Are aftermarket Fuel Pressure Regulators legal for Street Prepared class?
You would think this would be straight forward, but the SCCA solo rules lack consistency in phrasing.
"15.10.C.1. Carburetors, fuel injection, and intake manifolds are unrestricted subject to 15.10.D."
Great! Fuel Pressure Regulators are legal because they are an integral part of fuel injection which is unrestricted.
Maybe not because elsewhere in the Street Prepared rules fuel lines, fuel filters, fuel pumps, fuel reservoirs and tanks are all specifically discussed and regulated which I would also consider part of the fuel injection system- but there is no mention of fuel pressure regulators.
So is 15.10.C.1 above simply missing the "except for the following limitations:" clause such as in Street Modified 16.1.D?
"16.1.D Drivetrain and related components (e.g., induction, ignition, fuel systems) are unrestricted except for the following limitations:"?
Or are aftermarket fuel pressure regulators not allowed because the rules don't say you can (the SCCA solo fall back)?
"15.10.F. Emission control devices may be modified or removed. This permits the oil filler cap to be modified or substituted but does not allow valve covers or cam covers to be altered to install a breather or for any other purpose."
Great! The fuel pressure regulator is an emissions control device. In California if you have an aftermarket fuel pressure regulator on your car you will be issued a ticket for illegally modified emissions equipment and have to revert it back to stock and go to a smog referee to get the car inspected and signed off.
Now, in the 15.10.F. the rules say emissions control devices may be modified or removed. Then in the example the emissions device (oil filler cap? Really?) is SUBSTITUTED. Substitution is neither modification of a device nor removal of a device...
Where did substitution come into play?
Back in 15.2.C.1 substitution is specifically listed as an option not inferred from an example.
“15.2.C.11. A 2-point strut bar may be added, removed, modified, or substituted, but only with another two-point strut bar.”
So, can I substitute emissions control devices as in the example from 15.10.F?
Yes, that would allow aftermarket Fuel Pressure Regulators, but it could also allow me to substitute the air pump with another air pump (Hey! That’s a supercharger).
Finally, common sense would say that of course even though it is not written aftermarket fuel pressure regulators are allowed since I cannot see the old carb swapped Street pared cars running with stock fuel pressure regulators. Aftermarket carbs are notoriously picky about fuel pressure.