How To Write a Rule

[ShelbyRacer]

With that in your rulebook, do you install a cat, or do you throw it in the trash?

According to that rule, if you had a convertor (or more than one), you still need one, though it may be a high flow unit.

Where is that rule from?

[Andy Bettencourt]

Looks like Solo ST.

[JIgou]

That one is copy-pasted from Rallycross rules. Wouldn't surprise me if Solo ST was the template.

[ShelbyRacer]

Ah yes, RallyCross. I didn't think it was quite a Solo style.

If the class from which this is pulled is intended to be a street class, then the retention of operational emissions equipment is understandable. Also, given RallyCross' roots in Rally, remember that Rally cars must be street-legal (inspected and registered) for purposes of transits. I'm not certain if that philosophy has held over into RallyCross, but it wouldn't surprise me if it did...

[JIgou]

1. I can replace the exhaust from the head back. Materials are "any material". I pick a straight pipe with a small muffler.

Next up, I have to pay attention to a, b and c.

a. Exit behind the driver. No problem.

b. Comply with noise. No problem.

c.......
1. Any high flow cat is allowed.
2. Multiple cats may be replaced by a single cat, and the location of that single cat is specified.
3. If it didn't come with one, I don't have to have one.

Bolding is mine. I don't see anything in there that says I need to keep a cat. I'm ALLOWED to have a high-flow cat - no requirements there. I'm ALLOWED to replace two factory cats with one, and if I do that I'm restricted on its location. Only requirement is location. If the car didn't come with one, I don't need to add one. Again, no requirements.

It may very well be the intent that a cat is required, but I would have NO problem showing up with no cat and pointing at this rule in support of that.

[JIgou]

Oh, and to add - this is RallyCross "Prepared" class.

[Andy Bettencourt]

1. I can replace the exhaust from the head back. Materials are "any material". I pick a straight pipe with a small muffler.

Next up, I have to pay attention to a, b and c.

a. Exit behind the driver. No problem.

b. Comply with noise. No problem.

c.......
1. Any high flow cat is allowed.
2. Multiple cats may be replaced by a single cat, and the location of that single cat is specified.
3. If it didn't come with one, I don't have to have one.

Bolding is mine. I don't see anything in there that says I need to keep a cat. I'm ALLOWED to have a high-flow cat - no requirements there. I'm ALLOWED to replace two factory cats with one, and if I do that I'm restricted on its location. Only requirement is location. If the car didn't come with one, I don't need to add one. Again, no requirements.

It may very well be the intent that a cat is required, but I would have NO problem showing up with no cat and pointing at this rule in support of that.

The key piece is #3. It specifies when you can NOT have one.

[ShelbyRacer]

The key piece is #3. It specifies when you can NOT have one.

Agreed, as that was my key issue.

But Jarrod, I'd agree that the rule could be much more clear. In the end, you could show up without one, and you could use that rule as a point of issue. But I also think if it came down to it, you'd lose in an official sense.