[Joel Koontz]

I need to buy and install a fuel system to use when I add NOS to my car. I have never had the Car to a track, and won't, because it is a convertible and has no cage. I would guess it is approx. 400/425 HP. I have a G-Tech and the best run with it has been 12.82 at 117 mph. From what I have read G-Tech will usually give a close ET but is likely to read 3/5 MPH high. As you can tell by the ET/MPH I have very poor traction. I am planning suspension and tire changes to improve traction. The car is a 68 GTO. It currently has a a 462 with RA 4 cam, Rhoades Lifters, ported(by me) 6x#4 heads, 1.65 HS Rockers, 66 Tri-Power, MSD 6AL, headers and 3" exhaust with Xover. Switch Pitch Turbo 400, 3.31 posi 12 bolt and 275/60/15 Radial TAs.

I will probably add a NOS Cheater(150-250HP) system this year and may do additional work to the motor that will increase N/A power. I want to build a fuel system capable of 700 HP.

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This is the fuel system I plan to use, unless someone talks me out of it:

AN 12 line from tank to Perma Cool Canister Filter (filter looks like an oil filter, flows 25 GPM), AN 12 line to BG 220 HR Pump (the electric pump will only be activated when the TH-400 Kickdown Switch is on), 1/2" line to Edelbrock Victor Mechanical Fuel Pump (modified to work on Pontiac), Y-Block with AN 8 line to Deadhead Regulator and then AN 6 to Tri-Power, AN 8 line from other side of Y-Block to Return Regulator (comes with the BG Pump), then AN 6 to NOS Fuel Solenoid (I will install a low pressure shut off switch) and a 1/2" return line to the tank or filter (see question below)

My reasons for choosing this setup are:

1. To keep the number of fuel lines to a minimum.

2. Street car so it will run on Mechanical Fuel Pump 98 percent of the time.

3. I plan on using an Edelbrock Victor Mechanical Pump because it has 1/2" NPT in and out connections (most others have 1/4 or 3/8 NPT)and this should minimize restrictions when Electric Pump is operating.

4. Relatively simple (compared to other options)

If you think this would be a good system, please say so. If not, please state EXACTLY what you think is "wrong with it" and SPECIFY why you do not think it would work well.

A couple of specific questions I have:

1. Will the regulator setup I have described work OK. If not, why not? I have read that you cannot use any other regulator in a system with a return regulator but I do not know why not. The Deadhead Regulator(to carbs) will always be set lower than the Return Regulator (to NOS Fuel Solenoid) so it seems to me like it should work.

2. The Perma Cool Fuel Filter has two 1/2" NPT Inlet Ports. Can I hook one of the lines to the tank and the other to the return line? If not, why not?

Please give your suggestions and comments. I need to get components ordered ASAP.

Thanks, Joel

[Joel Koontz]

I need to buy and install a fuel system to use when I add NOS to my car. I have never had the Car to a track, and won't, because it is a convertible and has no cage. I would guess it is approx. 400/425 HP. I have a G-Tech and the best run with it has been 12.82 at 117 mph. From what I have read G-Tech will usually give a close ET but is likely to read 3/5 MPH high. As you can tell by the ET/MPH I have very poor traction. I am planning suspension and tire changes to improve traction. The car is a 68 GTO. It currently has a a 462 with RA 4 cam, Rhoades Lifters, ported(by me) 6x#4 heads, 1.65 HS Rockers, 66 Tri-Power, MSD 6AL, headers and 3" exhaust with Xover. Switch Pitch Turbo 400, 3.31 posi 12 bolt and 275/60/15 Radial TAs.

I will probably add a NOS Cheater(150-250HP) system this year and may do additional work to the motor that will increase N/A power. I want to build a fuel system capable of 700 HP.

******************************************

This is the fuel system I plan to use, unless someone talks me out of it:

AN 12 line from tank to Perma Cool Canister Filter (filter looks like an oil filter, flows 25 GPM), AN 12 line to BG 220 HR Pump (the electric pump will only be activated when the TH-400 Kickdown Switch is on), 1/2" line to Edelbrock Victor Mechanical Fuel Pump (modified to work on Pontiac), Y-Block with AN 8 line to Deadhead Regulator and then AN 6 to Tri-Power, AN 8 line from other side of Y-Block to Return Regulator (comes with the BG Pump), then AN 6 to NOS Fuel Solenoid (I will install a low pressure shut off switch) and a 1/2" return line to the tank or filter (see question below)

My reasons for choosing this setup are:

1. To keep the number of fuel lines to a minimum.

2. Street car so it will run on Mechanical Fuel Pump 98 percent of the time.

3. I plan on using an Edelbrock Victor Mechanical Pump because it has 1/2" NPT in and out connections (most others have 1/4 or 3/8 NPT)and this should minimize restrictions when Electric Pump is operating.

4. Relatively simple (compared to other options)

If you think this would be a good system, please say so. If not, please state EXACTLY what you think is "wrong with it" and SPECIFY why you do not think it would work well.

A couple of specific questions I have:

1. Will the regulator setup I have described work OK. If not, why not? I have read that you cannot use any other regulator in a system with a return regulator but I do not know why not. The Deadhead Regulator(to carbs) will always be set lower than the Return Regulator (to NOS Fuel Solenoid) so it seems to me like it should work.

2. The Perma Cool Fuel Filter has two 1/2" NPT Inlet Ports. Can I hook one of the lines to the tank and the other to the return line? If not, why not?

Please give your suggestions and comments. I need to get components ordered ASAP.

Thanks, Joel

[Old Man Taylor]

I was not able to understand your description of so many regulators, and the term “deadhead” regulator. I will tell you what I have on my nitrous powered tri-power that works fine. I have a Fram filter at the tank. A ½” line goes to the Carter 4594 electric pump. A half inch line goes from there to the Carter mechanical pump. The output of the Carter Mechanical pump goes to a Y fitting. There are two 3/8” lines on the output of the Y. Each goes to an independent Holley regulator, one for the tri-power and one for the nitrous solenoid. Both lines are 3/8”. I do not have a return line. The car ran 130 in the quarter without leaning out. The parts sound old because they are. This is the system I set up in 1978.

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Jim


[This message has been edited by Old Man Taylor at home (edited 03-28-2001).]

[77TA]

I think I would tie the fuel pump to the NOS activation switch not to a switch on the carb that might cause undue cycling of the pump and pressure flucations. It might not hurt anyhing but I think having the switch that arms the NOS system also start the pump would be a better way to do it. If your not running a aftermarket ignition this might be a good time to upgrade to a crane or MSD or something that would give you autotiming retard when you spray. That will keep you from having to pull timing out that could hurt the motor under non N2O conditions. I don't fully understand your regulator setup seems like you have and extra in there you don't need. I don't think you need a 1/2" return line either. I am not a N2O person though I have considered it for a future mod myself just take what I have said and think about it maybe it makes sense maybe not.

Good Luck !!

[Joel Koontz]

Jim, you gave me info on your fuel system a couple months ago. The fact that your system has worked well for a long time is one of the reasons I thought my proposed system should work OK. I have posted NOS fuel system questions on other sites and have gotten several responses suggesting I should have a completely seperate NOS fuel supply system and others that say I should not run an Electic Fuel Pump thru the Mechanical Pump (which would require 2 seperate fuel systems or an Electric Fuel Pump only system)

I have seen regulators that do not have a return line referred to as "Deadhead Regulators". Most of what I have read says that a Return Style Regulator has less fluctuation and should be used for Nitrous. I don't think the carbs are near as sensitive and therefore I thought they would be OK with a Deadhead Regulator. Based upon your experience I could problably use 2 Deadhead Regulators and not need a return line. I may want to run a return line just to keep the Mechanical Fuel Pump from having to work so hard under light throttle conditions.

77TA, you may have a good point about potential pressure fluctuations if I try switching the Electric Fuel Pump on with a throttle switch. An Edelbrock Victor Mechanical Fuel Pump should supply enough fuel for the motor alone so switching the Electric Fuel Pump on with the "Nitrous Arming Switch" may be a better way to do it.

Thanks, Joel

[Old Man Taylor]

I do not like the idea of turning on the electric pump simultaneous with the nitrous enable. It may be overkill, but I am afraid of instant starvation. You usually know when you are going to use the nitrous. I have a toggle switch under my dashboard that turns on the electric pump. I put the enable switch on the linkage at the back carburetor so the nitrous is on as soon as the carbs are wide open. I also have an enable/disable switch for the nitrous under the dash.

------------------
Jim

[Joel Koontz]

Jim, what you described as the enable/disable switch is what I meant when I said the "Nitrous Arming Switch". I would not connect the Electric Fuel Pump to the actual "Nitrous Activation Switch" for the reasons you mentioned.

Thanks, Joel