how much NOS can the stock fule pumps handle trans am

79 trans am
pontiac 400
stock fule pump
how much NOS can be used with a stock fule pump and still be safe
thanks  

None. Never use a stock fuel pump with Nos for the following reasons.

1. Pressure. most stock pumps only make 2-5 bls of pressure. An electric pump will allow you to use a regulator to control pressure. Fuel pressure is the only control you have over the fuel ratio for the Nos system. Different Nos jets for various HP amounts will all require different pressure settings as well. Instructions will be included in the kit for recommended pressures.

2. Flow. Stock mechanical pumps only have enough flow for about 350hp.

3. Failure. If you are running Nos, you must have a fuel system that can be counted on all the time. If you ever loose pressure with Nos, you will likely cause major damage such as blowing a hole in a piston, burning the head, etc. Make sure you have a fuel pressure gauge in the car, and EVERY time you are the top end of the track check it to be sure your are holding pressure. You burn the most amount of fuel in top gear, this is where you will start to see any weakness in the pump.

Run a Hobbs safety pressure switch mounted on the front of the fuel solenoid. You can set it to turn off if flowing pressure drops 1psi.

Even if you have an electric fuel pump, it is a good idea to run a separate fuel system and pump for the Nos, if you are going to use more then a 75hp shot. Again safety as a Holley Blue, or Holey Black only truly flow about 60% of what they advertise. Take any electric pump you buy in to a shop to be flow tested as well before installing. If you do spend the $$$ on a real fuel pump, then run 2 pressure regulators. One for the Carb and the other for the Nos.

If you plan on running, or to one day upgrade to more then a 200hp shot, a second fuel pump can be easily set up with its own fuel cell allowing you to run C12 or C16 race fuel. Large amounts of Nos produce extreme cylinder pressure, and will cause detonation no matter how much timing you pull out. Leaded race fuel will compensate and eliminate any detonation.

Nos can be a great inexpensive way to build power. But, it is also the most dangerous, and I see so many engine failures and expenses after a cheap system is installed. With an investment in a safe reliable fuel system and a quality ignition box with adjustable retard, you can have long term fun with little worries.