SLP vs. BMR vs. Spohn vs. Whiteline Sway bars... is thicker better?

[2quick]

If they were the same in every way other than hollow and, solid then the solid bar would be more stiff than the hollow bar. That doesn't necessarily mean that it is better or will out perform the hollow bar. There is a point where to stiff of a bar is not good. It comes down to weather or not the bars are design to balance the car in a way that the driver wants. Under steer / over steer and so on. Thats why when ever possible we make our bars with adjust-ability to them. The driver can change to there style of driving.

[BMR guy]

Originally Posted by Camaro427

There is a difference between hollow and solid bars. No matter how thick the hollow bar is, if they are both the same diameter and dimensions, the solid bar will outperform the hollow bar every time.

Everybody understands that there is a difference between solid and hollow bars, that is not in dispute. They both can work just fine but what determines how well they work is how properly matched the rates are for the given application. The rate is everything whether you accomplish it with solid bar stock or DOM tubing. The blank claim that a solid bar will outperform a hollow bar (given identical dimensions) is purely subjective since the requirements can and are being accomplished with each design.

[Camaro427]

I totally agree that you can go too far on a bar. A bar needs to be the last thing you do after you do an overall upgrade, which ranges from dampers, coils to tires and wheels.

But in all cases, given the exact dimensions, a solid bar will outperform a hollow bar by at least 30% minimum. This is pretty easy to figure out mathematically

[JDP Motorsports]

I suggest going with the Pfadt bars if you're planning on doing any tracking and they are also excellent on the street. Sway bars control roll stiffness as well as balance the chassis. GM designed the car to understeer as this is "safer" for the average driver on the street. The way to combat this in the 5th gen is by increasing the rear roll stiffness substantially while increasing the front moderately.



Front Sway Rates


Rear Sway Rates


The charts above clearly show how much stiffer the OEM front bar is in relation to the OEM rear bar. To get the chassis to a neutral state the rear sway stiffness must be increased dramatically to achieve this while the front bar is only increased marginally. A lot of manufactures simply take the OEM rate and multiply it by a nominal number (Same % front and rear) to achieve less body roll and the car does feel more responsive. The problem in this case is the front tire becomes overloaded faster leading to overstated understeer.

I spend a lot of time on the track as well as the street testing and this bar package balances the chassis the best IMHO. The drivabilty remains very similar to stock on the street while driving down the highway but 1 corner and you'll know your Camaro has been changed for the better. I also suggest going with the redesigned Pfadt endlinks; I've been running them for a while now and they are EXCELLENT!!

Please feel free to call, email or PM me anytime with questions. I'm always happy to help you find the best set up to achieve your ultimate goals. Have a good one and I'll talk to you soon!

Kind regards,

Jordan Priestley
888.308.6007

[JDP Motorsports]

Originally Posted by Camaro427

I totally agree that you can go too far on a bar. A bar needs to be the last thing you do after you do an overall upgrade, which ranges from dampers, coils to tires and wheels.

I'm going to have to disagree. I think a good set of Sways should be one of the first modifications. You need to bring balance to the chassis and sways are the means of doing that. Springs, dampers and bushings certainly make a substantial difference but sways are # 1 in my opinion.

Kind regards,

Jordan Priestley
888.308.6007

[JordonMusser]

wowza. Some mis information here. First of all they are ANTI sway bars, or better yet anti roll bars (ARBs)

Hollow vs Solid. Properly designed, hollow is better- period. However, given the design constraints imposed by the Camaro chassis, a solid bar (especially front) is prudent. Don't let solid vs hollow sway your decision. IE, a solid bar vs a hollow bar- stiffness difference is about +10% (give or take) yet the weight could be as much as 500%+. yes its low weight, but it is partial sprung and weight is NEVER good.

There is WAY more that goes into properly designing a bar than "track width and vehicle weight". Although its been awhile since I derived the equation by hand (I have kinematic software and matlab programs I have written to do it for me now).. It involves roll centers, ride frequency, motion ratios, grip levels and a few other things at a MINIMUM. Realistically we start looking at tire data and camber gain/steer camber as well to get as close as possible. The big boys do complete simulations.

We sell and install Pfadt stuff for our street customers. Not to piss on anybodies cheerios, but I feel like they have done their homework the best. not saying they have the end-all-be-all product, but they certainly have the best method to get there.

For somebody that is very serious about road racing/autocrossing or building a race car we of course recommend our anti roll bars (and matched shocks/springs of course). They are expensive, but carefully engineered and tested in GRAND-AM and World Challenge to be light and the proper stiffness, along with offering the correct range of adjustablity.

Very, VERY few people in the street car industry truly understand suspension design and setup. The ones that do often move on to pro level racing because they can make six figures doing so.

Ironically there is a manufacture who copied something off our cars last year for their ARBs (but made them out of press bent material instead of our CNC cut parts).... but they didn't take into account the whole SYSTEM which encompasses our shocks and springs, and thus they probably have one of the poorer setups. Obviously we don't carry this product.

[Camaro427]

Originally Posted by JordonMusser

wowza. Some mis information here. First of all they are ANTI sway bars, or better yet anti roll bars (ARBs)

Hollow vs Solid. Properly designed, hollow is better- period. However, given the design constraints imposed by the Camaro chassis, a solid bar (especially front) is prudent. Don't let solid vs hollow sway your decision. IE, a solid bar vs a hollow bar- stiffness difference is about +10% (give or take) yet the weight could be as much as 500%+. yes its low weight, but it is partial sprung and weight is NEVER good.

There is WAY more that goes into properly designing a bar than "track width and vehicle weight". Although its been awhile since I derived the equation by hand (I have kinematic software and matlab programs I have written to do it for me now).. It involves roll centers, ride frequency, motion ratios, grip levels and a few other things at a MINIMUM. Realistically we start looking at tire data and camber gain/steer camber as well to get as close as possible. The big boys do complete simulations.

We sell and install Pfadt stuff for our street customers. Not to piss on anybodies cheerios, but I feel like they have done their homework the best. not saying they have the end-all-be-all product, but they certainly have the best method to get there.

For somebody that is very serious about road racing/autocrossing or building a race car we of course recommend our anti roll bars (and matched shocks/springs of course). They are expensive, but carefully engineered and tested in GRAND-AM and World Challenge to be light and the proper stiffness, along with offering the correct range of adjustablity.

Very, VERY few people in the street car industry truly understand suspension design and setup. The ones that do often move on to pro level racing because they can make six figures doing so.

Ironically there is a manufacture who copied something off our cars last year for their ARBs (but made them out of press bent material instead of our CNC cut parts).... but they didn't take into account the whole SYSTEM which encompasses our shocks and springs, and thus they probably have one of the poorer setups. Obviously we don't carry this product.

I totally disagree with you! My comments are specifically targeted to the Camaro. And you are correct. There are limitations in dimensions, yet most vehicles have limitations as well. With respect to strength,math does not lie. Up to and including a hollow bar that has .300 wall thickness, a 32mm solid bar will outperform in terms of strength, a hollow. The math is on this forum somewheres.

[JordonMusser]

You can disagree all you want, but it's true

You are confusing terms here. Strength refers to the material property that involves yielding for failure. (fatigue life also, which is more likely to occur on an ARB and is dependent surface finish, heat treating etc). When discussing anti roll bars we are primarily concerned with modulus (or the 'springiness' of the material). Anti roll bars (when reasonably well designed) don't break(aka lack of strength).

A solid bar will always be stiffer and "stronger" than an equivalent hollow bar. However, if you don't NEED the bar to be stronger it is just added weight.

You missed my above rough example. A .120 wall 1" ARB is only about 10% softer than a SOLID 1" bar, yet weights a lot more.. 10% loss of stiffness, yet is a lot lighter.

Highly evolved bars like in NASCAR are CRAZY thin, like .050 wall sometimes. But they are bigger around. They get all the stiffness they need, and save a ton of weight.

Hope that makes sense, Ive seen people bicker over "ARB strength" when it is basically irrelevant. Unless you are building crazy thin bars (like the NASCAR example of a 2" OD, .050 wall tube) you aren't going to break the bar itself.

My personal Camaro street car has a mild steel (not even chro-mo) .090 wall ARB on it, and it has never had any issues.

Edit:
here are some real world numbers.

A solid 1.000 bar vs a 1.125" hollow (.120 wall) bar.

The hollow bar is virtually the same stiffness (1.5% or so stiffer actually).

The solid bar (assuming 36" long, and no levers which is actually optimistic) weights about 8lbs
The hollow bar, that is STIFFER, weights about 4lbs!

NEITHER will have any problems with strength (yielding because of max stress or fatigue life).


The only reason why (esp front) bars on the Camaro are solid is because of cost. They are a LOT cheaper to produce.