do you increase your percentages or decrease to add more fuel at wide open throttle vs rpm.

 

You should get your "part throttle" as close as possible to 128/128 before even attempting your WOT fuel settings. This seems to be the most common error "beginners" make with eprom burning; they concentrate on WOT and forget about part throttle. You may find that your part throttle is so overly rich that EVEN reducing your PE%add vs RPM to zero it STILL runs too rich.

But to answer your question, to lean your engine at WOT, you would reduce the amount of fuel added as a particular RPM range.

 

I don't think it's running too rich at wot, I didn't mention it's 406 tpi with mass air.
what would add more fuel......increasing the percentages?

 

Yep, increasing the percentage adds more fuel. As Glenn stated, you want to tune in your part-throttle block learns first so that you have an accurate baseline for your WOT tuning. If you've changed injectors (which I'm sure you have running a 406), you need to make sure the injector constant matches what the injectors flow at whatever fuel pressure you're running. If they're Ford SVO injectors, keep in mind that Ford rates their's at 38 psi while you're probably running several more psi than that. SVO 24# injectors flow about 26#/hr of fuel at normal GM pressures.

If your block learns are all high or low in nearly all of the block learn cells, you can use the injector constant to make a global change that would affect all of the BL cells. You can then use the MAF tables to fine-tune certain areas where your BL cells are higher or lower than 128. Once that's done, now you can accurately tune your WOT tables. I worked on the RPM table first to get my O2 curve in a flat line, then lowered it as a whole using the WOT vs. coolant temp table.

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Greg Westphal
'87 IROC 305TPI/A4

 

appreciate it Greg, That'll give a great starting place.
Yes, I am running ford 24lb svo fuel injectors, thanks for adding that in. They were alot cheaper.

by the way how do I need to adjust the single fire and double fire.... both to 26 lbs.

 

Ooof, 24# injectors on a 406?!? I'd put in 30#'ers in there to be safe. Have you calculated your duty cycle with the injector pulse widths you're getting?

You only need to adjust the double-fire injector constant, although you could adjust both to the same number since the single-fire constant is ignored. Which tuner program are you using? I know that GMEPro, TunerCat, and WinBin all have the injector constants...

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Greg Westphal
'87 IROC 305TPI/A4

 

Greg,

The lightbulb just clicked on. When running at WOT the output from my O2 sensor always drops over the course of a pass, indicating lean out. I had assumed this was because the chip was incrementally leaning the AFR with RPM. This has been proven false upon review of the BIN file. What's really happening is that my MAF is under-reporting airflow due to the removal of the screens and fins, resulting in injector pulsewidths that are too low. Now you've given me a parameter (O2 output @ WOT) I can monitor to tweak the MAF scalars at high air flow rates.

 

406 with MAF, I doubt you'll really ever get it more then OK. I'd be MAP, and with at least 30s if not maybe bigger injectors.

 

I'm using the tuner cat 6E tdf file. I got the 24lbers reasonable. I haven't found a set of 30's yet. I got a buddy running the exact set up except with a speed pro. He was able to get by on 24lbers until he started spraying a little gas. Then he went to 30's. A matter of fact I bought his old injectors. I really don't know how to calculate the duty cycle.... I'll look it up though.
Even with a 406 it's a mild set up. A custom comp roller cam with about 272 adv duration , .510, 540 lift. with g2 trickflow heads. nice quiet idle....

 

Hmmmm, with a mild cam like that and not revving too high, you should be fine with 24# injectors for now. Since the time available to inject fuel is less with more revs, you have a greater chance of maxing out your duty cycles with more revs than more cubic inches, although either one or a combination thereof will do it.

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Greg Westphal
'87 IROC 305TPI/A4

 

I still have the stock intake(ported) with slp runner (ported). So I'll just be shifting around (5500 or 5600) or she'll fall flat on her nose from a lack of air.
Thanks for the replies Greg, nice hearing from a mass air guy.