Tips and advice on setting up car for Autocross
 

Years ago I used to attend local autocross events with my car. I'm the first to admit that while I was having a lot of fun, I wasn't very competitive running in ASP. Never took lessons and always ran PAX with street tires on the OEM wheels. Gave it up while my daughter was in college to ease the family budget...and I worked a lot of weekends back in the day anyway. Now semi-retired I'm hoping to get back into next spring and looking for any advice.
Right now the car has this:
Adjustable front sway with a RB swaybar mount reinforcement.
Stock rear sway.
Ground Control adjustable height coilovers with Bilsteins. I THINK the current spring rate is 350F 300R, but I also have a set of 400 springs.
MS front strut bar.


I also have a set of used Schroth harnesses and an old M2 harness bar I picked up over the years, neither of which are installed yet.
My plan is to run 245/45 R compounds on the old stock wheels (reinforced design). Also hoping to pick up a used trailer since the main venue to me is about an hour away.
I haven't checked the rule book for a while but assume my car will still honestly 'tech' in A Street Prepared. My goal is to just be competitive (i.e. not embarrass myself) locally after taking in a local school and some seat time. Just wish they had a class for chubby old guys like they do for "ladies".
So what am I missing?

In general, the adage is
1. Seat time

Im not that great of a driver. I figured 245's were wide enough...no?

If you are going to be serious about being fast, get wider wheels and the widest sticky tires you can get. If you are just going for fun, use your old wheels with the 245/45 tires. Hoosiers for those rims will cost you over a grand :(.

I'm running 1.6 negative camber in front, and 1.3 negative in the back. This setting doesnt kill my tires on the street (I dont drive the car much), and works well for autocrossing.

The most important thing is to have fun. Good luck.

Suspension is a system. Wider wheels and wide, sticky tires provide more grip but they may also necessitate stiffer suspension to keep from rolling over and rubbing fenders. You'll be ahead of the curve on just about any dedicated autocross tire even in the 225 or 245 widths.

Even with 245's youll need higher spring rates if running sticky r-comp tires.
Front adjustable sway-bar and stock rear is what I prefer.
I really advice you to run a more aggressive alignment, -2.5 camber front from -2 rear is what I like and it works on the street as well without any wear issues. On my car, I max out the front camber to be the most negative as possible (-2.7 degrees) and I still wish I could get more. Other than that, seat time is the best mod.

I run -3.2 degrees up front on Hoosiers, and I found that when I ran a bit less than that I was prematurely wearing the outside shoulders of my front tires

this is a big of a deep dive, but road racing we're running 205's on a 9" wheel, so while 245 is wide enough as a tire, you really want to put it on a bigger wheel. also one of the reasons what something like a hoosier is stickier is because it runs wide, so a 245 hoosier is closer to a 225 in most other tires.

for a start, you probably want something that is good but will last longer than the 2 laps the hoosiers do, and works with the stock wheels.

I have no illusions Adam and ASP, at least locally, was pretty tough. Like most golfers I know, I'd just like to see improvement and that would make it more fun. Doubt I'll be going with Hoosiers, probably something a little more reasonable. But thanks for your settings, I meant to ask that question.

Thanks everyone for the input.
The RB swaybar brace has always been enough for the street on 255 street tires but thinking that won't be the case with R compounds...even just some Hankooks. What are the choices in the stronger SB mounts these days?

As mentioned previously, priority #1 is seat time. Get out there and who cares how you do. This will then give you information on what adjustments you need to make to your car. Sway bars fine tune your suspension and you are really just guessing if you don't have any feedback on what your car is doing. FWIW, if you are pushing stock HP levels, stock tire size (225) is adequate and you really don't know they aren't adequate until you get out there. As for your sway bar mounts, if it was me I would use what I have until they show any stress. You may not need to upgrade.

I ran A6/A7s for 4 years with stock sway bars and stock mounts. Last year I installed widefoot mounts and when I examined the car there hadn't been any damage done

i'm sure your upgraded sway bar stuff is tight, but if you want to be proactive here are a couple of tips.

1. when you put sticky tires on the miata/FD the lower control arm alignment bolts can move. after you get an alignment you need to tighten them, we basically as tight as you can get them. for the Miata Mazda sells a new bolt which is finer thread, i think the FD bolt might do the same thing. stock spec is 85lbs-ft, we go tighter racing.

2. its a good idea to go around and just make sure all the chassis stuff is tight.

Thanks Tom. Have no doubt the 'seat time' advice is the ticket. But I do have some hope of getting at least some instruction next year...just for the technical aspects. The 'not caring how I do' part will be a little harder. I'm pushing maybe 350 crank/300 whp. Nothing crazy and plenty for my skills.
You know some years ago I was chasing a weird steering issue that ended up just being worn tie-rod ends. But in the process I checked those bolts. They were tight then, but I'll definitely put them on the list along with the all rest. :icon_tup: Thanks.

I would run a 225 wide tire on an 8" wide wheel if you are running the stock wheels. I like the slight stretch to stretched tire. its more efficient, more direct, and more predictable.

Floppy side wall tires are just gross to drive on.

I disagree. Put down the most rubber you can to the pavement. Go with 245/45s. Race tires dont have floppy sidewalls