No WB, so how much to richen up for cutout?

**rel3rd** · 10-20-2008, 01:10 PM

In everyone's experience, (percentage-wise) how much did you have to richen up your WOT to get near the same a/f ratio as when it is closed?

I don't own a wideband yet, and was going to modify a few tunes for the cutout, so that I could simply reflash and try it out at the track...

Thanks for any help or suggestions...

**Frost** · 10-20-2008, 10:32 PM

It's negligible in most cases.

**Firebirdjones** · 10-21-2008, 04:33 PM

I'm going to step out on a limb here and say that you probably won't see enough change from a cutout to worry about the AFR. But it depends on the system design.

Reason I say this,,,is I run a pair of 3 inch electric cutouts on my chevelle,,,,and with the wideband hooked up,,,,I can open and close the cutouts while running and I only see a change of 13:1 AFR closed to 13:2 AFR while open.

This car has a pretty efficient system when closed though,,,,but even with dual cutouts right at the header collectors I don't see much change.

Maybe on a car with a more restrictive system this could be an issue,,,such as a single system on a camaro,,,,or maybe having only one cutout as many people install on these 4th gens. Any of these things could change the outcome. Without the wideband it's somewhat of a guessing game.