Robertatl123

Hello,

I bought a 14 GT last December after autocrossing a S2000 STR car for 7 years. Needless to say, this has been a relatively big change for me, but I find the improvements over the last generation that I owned ('00 Saleen S281) to be phenomenal. My current car is essentially a clean slate. The only performance options that I have are the 3.73 diff and the front strut tower brace. Everything else is standard equipment.

The unfortunate thing is that I am still unsure which class I want to be in, STU or CAM, but I can at least ask for advice on the common parts. My goals with the car are that I want it to be locally competitive in a street tire class, but with the compromise that this is my DD.

Anyway, here are my questions:

1) Would Koni Yellows and sport springs work fine or is a coil-over set up that much better?

2) How low can I drop the car without causing too much damage to the underside? I live in a city that is not too friendly to lowered cars.

3) I am planning on going with 18in wheels to fit over 4 piston Brembos. How wide could I go with wheel/tire combination without having to roll the fenders?

4) Is it beneficial to go with adjustable sway bars for both front and back or just the front?

5) Even though I have experience, I consider myself a mid-pack competitor at best. Would I see a difference with my times using a Watts link over an adjustable Panard rod? Also, are there any draw backs with a Watts link being used on a DD?

Any advice regarding the plethora of parts out there would also be appreciated.

I know these questions have probably been asked, but I could not seem to find the exact answer I was look for on the various forums.

Regards,

Robert

Norm Peterson

I can answer a couple of your questions before I have to leave.


3) The picture below shows that with around -2° camber, 285/35-18 Michelin PSS on Forgestar F14 wheels in 18 x 11 will fit on an unlowered GT ('08) with no rubbing even during track day sessions with the tires "talking". There's just over 1mm wheel and tire clearances to the strut. Contact Vorshlag for more information, as this is a pretty tight fit, but it supposedly tolerates some lowering.







4) I'd always go with both bars being adjustable.




Norm

jRaskell

I run my Mustang in STU and my mods are in my sig.

Question, you say your only options are 3.73 gears and strut tower brace, but then you talk about clearing the Brembo 4 piston calipers. Is that an upgrade you plan on doing, or do you in fact have the Brembo brake package? For AutoX, the factory rotors/calipers hold up just fine. You'll want better pads for sure though, especially if you ever dual-drive the car. I literally smoked my front pads the first time I ran an event with a co-driver. My co-driver was a national champ though.

The main reason I ask is, if you had the Brembo brake package, running F-Street would be a viable option. If you're on the 18x8 wheels, you just aren't going to be able to put a big enough tire on it to compete in FS, but with a 9" wide wheel FS becomes viable.

Koni yellows + lowering springs are viable STU/CAM parts. They're even viable ESP parts. There are two benefits of a high-end coilover kit compared to that setup. First is being able to precisely set your ride height and spring rates. Second is greater control over your damping adjustments, but you need the know-how to tune the dampers to be able to take advantage of those adjustments.

With good springs/dampers, 1" front & 1.5" rear drop shouldn't be that much of an issue. That's about what I got with the Ultralites and it's fine for most of New England driving.

I swapped both bars, but I couldn't say that's better than just running a front bar.

I have the same question regarding Watts Links myself. It's on my todo list, but near the bottom of it.

darksky1984

If you must run street tires run in CAM instead of STU. The mustang can possibly complete locally in STU if the other STU cars aren't set up properly or have good drivers. But if they are real STU cars ie: 350z, EVO, STI then you won't stand a chance. CAM is better for heavy cars like ours on street tires. You can grab yourself some 18x10.5 from stranoparts.com and will be able to run a 315 tire on all four corners. CAM also allows you to do more to your car than STU, less rule book checking.

I used to run STU and I was fast locally but If I went to a Dallas meet I probably would have been killed. Go either CAM or if you jump to slicks go ESP.

I also run the Koni/ Steeda ultralite set up and have minimal rubbing. If I'm careful how I drive and don't try to take steep ramps straight on I'm fine. Also if you get sway bars get both the front and back at the same time.

Just my 2 cents.

john@steeda

To start off-

There really is not much of a comparison at all with the springs/konis vs coilovers.. Coilovers would be the way to go to dial in the suspension . Much better rate of adjustment . (our Steeda system for s197 has the Highest range of adjustment of any system available) Now you asked if the konis with springs would work fine- of course they will work fine.. all depends on how far you want to take this.. I have the konis and sports and I personally love it..

Now the watts link- with this unit you have much more predictability with handling. The watts link nearly eliminates lateral roll in the middle of its opening range. There are no drawback to use it for daily driving either.. We just had a customer that is heavy into autocross and he loves this, and claimed it made a huge difference.. One of our sales guys has it and he would be the guy to speak to about the questions in this post.. His name is Rodney.. I would give him a call and speak to him, pick his brain.. he is a genius with this area. Give him a call here at Steeda- 954 960-0774

Robertatl123

Thanks for the advice!

What helped you decide to go with Ultralites over higher rate springs? I ask because American Muscles blog stated they are essentially OE spec rates.

jRaskell, your assumption is correct, but I have the 19x8.5 on it now. I did run FS last year, but I like to tinker with my cars. I was planning on upgrading to the Brembos, but I will take your advice and try better pads. I traditionally used Hawk HPS since I like their initial bite, but that was on a lighter car. What do you use?

darksky1984, I fully agree with you that CAM is a better home for my car. The problem is that no one competed in CAM last year and my region gave it a PAX of 1.000 since it is considered a "fun" class. STU has regular competitors and a PAX so that I can better compare my times. Besides have a little competition makes the season more fun. I am hoping that the class draws in competition or a PAX next season, but that is a wait and see scenario.

John, thanks for giving Rodney's info. I will probably give you guys a call when I have my budget and general parts list figured out.

darksky1984

I run the ultralites because they were recommended by Sam Strano as the springs to run for auto-x and time trials. They have worked well for me. If you do STU Vorshlag sells good 18x10 wheels that are perfect for running 285mm tires. They also sell carbotech brakes that work much better than Hawk HPS pads. I currently run XP12's on all four corners and the car has never stopped so quickly.

jRaskell

The ultralites are 195front/175rear, not exactly what I would call essentially OE rate (136front/142rear).

I'm running the Hawk HPS pads myself and they work just fine for AutoX use. They do dust up more than street pads but are otherwise just fine for street use as well. My car is my daily driver as well, and I put 12-13k miles on it yearly in all weather, so I try to avoid anything that compromises streetability.

If I ever decide to do track days, I'll likely get a dedicated pad/rotor setup that I swap out at events, but I'm perfectly happy just focusing on AutoX right now. There isn't really a pad out there that'll hold up to hard track usage and still be suitable for daily driving.

It should get a real PAX next year. PAX is based on actual historical result data, and with CAM being a new class, there was no historical data to generate a PAX from. Regardless of PAX or what class you decide to run in, you're free to compare your results against any other results however you want. I always compare my times to what the ESP cars are running just to see how far behind them I am even on Street tires.

darksky1984

Link to all of the major springs made and their spring rates.

Norm Peterson

200/175 is definitely firmer than stock, but still pretty soft in comparison to the coilover spring rates that people are using (400+ up front . . . and up).

I've had HPS pads on three different cars, and never considered them to be dusty. HP+ on the other hand, are tremendously dusty, noisy . . . and they aggressively eat rotors in street driving.

The Carbotechs are not quite as dusty as HP+, while being very gentle on your rotors. If you can stand the dust and a little noise, you can easily get away with driving XP8s on the street, and they're still good enough for entry-level track time. XP10s and higher give up increasing amounts of streetability for progressively better track capability.

About PAX for CAM. There is no way it should be higher than the CP index, which I think was 0.864 this past season. As a completely WAG, maybe 0.84-ish.

I used to do the same thing about comparing times across classes when running cars that had to run in CP or EP because of previous mods done strictly to suit street driving preferences and which I either wasn't the least bit interested in undoing or that could not be physically undone even if I wanted to.


Norm