I would agree. The strut towers in the front are a "suspension pick up point". There is an angular load on the towers. The chassis flexing in this area (along the strut housing centerline) changes the "suspension characteristics and geometry" of the vehicle. The really evil thing is that it happens during cornering. This makes it a variable. May move some, may move allot. The fact is you will never know how much it is effecting the handling.

as Mantis stated, The rear area does not have angular load paths that will try to push the two towers towards each other. Only up and down along the spring and shock centerlines. A bar crossing the two will not stop up and down movement.

My opinion is they use them so they will have a place two hang their 5 point harnesses. The worst place they could.

-billy

 

Alright,

I hope that the forum member that I just stop this picture from doesn't mind ... Anyhow, I guess i shouldn't really call it rear"sturt" bar more of a strenghtener bar of sort to help ... tell me if this would be useless.

I have indicated in 2 red bars where the positioning of them would be. As youcan tell its more from right under the rear window on both sides to the rear hatch lock mechanism

 

I think if you copied somehting like the mazdatrix black one, would be sweet. My friend has that one and it is pretty good. Except, you could make it to where insted its attached to two nuts you can make a plate, weld it on and have it bolted down with the four nuts. ??, Jsut wondering. Prolly wouldn't be able to buy though(me)

 

About the only thing a rear strut bar is good for is it can provide an attachment point for harness belts. Other than that, it's bling bling. Cusco, iirc, makes a triangulated rear bar for the 2nd gens. It consists of a top cross bar, the 2 angled bars that go from the strut tops/sides and meet in the middle at the floor.

 

On cars with large hatches, like an 80's Laser/Daytona, there's a lack of torsional rigidity back there because of the big friggin' hole in the body made by the latch.

on 1st gen RX-7s, not only is the latch tiny but the space between the inner and outer walls of the hatch area is huge, resulting in large, twist-resistant box sections. Your proposed brace wouldn't do much except make the rear luggage area next to impossible to use.

Again, a front strut tower bar is practical but in the rear the body is already very stiff - and this coming from a guy who's had the misfortune to smack an FB nose-first into a concrete barrier, and on another occasion roll off a mountain highway into a rocky ravine. Short of a side impact from an SUV, these cars are pretty tough save for the long nose offering little support to the front towers.

 

I'm surprised that no one mentioned that the rear shock towers don't actually carry the weight of the car like the front strut towers. As stated there is just up and down movement, with probably no more than 200lb or so force on the tower. Just look at the rear of a FB. It just looks ultra stiff on top of actually being stiff. My car does have some stiffening in it (mustang convertable "frame rails") but its probably the stiffest car I have worked on. I can lift the rear corner of the car and the front corner on the same side will just about lift the wheel off the ground pretty quickly, and I can still open the doors without a problem. Any other car I had if I did that would bind up the doors.

Also, the reason I asked about clearance for camber plates is because the Mazdatrix ones require cutting of the original strut top to clear the plate fully. Wasn't sure if the RESpeed ones were the same.

 

Ya Billy has been going to quite some lenght to make things just a bolt on process for us. Which really does help, becase not everyone has the skill/equipment to do everything.

 

I like the look of the old school RE products. The rear isnt that big of a deal from what i have heard. I would how ever like to have a rear shock brace.

 

Any pics of what you were looking at?

 

Bump for great justice

 

Sorry guys for taking so long for updates, busy at both end and being citys apart doesn't help much neither. Anyhow here they are as promised the higher res pictures to show things more clearly. In here you can see where the engine brace mounts at and how things work. As you can tell this is a pretty rough piece, its what he has on his car, but things can be cleaned up pretty good. Once I get one to my house and spend a little more love into it, you will see how they clean up .

PS:The pictured bar does not have the grounding points piece in there.

Also for the People that want the RE design (the one that Trochoid has on his wide body car which can be found in one of the links in page one) We would be able to this. I just waiting on a measuremt from Scott so that I can take the design to get them cut up via a plasma cutter, and fromthere we can do all the rest of the stuff. As i mentioned before the RE speed one will be easier to produce so might be cheaper, and also might be lighter won't know this till i put them side by side though and scale them.

As for which one is better and more rigid, I'm not 100% sure but maybe someone more experienced would like to discuss that .

 

What your selling is junk

 

Make something very solid like this.

 

That has top be the cheeziest pieces of garbage I have seen in fabrication.
Anyone stupid enough to waste there money on one is even more stupid!.
Must have a lot of $$$ to throw in the toilet

 

Well looks like RE bars it might me ...

 

you wouldn't be getting so much hate if you spent a little more time on it. If you could get it closer to the Cusoco bar at a better price point then you'd have something. The RE bar is a simple solution. It only prevents inward and outward movement. It does little to nothing for twisting and for and aft movement.

 

Ya as i mentioned this is a bad pic to put up .. but it was the only one that he had. It makes a whole lot of a difference once things are grinded up and make more smooth and pretty ... anybody thats done bodywork knows what i'm talking about ... I was actually a little hesistant myself to put these pictures up.

As for the twisting, funny you mentioned that because that was his first thoughts about the twisting in the car.

 

i would check out www.awrracing.com for a solid usefull strut bar

 

Easy guys, this is called the product developement phase. Bagging on someone's efforts to bring a product out is not helpful. Constructive criticism is more appropriate. If you had ever designed an item from scratch, you would understand that the first few items made will not be up to the quality of the final product.

Sam, I find the added bracket to tie down the engine interesting. I'm not sure if it will perform as expected though. Adding the RB engie brace to that will work better. Bracing only the front part of the engine may simply move all of the torque flex father back in the drivetrain and stess the tranny mount more.

I've take the RE brace off, will be sending scans soon. The firewall brace has compund angle cut on the tube ends and may be difficult to get accurate measurements on. I may just bring those with me so you can make copies of them.

 

First thing first. Are you referring to me???

 

This comming from a guy that has all of 127 posts on the forums. You really aren't making a good impression here, and with that post count shouldn't be making comments like this. Watch it or you might find yourself unliked by a lot of people on the board.

More on topic though, I think you need to mabey add some bracing in there, mabey fill in the triangulated piece with some 100 thou thick sheet metal. Also, get rid of the adjustment in the middle, if its built right that shouldn't be needed at all. All cars should be virtually the same as far as this measurement goes so having adjustment there is only adding a flex point. Otherwise it looks like a very good start. Hope to see some more progress.

 

The adjusters aren't a bad idea. The strut bar on my 2nd gen has them at both ends. I believe he put his where he did so the alt belt can still be adjusted. If the adjusters have enough thread depth, the bar shouldn't flex and tying to the engine take out any flex that might inccur due to the adjusters.

 

Thats a good point trochoid, I didn't think of that. But now that I do think of that, the threaded rod is probably stiffer than the tubing the bar is made of, depending on grade of steel and whatnot. As long as there is enough threading into the tubes then that should work fine I guess.

 

I still dont know about the adjustment being in the middle, it just doesnt seem right to me. It should be two adjusters, one on each end of the bar. It doesnt really help alternator adjustment because the center adjuster is only slightly smaller than the rod itself anyway, and since it isnt attached with heims like other bars it creates a weird flex in the center if you try to close or open the gap. That creates a lot of stress one a small area which will soften and eventually break it somewhere in that area.

The reason i know this is that i thought i would make one like the one your buddy made and within one season on my ITA racecar it not only was worse than the one i had on the car originally (the exact one that wackyracer has pictured, which is still on both my racecar and street car), but it broke two races before the end of the season. After that happened i put the original one back on and then made a copy of it at work for my street car.

 

I agree that Paulied3 was a bit rude, but I have to agree the workmanship shown is poor even for a prototype. If you are going to sell a welded assembly, you need to find someone who knows how to weld.

Even more important, you need to find someone to design it who has some idea of the purpose of a strut brace and the load paths involved. The fact that the cross bar is attached to the engine clearly shows a total lack of the required knowledge and understanding. Furthermore, if it is not triangulated back to the firewall, it will provide little or no benefit.

I fabricated mine from round aluminum alloy bar stock, 6061 as I recall. The strut attach plates are steel, of course. I bored and threaded the bars to accept the rod end bearings. With my engine and intake system, the clearance issues were different from the GSL-SE of course, and required raising the cross bar slightly.