Chassis Bracing

[Roadracer350]

OK I did a search but didn't find an answer to my question really. With the chassis on the S197 with a cage inside do I really need to put stiffening bars under the tub? Im asking about the Stifler pieces, A-arm braces, jacking rails, sub frame connectors etc. Im kicking this around to see what if anyone has done. According to these websites you need this stuff to "go fast". Im calling bullshit but before I do I want to ask. Hell i already have a cage in this thing strong enough to drop off a 3 story building and still drive off. I don't want it to be so stiff that it wont soak up imperfections but I want it stiff enough to rail around the corners. Am I making any sense? Need less coffee...

 

[FR500GT]

I think you need to stop modding and start driving this thing

 

[Roadracer350]

I SO want to!!! The watts hasn't showed yet plus the wheels and calipers are at powder coat. I still need to buy the suspension pieces, intake and some little stuff. Im hoping she will be done by first part of march!

 

[Vorshlag-Fair]

This seems like possibly you might be slipping into over-analysis? Not knocking that - it helps to stay on top of the tech and maximize your car, but the bolt-on braces and brackets don't really do a whole lot on a fully caged race car. I get where this stems from - so many companies make so many brackets and ding-dongs they it all must make the car faster, right?

I call this trap Steelitus (stolen term from others). That is when you are bolting on more and more bracing to the point that you are just adding more "steel weights" to a car. Steelitus is a very easy trap to fall into, but honestly, the S197 chassis is SO much stiffer than its predecessors (Fox, SN95) that even with ZERO brackets and bracing they are stiffer than the previous Mustangs that have every aftermarket bracket available.

While all of those bolt-on bracket doo-dads are pretty, they really don't make your car faster on a race track. Just heavier, except in the wallet. If you have a caged race car you could probably chuck all of the braces in the trash and notice no difference. If you are doing consistent track testing - try it. Get some consistent laps in on a test day then unbolt all of this extra "accoutrement" and see if your lap times change at all. They might not change, but they might get faster - if you are removing significant amounts of steel.

I don't have any of this stuff on my S197, which we run on the same tracks and on the same days as American Iron racers. We're 3 seconds quicker than the AI track record (Boss 302-S) with an "un-braced", un-caged, 3750 pound daily driven street car. We just have wider tires (315mm vs 275mm for AI) and decent aero, on nearly stock engine. That is going against a field full of caged, stiffened-to-hell, dedicated race cars that weight 400+ pounds less. And we haven't seen any chassis or body cracks on the car, and it has no creaks or squeaks, even after two years of track use and 20,000 street miles. So apparently the stock chassis isn't too floppy sloppy?

I dunno... that isn't remotely a definitive test of bolt-on braces or brackets, and many other variables are at play, but it does make your wonder if any of that stuff is even necessary.

Drive it!

 

[Roadracer350]

See that is exactly what I was thinking! I actually tried calling you today Terry to discuss this. Im not going to worry about that mess i'm just going to concentrate on the susp set up when I get it and a hair bit more power and tyres. Thanks guys!

 

[Norm Peterson]

What year is your car? Doesn't it already have a front LCA brace as OE?


Norm

 

[Roadracer350]

Its an 06 FR500S that I picked up and was pretty much stripped of everything with damage to the front bumper, rear bumper and both front fenders. I have been putting it together for about 3 years. My divorce put it on hold for a bit but shes moving forward now. They stripped everything including the stickers on the body and the quick disconnect for the steering wheel and all wiring.

 

[BadPiggy]

Its an 06 FR500S that I picked up and was pretty much stripped of everything with damage to the front bumper, rear bumper and both front fenders. I have been putting it together for about 3 years. My divorce put it on hold for a bit but shes moving forward now. They stripped everything including the stickers on the body and the quick disconnect for the steering wheel and all wiring.

In other words...it was a raped pony?

 

[Roadracer350]

Yea pretty much she was violated!!!

 

[Vorshlag-Fair]

See that is exactly what I was thinking! I actually tried calling you today Terry to discuss this. Im not going to worry about that mess i'm just going to concentrate on the susp set up when I get it and a hair bit more power and tyres. Thanks guys!

Sorry if I missed you - I've been on the phone for much of the day. If you call ask for me or JasonM (modernbeat) and we will be glad to spitball some ideas with ya. He and I both have two and a half decades of racing (and parts buying) experience, so we've both probably wasted more money on useless automotive doo-dads than we care to admit.

 

[Roadracer350]

That's why I wanted to ask cause the videos I have see of these cars at the track have shown them lifting 1 wheel in the air on some corners and that is a pretty stiff ass chassis if you ask me.

 

[Sam Strano]

A stiff chassis is never a bad idea. That said, this car isn't a noodle and in fact they are stiffer all the time. 2005's are the most flexy and I've seen a convertible yank a front tire damned near a foot in the air autocrossing. How flexy is it?

 

[ArizonaGT]

If you're starting with a 500S, you've got a cage in there already which should make it pretty damn good from the get-go.

 

[kevinatfms]

i think you have all forgotten that the factory FR500S cars were seam welded. that adds a considerable amount of stiffening to the chassis, then add roll cage and you have one stiff car.

i have driven a few seam welded cars(05+ cars) that had zero chassis bracing and they were some of the stiffest cars i have driven. i had subframe connectors, strut braces(both front and rear) and noticed nothing going back to zero bracing, which i still run today.

 

[kevinatfms]

oh and to OP, if they stripped everything, arent you just starting with a BIW? what did you actually get? photos?

is it a true FR500S? or is it a BIW/caged car?

if its an FR500s check to make sure the seams are still intact and none of the welds are broken, it happened alot when they got into significant wrecks.

 

[Roadracer350]

Yea the seams are welded but none are busted. The story is it got tail happy at road atlanta and spun around going nose first in the wall hence the front number and both front fenders then came around and hit the rear bumper.

 

[DocB]

The FR500S is not seam welded.
The FR500C is seam welded.

 

[kevinatfms]

The FR500S is not seam welded.
The FR500C is seam welded.

i thought all the factory cars were? wow, you learn something new every day.

OP-if the car has been seam welded, was it originally a factory car(FR500C) or done by a shop? either way, that significantly increases chassis rigidity.

 

[Sky Render]

Both wheels off the ground, only one jack stand. (This was actually taken at Kevin's house, LOL.) The only chassis stiffening I have is a Whiteline strut tower brace.

I certainly don't think you need any more bracing if you have a cage.

 

[kevinatfms]

i wish i had a picture of my buddys 03 cobra, he has zero chassis bracing and at almost the same position in the driveway and the car flexes like a wet noodle.

ill see if i can dig it up and post it.