AFR and KPA different in 3rd versus 4th gear

[jon6.0]

Something I noticed this morning doing a 2-3-4 pull. My AFR was 11.0-11.2 in 3rd gear and reached 178kpa on the MAP at the top of 3rd. In 4th gear it was 10.7-10.8 and the MAP was only 165kpa. Boost was basically a flat line from 6000-6800 in 4th. I was between 160-165kpa in that range and was a very gentle slope up to 165kpa. Is it that the blower is maxed out and that's all she's got in her? Since it's less boost in 4th gear does that explain why 4th was richer? I'm driving the blower 10% past rated impeller speed.

[jon6.0]

Screen shot of 4th gear.

[jon6.0]

Also, what table needs to be changed to keep the timing from shooting up during a shift?

[Force]

You may already know this but the afr for boost should be around 11.7:1. Might be an idea to drop timing a tad and set fuel first and then bring up the timing again to where you are now. Put your tune on here and a full scan and then we can see what could be the problem. If we can see your timing table then it helps. There can definitely be a difference in afr when there is a different load in different gears. I am only new to tuning but there are lots of very knowledgeable tuners on here.

[jon6.0]

I'm at work and can't post my tune until I get home tonight. I'm using methanol injection at 25gph and not just gasoline. Seems like most recommend 11-11.5 for a pump gas plus meth deal. Obviously every car is different, but I was going to shoot for 11-11.2 on mine. I also like to run things a little richer since the ambient temp is so hot here in Phoenix. 105-110F right now during the day. In another month it will be 110-115F.

[Force]

Ahh ok. meth injection. Put your tune up when you can. Not sure about the boost being less in 4th. It should be the same I would think. it is higher revs where it would normally drop if it is running out.

[jon6.0]

I posted this on Corvette Forum also. One of the guys over there thinks it's the blower being maxed out. Since the engine is consuming more air under load in 4th it would show a lower boost for the same impeller speed.