bbywu's post reminded me: All else being equal, hollow bars are better than solid as they are lighter.

Does anyone know if a sway bar is considered sprung or unsprung weight?

 

KA...you may want to look at this too:

http://forums.rennlist.com/rennforum...997-2-gt3.html

 

I'd vote for sprung...I tend to think that everything below the springs is unsprung...

 

For some reason I am feeling very weird here... I really had a great feel with the GMG's
H&R has a larger diameter but also not hollow inside. I have not heard any of H&R's feedback or someone who has used their application.

This keeps on getting deeper and more complicated... I am about to grab some popcorn and sit here.

 

He is in TX too... I wonder what city, I am going to hit him up.

 

I vote sprung.

 

The way we develop bars is to actually order a set from our manufacturer built to our estimated specs(our owner won the daytona 24 and is incredible with suspension) and bolt it on a car and figure out if it works or if it doesnt. With our latest bar, that we are about to announce, we have gone through 5 iterations before settling on what we think is perfect.

Remember buying the stiffest bar available isnt the answer, the answer is to develop a system that works... We sell our bars seperately but we prefer to sell our suspension packages as we know they work.

feel free if you have any other questions.

 

I can't argue with this excellent approach. Now I am curious what TPC would come up with!
What coilover were you using during development of this bar?

BTW, I understand perfectly that vendors need to withhold proprietary information, but please when your product comes out at least the percentage change from stock at each hole must be listed. Thanks for sharing.

 

We test our sways on all different setups... our stock turbo has custom sprung/valved PSS10s, but we have installed the same bar on JRZ(our shock of choice) and on stock cars. If the bar is built to a good enough level, the range of adjustment should be able to accomodate stock suspension through just shy of race suspension. It is all about having a well rounded product. Our bars are expensive because we go through this testing and only bend a certain number at a time as we are always evolving our design.

 

KA, how's the popcorn? Thanks to this thread, I've learned something. For example, it seems everyone's bar is around 50% stiffer than stock at the rear. That is, there does not seem to be much variation as far as that most important parameter is concerned; so hopefully your choice would not break or make your car's suspension feel.

BTW, now I am curious. How was it determined that your GMG sway bar was "bent"?
I've heard of broken and/or bent drop link, not as much the sway bar. In fact, since you had stock drop link (right?), I am now extremely puzzled as to how the weak rubber joint stock drop link could bend the bar.
Is it possible the problem was with installation?

 

Most numbers are calculated by the old school "U" shape sway bar design dating back to the 70's, Pre Mermel LOL. Because of the complexity of the bends in the 997TT rear sway bar, you simply cannot use this basic formula to calculate that "our bar is 50% stronger". It does not work like that. It really does not matter what you have won or read, the true numbers of the sway bar can only be calculated by being put on a "bench tester" to calculate the load. I guarantee that none of the sway bars out there have this done as most are just reversed engineered of the stock ones to a different diameter with adjustment holes. I just got off the phone with our engineer and he told me this, "I can give you the U shaped number, but it is worthless. Each bend in the bar changes the stiffness in certain areas..."

So next week, he will take our bar and place it on the machine to get true actual numbers of how the Agency Power is compared to stock...

 

I believe only a portion of the mass associated with springs, shocks, links, and sways may considered unsprung.

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Cannaga - front sway bar only goes in one way. Not to cause issue, but when KA was here, he had mentioned of hitting some debris in the road and that the bar was possibly bent. Whether that was or was not the issue, we discussed and agreed on installing our Agency Power bars with his Motons for him to demo out and give his review. I have personally run both the GMG and Agency Power bars, can't say there is a large noticeable difference for a street car. Like you said above since most bars "appear" to be 50% stronger, whether that will change handling is yet to be determined.

Just for reference since we are discussing the rear bar, here is a shot of the GMG installed and the Agency Power installed.

 

The nerd in me has to respond to this.

This makes sense. because one end of, say the rear toe control arm is connected to the chassis, which makes it sprung, while the other is to the wheel carriage, which makes it unsprung?

In the case of the sway bar, it's held up by 2 points each side:
1. the drop link (unsprung)
2. urethrane bushing on the chassis (sprung)
My vote would also be sprung btw; maybe 90%.

 

Delicious actually!
Well here it goes...
I had the JIC on and the GMG sway bars. I hit a pot hole and the car started drifting a bit to the right. Did an alignment, was not it. disconnected the front sway bar links (those were actually left over from my PSS10's as the stock ones were too short to fit on the JIC's) at the end of the day I do not think there was anything wrong with the sway bars. the set of the JIC's actually had two options, use the drop link at the pinch bolt or the top section just like stock (WRONG!!!!) I could have probably used the same drop links i have on now (today found a loose one by the way) and would have been fine. I just went crazy and said change the whole thing! that's actually my style if you can tell from what i am doing now.

Another find... off topic but suspension related...
The hoes that links the bottom of the shock goes up in the fender and links to the remote canister was rubbing on the inside of the rim and it went through all the way to the steel breaded part of the hoes, no leaks thank GOD. Called Moton, wonderful guys by the way, told me not to worry and rotate the strut inwards 45 degrees and it should take care of it but !@#!$@@#$%@$%%^$%'ing eh! how many things can go wrong huh???
Car back together... will post impressions soon.