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Re: Atomic EFI Update
[Re: fuseable]
#1283571
09/21/12 12:48 PM
09/21/12 12:48 PM
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Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
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master
Joined: Dec 2006
Posts: 3,533
Indiana
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Quote:
The carb tuning may have left some on the table. When using the wide band I could never get all aspects of the carb tune good at the same time. I found to get a good idle tune you gave up some in the cruze tune, to get a good wide open throttle tune you gave up some in the cruze area, or the part throttle area, and vice a verse. I adjusted for 3 years always trying to get it better with a tweak here and an air bleed adj. there. What I always ended up with was a compromise of all ckt's of the carburetor tune. I think with the EFI it nails it in all areas. I am no expert but it is just my 2 cents.
And this is the issue with carbs. Average carb guy sets for smoothness, clean plugs, non-stinky-rich exhaust, then tweaks for more power. Unless he has a WB, he has no idea that his carb is compromising in one area of another. EFI not only offers significantly greater adjustability, but it monitors and adjusts itself too.
Last edited by Fury Fan; 09/21/12 12:50 PM.
Parts I seek:
driver doorpanel, 65 Sport Fury, prefer black, needs to be 7-8 on 10 scale, might buy set
16" x 6" Dodge truck wheel(s), from early 70s?, takes 9" dogdish - need for a research job so cheaper is better.
69-73 C-body caliper brackets and/or splashields
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Re: Atomic EFI Update
[Re: DaytonaTurbo]
#1283572
09/21/12 01:02 PM
09/21/12 01:02 PM
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Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
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master
Joined: Dec 2006
Posts: 3,533
Indiana
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Quote:
Quote:
May I ask why you altered the system and went with a return line? The Magnums have returnless fuel systems and they seem to work ok.
The magnums do have a return regulator, it's just installed at the gas tank. GM did similar with their ls engines. I don't know the reasoning for it, but it doesn't seem to cause a problem.
Most 'new' OEM EFI systems are returnless (from perhaps 2002 and up?).
- If you put a regulator at the rear, you just saved the cost of the return plumbing (which is a big savings at OEM level).
- However, if you add a PWM controller to the engine ECU, you can now alter pump speed/output to match engine needs, with savings of regulator cost, albeit with some expense of PWM circuitry.
- Another benefit of the returnless system is that you aren't constantly cycling excess fuel thru the fuel rails, heating it up, and returnign it to the tank (thereby taxing the Evap system). Remember that the volume of fuel cycled is highest when engine load is lowest, and most street vehicles spend most time at low load (as compared to WOT). I have heard of some hotrodder guys with return-type EFI systems 'boiling' fuel in the tank and cooking their fuel pumps on the multi-hour Power Tour-type drives.
At teh OEM level, returnless is a win-win.
Parts I seek:
driver doorpanel, 65 Sport Fury, prefer black, needs to be 7-8 on 10 scale, might buy set
16" x 6" Dodge truck wheel(s), from early 70s?, takes 9" dogdish - need for a research job so cheaper is better.
69-73 C-body caliper brackets and/or splashields
Send a PM.
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Re: Atomic EFI Update
[Re: Fury Fan]
#1283573
09/21/12 01:19 PM
09/21/12 01:19 PM
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Joined: May 2004
Posts: 12,409
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,409
Taxes & Virus's R-US, NY
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The EZ-efi from FAST is a good system, but Rich is correct about the low vacuum sensativity. If your not pulling at least 10" on vacuum at idle, it will not hit the target A/F until it get what it considers full vacuum...I have fought with this issue myself, and sometimes miss what you can do with a fully progamable open system. My solution was a custom curved distributer that has more timing at idle than a factory one.
The other issue with the Mopars seems to be cold starts. I have also had this issue when you first fire it up and it dies unless you have your foot on it...When I talked with Rich, he had a neat idea. Run the fuel pressure higher than 43lbs, but leave the computer thinking it was still at 43lbs. In essence your giving the motor a bigger start up shot of fuel until the computer see's the O2 reading.
I have done this, and it works pretty well, unless you hit the gas hard while its still cold, you can actually flood the engine for an instant and stall it...The other extreme.
And as stated, follow the instructions!
The other issue is more of an annouyence really during start-up, you have to push a few buttons to have the read out actually show anything other than "Comm Error"....It should just boot to the main live screen.
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Re: Atomic EFI Update
[Re: Dragula]
#1283574
09/23/12 06:50 PM
09/23/12 06:50 PM
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Joined: Jan 2005
Posts: 12,422
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,422
Kalispell Mt.
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Pretty much all new cars are returnless now, it is done for emmisions control and MPG. The fuel in the tank won't get heated and evaporate nearly as fast. This will also make the fuel last longer (time wise) as all the lighter molecules stay in the tank longer instead of leaving the mix and leaving heavy long chain hard to burn molecules. You will also get better mpg because the fuel is now hotter when injected so it evaporates in the intake and obviously since your fuel in your tank is not evaporateing you get more of it into the engine over the course of useing the tank.
Now for drag raceing it (a return system)could be usefull to build a couple more HP, especially with a throttle body injection. The fuel will be continually cooling the throttle body (while running) and that will cool the air/fuel mix in the manifold and allow more molecules to be packed into the cylinder and could also help with detonation if you are running borderline fuel octane for your engine.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Atomic EFI Update
[Re: HotRodDave]
#1283575
09/24/12 10:11 PM
09/24/12 10:11 PM
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Joined: Jan 2003
Posts: 3,704
MICHIGAN
DynoDave
master
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master
Joined: Jan 2003
Posts: 3,704
MICHIGAN
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Quote:
The fuel in the tank won't get heated and evaporate nearly as fast. This will also make the fuel last longer (time wise) as all the lighter molecules stay in the tank longer instead of leaving the mix and leaving heavy long chain hard to burn molecules. You will also get better mpg because the fuel is now hotter when injected so it evaporates in the intake and obviously since your fuel in your tank is not evaporateing you get more of it into the engine over the course of useing the tank.
Any reason a person could use a fuel cooler on the return line, like some diesels (Duramax) do?
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