I'm new to the FTE but have been lurking around this thread for some time. Can't wait to see whether you can liberate some more ponies from the old fo'sixty especially below three grand. If I lived closer to you I would come over and help spin some wrenches....

 

Well, were finally back in business. Got the truck fired up and running with the new heads and should be on the dyno this week. I've been doing some preliminary tuning with the BBK adjustable fuel pressure regulator and reading A/F changes with the LM1 wideband 02. We definitely picked up airflow, with the stock fuel pressure regulator the truck was scary lean (16:1) at mid and upper rpm range. I put on the adjustable regulator and started cranking down on the thing and still am not able to get a decent A/F ratio. The richest ratio we can get at full load and high rpm is in the upper 14's, when ideally the engine should be closer to 12.8-13.2:1. We are loosing some power for sure, but to be fair we will back to back test it as is and see what it will pull. It feels stronger and throttle response was significantly improved. The truck sounds completely different throughout the rpm range. I hope we can at least get enough gain to make all this worth while on a stock fuel pump, ecu, injector set-up but to maximize the airflow gains we need more fuel. I haven't hooked up a fuel pressure gauge to check what the pressure is doing under load, but I suspect we are either out of pump (sounds hard to believe but I could be wrong), have a clogged fuel filter or are out of injector. I plan to change the filter before the dyno session and see if anything changes. Hopefully we can figure this out. Any first hand experience from you guys pushing decent power with the stock pump?

Stay tuned....

 

What's the catch code of the ECU. It's the triple size font (probably 3 letters and one digit) on the ECU socket barely visible with a mirror inside the fender. It's probably also on a small decal on the rear of the driver's door.

Sounds like a good airflow increase.

 

Here's a pic of the driver door.

 

Try this on for size

 

Thanks. That translates to a F6TF12A650-AHA which is a catch code of ALT0.

That would have had an open loop max AFR of 13.15 as stock, and has about 14% headroom to increase the volumetric efficiency in its internal tables, for simple recalibration. I'm about to do a retune on my 460 after a mild cam change. I doubt if I'll have the VE gains you have though. It'll be interesting to see.

There's a LOT going on inside these ECUs, so make sure you get a tuner who really understands Ford Speed Density, and E4ODs.

 

Do you have a recommendation of someone who knows these ECU's really well? After we re-dyno the combo and rule out a fuel delivery issue in the system I suppose the next step is a tune. Thanks for your help.

 

Well, I thought I would throw it on the dyno for the hell of it and ended up wasting a bunch of time. No matter what I do to the fuel pressure, I just can't get the A/F anywhere near where it needs to be. To make it worse, the dyno's wideband 02 was still broken so I was reading off an LMI trying to tune with no reference to rpm other than rigging up the LM1 next to the tach and recording with a video camera. To top it off the video I tried to keep to use for tuning a chip somehow disappeared from my camera to the computer. The "richest" I could get at peak horsepower was about 15.5:1 A/F. Even then the A/F curve was all over the place. The dyno graph looks just like the A/F curve, very bouncy and all over the place. Either I have a major fuel delivery problem or these speed density systems just can't compensate for mild mods and a little head porting. I was expecting we could just add fuel pressure to solve the problem but now it looks like a custom tuned chip is in order. All in all, at this point without a tune I don't recommend porting the heads on your truck if you already have some mods done. All said and done we picked up 10hp and 5 ft.# torque back to back... take it for what it's worth. After I have some time to relax I will look into a tune and see what we can get out of it but right now I need a break! Thanks for following the thread.

 

Speed Density systems don't compensate at all. Like all fuel injection systems, the amount of air entering the engine is evaluated, then together with the desired mixture value, the amount of fuel is computed.

For Speed Density, the amount of air is computed from the engine size, the air temperature, the manifold pressure, an exhaust back pressure estimate, and is adjusted by a Volumetric Efficiency calibration table.

You've just made the engine flow more air, primarily in the higher rpm range, so the back pressure may be a little different, but primarily the volumetric efficiency is now wrong. Cam changes which affect the amount of manifold vacuum produced make things harder, but you haven't done that.

Upping the fuel pressure would richen the mixture everywhere, probably making it too rich at lower power and idle. It would have been a good idea for initial testing, but not a good long term plan. There are also timers in the ECU varying the desired mixture at full throttle over time. Probably this affected your dyno readings also.

Michael

 

Silly question, here, but have you flow/pressure tested the system at the rail? My manual seems to indicate that you need at least 5.6oz in ten seconds and minimum of 30psi.after deenergization.

 

Well, I rigged up a remote fuel pressure gauge to check pressure at the rail under load and it drops at least 10psi of pressure from cruise to full load. It is currently set at 34# w/ vac connected and it drops to about 22#. Changing fuel filter tomorrow and we'll see what happens.

 

Stock 140,000 mile motorcraft fuel filter FTL!!!

Changed it out and fuel pressure is holding steady- we have plenty of fuel! Dyno scheduled for tuesday.

 

LOL!

 

I want to hear what happened on the dyno!

 

Dyno session moved to tomorrow unfortunately, and it's supposed to be hot again....