Have a blowdown tube but it's not attached to the bottle yet. My question is does it have to be vented outside the car to be NHRA legal? What do your techs say about it venting inside the car? My local track is Bristol so they might be a little more strict. Thanks in advance. Brian.

 

Yes, it has to be vented outside the passenger compartment. Other wise what would be the point in even having one?
I've had a couple of techs check it and some not.

 

Sect 16 - General Regulations, 1:9 Nitrous Oxide:


This isn't just a matter of tech.... its a basic saftey requirement. A cloud of nitrous inside the car will block you vision, and could conceivably asphyxiate you. Don't take a chance.

 

If we were to have a true "trunk", a blowdown tube would not be necessary since the nitrous would not vent into the passenger compartment. Since we have a hatchback, our trunk is considered a part of the passenger compartment.

I'd just mount your bottle in the spare tire well and route the blowdown tube through the floor.