Strut tower bar, noticable difference?
 

So I had a strut tower bar on both the front and rear and didn't notice much difference in the handling department. This was when I was running Blue shocks and ST front springs. Well, the front strut tower bar was a homemade version, so I assume that did little to nothing. It was pretty easy to put on. The rear I have is a CP Racing. YES I know you guys think it does nothing, but any extra stability is... well, extra stability.

So my question is this: With my Coilovers on and the Blues, should I feel a bigger increase with the strut tower bar than before? I swear I hardly felt a thing (probably placebo I was feeling too) With the old homemade bar. And no, I did not make it.



So, strut tower bars, worth it in the long run? These will be next in line after my respeed sway bars :D

Oh and also, while I was at ZOOM FEST, Billy was down there and had a spare front sway bar down there. I got to feel the difference in weight between that AND the RB bar! Man that RB bar is heavy!


*shameless plug*

i had an RB bar on my black gsl-se, and it made the car understeer more, so it WAS doing something!

this was at the track too, on the street it wasnt that noticeable, AND its something you'd tune out if you did the suspension...

Well I have ReSpeed race coilovers, so I can corner tune (anyone know anyone around NC that can do that?).

As far as your understeer issue went, was it always understeer (2nd gear and up) or could you power out of it?

Every sanctioning body has rules about strut bars and if they can be used in specific classes. That tells me they work. Granted I doubt anyone has mounted a car to a chassis twist test rig to see :)

-billy

After I put that 2G strut bar on my car I think I could notice it and my windows now rattle some when I go over the odd bump or two which tells me the forces are being shared across the car differently than before the bar. I remember back in the day you couldn't tie the strut bar to the firewall in most solo classes.

I did notice a change in chassis stiffness when I went from my '82 (183k when it rusted out) with the old school one piece RB triangulated strut bar to my '85 (just rolled 101k) without it. Same suspension setup. My '85 feels much less connected to the road, and I get a lot more cowl shake, which is an indication of a chassis that isn't very stiff (you get cowl shake in convertibles, it's when you hit a bump and your mirror shakes really bad)

My suspension setup is:
RB Springs
Illumina's in front (setting #2)
Blue's in the rear
stock bars front and rear.

I have the RE-Speed 3-point strut brace, but I also put poly bushings in my suspension so I can't really tell if it made a difference. The car doesn't flex as much when I jack up the front, so I imagine that's from the strut brace. Used to be my doors wouldn't shut smoothly when I had the front up in the air, now they open and close fine.

This has always been a question I've struggled with. Do they help? Or are they just dead weight? Really though, I don't see how they could hurt. They have to be worth at least what they weigh. The triangulated front bar is not allowed in CSP, but the non-triangulated bar is.

Another question I have is this; would a strut bar make a bigger difference in a car on stock suspension, or one on a good firm suspension like mine? I would think that with the stock suspension, you get more suspension movement therefore more potential for twisting of the body.

But I guess I won't really know until I actually try it out. I do know that the Respeed strut bar is yet another work of art, and it sure would look good under my hood, and sometimes that enough to justify the purchase. :)

And as far as the weight difference between the Racing Beat swaybar and the Respeed model, you really have to feel it to believe it. The Respeed bar looks so much beefier than the RB bar, but weighs a fraction of what the RB does. Superior materials, design, and construction pays off big time! My car feels much happier since I removed that chunk of iron from her nose and put on the hollow bar...


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backwards! think of it like the more grip the tires make, the stiffer the suspension you need, and the more you need to stiffen the chassis...

or the more loads you have on the body, the more its going to flex, we put load on with better traction....

I always drool at your Avatar.

in real life, when its running it drools back

:lol::lol: Hahahha! :lol::lol:

I actually lol'd.


EDIT: AzRR... Arizona rotary rockets?

yep! at idle there are these little droplets of fuel bouncing around the top of the carb.

azrr = arizona rotary rockets, tom and glen are cool

:rlaugh: Same here, I genuinely lol'd.

max lols. I was considering putting the re-speed triangulated bar in my 82 along with the coilovers, sway bars, and poly bushings. I hang around with some MG guys in seattle, and I can tell a minimal difference between w/bar and w/o. Haven't driven any other 7s but mine, so I can't speak to that vein but it does make some difference.

With all the talk here about chasis flex and noone mentions the fender braces or k- brace used on some cars. I would like to see re-speed or rotaryshack build a set for the FB.
They are available for the FC and FD. I posted in the product idea/development area w/ a pic of a set for FD's

I have the RB one and the difference is def subtle. Admittedly I have cut eibach springs and blues all around as well...but I tell you what...it sure looks cool under the hood! :icon_tup:

I upgraded so many parts of the suspension at the same time I installed the Rotary Engineering 3 piece strut bar that I can't point to any particular difference. However, on my FC, a strut bar and cone filter were the first 2 mods and I did notice a difference from just the cheap eBay one piece bar. Imho, does it make a difference, yes. It would make even more of a difference if one could cross brace between the tops of the strut towers and the opposite frame rail. Unfortunately there are too many engine parts in the way to do that effectively.

When one pictures the dynamic forces applied to the suspension during cornering, the car should achieve more traction if the outside strut tower top pulled inward, the inside one pulled outward. That should give a better footprint for the tire. The only place I've ever seen this applied is on road graders where the front wheels actually tilt into the direction of the turn.

Camber plates can increase inward tilt, some is already built into the alignment settings.

On a street RX7 with street tires that has a stock or only mildly modified suspension....a strut brace probably doesn't do that much.

On a racecar, track car, and or an autox car that has stiff springs and sticky tires a strut brace is very important. In my opinion you should connect the struts and triangulate back to the weld seam on the firewall if your racing class allows it. If your racing class only allows a single brace between the strut towers, it is still worth it.

A stamped steel uni-body moves and flexes when you start loading it in a racing environment. In the case of a Mac-strut car like an RX7, allowing the strut towers to move means that you are allowing the suspension alignment to change. Driving and tuning a car that has an inconsistent alignment is a pain....it would be like having bad suspension bushings.

Below are some pictures of the engine compartment from the Mustang I autox'd in CP during my life before I discovered RX7's. I built this car through several phases from E Street Prepared to C Prepared. As the tires got bigger 7" wide to 12" wide the chassis had to get stiffer to cope with them.

A couple of things are significant in the photos. One, each strut tower is braced with four separate connections including the factory unibody. Second, the strut brace that connected the two towers was adjustable and it was possible pre-load the strut towers enough change camber settings using just that one bar. The bottom line is that this car had a really freaking stiff chasiss and it still could be flexed. Note that the two connections at the top of each tower that go to the firewall are actually attached to the roll cage in the interior as well as the firewall that they pass through.


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