Strut bar design

[300zxrb26dett]

I am linking this thread to the one I started on Clubprotege.com so you guys dont have to join over there to post feedback and comments.

To summarize, i came up with my own design for a strut bar that addresses many issues with the current designs available out there, and now I am working together with Jim Pierce to build it. If you dont know who Jim is, he is the guy who built the Tubular lower control arms I had linked in this forum a few months ago along with many other cool items he builds, but mostly for escorts.

For those of you that are not members over there, you can just leave your comments in this thread.

http://www.clubprotege.com/forum/showth ... bar-design

[Sleeper6]

Im interested in one maybe 2 if you can find a way to make a mount to the firewall on a millenia mx. Also Im curious if your tubing that goes over the strut mount fasteners are large enough for the stock nuts, yours look like they are smaller on those coilovers. Oh if your interested I could send you a mx strut mount and hardware to test fit.

[300zxrb26dett]

The nuts I am using are actually the stock nuts that came on my car. I would think they are the same as an MX since we can interchange struts between escort, mx, and pro. Are the MX mounts different then the pro/323 escort ones as far as height? I will check some pictures on rockauto for now to get an idea.


I will let you know if we need those mounts since we are kinda feeling this out to see if there is enough interest in them first.

[Ryan]

I only skimmed the first few pages and I see a bit of misunderstanding already. Your posts in particular are accurate as far as I can tell, but others don't understand really.

Forget the bar absorbing any amount of independent up/down movement of the strut towers. That tiny bit of flex will never be counted by any bar that will fit under the hood. It would need a massive moment of inertia to counter the moment between the towers, which would require a decent height. This now makes a 1 piece bar no more of an advantage than a 2 or 1 joint one (well, the 2/1 joint is adjustable, so minus one point for a one piece)

so that leaves only the in/out movement. Now any 1 joint or 2 joint design will be fine as long as its fastened at two points along that axis at either tower, and if there is a part that raises the bar to clear the motor, it is properly gusseted or at least a good one piece design. (so the point where the bar mounts cannot move independent of the strut tower)

square vs round tubing, doesn't matter if you chose similar dimensions. We're working in compression/tension, its just cross sectional surface area that matters.

The sneak preview of your design looks good from the top. I'm curious how it looks from the side. The gusset on the inside could probably be optimized, though.

Perhaps move that outer-most brace (front to back bolt, on the outside of the car) inside to the triangle, and remove the little gussets, making an A shape. Save some welding, and wind up with the same thing.


The triangulation idea is excellent. Too bad the firewall is a metal-fibre-metal sandwich and you can't just bolt a tab in place. Well, you could, but it wouldn't be ideal. The MC support is also a sweet idea. Anything to add to braking response is awesome.

I looked up those frog legs too, neat idea, tying the outside down...

[_-Night-Shade-_]

Good stuff man, your mounts seem very similar to the CorkSport style strut bars for our cars which are probably some of the best strut bars you can get for the BG chassis (as well as the Mazdaspeed ones and Ultra 1-piece) as they are 3-piece but non-adjustable so they have less flex. I like that you are trying to incorporate something to hold the MC! That's definitely a big issue in these cars, the firewall is pretty slim so there's always flex which reduces brake feel. As far as MX-3s go I think the biggest problem is that there are barely any strut bars that work with the Millenia IM - they will either hit it or not clear the hood if you mod them. So if you can overcome that when you're designing yours that's definitely a plus. Good luck!

[300zxrb26dett]

@Ryan: To be honest I really dont have a clue what your meaning in the first part of the post, so If you can make a drawing of what your talking about it would help me understand since I am a very visual person:)
The bar that goes across to connect the plates will not even be tubing. You will see later. Also I will get a side shot for you soon.

Triangulation will be difficult anyway since there is not really much room for it on a BG firewall, but Jim wants to see what he can do to incorporate it, and I think I have an idea on where it would have more effect then simply bolting it to a flat spot on the wall. I was also thinking to make it a bolt on option for later if possible, so people did not have to spend money on the whole thing at one time, and could piece it together. Buy the strut bar, later buy the add on for triangulation, later buy the MC brace, but as we all know concept and reality are 2 different things, so I will not promise this will happen, just hoping for now:)



Can someone provide some detailed pics and measurements for the cars equipped with Millenia manifolds, so we can see what needs to be done to make it work. So far it will be no problem to handle escorts and BP equipped cars, but it sounds like the KL ones may be an issue. I would like to be able to have one bar for all cars but we will see how it works out.

[Mooneggs]

I'm not sure if it makes sense to have one design... to my knowledge the millenia IM is one of the tallest out there so your design would be really tall in any of the other engine bays...

the Mazdaspeed strut bar just barely clears the millenia IM (without thermospacers) but you have to have the bar on one layer of nuts/washers...

I have pics in this post in my worklog: http://www.mx-3.com/phpBB3/viewtopic.ph ... 27#p542927

You'll notice that the MS bar comes off the front and not the middle and the bar is longer than the Corksport one (I have comparison pics). I believe this is the only way you will be able to accomodate the KLZE guys... You can't go over the middle because then you have hood closing issues.

[300zxrb26dett]

Here is a side shot:


@Mooneggs

After looking at your pictures I honestly dont think it will be that difficult to make one style of bar to fit all cars, its just the M/C brace will have to be different. I have to run the bar further forward anyway since the Ford M/C's stick out further then the Mazda ones do and there is approximately 2" of headroom from the top of the Escort M/C before the hood will interfere, So I think if we make it to fit the millenia manifold, there will be no problem for other cars either.

It makes sense to have one design mostly for the fact this is a custom product and so we need to cover more cars to get enough people committed to keep the cost down on it. If Jim has to make more then one kind of spreader bar and make more then one Jig, then it more labor etc, so I want to avoid it if possible.

[300zxrb26dett]

Pics of the endplate:





The spreader bar will basically be 2 pieces of flat stock arranged vertically with a gap in between:

o-_-_-_-_-_-_-_-_-o Imagine your looking down on this and the lines you see are the edges of the flat stock. Now to give the strength front to back it will have flat stock welded in between, horizontal to the 2 vertical pieces to form a ladder.

It will be fairly easy this way to bend around an obstruction like say the master cylinder or a Millenia intake manifold for the MX3 guys. I have a feeling that giving the bar a little height and bending it just after each endplate to move it forward in the bay will allow it to work for all cars.

The Master Cylinder brace will then be the only part that will have to be made different at that point.

[Ryan]

Ah, it doesn't have the feature I was talking about.

I'd still consider putting an brace in the middle, either between the inner two strut bolts, or where the gussets attach, to make it an A shape.

So the spreader is an I beam? H beam? Or a ladder version of I or H?

[300zxrb26dett]

Ah, it doesn't have the feature I was talking about.

I'd still consider putting an brace in the middle, either between the inner two strut bolts, or where the gussets attach, to make it an A shape.

So the spreader is an I beam? H beam? Or a ladder version of I or H?

What feature would that be?

Again show me what your talking about with pictures, it will help tremendously:)

I beam, H beam= same difference. Depending on the size of the flat stock, will determine what letter it becomes, and it will be a ladder like I stated in my last post.

[Josh]

I think the strut mount is a bit overkill. You could see the strength you want and use less material in the process. Can you fit a socket in those holes?

[Mooneggs]

Why not use something similar to the Mazdaspeed design? Not only is it lighter than any other bar I have had, it's also the simplest. I guess I thought the bar would come off the front and be straight instead of bending the bar.... That seems like a heck of a bend in the bar... do you have someone with a ZE/Millenia IM to test on?

[300zxrb26dett]

I think the strut mount is a bit overkill. You could see the strength you want and use less material in the process. Can you fit a socket in those holes?

There really is not much to it, but if you have some suggestions then I am open, and how do you think i tightened it down haha?

Oh and like I stated before, draw a picture or what your suggestion is it helps a lot.

[300zxrb26dett]

Why not use something similar to the Mazdaspeed design? Not only is it lighter than any other bar I have had, it's also the simplest. I guess I thought the bar would come off the front and be straight instead of bending the bar.... That seems like a heck of a bend in the bar... do you have someone with a ZE/Millenia IM to test on?

??? I think your missing the point on this.

This design is multipiece so its easily removed, and stronger/ more rigid then a 1 piece, and designed to eliminate the pivot point of your standard crop of multipiece bars. These were my main goals. To make something that is bolt-in, and provide the benefit of welding a bar in between the towers, for the non dedicated race cars.

How the bar is going to be routed is not final man, I was only throwing that idea out there.

Do you think a bend in the bar will have an effect on its strength? just curious?

There would have to be someone in southern California where Jim's shop is located, to test fit. So if this project moves forward, then I will be looking for a test subject:)