Need a straight answer on strut tower braces.

[Tommychu]

Whooh. At least we're all talking much more sensibly.
I am no ricer at all but have driven little square boxes of many stripes since 1969. And stupidly trying to improve upon each one. I was gifted a 64 Mini 850 from an elderly lady that wanted her lo-mile car appreciated. It was in beautiful shape (we're talking 1974 here) and was the original model with rubber donut suspension, exterior hinges and sliding windows and with a push button starter on the floor, long springy shift coming right out from the firewall and an 850cc (albeit in perfect shape) "lawn-mower" engine out front. It promptly got the whole treatment of front discs and an "S" engine, short throw transmission, and gauge cluster but you know what: I really should have left it alone and enjoyed it for what it was. Under those circumstances I might have still had it to this day.

And that's a respectable school of thought. Trust the Guys Who Are Smarter Than Me to do the job they get paid more than I will ever make to do. Some follow it as gospel, and I'll admit I'm not one of those people; I tinker a lot. But to tinker and have good results you have to follow it to some degree.
Example:
(bolded for emphasis)

I prefer to work withing the factory dimensions and with as much OEM equipment as possible before relying on one off, exotic, race parts. There are a couple good reasons for this. It lowers the cost of replacing parts and the factory has a much bigger budget than I do, and they weren't screwing around when they designed these parts to begin with. The chassis and suspension parts were designed to work together for hundreds of thousands of miles, that's much longer than most race parts last. So I like to push the limits of the factory components until they break and make improvements based on the failures. Most of the time, minor adjustments can be made to OEM parts to give the car a handling advantage. With this said, a great handling Festiva is not that far away! These cars don't require much to out handle just about anything on the road.

And we all know Charlie can make a Festiva dance.

But I'm getting off track here. What I'm trying to say, darkfact, is that if you want the car to handle well you should buy the parts that are MOST effective in making the car handle. Set some goals for the project, spend as much time as possible researching the best way to achieve them, and work towards them, nothing else. If you don't, you'll end up throwing every FAST AND FURIOUS speedshop part you see at it on impulse. That kind of impulse is the reason you started this thread. If you do things that way you'll end up broke AND having a car that doesn't do what you wanted it to do in the first place.

[festyfreak39]

I have video of my festiva door opening while cornering with 13x8" slicks. the top of the door would open a good 2-3" depending on the corner. This is without a cage/chassis bracing.

[Bert]

I have video of my festiva door opening while cornering with 13x8" slicks. the top of the door would open a good 2-3" depending on the corner. This is without a cage/chassis bracing.

In my experience these little cars are pretty darn rigid in their own right. When you jack up one corner the entire car lifts up on that side and at the very worst the door on that side is not aligned quite as well upon closing or opening. That is amazing to see within the context of a 20 year old car.
Austin Minis literally 'cornered the market' for rally and race cars in the early to late 60s for similar reasons but they could only be made sturdy by virtue of sub-frames to carry the engine and suspension. I got to drive a 67 Chevelle (with a GD big engine and beefed-up suspension) a few years ago and was thoroughly appalled at how flexible (loose!) that car was. Metal fatigue must have been a common feature in those types of cars when they were driven hard. GM must not have considered rigidity as a virtue when they were "building" cars in the 60s and probably even the 70s and 80s. And from reading other comments on this forum I gather the Mickey Mouse front strut brace on my dad's Chevy Lumina is there only to afterthought augment the structural purpose of a glass windshield.
It could well be that Festys could benefit from some sort of front and/or rear strut brace (if the car is over-powered and/or driven to the max) but from an engineering standpoint some sort of cross bracing is required. And by cross brace I mean a literal "X" shape preferably in two dimensions. Try it sometime: one or two boards nailed across the top of 2 fence posts does nothing to improve rigidity whereas 2 boards nailed on in the shape of a cross will make the posts immovable during a perpendicular application of force.

[sketchman]

Uhm, wouldn't a board nailed across the top of two boards stop the tops from moving together or apart? Kinda the point of a strut bar, or so I thought.

[Bert]

Uhm, wouldn't a board nailed across the top of two boards stop the tops from moving together or apart? Kinda the point of a strut bar, or so I thought.

Rather than argue about this I will await some sort of real numbers or other proof that a strut bar makes any difference. Were someone to mount a tensiometer or some such measuring device across the towers of a Festy and then spiritedly rod it around a track I'd be curious to see or hear how much flex there really is with and without a bar.

[defprun]

I had a nice triangulated unit on my 1st generation RX-7 that bolted to the struts as well as the firewall, I'm pretty sure it's the reason I was still able to drive my car around for another 6 months while the Oldsmobile Ciera I hit's front end collapsed in on itself.

Definately something to look into or fab.

[sketchman]

Rather than argue about this.....

To clarify, I didn't mean to argue that it works or doesn't. I just didn't understand your illustration.

I've no idea if they work or not, though I'd like to see proof either way too.

[Aaronbrook37]

My wideband data-logger has a corner and straight-line accelerometer integrated into it that I can datalog and monitor. We'll see how many G's a stock Festiva can pull without a strut bar and go from there. I might do some comparative testing in the future for you guys to see what if anything a strut bar really does. I'd have to come up with a design for one first that'll clear the intake manifold on my B6T though. Of course, my Festiva's handling is far from stock... but it might be useful for studying purposes.

[defprun]

It also depends on the build of the strut bar. The one I had was built with slight bends in solid steel tubing with 1/4 inch steel plate bolted to the struts. Something with aluminum tubing and wobbly strut tops threaded into it wont perform as well.

[Aaronbrook37]

It also depends on the build of the strut bar. The one I had was built with slight bends in solid steel tubing with 1/4 inch steel plate bolted to the struts. Something with aluminum tubing and wobbly strut tops threaded into it wont perform as well.

True... took forever to hacksaw and weld my control arm brace, because the steel was pretty solid stuff!

http://img.photobucket.com/albums/v203/aaronbrook/Festiva/DSC02398.jpg

[festyfreak39]

boom. home made frog arms:


non home made frog arms:


problem solved. dead simple to dupilcate

[sketchman]

There's no plate in the DIY ones, though. I would think that'll make a huge difference.

[FestYboy]

^ agree

[DriverOne]

Re: Need a straight answer on strut tower braces.

What're the physics behind the frog arms?

[Bert]

What're the physics behind the frog arms?

Strut towers don't get anywhere near the chance to flex in any direction. Festyfreak39 has hit the nail right on the head with something that should work. Now as to exactly how much difference those frog-arms make is another thing. I wouldn't mind hearing all about that.