Originally Posted by ronburgundy

carbs are for quitters.

Originally Posted by JackandJanet

Now, now - you haven't really had fun until you've tried to get a tri-carb setup adjusted right.

- Jack

Originally Posted by JackandJanet

Thanks, I knew increasing WOT would not be ideal at all, but thought it might help until a custom fuel map could be generated. The reference to fuel trims is actually on Pg 70 and 71 in s1.pdf, but as I understand it, the PCM tries to keep the air/fuel ratio cycling around an ideal point based on what the O2 sensors see and report to generate the STFT pulses to the injectors. Yet, because people report symptoms of running lean (white, worn plugs, etc.) the PCM must not be able to do it if the baseline settings are too far out of whack and the LTFT values have reached a limit that prevents compensation for the larger deviations.

Or am I missing something here? (Wouldn't be the first time). :o Carburetors were certainly simpler.

- Jack

Originally Posted by Bluejay

Two mechanical Holley four barrels on a 427 were a snap.

Originally Posted by gregk63

what is the web site for PHP ?

Originally Posted by ASEMechanic

I can see we are going to go 'round & 'round on this issue. Hopefully this will settle the debate. Maybe it won't... who knows?

This dyno plot was made on a 2004 F150, both before and after installing an AFE CAI kit. The runs were about 50 minutes apart, which was the time it took me to install the CAI. All test conditions were the same and the engine was at full operating temperature (both ECT and EOT) when making both runs. Take it for what it's worth.

(click for larger image)


Unfortunately, the sampling software didn't correctly log the AFR from the meter but fortunately we did make a note of the AFR for each WOT run because as soon as I saw the results, I was on the phone with AFE.

Stock w/o CAI- 14.4 AFR (+/- .1)
Stock w/AFE - 15.6 AFR (+/- .1)

When I contacted AFE about this issue, I was basically told I didn't know what I was doing and I was supposed to have let the PCM "relearn" the fuel curves. Now I didn't necessarily disagree with this so after running about an hour on the dyno at varying speeds, loads, and throttle positions, I did a few more runs with exactly the same results. What's even funnier is that when I put the stock airbox back on, my power curve and AFRs returned to normal... WIHTOUT having to relearn any fuel maps.

I will say that after correcting the fueling and MAF tables to compensate for the airflow offset cause by the CAI, the truck picked up about 8 HP above 3000 RPM. Oddly, it's nearly the same 8 HP we picked up at the same RPM by removing the snorkel from the fender. Go figure. Oh, and the stock airbox didn't DRONE!

Again, take it for what it's worth. In my opinion, the stock airbox on the F150 provides more than enough flow, at least for a naturally aspirated application. Supercharged or other Forced Induction applications will certainly be different and airflow requirements are dramatically changed in these applications.

Hope this helps.

Originally Posted by skyhikr

At the bottom of your chart it says 2009 f-150. Is that a typo?

Originally Posted by Bluejay

No, it was a 2009 5.4

Originally Posted by skyhikr

In the text of his post he said it was for an 04.