donutsdemise

Am I interpreting the 2011 rules for FS correctly below?

Wheels and tires: same size as stock
Shocks: free
Strut mount: stock
Front Sway: free, brackets, too.
Rear Sway: must remain stock
Springs: must remain stock

Vehicle in question is a 2012 GT, Brembo.

jsnyng

Wheels can be +/- 5mm (I think) from factory offset so you could run +37 - +47. For 2012, you can change front OR rear swaybar. You are correct on the other items. Are you planning on running R-comps or street tires? For tires you can run as big as you can get to fit on a 19x9" wheel.

donutsdemise

Thanks, planning on a street tire class which is what I thought FS was.

That may be good news re. the rear sway as I think Sam said the rear is a bit too big with stock springs. I notice you said OR meaning can't change both bars, right?

jsnyng

FS is most definitely not a street tire class as most new to the sport would assume. If the class doesn't start with ST* like STX, STU, STF, STC, STR, etc. then it is a race tire/DOT R-Comp class. This year, both National Tour events and the National Championships are going to have a Stock class index class for those who want to run Stock on street tires. I don't know if your local region is going to offer that index class or not, but it is worth looking into if you don't want to drop the money on Hoo$ier$. What that means is that ALL stock class cars AS, BS, CS, DS, ES, FS, etc. would run together and would have their times be compared against a PAX value for the class.

Example: Let's say you run FS in your Mustang and run the course in exactly 60 seconds. The 2012 PAX value for FS is 0.825. You would multiply 60*0.825 and have your time of 49.5 seconds. Let's say a C5/C6 Corvette is running SS and runs the course in 59 seconds. The PAX for SS for 2012 is 0.858. Multiply 59*0.858, and their run is scored as 50.622 seconds. Even though they ran the course in less RAW time than you did, you still win because your PAX index time was faster.

As for the swaybars, you are correct that you can do either the front or the back but not both. That is a new rule for 2012.

donutsdemise

Thanks for the clarification. I posted to my local region to see if they are doing the stock class index class.

Seeing how I already have a Sparco seat kicking around, it probably wouldn't be a large leap to STU since I planned to do shocks for FS and that's a good time to do springs which are allowed in STU. Both sways are free in STU (at least in the 2011 rules I'm looking at).

jsnyng

If you run a 265 width or narrower tire on a 9" or narrower wheel, you can run the Mustang in STX. If you're going to run 275/285, that would bump you to STU. You can also do a LOT more mods in STX/STU if you want to. Camber plates, headers, CAI, ECU tune, and a lot more are legal in the ST* classes.

Whiskey11

The ST* re-organization has put all 5.0L and below mustangs in STX so he is stuck with 265s on a 9" rim.

I had a thread not to long ago about exactly prepping an s197 for STX and to be honest, it doesn't look terribly appealing. The new 5.0s are simply too much car for 265 wheels on 9" wide wheels. Just bench racing it is insane for PAX (and you would be competing against much lighter vehicles like the RX8. I plan on doing it, mainly to irritate a friend who says it is stupid to race their, and because a6s are pricey and it is a great class to have fun in.

However, I recommend highly, that you take a full year at a minimum and race on stock tires and suspension so you know what needs improving. Maybe you can keep the stock rear bar and ballance it with a heavier front, maybe you don't need shocks (actually..........). The biggest thing if you are hellbent on modding is going to be an alignment. I'm not sure if the 10+ s197s have the ford camber bolts open to them like my years do, but I imagine they do. Pricey, but you will want the max camber you can get. Probably neutral toe as well to take advantage of your tires.

Also, call Sam, he was very helpful when I called pretty much aiming down this same path and had excellent recommendations!

Whiskey11

To add to my above because I can't edit (either the mobile theme or access restriction which is silly), the bench racing FS vs STX is scary. To PAX the same as an F stock S197 in STX, you basically have to run the same time. If an F stock s197 runs the course in 60s, an STX s197 has to run it in 60.219, but you do so without a6s but with better suspension. A6s are a pretty big advantage time wise, a couple of seconds or more off of the same car with proper STX tires on the nationals pavement if I have read and understood correctly. Add in that you are, at best 3500lbs with driver in STX trim compared to a prepped RX8 or bimmer around 3000-3100 and more usable HP (not burning rubber at 412HP :P) it makes the prospect of a competitive 5.0 in STX unlikely, but it could be an insanely fun local car which is where I am planning to compete with mine.

donutsdemise

That is good advice re. the first year with my new car. I will probably install Koni Yellow Single Adjustables because I have noticed a lack 'o damping with the Brembo package and I usually install those shocks on any car of mine I think would benefit from them.

I hear you on the camber and toe. I used to autocross an under-powered car in FSP and did everything I could with the suspension and alignment.

Wondering how the big 19's (255/40R19 Pirelli Pzero Nero summer's) and 3.31 rear axle ratio will play. It is fine with me if I end up with bald tires by summer's end so I can get some all-seasons on those rims.

Can5.0

1st full season fully stock on those Pirellis; 3.73 gears and they're toast. Up here in Canada a season is 8 races. By my last race I was sliding on every turn. Rotated my tires after every competition too. Then again. I did drive a lot in the summer as well. Regardless, I won 1st overall for the class in 2011 which included non-Z06 corvettes an early 80s Porsche 911 and a few E90 bmws. So faired well in my opinion despite slippery tires.