Okay I installed a new fuel regulator and filter up under the hood so that I can adjust my fuel pressure my self. I have made a short test drive and the results are looking promising. It never got above 13.1 AFR thru 2nd gear . Sunday I am going to the track if it opens and will start tweeking the pressure and see what happens at the top of third gear which is where it really likes to lean out. I will take some Pics tomorrow and post them.

http://s826.photobucket.com/albums/z...tor%20Install/

 

Great idea Woody, I mean Xray!

I take it you bypassed the stock filter/regulator? Are you using a stock unit up front now? Looking forward to the pics.

I've never had lean AFR issues with or without my tunes. I guessing it's cuz I'm at 4600' elevation.

 

It is a Aeromotive pressure regulator #13101 adjustable between 40 to 70 psi.

 

A few questions Xray:

What was the highest AFR you were at before?

What psi of fuel pressure took it down to 13?

What fuel pump are you running?

What did it to to your overall AFR in the low and midrange, surely it was richened as well?

 

Good to see others in the chase. Just be real sure that the high pressure fuel lines are safe so you wont be another rocket form Titusville. Had a friend that lost his car from fuel accident, not a good thing, Woody Enjoy the weekend.

 

I have added a link for pics to my first post. Yes woody I did use Hi Pressure fuel line I did not want to try to go into orbit by crossfire I would rather use the shuttle.

What was the highest AFR you were at before? 15 to 15.5

What psi of fuel pressure took it down to 13? last night I did not have the return line hooked up yet so the pressure was messed up I will give all the data as to what pressure does what when I finally get to the track.

What fuel pump are you running? Factory pump. It hit 130psi with the return line blocked off.

What did it to to your overall AFR in the low and midrange, surely it was richened as well? My low end AFR did richen some. My intent is once I get the top end where I want it I will send a bunch of data logs to Jerry and send them my computer and have them tweek it for me.

 

this is maybe what we have all been looking for ,,, thanks Paul, now go play. jim

 

xray,
How about a simple schematic on factory plumbing vs your mod plumbing.... with your results of course...

as usual, it looks like there is more than one way to skin this cat.....


(no offense to the cat lovers.. )

 

never mind......

 

SRT 6 Sevice Manual Section 14 fuel system. Here are the pages P.2940 2947thru2950 2954 & 2955.

If you look at the fuel filter it has two fittings on each end. Looking at the filter from the back of the car the bottom fitting on the left hooks directly to the fuel pump. The hose on the opposite side is the supply line for the fuel rail. I just hooked them together and presto full pressure to the front of the car. The hose that hooks up to the middle of the filter on the input side is the return line to the tank and the hose opposite it is a atmospheric line to the pressure regulator so it can compensate as you drive thru different elevations. You will need to run a high pressure fuel line from the factory return line up to your new pressure regulator. If you try and just block off the return you will be pushing betwee 80 and 130 PSi. How do I know this because that is how I did it at first and the lowest I could get the pressure was 80 PSI. Hooked up return line and now I have full control.

I cut the fuel line under the hood and installed the new fuel filter and regulator right there.

 

Xray, thanks for the inclusive response, this is good stuff!

Out of about 12 different Jerry tunes the only thing we didnt try was richening AFR's via hard ware then leaning it back out down low via software. I am really anticipating results. This was an idea myself and some other members had discussed, but we were at the point of piggy back ecu's. It would be much simpler if Jerry can come through with an appropriate tune. Im suprised that as my tuner he never suggested going this route.

A couple more questions:

If you run the lines directly in and out of the factory fpr as you suggested what happens to the fuel going from the return line down to the tank. Will the fuel tank leak out indefinitely? Does the fpr remain shut 100%, last thing we want is to leak fuel.

Also, you mentioned fuel pressures fluctuating from 80psi to 130. At what load was it where. I assume down low 130 then up top falls off to 80?

 

One more thing dude you might already know this, but if your referring to that rubber hose that connects to the fuel rail you might want to reconsider. The adjustable fpr needs to be after the injectors, so you will be tapping into the end(towards front of car) of the fuel rail remove the schrader valve and purchase the proper a/n fitting to attach the return line.

Maybe i just misread but better safe then sorry. BTW, thanks for actually going out there and getting your hands dirty rather than wait for someone else to try and fix this ongoing lean issue. In other words the more we duplicate and check each others work the better we will ensure reliable results. Scientific method.

 

Just out of curiousity why do so many think pressure is the answer? Also with the increase in pressure you are making it very hard on the injector pintals. How is the SL55 making over 650 horses with only using a factory pump with operating psi between 54-60 psi ??. I guess I just don't get the whole re-inventing the wheel stuff. There is a 15 minute solution to the fueling problem that leaves the car perfectly stock no cutting lines splicing wires....... is $335 just too much money to spend for the easy fix??? anyway enjoy your projects I'm done

 

not sure but we are not stock once we get the tune and a pully, the sl55's ecu is set up to give the injectories the fuel they need at a certin psi(boost) makes it work stock,, now the crossfire has a tune and a pully so the psi (boost) is higher than stock (that means the psi (boost) pushes the fuel back ,, ( example ) put air in a flat tire no problem now put air into a truck tire that already has 100lbs in it ,, the air goes in slow ir at all the same with fuel the psi set by the ecu is good for stock just don;t add boost and you are fine, the sl55 pump by itself will not change a thing on our car. (correct me if i am wrong) filter/ reg. has to be changed also. a in line pump in front of the reg will change our psi, u would need another reg to decrease the psi of fuel. now that i am confused see what you can do. jim

 

You assume it is the pressure in the cylinder limiting the exit of fuel from the injector, and not the lack of volume in the rails, so yeah your wrong

 

Okay I hooked up the fuel pump directly to the new regulator and ran a return line back to the fac return going to the tank. The only line still hooked up to the fact filter is the atmospheric line which is unused. the reason I was getting 130 psi and could not adjust it any lower than 80 is because I did not have a return line hooked up I had the return sealed which meant the regulator had no way to bleed off excess pressure. I am not sure what you are asking about the fuel rail I used the factory supply line and just inserted the new filter and reg in it.

Bulldogger I agree with what you are saying about more volume my question is how do you get more volume with out 1 of 2 things increased pressure or larger diameter fuel lines. I know for a good while now you have been a proponent of the sl55 fuel pump. What kind of AFR's are you running with it. My solution is not cheaper and def takes longer but I just could not figure out how a different pump going thru the same regulator and lines could solve the problem. Please Explain how it works.

 

Same way a boat prop works by changing the pitch on the impellar. The pressure in the line is only a factor if the pump you are using is maxing out the lines capability. Both the SRT6 and SL55 pumps have the same sized inlet and outlet. The SL55 pump is slightly longer and moves more LPH. Think of you garden house 1/2 open compared to full open, same size line but your moving more volume. Everyone assumes the fuel rail size is too small and maxed out, why???

 

82 psi max afr 13.2 Much better than afr's in the fifteens

 

Sorry for the confusion. Can you post a pic?

Im trying to figure out where your new filter and regulator is located, before or after the fuel rail...

edit: nm about the pic i dont know how i missed the link, maybe you posted it after the fact.

 

I never needed more than 65 psi to go dog rich ot high load, boost, and rpm. I would suggest that the regulator be mounted in the rear where the original is, the return hose is not long and you dont need to worry about the chance of a leak.

Tank to pump '

Pump to regulator

Regulator output to the fuel rail

Regulator return to a tee connection coming FROM the tank that feeds the pump. Short and sweet piping and little extra line. Woody

I am still working on a different approach that is similar but self regulating. WHEN it is working Ill report on it.

WW