Official Suspension Bars and Braces Thread

[license2ill]

Originally Posted by aackthpt It's well established in other threads that you can't compare stiffness values across testing methods. You also can't really compare test values vs. calculated values. If everyone testing a bar also tested a stock bar, and gives their test values for both, you may be able to calculate % over stock for each and have a useful comparison. If everyone gives their stiffness in percentage of stock, and don't make mistakes like "20% vs. 120% stiffer" as we were discussing, and they actually tested a stock bar vs. their own, we again might be able to make comparisons.

Yeah, It shouldn't be up to customers when companies are making claims based on unspecified testing methods. I don't care how many different ways exist, but when there's numbers and percentages being used to sell something, it should be explained for meaning.

[Inquisitive]

Originally Posted by TiGraySpeed6 The pic you're using currently for the Steeda rear Adj. End Link is the one I posted to compare the Steeda adjustable with the RacingBeat unit. Probably should switch that for the actual Steeda product image to avoid confusion.

Although I prefer your image for its comparative perspective, which none of the other images possess, out of respect, I accede to your request and have updated to the Steeda product image.

Thanks for the Racing Beat RSB End Links info, which I have also now included.

Originally Posted by some call me...Tim Thanks much for this info. Informative and concise. Not necessarily the most sought after item in the list but thought I'd add that Corksport does make a skid plate for both Speed 3s. I believe completely identical to each other.

Thanks, I have added the CS MS3 Gen1 Skid Plate as well.

@Spencer@CorkSport; Have you discontinued the CorkSport Lower Front Brace / Front Lower Arm Brace and / or importing the Autoexe Front Lower Arm Brace?

.

[SpencerC]

Originally Posted by Inquisitive @Spencer@CorkSport; Have you discontinued the CorkSport Lower Front Brace / Front Lower Arm Brace and / or importing the Autoexe Front Lower Arm Brace? .

We aren't making the lower control arm bar / brace if that is the one you are talking about. We had to many people complain that it was hitting.

[greatdane68]

Originally Posted by Spencer@CorkSport We aren't making the lower control arm bar / brace if that is the one you are talking about. We had to many people complain that it was hitting.

I haven't had a problem with mine, except for when I went to change my oil, but that was minor.
What was it hitting?

[Crarrs]

Originally Posted by license2ill Yeah, It shouldn't be up to customers when companies are making claims based on unspecified testing methods. I don't care how many different ways exist, but when there's numbers and percentages being used to sell something, it should be explained for meaning.

It's not up to companies to make sure their competition is using the same methods to make their claims, either. You need to figure out what you think will work best for your requirements. This is part of modding.

That said, what calculations/datalogging have you run on your current suspension that makes you believe a 15-20% difference in RSB stiffness is going to drastically impact the capability of one bar over another for your needs?

tl;dr
Buy the one you think is the prettiest. You probably aren't going to be able to tell the difference on your commute.

[phate]

Originally Posted by license2ill The lbs/in would indicate 300%, if the 479lbs/in for stock as stated by JBR is accurate. JBR indicates the rate is at 1" of travel, but that still doesn't explain the Hotchkis number completely.

JBR's description of rate makes no fucking sense at all.




They do make sense if you do the calculations for the bar, but it is the bar's rate, at the end link hole, holding 1 side static. Since there is a motion ratio involved, it will reduce the bar's effectiveness, and in roll you get deflection on both sides of the bar...

If you want to relate it to body roll, it is most common to express the resistance to roll in terms of lb-in/1° body roll, where it takes motion ratio and track width into account. Otherwise, just the bench rate is great, none of this "lb/in/in body roll".

Originally Posted by aackthpt It's well established in other threads that you can't compare stiffness values across testing methods. You also can't really compare test values vs. calculated values. If everyone testing a bar also tested a stock bar, and gives their test values for both, you may be able to calculate % over stock for each and have a useful comparison. If everyone gives their stiffness in percentage of stock, and don't make mistakes like "20% vs. 120% stiffer" as we were discussing, and they actually tested a stock bar vs. their own, we again might be able to make comparisons.

I doubt many companies bench test their bars. I know Whiteline does not, they told me that on the phone.

Most of the time, you can get a good idea of how much stiffer a simple bar is by looking at the change in diameter. Whiteline has a pretty decent chart showing this, here:



If you are changing from solid to hollow, or vice versa, this chart doesn't apply. Like I said, though, it's not 100% accurate anyway. Just a decent means of estimating % change.

[license2ill]

Originally Posted by phate JBR's description of rate makes no fucking sense at all. They do make sense if you do the calculations for the bar, but it is the bar's rate, at the end link hole, holding 1 side static. Since there is a motion ratio involved, it will reduce the bar's effectiveness, and in roll you get deflection on both sides of the bar... If you want to relate it to body roll, it is most common to express the resistance to roll in terms of lb-in/1° body roll, where it takes motion ratio and track width into account. Otherwise, just the bench rate is great, none of this "lb/in/in body roll". I doubt many companies bench test their bars. I know Whiteline does not, they told me that on the phone. Most of the time, you can get a good idea of how much stiffer a simple bar is by looking at the change in diameter. Whiteline has a pretty decent chart showing this, here: If you are changing from solid to hollow, or vice versa, this chart doesn't apply. Like I said, though, it's not 100% accurate anyway. Just a decent means of estimating % change.

I found this page on Whiteline's site that goes a little more in depth about adjutment holes and that chart you included. From the looks of it, the Whiteline bar is much more mild with a 16% and 35% increase from stock 26mm(adding 1 and 2mm on the chart), unless JBR's right about stock being 25mm. The Whiteline rear bar should be 36% and 57% stiffer if stock is actually 25mm.

http://www.whiteline.com.au/docs/bulletins/BL-281.pdf

I also found some info about the Progress 32mm hollow rear bar on another forum that states the stock rate of 862lbs/in. They also state the factory bar as measuring 25mm. The Progress bar has two settings: 56% stiffer than the stock sway bar with a rate of 1342.89 lbs/in
and 79% stiffer than the stock sway bar with a rate of 1542.27 lbs/in.

Progress Technology Rear Sway Bar Review

That info on the Progress bar seems to roughly align with the Hotchkis numbers of 95% stiffer than the stock sway bar with a rate of 1625 lbs/in and 140% stiffer than the stock sway bar with a rate of 2030 lbs/in. But how the Hotchkis is supposed to be so dramatically more stiff than the with what looks like the same measurements and attachment points is another question though. How Corksport's 28mm hollow bar is only 14% stiffer at one point and a whole 80% more stiff at the inside attachment point is another question too, unless they are in fact basing their claims on JBR's numbers.

For a piece that folks are saying is interchangeable amongst manufacturers, establishing a baseline of credibility to allow for a look at features and warranties is proving difficult yet again.

[Inquisitive]

Originally Posted by Inquisitive …If I were a competing manufacturer…

No fear, shipping costs would make me uncompetitive. Speaking of shipping costs, JBR ships for free yet for CS you must add $100.20 ($100.30) for US shipments. As an aside, shipping and customs fees usually doubles the cost of anything I purchase and I need 12 of my currency units for every US dollar (with lower local earning potential and lower purchasing power).

Back to marketing: Where is the mention of R&D in their ads? Where is the sponsorship (of Nator)? Where do they claim that Nator endorses their products? Back to general point, where is the standard testing facility mentioned (or ISO manufacturing standards)?

I thought that aluminium is usually more brittle than most other metals (not a good choice for a RSB?). Would mild steel work (backed by a lifetime warranty)? Is weight really a consideration (no marketing value) given that it is below the centre of gravity?

Where is the DIY stuff? Surely welding a cross bar near the end to the middle would stiffen the RSB (bad or impractical design?).

Are we doing our bit? If we asked vendors to provide the testing measurements, make modifications or provide a bulk discount, are we prepared to place orders in advance?

[license2ill]

Originally Posted by Inquisitive No fear, shipping costs would make me uncompetitive. Speaking of shipping costs, JBR ships for free yet for CS you must add $100.20 ($100.30) for US shipments. As an aside, shipping and customs fees usually doubles the cost of anything I purchase and I need 12 of my currency units for every US dollar (with lower local earning potential and lower purchasing power). Back to marketing: Where is the mention of R&D in their ads? Where is the sponsorship (of Nator)? Where do they claim that Nator endorses their products? Back to general point, where is the standard testing facility mentioned (or ISO manufacturing standards)? I thought that aluminium is usually more brittle than most other metals (not a good choice for a RSB?). Would mild steel work (backed by a lifetime warranty)? Is weight really a consideration (no marketing value) given that it is below the centre of gravity? Where is the DIY stuff? Surely welding a cross bar near the end to the middle would stiffen the RSB (bad or impractical design?). Are we doing our bit? If we asked vendors to provide the testing measurements, make modifications or provide a bulk discount, are we prepared to place orders in advance?

They're all steel tubes, but the CS comes with some nice billet aluminum, greasable clamps for the extra. JBR offers billet brackets on his $300 thick tube, or for an extra $90 on the standard version..

I'm still wondering if the stock rear sway bar is actually 25mm or 26mm, and if the Hotchkis is thicker material than the Progress bar, and how a 28mm CS bar achieves the numbers or if they really even mean 14% stiffer. The gap from hole to hole on the CS bar can't make for that dramatic of a difference, and at 28mm, it should be slightly stiffer than the 27mm Whiteline, but less than the 32mm bars.

Where are JBR's numbers coming from and how do they relate to the numbers for the other 32mm bars out there?

[mituc]

Originally Posted by license2ill I'm still wondering if the stock rear sway bar is actually 25mm or 26mm,

The factory rear sway bar is 25mm, front is 26.

[aackthpt]

Originally Posted by Inquisitive Where is the DIY stuff? Surely welding a cross bar near the end to the middle would stiffen the RSB (bad or impractical design?).

I don't know anything about it but @maisonvi; has a DIY RSB according to his sig.

[maisonvi]

Originally Posted by aackthpt I don't know anything about it but @maisonvi; has a DIY RSB according to his sig.

I did make my own RSB. 2 ways to make a RSB stiffer (well 2 of many ways, but for practical purposes just 2) Diameter of the bar, and thickness of the wall. Go bigger on either and the spring becomes stiffer.

I did the math on my bar vs the stock bar to calculate spring stiffness and made it according to what I wanted.

Also, material can be changed as well, but I was set on 4140 as my material, so that wasnt an option for me

[aackthpt]

Originally Posted by Crarrs Buy the one you think is the prettiest. You probably aren't going to be able to tell the difference on your commute.

So basically you're saying it's rice? Hmm. Based on this, you might be right.

And you're right, 80% of commutes I wouldn't be able to tell the difference. But if I install a mega stiffness bar and come around a freeway overpass doing 60+, encounter a traffic jam requiring immediate near-maximal braking, and the car snap-oversteers I'd know it. And that type of traffic situation happens WAY more than I'd like.

But you're right that 15-20% probably won't change anything.