That would definitely hold true with the ol original 525 sc. Egads that was bad.

I bet prob even richer than that.

Last night was seeing what some of the oem cars are at wot

Supercharged Z06 vette, low 10s stock

LS2 GTOs upper 11's stock.

Cadillac northstar V8, low 10s.

I put my wideband on my 454 Vortec dually engine, a whopping 300hp 454, afr at wot mid 12s . I wanna say after 60 seconds, it goes even richer . Never had a chance to hold it wot 60 seconds to verify lol

I did but it was brief and limited sample on a 350 Mag EFI/MP. Cold start idle was about 12.2 or so. Leaned to mid 12's at warm up. Low MAP (40 kPa) and up in the rpm band was in the 11s. I didn't get any other load data points. Swapping out the KEIHIN 5JAB (Keihin) KN-1 24 lb/hr stock injectors for RC Injection 42 lb units with a stock tune brought the idle AFR into the 10's. Excessive I know, but I was experimenting.

I target an AFR of 14 or so no load idle, 13.8 ish in gear idle and 12.8-13.2 for the majority of the operating envelope except WOT which I roll it to 12.5 or richer. I have successfully run at cruise rpm 3200 ish rpm at 14.0 AFR with no adverse affects (knock, timing retard etc) but it spooks me so I don't make that a habit. This is for a N/A application obviously.

With running 14.0 afr just curious what the base ring of the plugs looked like? I typically run on the edge and just curious.

For years I built and ran performance engines without afr o2 wideband and would try and jet for pretty much a full turn in color on coldest day. I had I down pretty good with jetting vs temp etc from a baseline established. Never melted one down to this day however.... Wideband from here on out.

Plug looked normal but it probably only ran this way for 20-30 minutes total. This wasn't some extreme big inch high HP motor. Simple 377 EFI stroker, Dart heads, Crower cam etc. I didn't run it for a season that way, just one of my tunes ended up being in the 14s AFR wise at cruise. I fattened up that part of the fuel table and marched on. AFR at WOT was still 12.5 or less even with this particular tune.

I've also changed the altitude/baro compensation tables from the Mercury setting of Zero to non-zero numbers. Since this changes the fuel map globally it can work wonders quickly if you have a tune that was great one day but a little off the next due to atmospherics. Anyways I digress...

Some awesome techknowledgey out there. Its amazing when you let just a couple or few years slip by with other things going on in your life how quickly you can get behind on some pretty slick stuff regarding engines and components. I'm in the golf business and not much changes other than the way you market and clubs change a fraction every year it seems. I enjoy doing my best to make up for lost time and to keep current but when it comes right down to it I still like old school. "fuel-spark-compression" lol.

I had a little testing this weekend. I changed out both power valves from 6.5 to 4.5 and now getting a steady 11.5 - 11.8 across the board with a touch in to the 12s every so often. Currently #78 jets in the primaries and bought a pair of #76 and #74. Jump straight down to the #74s?

Did you replace a standard pv with a high flow version?

I hope not. Part #25-45 from QF. No mention of it being a high flow version.