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Discussion Starter · #1 · (Edited)
Well the real reason for a return system is you could use a 1to1 fuel pressure regulator, per every psi of boost you'll get a psi of fuel pressure.

with a return system you'll be able to better tune the car for driveability as well as WOT, and not worry about taking out so much fuel out, since it will be there only when u need it WOT under boost.
QUOTE FROM BLACKSRT-4U

SO W/ A STOCK TURBO, RETURN LINE AND FPR 1T01 IS IT POSIBLE TO TURN THE FUEL PRESSURE DOWN TO A SAFE PSI/ AFR FOR LOW BOOST/VAC (DRIVEABILITY) AND STILL NOT LEAN OUT AT WOT. IF TRUE THAT WOULD USE LESS GAS AT LOW BOOST OR VAC AND FUEL PRESSURE WOULD GO UP AS BOOST WOULD. ANOTHER ?. IS THERE A WAY TO RAISE FUEL 2 TO 1 LBS OF BOOST. IF IM WAY OF THINKING IS RETARED LET ME KNOW...
 

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Not sure what the question is here, but let's think about it this way...if you're running 750s in your car obviously it would be way too much fuel at 58psi when idling, so you bump the fuel pressure down at idle. Still you're not dropping them low enough with the fpr at 43psi to give less fuel than stage 1 injectors and maybe not even low enough to give less fuel than stage 2 injectors. So really you're only bumping the fuel pressure down at idle to make the car run correctly, not to save gas mileage. If you want to save gas, you'd better take that big turbo off and run your stock injectors mang. Atleast thats what I get out of it
 

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Discussion Starter · #3 ·
Ok Let Me Refraise That 2005 Bone Stock Srt4. Can You Lower Your Fuel Delivery To A Safe Afr At Idle And W/ A Return Line A Fpr And Have The Fuel Pressure Raise W/ Boost To Maintain A Safe Afr. Keep In Mind That Im Not Looking For A Big Peformace Gains But Beter Gas Mileage And A Safe Afr
 

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Fuel pressure is simply a measure of the supply available for the injectors. The injectors open at a certain interval for a certain length of time. If you're seeking to tweak the fuel economy then you will need to modify the length of time the injectors are open (pulse width).

At idle your car operates in closed loop meaning the computer actively fine tunes the pulse width based on the air/fuel ratio in the exhaust. If you're seeking better fuel economy at cruise or idle then you need to concentrate on burning the fuel more completely; ie ignition.
issuez
 

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if your pressure is too low the spray and atomization patterns can be affected leading to pooling and the afr's going all stupid because its suddenly rich then suddenly lean. The newer cars are up past 80psi, subarus are up there and i think the new Corvettes are more than that. Some of it is for emissions, but most of the improvements auto makers do because of emissions raise gas mileage as well.
 

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Discussion Starter · #6 ·
So What Could I Do To Burn The Fuel Beter. Hotter Plugs And How Do You Change Injector Pulse. The Thing Is That I Dont Race That Often, Weekend Maybe But I Do Drive Far For Work And My Wife And I Spend 600-700 Dollars A Mouth On Gas Alone So Anything Helps
 

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OP's_srt said:
So What Could I Do To Burn The Fuel Beter. Hotter Plugs And How Do You Change Injector Pulse. The Thing Is That I Dont Race That Often, Weekend Maybe But I Do Drive Far For Work And My Wife And I Spend 600-700 Dollars A Mouth On Gas Alone So Anything Helps
idle and cruise pulse width runs closed loop. So its constantly changed in response to the O2 to get a stoich A/F(14.7:1.) A change in fuel pressure has ZERO affect in changing this. If the pressure is lower and effectively less fuel is sprayed for a given pulse width, the ecu will just jack the pulse width up to try to match the 14.7:1 A/F. So the end result is the SAME amount of fuel is used.

A good way to get an extra 1-2mpg is not to buy the junk "oxygenated" tree hugger, Minna-sotta' gas. The last time i was there only the premium gas was non-oxygenated, so maybe there might not be any actual cash savings in this.

Other than that, you can buy an Innovate Lc-1 and run its analog output to the factory's O2 input to the ecu. By changing the slope of this output(volts vs. A/F) you can effectively change the ecu closed loop swithc point from 14.7:1 to a more mpg friendly 15:1-17:1. This method is good for a couple more mpg BUT IS NOT emmissoins compliant. Your NOx levels will probably not pass. but,,,, it doesn't take long to flip open the laptop for a quick change back before going to get tested.:thumbsup:
 

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It's very simple; Geo Metro. They're on ebay all around you; check your local craigs list as well. It'll cost less than what you spend on gas in a month and don't talk shit about it being a death box after seeing how these things performed in crash testing.
issuez
 

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duster360 said:
OP's_srt said:
600-700 Dollars A Mouth On Gas Alone So Anything Helps
You spend over 2X what my wife and i spend a month! Whats does your wife drive?? Whatever it is it must be getting about 10mpg!

For refference your Srt should be getting between 24-30mpg on the highway
Dude, I only get about 17-20mpg on the highway... :crying:
 

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Huh

Iduno, but since I replaced my stock O2 housing with maxxfab 3"O2 connected to my turboback 2.5 inch exhaust to Aero Turbine Muffler on my Mopar stage 2 controlled SRT, it is getting over 30mpg consistantly going back and forth to work. A couple times now it's gotten around 36mpg. Iduno. I fuel up, go home 16miles then back to work 18miles then back to gas station 2miles and fuel up again. Only 1 gallon is used. Pretty freaking awsome if you ask me. A/F gauge is reading normal and car is just as fast as ever. Wierd. Before muffler and O2 housing I could only get around 26mpg at best. Aero Turbine too mentioned that it would improve Gas mileage with it's turbine effect by causing a increased exhaust flow due to muffler turbine design. Think it's a combination of two. Anyone else hear of gas mileage like this on a SRT-4?
 
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