Very Rich A/F...any ideas?

[Copperhead]

Went to dyno today. Since the last run I've had, I lost 30RWHP and 20 Ft-lbs. (Prev numbers in sig, today's were 433RWHP and 470tq)

But my A/F from 4k and up has gone from 12:1 to 10:1 and maybe even lower (the scale only went to 10). From 2k to 4k RPM was only half a point richer.

The only things I've changed since the last run was I took off my cats (and turned off the rear 02 sensors with the Predator.) And I also switced from a 1st gen Denscharger to a 2nd gen (which moved the MAF sensor from the 9 o'clock to 12 o'clock position.

It was also cooler and dryer today. This seems weird. Could the MAF placement affect the A/F that much?

Could the richness account for the lost HP?

FYI, I also saw a brand new ZO6 with a tune, borla exhaust, and aftermarket air filter kit lay down 365RWHP. Beautiful car.

Thoughts?

 

[SVT 03 Cobra]

Originally posted by Copperhead


But my A/F from 4k and up has gone from 12:1 to 10:1 and maybe even lower (the scale only went to 10). From 2k to 4k RPM was only half a point richer.

remove fuel up top, either with the predator, or a good chip tune

It was also cooler and dryer today. This seems weird. Could the MAF placement affect the A/F that much?

MAF placement has had affect on A/F in some cars, if it could affect A/F this much? :shrug:

Could the richness account for the lost HP?

Absolutaly

 

[cobra_bill]

Try reseting your computer, it helped my car a bunch.

Bill