Front Anti-Roll Bars


Since we now allow smaller front sway bars, why not allow them to be adjustable? They effectively are adjustable under the current rules…you just need to change the whole bar. I propose changing the rule from: An unmodified non-adjustable front anti-roll bar, 22mm at the largest cylindrical point and an unmodified adjustable rear anti-roll bar, 19mm at the largest cylindrical point are permitted.

To: An unmodified adjustable front anti-roll bar, 22mm at the largest cylindrical point and an unmodified adjustable rear anti-roll bar, 19mm at the largest cylindrical point are permitted.


The rule allows only a 22mm sway in the front and only a 19mm sway bar in the rear. I dont think we should start getting into any more adjustability than the current sway bars give via the end links.


Let me try to help by providing the history of how we got to the current rule.

Obviously OEM sway bars are little wimpy things. The original SpecE30 rule, I think unchanged from it’s inception to Dec17, was intended to limit the size of the sways to 19/22. That was written with the assumption that everyone wanted stiffer sways, so it was targeted at the guy scheming re. how to do oversize bars. Since our cars were under-sprung, it was a reasonable assumption, imo.

The rule did not attempt to restrict smaller sway bars, because it was (prob accurately) assumed that smaller sways would be a disadvantage so no one would bother.,

We had some issues in 2017 Champ events (Sebring only?). This is 2nd hand so I might not have all the facts exactly right. There was an attempt to measure sways at Impound to confirm that they were legit. But it was found that measuring them was actually a little tricky. If the “can’t exceed” is 22m, what do you do when the dia at a bend exceeds that? Sure, that seems silly, but ask around re. Valvegate and you’ll understand that this sort of " no one would care" thing can have serious consequences.

There was a perception that the rule needed clarity re. how to make the measurement. So Shawn put in verbage that referenced “largest cylindrical point”.

Fast forward to today and our new springs. It is not necessarily a given anymore that stiff sways are good, so maybe someone might want to adjust the front bar weaker by installing a thinner bar. And now the rule seems to allow that, even it that wasn’t the intent.

Personally, I would be against additional adjustability. More adjustabilityadds complexity. It rewards those with the time and money to do additional testing of suspension adjustments. My thought is that we should just fix the wording to more closely reflect what was intended…the front bar needs to be 22mm.


Well, let’s clarify the rule then so that some folks don’t go out and buy/test/use softer bars. Theoretically, I could change a front bar to say a 19mm bar if the forecast called for rain. I would never bother, but maybe some more competitive, higher-budget folks might be inclined to do so at the Nationals.


I agree, and you’ve done everyone a service spotting the issue. But pls be patient and give Shawn time to address it. I’m a reliable source of hot air, but my actual authority is not an inch more than the SE guys allow me from month to month as their mouth piece(*).

(*) Try not to imagine sexual connotation there, no matter the temptation. I flat-ass couldn’t come up with a better way to say that.



I need to wash my eyes out now. :stuck_out_tongue_winking_eye:


I needed a word that implied that it was the group of SE racers that made the decisions as to how their group runs. I’m just the guy that articulates what they want, and organizes things behind the scenes. And writes lots of long emails that make people’s eyes glaze over.


I’m still looking for some clarification of this rule. Is this forum dead or not? How do these rules get made? Who is in charge? I’m willing to contribute to the process.


Most rule changes get submitted in the Fall and debated by the directors. I’ve got your rule change request on my list and I’ll present it in Oct. The only exceptions to the process are those instances where the issue is so important that it needs to be considered immed. If you feel that’s the case I’ll get some immediate feedback from Shawn.


I think it’s a pretty big deal to have changed the rule to now allow any size sway bar up to some max. I suspect that with some testing, folks would find that with the new stiffer springs, a softer bar is advantageous in certain conditions or on certain tracks. Hence my original proposal to say, why not just allow an adjustable bar in front which is a cheaper and easier solution to changing the bar stiffness. Likewise for the rear. One may find that a 16mm adjustable is better than a 19mm adjustable bar.

But, I’d be happy with clarifying the rule to what you say was the original intent - front bar is either 22mm or stock. Rear bar is 19mm (and can be adjustable), or it is stock.


But what you describe did not happen. The rule was changed to make “how to measure” more clear. There was no change made with the intent of allowing smaller bars. That was an unintended consequence of the wording, and you helped everyone by spotting the problem.

I certainly agree that it’s entirely reasonable to ask for a public clarification of the language. So Shawn will probably just issue some clarification that the swaybar rule remains 19/22, not “up to”.

I talked to Shawn a couple times over the past week. NASA HQ and SoCal responsibilities have him running 20+hrs/day. If he keeps going like this he’s going to kill himself, then will become national director and we’ll all be hosed. Nats at COTA is still months out. Pls be patient. The rule is 19/22, not “up to”. It’s been that way since the start of the series. The new language is ambiguous, but the rule is not. A small bar would not survive COTA Impound. An attempt to point to ambiguous language to support the small bar would be greeted with peels of laughter.


The language is not ambiguous. It very clearly indicates that one can run any size bar they want up to the max. I get the history, but times have changed. Now we have real springs and the size of your sway bar matters. So fix the wording to match the intent.

I’d like to go to Nationals with a smaller bar to just make my argument against the rule wording, but I’m too slow to be impounded.


You’ve gotten really fast these last couple years. We’ll be seeing you in Impound at COTA I bet.

Give Shawn a couple days to catch up on rack time. This is just a little disconnect between “the rule” and “the language”. Count coup for having spotted the flaw.


Its a big thread and I honestly dont have the time to get caught up but I did glimpse at a few comments. So please forgive be if I have missed anything.

The reason why the rule was changed to read: An unmodified non-adjustable front anti-roll bar, measuring no larger than 22mm at the largest cylindrical point and an unmodified adjustable rear anti-roll bar, measuring no larger than 19mm at the largest cylindrical point are permitted. are required. Manufacturer is free, unless specified in these regulations. A “Manufacturer” is defined as a company conducting commercial business in a specific location and which produces/builds a minimum of 15 anti roll bar sets of the same design, per year. Diameter measurements must be consistent over the entire length of the bar. Flattening of the bar ends by the manufacturer to facilitate end link mounting is permitted. These flat areas will not be subject to the maximum specified measurement.

The words “no larger” were added in 2 places because I realized that some drivers still ran on the stock swaybars. The intent was to not make their cars illegal because they didn’t buy the then required swaybar size when they should, by the spirit of the rules, be allowed to run the stock swaybar if they choose to do so. A cheaper alternative AND it did allow for some tunability if people wanted a softer option. The change had nothing to do with the springs, it was more of a clarification for those who still ran the stock swaybars. Technically, the way it was written, using the stock swaybars were illegal. Now it’s not.

The way I read it, you can use the stock size bar or the listed size.



the way it reads is that you can run any bar smaller then 22mm or 19mm. big huge loophole


Whats the loophole?


Zurbo…been shouting this since the inception of SE30. Seemingly has not been addressed because class management believes every e30 chassis is the same. In other words, makes too much sense:face_with_symbols_over_mouth:


Size dose not = stiffness. Spring material and lever length are as important as width.
What if the bar was square and just came to a 22mm point to rotate on?
We build a straight rear bar with spline ends to make it small and strong it’s 16mm but as strong as all the 19mm bars we have rated.
If you just open the rule to any sway bar like other E30 classes (PRO3) then you will have a few guys that try every bar out there sure but soon you would find that there would be a pair of bars that every one likes the best.

If someone wants a stiffer 22mm front bar it can be made so guys with money and time to test can still have an upper hand.

Just my out side looking in view.

Hank Moore
Advanced Auto Fabrication


It’s pretty much open now just with a max. OEM bars were still permitted so 16 and 20 were allowed just couldn’t be adjustable.