sound so bad, but that also removes front /rear brake bias. That can’t be compensated for by good driving. At an Autocross I watched a PP2 rotate into the woods and hit a bystander after the stop box likely because of this. As far as I can tell, track mode and the 7 second toggle does disable everything you’d want as discussed above.

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