Roadkiller

When I'm cruising around 75 and floor it, it seems like a lack of power. When I let up on the throttle a little and ease back in it... much more power. Where should I change my settings?

Thank you,
Larry

Tuned Performance

iTrader: (92)

What’s your afr at wot ?
Or is this a ae bog?

ULTM8Z

I wouldn't change anything unless you can put a WB on it and see where you currently stand and then see the results of changes.

Roadkiller

Thanks for the replies,
I don't have a wide band O2.
I Noticed that I do get 1-3 degree knock retard when I get on the throttle at around 75mph, that could be why it feels a little bogish.

ULTM8Z

Your description does sound rich though...

What's likely happening is you're coming out of PE (power enrich) mode when letting off the throttle. ECM then starts leaning you out to stoich ~14.7 and you start picking up some power.

What's your BLM just prior to going into WOT? If it's >128, the ECM will richen up the PE AFR even more... and GM's PE AFR values were already too rich to begin with.

I.e., Let's say GM programmed in 11:1 at PE and your BLM was say, 134, just prior to going into PE. Then the ECM would then richen up the PE AFR by a factor of 134/128 = ~1.05, making your new commanded AFR 10.5, which is PIG rich...

So, you could improve things a little by ensuring your BLMs are 128 or less prior to going into WOT. That would at least keep you at the factory commanded AFR.

Roadkiller

That does make sense. My BLM is 124 @1975 RPM and MAP is 60.54. My BLM mostly stays between 124 and 132.

Thanks