I'd like to mount my fuel pressure regulator on the firewall of my car. Is there a tech issue about it being in the same plane as the flywheel/ flex plate?

Yes...not supposed to mount them on the firewall.

Rulebook clearly states that is the ONLY place you can't mount it.

IHRA rulebook Page 81

http://www.mydigitalpublication.com/publication/?m=1203&l=1#{"issue_id":285638,"page":0}


Joe

I just read page 81 and it basically says you can mount it there. Read the last 2 sentences.

Old rule book, but:

1:5 FUEL SYSTEMS
Location: All fuel tanks, lines, pumps, valves, etc. must be outside
of the driver’s compartment and within the confines of the frame
and/or steel body. Cool cans, fuel-distribution blocks, etc. must be
located at least 6 inches forward of the flywheel/bellhousing area on
rear-wheel-drive (RWD) vehicles, and on opposite side of
flywheel/housing area on front-wheel-drive (FWD) vehicles. Fuel
pressure gauge isolators, with steel braided line, may be mounted
on firewall.

On old Mopars, the firewall is definitely not 6" forward of the flywheel/bellhousing area.
Why would it be legal to mount a regulator, but not a fuel distribution block, on the firewall?

Negative on firewall mount. That is a definite no-no

I have seen them mounted IFO the front carb or on the fenderwell. Front of the carb supposedly is the ideal location.

Exactly what it says in the 2016 book. It's always been nothing with fuel in it on the firewall and fuel lines outside of the frame rail or otherwise protected. That's what I read "etc." meaning.

The IHRA book says "It must be mounted as far away as possible from the flexplate/flywheel area" if it's on the firewall. To me, that means out in the fenderwell or somewhere away from the engine. How far from the carb do we want the regulator to be?

People smarter than me have consistently told me that you want the regulator even with or in front of the carb so the low pressure side of the system is not having to move fuel against the G-forces. Sometimes we overlook the obvious simple things.

I've been told ideally you want it ahead of the carb.

That way when car launchs all the fuel in the lines running back to carb will be pushed back towards carb, helping eliminate a momentary lean condition..

The regulator is for the fuel solenoid for my nitrous. I have no inner fender wells and the area for the fuel inlet on my Holley is already crammed with solenoids, switchs, and the carbs fuel pressure regulator. Maybe I'll mount it to the frame rail ahead of the motor mount and snake the line between the alternator and block.

Mine with no inner fender wells. Also run a protective steel plate where my line passes by the trans convertor / flex plate.