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Strut bars

Posted: August 4th, 2008, 1:14 pm
by TMP39
ok so i picked one up today with my door, and i put it on. do all strut bars have the same amount of holding power or is one better than the otehr

Re: Strut bars

Posted: August 4th, 2008, 8:17 pm
by wytbishop
The strut bar's major weakness is that it's not straight because it has to be made to clear the manifold. If it were straight it would act as a simple column and could be thinner and still have the same strength as a thicker curved (or non-straight) bar. Because of the bends in it, the bar will experience significant bending stress when the suspension loads it. But because there is very little deflection it's unlikely to be permanently deformed.

So in short, a larger diameter round bar would be better, but an elliptical bar would be best. Strong pins and sturdy mounting brackets would be best as well. If I were designing one, I'd use hollow, semi-elliptical tubing and brackets machined from billet rather that stamped steel.

That probably doesn't help you in any way. I just felt like geekin' out for a minute.

Re: Strut bars

Posted: August 4th, 2008, 8:38 pm
by fowljesse
I think the weak point is the bolts where the 3 parts bolt together. I have read that it does make a little difference between the prices. I have very good ones, and am happy with them, but am having a friend make solid ones. I agree with Wytbishop about the tubing.

Re: Strut bars

Posted: August 4th, 2008, 10:54 pm
by Nd4SpdSe
wytbishop wrote:So in short, a larger diameter round bar would be better, but an elliptical bar would be best. Strong pins and sturdy mounting brackets would be best as well. If I were designing one, I'd use hollow, semi-elliptical tubing and brackets machined from billet rather that stamped steel.
That's pretty much exactly the Corksport strut bar.

Re: Strut bars

Posted: August 5th, 2008, 12:58 am
by wytbishop
yeah I've never actually seen one...I was guessing.

Re: Strut bars

Posted: August 5th, 2008, 11:42 am
by fowljesse
Mine rear one is a CS. I imagine he's talking about something larger in dia. I would like to weld the wide ends of 2 Easton baseball bats together to make rear strut, and B pillar bars.

Re: Strut bars

Posted: August 5th, 2008, 12:04 pm
by wytbishop
I'll design a really nice one for you Jesse when I get a minute. I need to mount a straight steel bar with a load cell to determine the actual forces during hard cornering. Then it's a simple stress calcualtion to determine the necessary strength of the strut bar.

It'll be purdy.

Re: Strut bars

Posted: August 5th, 2008, 12:23 pm
by Nd4SpdSe
fowljesse wrote:Mine rear one is a CS.
You have a first or second revision?

Re: Strut bars

Posted: August 5th, 2008, 12:24 pm
by onlytrueromeo
If you're gunna design one, make a universal mx3 one that will fit over ALL engines :-D, Curve and Straight neck ZE, B6 BP, K8, KF? Screw the "washer mod"

Re: Strut bars

Posted: August 5th, 2008, 12:27 pm
by wytbishop
Done...as soon as I'm through with the poly bushings.

Re: Strut bars

Posted: August 5th, 2008, 12:45 pm
by fowljesse
That's cool, Wyt, that you can do that!
Nd4SpdSe, I have the 2nd one, and it's better than the 1st. I'm just greedy.

I think for the rear, 2 straight Easton bars about 2" dia. with the ends filled, and drilled, and flattened to about 1" would be simple, and as stiff as possible. For twist, you could weld an X bar between them. Something similar in the front, but in an arch, and have extra bars welded on, to extend to the outer bolts, in a wierd "Y", that way the force would go straight to the arc from each bolt equally. Also, if you did 2 bars, the peak of the ZE IM with pheno spacers would be between them.
I have the tools to make a mockup out of EMT conduit. I made a couple of geo domes to live in at Burning man out of it. 1 is a 2 vertex, the other, 4v.
I'm inspired again. When I'm done with the visors, and Poly windows, I'll look into producing these custom strut bars.

Re: Strut bars

Posted: August 5th, 2008, 1:05 pm
by wytbishop
woo hoo!!! it's a race!

Re: Strut bars

Posted: August 5th, 2008, 2:54 pm
by fowljesse
Oh.. Are you looking into producing them? I wouldn't want to compete, because we'd both lose $$. I'll check with you, if I decide to try it.
I think my design is great, though :wink:

Re: Strut bars

Posted: August 5th, 2008, 3:23 pm
by wytbishop
You're right of course...competition is sometimes counter productive. We should colaborate. I was thinking abou tthe physics of this last night and it's a pretty easy thing to make work and could be made quite affordably.

I like the little projects.

Re: Strut bars

Posted: August 5th, 2008, 4:15 pm
by Mooneggs
I would totally be down to help with this Jesse! I want a b pillar bar and a strut bar to fit over my ze with pheno spacers!!! :o