It's nice to see somebody show exactly what I've been saying. These trucks DO have a hideous tune on the PCM from the factory,and CAN benefit from a proper tune,and WILL gain power even with 87 octane. From looking at your A/F trace-you can see the lag time from enrichment making power to the wideband actually seeing the air fuel change in the exhaust. I'll bet there was a fair amount of spark knock causing that stock dyno trace to be so wobbly...the PCM was probably pulling timing during the pull from the knock sensor input.
JL
Second graph shows how a stock tune does not use power enrichment during WOT.
I was thinking about this at around 3AM laying in bed not getting any sleep
If it WERE to enrich at WOT, what would that do to the catalytic converter when pulling heavy loads for extended periods of time at WOT?
Wouldn't that be a reason NOT to enrich at WOT?
__________________
- art k. - Moderator for the Superduty, V10, and FE forums
'01 F250SD SC SB XLT V10 4x4 auto 3.73 Warn hubs Volant CAI, eBay headers and y-pipe - 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased! I've been wrong before, I'll be wrong again. Just wait and see.
I was thinking about this at around 3AM laying in bed not getting any sleep
If it WERE to enrich at WOT, what would that do to the catalytic converter when pulling heavy loads for extended periods of time at WOT?
Wouldn't that be a reason NOT to enrich at WOT?
Ford actually DOES enrich the fuel mixture when the PCM goes into "catalyst overtemp mode" and the commanded air/fuel is around 10.2:1. This is a short-term dump of fuel to cool the catalysts after a long time at high load and stoich air/fuel ratios. The catalyst will operate at a MUCH cooler temperature when the fuel ratio is less than or higher than stoich 14.64:1.
JL
Ford actually DOES enrich the fuel mixture when the PCM goes into "catalyst overtemp mode" and the commanded air/fuel is around 10.2:1. This is a short-term dump of fuel to cool the catalysts after a long time at high load and stoich air/fuel ratios. The catalyst will operate at a MUCH cooler temperature when the fuel ratio is less than or higher than stoich 14.64:1.
JL
Excellent point
We did 4-5 stock runs and they were all over the place in ref to power. All had the waves to them. Runs only lasted 6-8 seconds at WOT so most likely did not have time to dump fuel to cool catalyst.
Another major thank you for your time and effort. Good stuff! A couple comments:
- I really like my SCT Livewire. The ability to monitor multiple parameters live is helpful when debugging.
- I believe published stock hp was 275.
- PI conversion? I'm available to answer any questions on that. Mine is working out well.
- Comparing hp/torque figures from one dyno to another is notoriously problematic. Especially if you try to compare brands or especially technologies. On the other hand, multiple runs on the same machine to compare changes is useful. In other words, the absolute number is VERY arguable, but differences from run to run ARE meaningful.
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'99 F250 V10 Super Cab Long Bed 4x4. '06 short block, PI conversion, modded airbox, 5 Star custom tune, 315/75-16's, 4.30 LSD.
Why, yes, I am some kind of a geek engineer. Thank you for asking.
I think, with this thread, and Mike's continued involvement with his '99 V10, we might have a really indepth look at what can be done with the V10.
Would love to see what a set of PI heads would do, but before that happens, would love to have real-world data on what headers and other exhaust as well as intake upgrades do on the dyno.
ALSO - Mike, any chance of returning to stock and getting dyno runs with exhaust/intake upgrades to see what would happen for people that don't go with a tune?
__________________
- art k. - Moderator for the Superduty, V10, and FE forums
'01 F250SD SC SB XLT V10 4x4 auto 3.73 Warn hubs Volant CAI, eBay headers and y-pipe - 5-star custom tunes on SCT X3
'97 Cougar XR7 30th Anniv Edition 4.6L
'74 F250 Highboy FE390 deceased! I've been wrong before, I'll be wrong again. Just wait and see.
ALSO - Mike, any chance of returning to stock and getting dyno runs with exhaust/intake upgrades to see what would happen for people that don't go with a tune?
Sure can thats my plan to show it to have a good before after comparo.
Big Thanks!!, I certainly appreciate the support from everyone here on FTE.
I can hardly wait.If this turns out favorable for the Y and a CAI vendor you guys should get together and offer a performance package. (SCT, SPD, and Volant)
I have my Y-pipe (std '99 aluminized) still sitting in the box.... I picked it up in person on our way through Oregon and haven't had time to install.
I can send you mine if you have Jacob send yours to me when parts are in.
__________________
'99 F250 V10 Super Cab Long Bed 4x4. '06 short block, PI conversion, modded airbox, 5 Star custom tune, 315/75-16's, 4.30 LSD.
Why, yes, I am some kind of a geek engineer. Thank you for asking.
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Along with some other stuff.. 
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If this turns out favorable for the Y and a CAI vendor you guys should get together and offer a performance package. (SCT, SPD, and Volant)
