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View Full Version : Strut Tower Brace: Effective or no? (cc.com thread)



SmackDaddy
03-16-2006, 04:51 PM
I've always wondered if they were effective and to get past the marketing hype to the engineering/techinical side of the house lead me to a thread on corner carvers.

If you have the time to read and stomach this long thread, a lot of great information can be gleaned.

http://corner-carvers.com/forums/showthread.php?s=&threadid=448
http://www.corner-carvers.com/forums/showthread.php?t=5096

Since my CMC stang already had a STB, I probably won't remove it.. even though I should to get the weight off the nose.

Thoughts?

NASA13
03-16-2006, 05:37 PM
I cut one arm off of mine to swap boosters at the race and I swear it turns in better in that direction.

j3ffbrooks
03-16-2006, 11:14 PM
My AI car came with a strut tower brace not installed still in the MM packaging. I ran one race weekend at MSR C last season without it and the car was great. I then installed it for the next race weekend. I didn't do anything else to the car and I was pushing the car through every turn. Needless to say I took the brace off before the next race that day.

I think our FOX bodies are stiff enough with the cage and subframes already.

oz98cobra
03-30-2006, 03:56 AM
...
I think our FOX bodies are stiff enough with the cage and subframes already.

Only if your cage is tied into the strut towers through the firewall - otherwise, an STB will DEFINATELY provide an improvement.

Since CMC rules prohibit any roll cage forward of the firewall, an STB should be a worthwhile addition on CMC cars, and well worth the weight penalty.

For an AI car with a cage design that runs through the firewall to the strut towers, it is probably just useless weight. Of course if the AI car does not have the cage running to the trut towers, the an STB is the next best bandaid.

I've never read a more convoluted load of over analysed clap trap than all that BS about STBs in the CC posts linked to above (well, at least not since I last read one of the many other convoluted loads of over analysed clap trap on corner carvers ;) ).

I run a factory 96-97 STB with an improved firewall mounting setup on my 98 Cobra, and it does make a big difference. Contrary to Jeff's experience, the car is much worse on turn in without the brace. After hastily reinstalling the brace late one night before an event last year, I forgot to tighten the bolts that attach it to the firewall, and the first time I drove the car on the track, I was wondering what the hell was up with it - so much so that I came in before the session ended to investigate what was going on. Found the loose bolts, tightened them up, and the next session the car was back to it's usual feel.

Interestingly, you could see where the paint had been worn off about 1/4 inch either side of the brace where it sits on the firewall pinch weld from it moving side to side! Proof positive that a well designed and properly installed STB is significantly improving torsional rigidity in a Mustang.

I have since noticed that this can easily be reproduced or demonstrated - loosen the firewall STB bolts, jack the car from under one front control arm, and watch the movement as the body flexes. I haven't actually bothered, but I'm sure you could measure the difference in droop of the unsupported side of the car due to flex with the brace secured or loose. It's surprising one of the armchair engineers debating STBs in that old CC thread didn't think to try something as simple as this?

Obviously, this amount of body flex is going to have a negative effect on handling, so Jeff, if you don't have your cage running through to the strut towers, it might be worth giving that strut tower brace another try.

mitchntx
03-30-2006, 08:32 AM
Daron, if the body is flexing tht much, hood, door and hatch seams would be collapsing and the paint would be wrinkling.

STB is marketing hype at it's finest.

mitchntx
03-30-2006, 08:33 AM
I take that back, I think everyone should run an STB. The extra 10lbs of nose weight won't cause any problems. :twisted:

oz98cobra
04-03-2006, 02:51 PM
Daron, if the body is flexing tht much, hood, door and hatch seams would be collapsing and the paint would be wrinkling.

STB is marketing hype at it's finest.

Sorry Mitch, have to disagree - maybe all that extra pork in the f-bodies stiffens the bodies so you don't need any bracing, but it's a different story for Mustangs - the body flex is ENORMOUS - especially under racing conditions. You need do nothing more than play with a car up on jack stands and a jack under various points to see just how ugly it is.

A properly mounted STB on a Mustang is not a substitute for extending a roll cage through to the strut towers, but it does provide a measurable benefit for cars that don't or can't have a forward extending cage.

Note I said properly mounted - most aren't in my opinion - if anyone is interested to know more, come look at my Cobra in the pits sometime and I'll show you how I mounted it.

j3ffbrooks
04-05-2006, 12:04 PM
Obviously, this amount of body flex is going to have a negative effect on handling, so Jeff, if you don't have your cage running through to the strut towers, it might be worth giving that strut tower brace another try.

I suppose it really comes down to how you have your car set up. I know how flexable the frame is on a FOX, but I believe it is possible for your car to be too stiff. I realize I could spend an entire day at the track setting up my suspension to work with the STB, but I would rather not. Since it works the way it is now, I'll be going without a STB for now.