Been a while since I looked at it, but that sounds right. IIRC, That was a number someone else mentioned and I just used it as a reference. I don't remember if I actually measured the bar myself.

 

...still waiting to hear from a couple of the manufacturers, giving up on most of them except Progress Auto, 3 emails and a phone call later and still no love They did tell me the larger 27mm is no longer available though.

 

oh, and anyone know the wall thickness of the 24mm Hotchkis rear bar?

[edit]found some good reading here, basically what I'm looking for but for the wrong car
http://forum.miata.net/vb/showthread.php?t=486374

 

I don't see Robispec or Swift on this list.

 

Here's what I got about swift, *

Product Description

Swift Stabilizer bars are made with the same material as Swift Springs. They reduce roll without overpowering the lateral traction limits of your tires. This provides drivers with the best of both worlds, less roll to minimize unnecessary weight transfer, and soft enough to maximize traction.

SWIFT DOES NOT RATE STABILIZER BARS BY THICKNESS. Why? Because most manufacturers use different materials for their bars and some use hollow bars to reduce weight. Do you think one inch thick bar of glass moves and reacts the same as a 1 inch thick bar of steal? Of course not. Hollow bars are even worst, unless you know the thickness of the wall of the bar and the take up (how much material is used) on the bends, you cannot use formulas to establish the torsion rate.

TORSION RATE? The best way to compare a aftermarket stabilizer bar for your vehicle is to compare the torsion rate (the measured level of resistance the bar provides against roll) of the new bar. We use 100% to the stock OEM bars. With this measurement you have a measurable factor you can use if you are setting up your vehicles suspension for maximum performance.

Why aren?t they adjustable? In Swift's engineers best response, the reliability and durability of the bar is the main reason. By using custom end links, one may make these bars adjustable. Some companies use threaded ends or centers to control torsion, while this does work, it also may create a weak point in the system which can cause the bar to bend, crack, or break off. If we flatten the ends and add multiple holes, you weaken the mount points to stress fractures and cracking over time.

The second reason is the engineering of the bar itself. If you have seen many sway bars, you will immediately notice many more bends in Swift's Stabilizer bars. We use the bends to control torsion characteristics and flex thresholds. This provides a vehicle with a very comprehensive anti roll system that can increase the performance of the suspension for both street and track performance.

 

I had to google the above, because I couldn't believe that Swift would write such nonsense. I found the same babble on several vendor sites, but not Swift's. I'm not saying that Swift had nothing to do with writing said nonsense, but, as of now, I won't blame them.

 

Whoa, was that response from a secretary at Swift? Diameter absolutely matters more than material (show me a bar not made from some variant of spring steel). A 26mm with a 1mm OD change is a larger difference than coring out 50% of the ID.

Plus, mounting the bar... Need the right bushing diameters.

 

Dammit, I guess I need to take my glass swaybars off.

 

^Dibs, PM sent

 

Forgive me if this has already been discussed, but if you look at the tab-like brackets for the connection between the rear sway-bar and the upper LCA, it's clear that a new bracket with multiple holes (very much like the adjustable Cusco brackets for the front) could be made very easily. If folks are looking for adjustability from the OE rear bar or a wider range of options from an aftermarket bar, I would get a fabricator to make some new rear brackets.

 

IIRC at least on the CT9A there isnt a bolted on bracket like on the front LCA but rather a tab which is cast into the upper control arm. Now Im not under my car but I'm almost positive that is the case which would essentially make what you suggested impossible.

 

Well, nothings impossible but you're right on the tab. It would be tough to make something that clamped to the control. Plus I don't think its really needed with the huge range of bars available and how easy they are to swap out.

 

Sure anything is possible but it's not an apples to apples comparison between the front and the rear. Plus I completely agree about your last statement regarding ease of swapping the rear bar.

The front bar is a PITA and the rear bar is a 10 minute ordeal. It is for that exact reason that the adjustable front bar appealed to me as I dont want to put in a larger front bar right now.

Im not sure if this has been done yet but my plan is to utilize the adjustable front bracket to hopefully give me enough roll resistance to match what I have going on in the rear. I have spoken with Rick countless times about this and actually have a bracket in transit to me.

Currently Im using a Perrin RBS (25mm) on full soft and I have my FSB drilled. Im hoping the combination of the bracket and my DIY mod on the front will be enought to match what I have going on in the rear. I upped the rates on my Ohlins this year to 10K F 11.7K (650#) R but unfortunately after last weekends auto-x I found that my inside rear is still finding itself way up in the air on corner entry.

Im willing to bet that if I put back on my stock rear bar it will no longer tripod or at least will not tripod nearly as much but I like the idea of leveraging larger bars rather than just springs since my car is still daily driven.

 

Does not the correct "fix" for tripodding at entry depend on why it is happening? If you're lifting the inside rear due to body-roll, you want to increase total roll resistance in any manner, which could include more rear bar. But if you're lifting the inside rear because the outside rear is highly compressed and the rear bar is lifting the inside rear, then you might want less rear bar, instead. And why be so concerned about the inside rear being off the ground, anyway? It's not like getting it to just touch the ground is going to give it any grip. You'd have to make a huge change before that wheel starts contributing. If you like what the car is doing, does it matter how many tires are on the ground?

(Sorry, that was rambling.)

 

Well, you make a couple good points. To answer your main question, or at least attempt to, I don't know why I want to keep all four wheels on the ground. I've discussed this countless times and it's not that my car is doing something that I don't like, but rather that I feel like that wheel dangling in the air is not optimal.

I guess I'm sorta bummed out because I assumed that after making the jump from Bilsteins springs and plates to true coils the wheels would remain planted. Afterall I'm not even running real sticky rubber. My current rates should be more than enough for 255 ZII's.

I think the the combination of it being too soft in the front along with a large rear bar not allowing independent wheel movement is enabling the inside rear to dance in the air.