I am familiar with the Aussie 23mm rear bar issue requiring boxing of the subframe (and some failures also I know with the old SCA 21mm). But I just noticed that the BAT 21mm bar advertizes that it "is the only bar that exactly matches all the stock bar curves so as to cause les stress on brackets"
So basically, any word on whether BATs bar has lead to similar bracket failures..??
Don't they all lead to bracket failures? I think its more about the stress put on the brackets by the bigger bar.
Thats my Q. I was assuming it was all bars but then the add suggested the BAT bar perhaps less prone (may be advertising BS too... And off the top of my head I could not specifically recall the BAT bar implicated in failures.
So, whats the scoop?
The BAT site suggests that the bar has some lateral freeplay because of the link designs. When the bar contacts the subframe at one of the bends, excessive pressure at the intermediate point breaks a bracket. The BAT bar has little "stops" that prevent any lateral movement through the bushings, so the bar never contacts the subframe.
That's their explanation, not mine. At least that's how I understood it. I have the 21mm bar. I like it.
Still have my SCA 21mm bar.....
no broken subframe mounts but I did bend brackets like no other. My fix, I bought the large U brackets and grooved poly bushings that Aussie recommended for his bar in the 21mm size.
I rigged it up using the stock bolt and mount and also went to the hardware store and bought some high grade bolts, lock nuts, and a few fat washers. I ran the bolt down the hole where the stock bracket notched into with a washer on each side. I ran the nut up and tightedned it down. Its been a year or more and no problems.
I've never autocrossed but I'm sure if I was still running the stock brackets I would have tore the subframe mounts off. Once the stock brackets bend themself out of shape it then is a constant banging sound where the bracket is hammering itself against the stock mount.
I have the BAT 21mm bar and stock brackets.. knock on wood.. I haven't had a problem with it.
First of all I think this should be moved to "suspension" so we can get more results.
But I am wondering the exact same thing, I've had a new bat 21mm bar and bushings in my basement for a couple months now and with the warmer weather I'm getting ready to install it.
I don't know if I want to install it if its just going to lead to failure. Or I want to know exactly what I have to do in order to prevent failure.
I have the SCA 21mm bar and needed subframe reinforcement.
Trying to recall here.... wasn't the BAT bar the same diameter as the stock bar, at 19mm, but BAT said they used some heat treatment to increase stiffness? If so, what a load of garbage.
I seem to recall we've been through this discussion before, and it went like this: if the BAT bar is the same diameter as the stock bar, then the stiffness will not be any different. Hence, there will not be any handling effects. If you want to look at this in a positive light, at least that means the mount loads won't go up, and hence the subframe will last.
As an engineer, I can't imagine the geometry bits, end stops, whatever, that BAT describes having anything to do with subframe durability. Take a look at the stock cantilevered mounts, and it is easy to see why larger bars lead to failure.
Check the archives, but yes, I recall some people having the same issues with the BAT bar as the Aussie bar wrt subframe/bracket failure. The great TH suggested to me that I consider reinforcement regardless of what bar I chose.
As for the diameter, check the archives again, but I think the BAT bar was something like 20.4 mm. The stock "19mm" bar is actually 18.x. To confuse matters even more, the early SE "19mm" bar and the later SVT "18mm" bar are, IIRC, exactly the same.
The BAT bar is indeed bigger in diameter and heavier than the SVT bar. I didn't need to use calipers when I swapped bars out. And it makes a *big* difference turning the car too -- remember that diameter in sway bars is a fourth power!!!