12-19-2002, 09:58:00 PM
I know, this has been here before but as said in one of the recent posts, it may be time for some new experiencies to be shared.
Myself, I am going to start spraying a little next year and will have to re-do the fuel system. I would like to do it once and right.
It was said here before that 'a single pump is a way to fly' and I am dying to hear why.
Also, what's wrong with the pressure switch?
How much better is the fogger over a big shot plate? I would be looking for 250-300 HP. I have a big pump, PE4450 and a BG regulator.
Please do not be afraid of 'stealing the post', I am looking for any experience I do not have.
12-19-2002, 11:24:00 PM
Gotta say I love this site and can't wait to see how this post goes? This will help me in my future one pump as well.
My 75 Camaro (http://www.geocities.com/oldschoolchevy1975/oldschool.html)
383 with AFR heads.
Old School for life!!!
12-20-2002, 01:00:00 AM
OK I'll blast this off. From a simple engineering standpoint there is no reason to run a second fuel system to supply the nitrous if a few basics are covered.
A) The pump can flow the required lbs/hr to fuel both the carb and the nitrous AT THE RATED DESIGN PRESSURE. Most folks don't realize as you raise the pressure you reduce the total flow per hour rating, be it lbs,gals or grams.
B) The fuel lines are sized properly.
C) I'd much prefer a return style system.
I can't see a reason to make things any more complecated than they already are.
A reason to run dual fuel sustems though may be as simple as wanting to be able to run 94 octane in the the main tank and switch to the 114 out of the fuel cell to run the ntrous. For my application, too complicated, I'll run small jets on the street and the big uns on the track (with the race fuel), where they belong.
70 SS 454 CI 650+HP All Aluminium Fuel Injected Small Block
12-20-2002, 03:18:00 AM
Fogger systems are superior to plate systems for the same reasons MFI is superior to a carburator. Better balance, less to worry about in the manifold (fuel tends to pool in any intake with a large plate system), and faster response.
As for the fuel system, I'll agree with Rick. K.I.S.S.
And, remember, the extra fuel and nitrous (which has a very high enthalpy) will require a massive spark to ignite. A ignition upgrade is in order, preferably a capacitive discharge ignition with a built-in rev limiter and retard for nitrous.
12-20-2002, 10:20:00 AM
This is a good start, I like it. So one pump is good if it can push enough fuel, I think I am covered here with some 400GPH and #10 line at 28PSI before regulator. What about the regulators? One for the carb and one for the solenoid? I think that's what 'slowsbc' mentioned recently. If so, they would be on a Y-block at the end of a main line, I suppose. Assuming the pump can compensate for the pressure drop when the solenoid opens, it would not effect the carb pressure, correct?
As far as the return line goes, if the pump already has an external return, is it necesary to have an other return line from the regulator? I was told NO. I understand that the dead head may cause the fuel to warm up in the line but other than that, any other issues? What about the kill switch? I used it last year and it worked well, are there any stories I missed? I also used the big plate with no problems. I see that fogger is better for even distribution but plate is just so much easier and cheaper (important right now). Is the possible fuel paddling a concern for backfires or fires or what? Also I used to use a Jacobs regulator that would launch at 50% shot and increase over the setable RPM range, any comments about the progressive controllers? Too hard on the solenoids? Any negative impact? I just liked it because it allowed me to launch without excessive spin, takes care of the timing retard and kills it if fuel pressure drops, carb not at WOT.
I think this is enough questions for now, anyone?
12-20-2002, 02:49:00 PM
Well, I found a few answers in a parallel post which I missed earlier...
12-20-2002, 05:21:00 PM
Why 1 pump is better than 2 in IMO..
1)Less money to buy one than 2..
3)If the pump goes bad for any reason going down the track it will kill the car. With a 2 pump setup if one pump goes bad the motor uses aluminum as fuel.
4)Less drainage on the battery
5)Less hoses and fittings
6)One less thing that can go wrong
What is wrong with a pressure switch (Hobbs pressure switch)?
Well nitrous does not like turning off and back on. The extra charge of the system going on of and on again can be detrimental to you motor. Never ever let off the throttle and stab it again when making a run..I know I know… you have seen a bunch of people do it before and get away with it. Well I have seen it also with people getting away with it. but then again I have seen what it does when you don’t. Remember you are not gonna break any world records or set the land speed record by getting back into it.
How much better is a fogger than a plate?
A fogger gives you individual tuning abilities where a plate is not so tuner friendly. Case and point. If you have 2 cylinders running lean on a plate. You will have to make the other cylinders run rich just to keep your 2 lean cylinders happy. With a fogger you can jet just those 2 cylinders.
I hope this information helps and remember this is my opinion so it is not set in stone..
12-20-2002, 06:55:00 PM
Thanks, that is a good info and I will keep it in mind.