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Discussion Starter · #1 ·
Is there anyway to calculate the fuel flow (lbs/hr) on a nitrous system fuel jet on a given fuel pressure..


I know that the way the jet is drilled and the weight of the fuel etc. makes a difference, but my interest is to know how much the fuel flow changes when i hit a bigger jet size..

Thanks
 

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Discussion Starter · #3 ·
Really the best most accurate way is to flow the actual system with the jets in question, in place and get the real numbers... SJ

I took a fogger nozzle and put it in between the fuel line, then spun the pump to the actual psi and let the nozzle spray in a cup for 60 sec. is that the correct way to flow it my self??

And will it be correct if i weight the fuel result like this example


Fuel 60 psi
fogger jet #16
Fuel after 60 sec = 0.314lbs * 60min. = 18.84 lbs/hr

thanks
 

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I don't see being able to get an accurate number "spinning" the pump up and trying to catch it. How do you time/measure the before and after part of when the pump starts getting up to spreed as well as drips down afterwards ??? Not sure what exactly your trying to do or figure out, measure by weight or time based volume isn't really the most accurate..

We have inline flow meters that actually measure the flowing PPH as the system is flowing and measure it live as it flows. Hope this helps.. Thanks, SJ
 

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Discussion Starter · #6 ·
I don't see being able to get an accurate number "spinning" the pump up and trying to catch it. How do you time/measure the before and after part of when the pump starts getting up to spreed as well as drips down afterwards ??? Not sure what exactly your trying to do or figure out, measure by weight or time based volume isn't really the most accurate..

We have inline flow meters that actually measure the flowing PPH as the system is flowing and measure it live as it flows. Hope this helps.. Thanks, SJ
OK well i did 4 test on the same jet and all of them were in +/- 0.01lbs

And i spin the pump up to get the pressure, start the time and move the nozzle in the bottle, and as soon as 1 minute goes by i remove the nozzle so it wount drip...

But that is the only way i can messure the acual flow my self.

I know that you flow system is the most acurate but that is not a std machine in my garage;)

What i am trying to get out of all this, is just a ballpoint on how to build my fuel table for my efi dry shot.
shooting a 28n jet should match a 14 fuel jet @60psi

14 jet flowed 13.7lbs/hr x 8 = 109.6lbs/hr
Others in here are runnig 110-120lbs/hr on a 30n jet so i would say that this messure is in the ballpoint range...
 

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Discussion Starter · #8 ·
You are in the ballpark for sure. Read the plugs after a pass and you'll see how close you are.
Thanks...
Im gonna try this setup;)

I am leaving for race next weekend the first in our series this year.

We have a 4.60 class (1/8mile) and we ran 4.90 on motor alone with out transbrake(boke) at a testrun 2weeks ago.
So i hope i only need to just spay it with the small jets to hit the 4.60's:p
 

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OK well i did 4 test on the same jet and all of them were in +/- 0.01lbs

And i spin the pump up to get the pressure, start the time and move the nozzle in the bottle, and as soon as 1 minute goes by i remove the nozzle so it wount drip...

But that is the only way i can messure the acual flow my self.

I know that you flow system is the most acurate but that is not a std machine in my garage;)

What i am trying to get out of all this, is just a ballpoint on how to build my fuel table for my efi dry shot.
shooting a 28n jet should match a 14 fuel jet @60psi

14 jet flowed 13.7lbs/hr x 8 = 109.6lbs/hr
Others in here are runnig 110-120lbs/hr on a 30n jet so i would say that this messure is in the ballpoint range...
I hear ya as well as understand.. Also as Mike B knows too, Kgiblin on here has some pretty good EFI info if you need as well.. Thanks and good luck with your set up.. SJ
 

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Kevin Giblin (Kgiblin on the Bullet) and Jeff Prock are very good with Dry N2O control. I'm slowwwwwly learning............ I have a decent handle on it, but those two guys been doing it a lot longer than me! They also have used the FAST stuff PLENTY!

I did my stuff with other ECM's. Will be using a new one which should make things 100% easier for me!
 

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Discussion Starter · #11 ·
Kevin Giblin (Kgiblin on the Bullet) and Jeff Prock are very good with Dry N2O control. I'm slowwwwwly learning............ I have a decent handle on it, but those two guys been doing it a lot longer than me! They also have used the FAST stuff PLENTY!

I did my stuff with other ECM's. Will be using a new one which should make things 100% easier for me!

What new ECM are you changing to??
 

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Thanks for the compliments guys. As I told you before Bovien if I can help you out fell free to give me a call. You just need a good baseline to start with and that is no problem.

KG
 

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Discussion Starter · #13 ·
Thanks i will do that...
 
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