Flowing fuel pressure ?s

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TE418
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Flowing fuel pressure ?s

#1 Post by TE418 » Sun Aug 20, 2006 11:24 pm

Im going crazy over this fuel pressure deal.

Im running a wilson pro-flo fogger system on my 565 CI chevy with 12 degree heads. Jetting is .028/.028 with the exception of #2 and #7 where the jetting is .030 fuel and .028 nos due to those cyliners running lean in the past.

If i do the math on the jetting i have i come up with .0806.

I had a buddy check the wilsonpro flow paperwork they say to run a .056 flow jet with the jetting im using.(I think they mean a .056 in each feed line when flowing the system)

Monty over on Yellowbullet wants me to run a .072 flow jet regardless of the jetting im using.

I need to get my system going for Labor Day but Im not comfortable running it until i get some consistant answers, its an expensive engine to be experimenting with so i need a safe tune up to start with im comfortable reading the plugs but i need a safe starting point.Any help would be great.

TE418
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#2 Post by TE418 » Mon Aug 21, 2006 12:33 am

Ok I thought about this some more and it seems my math and wilsons are very similar.

If I do the math on the flow jets Wilson reccomends (.056 x .056 x 2 then SQ RT) I get a similar flow jet diameter to what i got when i calculated my jetting which is making me feel better about using a .056 flow jet in each fuel feed line when i flow the system.

How do you calculate your actual flow jet sizes after finding the total diameter. i managed to get my .080 number but not sure how to get the actual jet number, i thought you simply divide it by 2 but that doesnt seem right.

hope Im making sence here.

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#3 Post by John_Heard » Mon Aug 21, 2006 8:45 am

For a single test jet, that comes out to be around a .079 jet (ignoring the slightly larger jets you have in 2/7). You're going to hear a lot of different opinions on what to do on flowing the system. The very most important thing is to decide which way you want to do it and stick with it. Personally I like to use the equivalent jet that is close to the size of what the system should flow.

One thing that I would recommend getting and that's Dave's Nitrous Master program, this will save you a lot of headaches and math. The program works well and is pretty close for most tuneups - close enough to get you in the ball park without hurting something, then you can make fine tuning adjustments based on what you see on the plugs. Just go out and buy this program - http://www.koehlerinjection.com/Koehler ... master.htm

It's well worth the price for the calculator alone, but you'll also find that it has some very helpful "help" files that are like a "brain dump" from Dave's head. This will get you started on your way and get you up to speed fast.

Steve-Place
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FLOWING PRESSURE

#4 Post by Steve-Place » Thu Aug 24, 2006 11:10 am

With a Fogger, Wilson recommends using ONE flow tool PER solenoid; TWO TOOLS WITH A FOGGER.
I don't understant why, but that's how their flow jet math is computed.

Essentially one for the left bank and one for the right. THAT is the difference in your math I believe. Remember, as an example, a 25 jet + a 25 jet does NOT equal a 50 jet in area.

I flow each regualtor as a seperate system regardles of the number of solenoids. Yours should be a 28 x 28 x 8 (cylinders) then sq root = 79.xxx That's how you get the math for the flow jet.

You're going to be way lean using the 56 jet to flow the whole system./b] I use use a #80 or even a #82 Holley Jet in their flow tool and flow the whole system at once. I have one and suggested a design change in their new threaded one thats coming out. That's our Corvette on Wilson's web page.

I am using the EXACT same FUEL jetting in mine as you are and a #74 was LEAN somewhat with the same fuel pressure. I used a 74 jet by accident. I intended to use an 84 WHICH WOULD HAVE BEEN WAYYY BETTER. As it was, I pilled-up the injector to make up the difference. Fuel is Fuel.

Think of flowing each regulator, instead of solenoids and it might help you understand what's happening. It helped me understand.

A person CAN use a 70 something jet BUT you have to adjust the fuel pressure REGULATOR to up the pressure ( how much?) and establish a fuel pressure baseline.

I used that method and it worked great up to the 500 hp setting then I developed a very mild lean condition stated above. I suspected it would be lean a little so I went with the #84 but accidently grabbed a #74! I need glasses.

If you use a 70-ish jet like suggested, you change fuel pressure. BUT, by how much? With the sq. area method, you keep the same fuel psi. Either way has pretty much equal acceptance.

Above 500 hp I use the 80-ish jet. At the track, if it's lean or rich, I change the pill in the injector to compensate.


Hope this helps,

Steve

TE418
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#5 Post by TE418 » Sun Aug 27, 2006 10:09 pm

Thanks for the replys. Ive been researching this some more and Im a little more comfortable with some of this but still have lots of questions.

Here is a pic of the flow tool I picked up, Ive been experimenting with it and it seems to work okay.My problem at the moment is the regulator, Ive decided to switch to a holley blue type since this product engineeriing one isnt consistant and sometimes creeps.I hear the holley one is the way to go for nos anyways.

Image

Ive decided to go with the sq. area type of jetting math, not the 70 something jet..The jetting is the same as what I posted earlier, I used a .080 flare jet (not a holley jet) and set it to 6.5 lbs. should I not use this type of tool and get 2 flow tools like wilson reccomends to set the fuel pressure? I dont see any difference but I will pick up their tools if I need to. If I end up using Wilsons flow tools I was going to run a .057 flare jets in each tool.the thing that concerned me about their tool was those small guages on the tools, are those accurate enough for fine tuning?

Last question for now is in regards to that comment about flowing each regulator rather than solenoids. I dont understand that, can you explain that please? Thanks for your detailed reply, I appreciate it.

Nice corvette BTW.

TE418

Steve-Place
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One step at a time.

#6 Post by Steve-Place » Sun Aug 27, 2006 11:43 pm

TE418,

If you had two systems, you would need a regulator for each system and then flow each one seperately. Looks like you have one system...one regulator. ( the carb regulator doesn't count in this case.)

With the Wilson two flow tool method, it comes out right at the same either way. A person can flow the whole system with one tool IF YOU HAVE A BIG ENOUGH FLARE JET.

I have two nitrous solenoids and two fuel solenoids but they come off one regulator... Whether you flow the 28 x 28 x 4, twice (each side) or the 28 x28 x 8, once...it comes out the same.

I'm guessing what Justin is gettng at by doing the two flow tools....since Fogger systems DON'T come with 84 fuel jets (that would be a 1500+hp system!) you have to split flow it to use the flare jets that came with the system.

Since foggers don't go that high in jets (?), you have to split the flow in two OR use the Holley jet method which the NEW threaded Wilson Flow Tools will be able to implement. My biggest fuel FLARE jet is a 46. I have to use the #84 Holley jet OR SPLIT FLOW the system like Wilson recommends with two flow tools. I surmise that is the reason they say to use two flow tools with a fogger. Until the new threaded flow tool comes out...

Also, you should have the gauge at the same level as the solenoid/regulator to get the most accurate reading. If I turn mine upside down, I get a different pressure reading. Make sure you write down your flow results, jet used, pressure, etc. You WON'T remember.

I use the small gauge as a base reference but refer to a big Autometer gauge mounted behind the hat/injector for actual fuel pressure numbers.

My pressure pegs the gauge when the system is armed. Big deal. A theory is this helps the fuel hit harder. It goes to the exact required pressure once the flow tool / system engages, though.

Do you have an air bypass line from each fuel solenoid? If you do, then you'll probably have to flow the system with the 84 jet if you "T" the solenoids together into a single line to the fuel tank. They'll be hooked together and not display a true fuel flowing pressure.

Long story short... use the single flow tool ( I use Wilson's) with the TOTAL area, Holley 84 (or whatever it figures out to be) jet. You can drill the flow tool end fitting out and tap it to accept a Holley jet but be careful or you'll gall and strip it out! It's made out of aluminum. Buying the new one from them that's threaded for a Holley jet, if its out yet.

=================NEXT-----------------------------------------

Start rich/safe on fuel pressure and come down 1/4 lb at a time. CHECK THE SPARK PLUGS for black specks and such or fuel wetness, etc.

Last, I don't know off-hand what tune-up that is, but its a 500hp on mine.
Start at the 200hp or so and work up. You can probably make two upgrades in a night easy enough...200 hp 200 hp change jets & re-flow fuel pressure then 300hp, 300hp and see where your at. Trying to start too big can be really difficult and expensive.

Thanks for the compliment.

Check out "Spark Plug Reading 101" by Mike Cantor


Hope this helps

Steve

TE418
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#7 Post by TE418 » Mon Aug 28, 2006 10:39 am

I had no trouble getting a .080 flare jet to flow my system from my local nitrous shop.. nos makes large flare jets.

Ive gotta run off to work and since I work in a shop I dont get to post on the internet all day while at work like all my friends.. what a bummer.LOL.

I have more questions, will post again tonight, those last 2 posts were a huge help, thanks a bunch.

TE418

TE418
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first question.

#8 Post by TE418 » Tue Aug 29, 2006 2:58 am

Do you have an air bypass line from each fuel solenoid? If you do, then you'll probably have to flow the system with the 84 jet if you "T" the solenoids together into a single line to the fuel tank. They'll be hooked together and not display a true fuel flowing pressure.
Im not really understanding this here.

yes i do have air bleeds..... are you saying that i need to have those air bleed lines inline with my flow tool when i se the fuel pressure? My air bleeds are just before the fuel solenoids and have .024 jets in them and return to the fuel cell.

TE418
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#9 Post by TE418 » Sun Sep 10, 2006 9:42 pm

Havent seen any action here in a while.. this thing still working?

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#10 Post by John_Heard » Sun Sep 10, 2006 9:50 pm

I'll answer for Steve, yes flow test it with the bleeds in place. That's what I do on mine, I think that more closely aproximates what the volume will be when the system is on.

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#11 Post by TE418 » Sun Sep 10, 2006 10:35 pm

thanks Beyond..

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#12 Post by TOMT » Mon Dec 18, 2006 5:22 pm

Hi there Guyz, Hey yep I read this thread and seen these flow gauges n tools that are out now. I have been running Nos 4 a few years now and came up with my own device years ago. Simple as to make.
I take off the fuel lines to the injectors, use the same jets, Say 28s, fit all 4 of these into my tool, connect the fuel lines onto the tool, plug the injectors on the manifold ( to stop air into motor ). Now I have one tool for each side, these then flow into a collection bottle. Simple?
I arm the system, bring the motor up to my rpm, hit the NOS, ( make sure your bottle is dead tho LOLOL ). Now with flowing this way I can set my reg to pressure, check my timing, check my fuel safety cut off, and if need be check my Mastermind. Also gives me a pretty good idea if both sides are flowing the same by compeering the bottles after.
This way solves the prob if you have airbleeds at the solenoids too, as you are flowing rite at the jet and not teed into the line at the reg.
I do this check if going up or down stages and doesnt take long to do. Works for me. 8-)
Any thoughts about this guyz??????
Work is a necessery evil, I,d rather be racing!
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#13 Post by John_Heard » Mon Dec 18, 2006 10:41 pm

TOMT that's a good way to do it, most people don't go to that much effort for making a fuel pressure change though. Most just use a single equivalent area jet and hook that to the regulator and make the pressure adjustment. Nothing wrong with what your doing though, and might catch a problem with a solenoid early too - like a bad seat or plugged line.

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#14 Post by TOMT » Wed Dec 20, 2006 3:02 pm

:-) Yep thats why I do it this way now, few years ago when we were running a plate and fogger, I melted a motor. Did the rebuild, checked the Nos, did a run n melted plugs. So came up with testing my way and found a faulty Fuel Solenoid!!!
Since then no probs, and its peice of mind. I no that your way of checking at the Reg is easier n quicker but....
It takes me about 15min from start to fin to check this way so its not bad? fiddly yes, nuthin better than droppin a jet on the manifold and the motor is hot lololol.
I have only come across this board this week and I,m lookin forward to reading and maybe gettin some questions answered by guyz that Race! :D
Work is a necessery evil, I,d rather be racing!
351 Motorsport
Glide
8.8s 175Nos
Street Legal
Lack of funds :)

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#15 Post by John_Heard » Wed Dec 20, 2006 3:19 pm

I can't blame you a bit for wanting to do the extra work, in fact it's a pretty darn good idea.

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