I've read Terry's build thread, and I'm quite envious of the work and effort that he has put into his car. Which is A LOT by the way.
Well, I get that it looks pretty racey, and we have done a few "big things" to our Mustang (namely - aero) that are tailored for another series (NASA Time Trial), but those have almost zero affect on autocross competitiveness. The numbered NASA TT classes have very few restrictions, but even still we've left a LOT of things off of our car that could make it faster in that series.
But when it comes to autocross-worthy mods, we haven't done
many of the things that are still allowed in ESP or Street Mod classes. We still have the full weight interior, air bags, A/C, radio, and more - all of which could come out for ESP/SM. Many ESP prepped cars at Nationals in 2012 were far more prepped than we were. Heck I was still on soft springs (450 then vs 800 now) and skinny tires back then (315s).
Our Mustang at the 2012 Solo Nationals, above. 18x11/18x12 wheels and 315mm Hoosiers under stock fenders. It wasn't well developed for ESP
Even now, we really only have
some of the common legal suspension and tire mods for ESP. Good shocks/springs/camber plates, swaybars, LCA brackets (not ESP legal), rear UCA and LCA arms (not ESP legal), front LCA bushings, a streetable Watts Link, and that's it. The Torsen T2-R we have was a nice upgrade but we didn't have that, or half of these suspension mods, back when we were in ESP. There's no magic or custom parts there - all of these are off-the-shelf pieces anyone can buy. We could have custom torque arm (the only time I'd add one of these to an S197 is to get around weird rules restrictions for autocrossing), 200+ pounds of street worthy parts would be removed, we would run a lighter transmission, a Boss 302 motor, and a lot of parts from another S197 Mustang that will go unnamed. It would be a LOT more radical than it is now, and not street legal.
The front and rear flares plus the aero we added for NASA TT3 use allow for more tire clearance, and the 18x12" wheels we run and 345mm rear tires are a little wider than we had before - but are all ESP legal. The aero works at higher speeds but is worthless in a parking lot. We ran 18x11 front and 18x12 rears before under stock fenders, but in ESP you can cut and hack the fenders more than we have, and you don't even have to run flares. Heck, the tires can poke out the fenders by a mile...
This 2006 Mustang beat us in ESP. It had 1000# springs, 335 tires, 100 less hp, no A/C or emissions, and was much lighter
What else have we done to our Mustang? Seats/roll bar/harnesses, but again, that was mostly for track safety. I wouldn't waste 63 pounds on a roll bar for an autocross car. Nor would I use the big rear wing, ducted hood or splitter - which itself catches cones regularly. ESP only allows for 1960s aero mods, like the rear spoiler we used to run. A splitter has almost no affect at autocross speeds.
So while it looks like we've done a ton of mods, anyone could replicate the ones relating to autocrossing for not a huge sum of money. I think we could keep it around $10K in parts, that matter for autocross? We actually have NOT installed a lot of "popular" suspension mods we see on daily driven and track prepped S197s all the time. Why? Because we don't feel they make any real difference, and are just "wallet lightening" mods. Things like bump steer correction kits, all of the bolt-on braces, sphericals in every bushing, tubular front crossmembers and control arms, a torque arm, SLA front suspension, 2-piece rotors, and on and on and on.
Left: Its BILLET, yo! Right: Don't even ask me what this trinket does...
Ultimately, we're talking about two different things here. You're talking about a world where you can create a class that would allow the mustang to be competitive on street tires.
I think he meant that there are places where a Mustang could run in
existing ST classes, and they could be more competitive, with just a
little bit of help. There are already "solid axle" specific allowances in ESP class, extra things these cars are allowed to do, to help competitiveness. That's what most of us feel is needed for these cars in STU.... just let the stick axle cars have rear LCA brackets, adjustable length rear lower control arms (they already have UCAs), and a little more tire than their much lighter foes in the same class (285mm ain't enough for a 3500 pound car).
With a few rear suspension allowances (left) and a bump up to 315mm tires (right) this car might have a chance in STU
I'm talking about reality where you can bitch and moan all that you want, and you're not going to get the SCCA to create another mustang class. With the current ruleset, the mustang will not be competitive on street tires. Not without a lot of money and effort to get there.
Even with a lot of money and effort the Mustang won't be competitive in STU, with the current rule set. Its a matter of physics... with 3500 pounds and 285mm tires, similar power levels (and power almost doesn't matter in autocross), the S197 is at a huge disadvantage to other RWD cars in STU. You can build an E36 M3 that has 285s (barely) and weighs 2900 pounds in STU form. Been there, done that, took home a 2nd at Nats and won STU-L twice with an E36 in STU. Our STU M3 was
600 pounds lighter than the S197 but could use the same max width tire -
how is that fair? The final "weight per tire width" ratio just blows the Mustang clean out of the running.
Then you have to look at the boost buggy AWD cars. Even with "only" a 245mm tire they are generally dominant in STU - they've won at Nats every year since 2005, save once. Its about being able to put the power to the ground out of each corner, and these cars can make plenty of power in STU - because the SEB cannot write rules that can be policed properly. Long story, don't get me started.
Ask me how I know...
If you want to be fast and competitive with the mustang without dumping tons of money into mods, buy a set of r-comps and run in F-Stock.
Yea, not so much anymore. R-compounds are dead and gone, so these now "F Street" cars are back to street tires, too. And "Stock" never allowed almost any useful mods - a swaybar and an air filter isn't going to attract very many S197 owners. And for the most part it was dominated that past 6+ years by 2007-08 Shelbys, because those cars came with lowering springs, bars and a bunch of other ESP-like parts. In reality all that F Stock offered was grip - the cars felt pretty awful to drive, whenever I raced in one. (I ran in F Stock for a few years, back in the day)
F Street isn't an option for 99.99% of Mustang owners that want to autocross. It appealed to a very select group of folks who only cared about being competitive in this one class. Some of my oldest friends are F Stock racers (including a few F Stock National champions) and they will go to the grave racing in that same class, heh. It is a rare bird that wants to drive a nearly stock Mustang, though.
Street Touring allows for so many more fun suspension mods that appeals to a MUCH larger audience of Mustang owners. And not having to do R compounds and race-only-mods that ESP allows is a big draw, too. In STU you can't: remove the a/c, remove the airbags, cut/flare the fenders, use a weird update/backdate drivetrain swap, port match the heads, swap intake manifolds, or remove the emissions equipment - like you can in ESP. ESP is an old class with old rules that ruin a car for street use. STU has so much promise, but the lack of a proportionally sized tire for the given weight of these cars is what kills it.
An S197 can fit 315s under stock fenders, and it would wake up these cars, if the STAC would only allow it...
