The V8 Owners Forum -

hi all, ive been thinking about running a seperate fuel tank and pump for the nos, is there anything wrong with doing this ,and does anything need to reset, rich

why run a second tank mate?
just run two pumps of the one tank, at least you will know if you got fuel or not then,
if your worried about pressure, put a pressure switch in line, then if it falls below a set pressure the nitrous won't trigger,
i run a single pump, for the efi and nitrous, (bosch 044 motorsport pump)
think stevie turbo runs these pumps too.

"running a seperate fuel tank and pump for the nos, is there anything wrong with doing this "

Yes Rich
There is a lot wrong with doing this. Your separate Nos fuel tank could run out and cause major engine damage unless you have it properly protected with a good quality fuel pressure switch. If you fit a good fuel safety switch to the Nos fuel line you should be ok.

I have a common fuel line from my main tank which splits two ways. One for the Carb pump, and one for the Nos pump. But I only have the cutout on the Nos fuel line.

When I race, I empty the 10 gallon tank and fill the 1.5 gallon tank. Then I connect the common fuel line to the small tank.

You can do what you want really. But you must make sure that if (NOS) system the fuel pressure drops to an unacceptable level, that the Nos shuts down.

ive got a fuel pressure cut off on the jacobs controller, its just the pump ive got which is a carter black top thing, i dont think it is strong enough to do both, so i got a edelbrock 140 gph pump , i was going to use the carter for the nos fuel line and the edelbrock for the carb, i can get a 1.2 gallon tank for 55 quid, the nos only gets used on race day, rich and i forgot ive got 2 pressure regulators and 2 oil filled fuel pressure gauges so i can adjust each fuel supply, or have i gone overkill again,

Sounds good Rich. I use a Carter Marine pump on the carb side and a Holley red top for the nos.
I have my nos petrol gauge on the dash and the carb gauge under the bonnet. For safety, it doesnt matter if the carb fuel supply drops off as long as you have the nos fuel side protected and the nos to petrol ratio set right. The worst that can happen if you lose the carb fuel on a nitrous pass is a loss of power as you should still be delivering enough petrol to satisfy the needs of the nitrous charge. I find the Carter pumps are very prone to damage if you dont have a good filtration too.
Have two rear facing fuel outlets welded into your little tank. One for each system.

hi perry, the little tank will just do the nos fuel, ive still got the original fuel tank in the car for the carb side of it. was putting the small tank in the wheel well and run some 3/8 fuel pipe upto the nos fuel solanoid, is 3/8 pipe ok,

Rich
A 3/8th feed to the Nos solenoid will be plenty mate. Assuming you do not want to run over a 250 shot that is.

at the moment just going for 100 shot, but got to get the car running better first, thanks for the replies rich

Rich
If set up ok, any RV8 will swallow a 100 shot with no adverse effects mate.

cheers Perry, hope to have it ready for june 8th, but dizzy being a pain in the rear, thanks again Rich

I'm glad you might be ready for the 8th Rich. I'm still without pistons...

I may well pop up on the 8th anyway. Do you want me to bring any tuning gear if you make it? I can shove my funky strobe and vac gauge etc in the boot. I may even be able to bring the gas analyser if I can ever find my invertor unit.
I could also bring my little TDC tool if you want to double check anything. Allways willing to help if I can. Or I could bung my TDC tool in the post if you want to borrow it and see how to make your own.

Perry

What fuel pressure does a nitrous system require?

its not just pressure mate,
you need to make sure the flow is up to it also,
mine runs at 36psi, but im running efi, BUT with a bosch motorsport 044 pump which is rated at 200ltr/hr
my old rover efi pump struggled with 50-75bhp gas as the flow wernt upto it when on gas with the efi injectors firing at WOT.

Depends how much fuel pressure you have available. Its not just pressure though. You need adequate flow at that pressure.
If you are running NASP as you will be, you probably have 3-6 psi available. You can jet up for this on the system I use. Or you may be running EFI with 30-40 psi which you can also jet for.
I run two fuel pumps. One for the carb and one for the Nitrous. Carb at 4psi, Nitrous at 6psi.

I'm running 2 pumps (red top facets), 1 for everyday and the other to flick on when I'm really going to dry up the float bowls in the carbs! Was hoping it would also feed the nitrous demands but that may not be the case then!