rambunctious
Veteran
I have a NX wet system with a separate fuel reservoir and in line fuel pump.
my fuel pressure seems to vary way too much ( 6.0 psi - 8.5 psi in some cases)
is anyone with a similar system running an inline fuel regulator? or is a new, better regulated pump similar in price?
Ramb
my fuel pressure seems to vary way too much ( 6.0 psi - 8.5 psi in some cases)
is anyone with a similar system running an inline fuel regulator? or is a new, better regulated pump similar in price?
Ramb
Blown14psi
Pro
A 2 psi variance isn't worth worrying about unless it's not running right.
http://www.robietherobot.com/nitrousjetcalculator.htm
http://www.robietherobot.com/nitrousjetcalculator.htm
rambunctious
Veteran
the chart shows that for 6psi, 0.018 jets should be used
and for 9psi, 0.016 should be used. 30% less orifice area
or, physics tells me that for a given jet orifice. 9psi will flow 50% more fuel than 6psi
I didn't know how sensitive to A/F ratios Nitrous is
just wondering if i am running a very conservative (high) octane (110) and jetting(flowing) possibly 50% excessive fuel, if I was significantly hindering the potential performance.
I sure could use a dyno
Ramb
and for 9psi, 0.016 should be used. 30% less orifice area
or, physics tells me that for a given jet orifice. 9psi will flow 50% more fuel than 6psi
I didn't know how sensitive to A/F ratios Nitrous is
just wondering if i am running a very conservative (high) octane (110) and jetting(flowing) possibly 50% excessive fuel, if I was significantly hindering the potential performance.
I sure could use a dyno
Ramb
Blown14psi
Pro
I would jet it a little rich if anything especially if your using pump gas. With 110 fuel you could jet it leaner. The best way is to run it for 10 seconds pull over kill the engine and check the plugs. When you spray the bottle pressure drops causing the motor to run rich anyway.
I know it's a pain to pull the plugs but the more you do it the faster and easier it will be.
I know it's a pain to pull the plugs but the more you do it the faster and easier it will be.
longshot
Extreme
fuel pressure regulator
Probably an unreliable pressure gauge. I use the pump and gauge that came with the kit and my gauge seldom hits 5 lbs. the pumps according to Bruce put out a constant pressure of about 5 lbs which is what the jetting is based on. At least, that is what he explained to me when I questioned how to wire the fuel pump so it would not be running all the time. Good luck - Longshot
Probably an unreliable pressure gauge. I use the pump and gauge that came with the kit and my gauge seldom hits 5 lbs. the pumps according to Bruce put out a constant pressure of about 5 lbs which is what the jetting is based on. At least, that is what he explained to me when I questioned how to wire the fuel pump so it would not be running all the time. Good luck - Longshot
rambunctious
Veteran
the other thing I am thinking is i have the gage mounted rmotely ( on teh instrument cluster) with a long poly line from the solenoid to teh gage. maybe the air ( air/ fuel vapor mix) in this line is heating up from engine heat and pressure is rising???
I may try to bleed off most or all the air and see what this does
the cheapest pressure reg's i have found on ebay are about $40 with shipping.
Ramb
I may try to bleed off most or all the air and see what this does
the cheapest pressure reg's i have found on ebay are about $40 with shipping.
Ramb
longshot
Extreme
fuel pressure regulator
You hit the nail on the head. When trail riding and having all nos stuff turned off, my gauge reads as high as 5 psi. This has to be from the underhood temp. because it goes away when I shut off and let the sled cool way down. My lines go under the motor and up the chaincase side. Next time you're riding and have fuel pump for nos off, watch the pressure gauge and if it rises as you ride, get it good and hot then pull over and take a smoke break with the hood open to cool the engine compartment. I'll bet the pressure drops right off like mine.
You hit the nail on the head. When trail riding and having all nos stuff turned off, my gauge reads as high as 5 psi. This has to be from the underhood temp. because it goes away when I shut off and let the sled cool way down. My lines go under the motor and up the chaincase side. Next time you're riding and have fuel pump for nos off, watch the pressure gauge and if it rises as you ride, get it good and hot then pull over and take a smoke break with the hood open to cool the engine compartment. I'll bet the pressure drops right off like mine.
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