View Full Version : ABS in ST

03-01-2011, 04:16 PM
I just saw some posts on the scca forums that suggest the STU ABS rules are intended to allow all brake mods for the class AND abs, assuming the ABS components are stock.

I was under the impression that the rule was to allow ABS IF the car used the stock brakes, from MC to caliper and rotor.

I know there have been umpteen rewrites of late, but the language in the current GCR is:
9.1.4.O.12. Anti-Lock Braking Systems (ABS) are permitted on cars that use the OEM brake components as supplied.

so which is it?

Greg Amy
03-01-2011, 04:18 PM

You can run alternate brakes or ABS. How is your last sentence not clear on that point?

03-01-2011, 05:13 PM
Because the last sentence COULD refer to the OEM ABS components ONLY, and the rest of the system could be assumed as free.

Greg Amy
03-01-2011, 05:19 PM
Recommendations to clarify? The "old" World Challenge rules (the ones I used to create Modified Touring years ago) read:

Competitors may choose from one of the following front brake systems:
1) Stock OEM braking system
a) Unmodified Antilock Braking System (ABS) is allowed.
2) Aftermarket braking system
(description of allowance)

I guessing the current wording comes from the 2009 PRR for World Challenge.

Where on sccaforums is this discussion? - GA

03-01-2011, 05:26 PM

You can run alternate brakes or ABS. How is your last sentence not clear on that point?


second to last post.

like I said - my impression was ABS with stock brakes or open rotors and calipers up to the specified maxima. I PREFER this reading - and I gather from your post that you see it that wasy as well.

but there is comnfusion out there, and since Peter posts there often (if a single sentance on a regular basis can be considered a post) I figured he would have straitened it out if it were wrong.

generally - the ST rules are mess. "X may be done" "Y, Z, are forbidden" is a better way to right the rules. that, and deciding from the start if the rules are open with limits (permissive) or only allowed modifications (restrictive) and sticking with that standard throughout - at least within a section.

also - WRT ST rules - the weights should be in a single lookup area, the rules should be combined by class(I understand this is in the works)as there is too much lookingback and forth and general dischord in the current format.

some people will NEVER read all of the rules, either by willful ignorance of the limits they don't like or laziness. others will read and fail to understand. and others will make assumptions based on their existing paradigms. IT has trouble, this can't be easy.

03-01-2011, 05:27 PM
In the WC rules they use the words " unmodified Braking system"

In the ST rules you use the term, "OEM components"
"System" is all inclusive....

Greg Amy
03-01-2011, 05:38 PM
Chip, that post is from September...and it was in the context of the rules not allowing ABS in STU.

Do me a favor, Jake or Chip? Submit a quick request through the CRB system, with the language from the World challenge PRR (or something suitable) requesting clarification? The intent is - well, in my mind, and in my preference - to allow ABS but only for those cars without aftermarket rotors/calipers. We'll discuss it on the next concall to ensure that's the other members' intent as well. - GA

Greg Amy
03-01-2011, 06:47 PM
I just found a copy of the 2009 PRR, and ABS was disallowed in TC: Anti-Lock Braking Systems in TC
Any car equipped with an OE ABS system shall completely remove all
ABS components.

We'll need to pass that through the STAC to clarify and appropriately re-word intent. - GA

03-01-2011, 09:47 PM
tGA - I know the post was old, but there was a "statement of intent" and re-reading the rule, I could see where one might (try to?) read it as such.

Letter 4327

please clarify 9.1.4.O.12 anti lock brake allowances.

It has been read to mean that the "OEM components" are the entire braking system or just those "oem components" used for ABS function, in which case the full class caliper and rotor allowance is available.

I believe the intent is to allow ABS only with the complete braking system as supplied on the vehicle, master cylinder to calipers. I also believe that plumbing should be open so long as the OEM circuit configuration is maintained (to allow for clearance fo swapped motors, replacement of rubber lines, etc..)

I suggest the following wording:
12. ABS is permitted if
1. The system is that which was installed on the vehicle from the factory
2. The system is not modified in any way (lines may be rerouted or replaced but must follow the OEM schematics).
3. The brake calipers and rotors must be the original equiment pieces for the car.

cars not equipped with ABS may use any brake components allowed for their class.