How rich is too rich at WOT???

[SIZEMOREMK]

Tuner seems to think 10.5:1 to low 11:1 AFR is not too rich for a good portion of the dyno pull.

Sound right to anyone???

Car is a big ole Mercury Marauder; teksid based DOHC 9.5:1 compression; weird reverse split cam setup with 214 duration and .470 lift on the intake side, but stock exhaust cams; large custom intercooler; 13 PSI on a Paxton Novi 1200 centri blower... 93 octane...

 

[Bdubbs]

I'm no expert, but that seems quite rich to me. Being to rich isn't good either. If he wants your a/f to be on the richer side, I'd say 11.3-11.5 range. A/F under a 11 and your likely leaving hp on the table.

 

[Mach828]

My car would studder under WOT when I was tuning it and put the AFR in the 10s. You'll see on the dyno graph that the car's power graph will be choppy. When you lean it out, the graph will appear smoother. I wouldn't go richer than 11.0.

 

[Fopar]

That's not out of the ordinary for a turbo car, supercharged you can get away with a little leaner. But I'd agree with him, 10.5 is the lowest I like to see. That said some cars run richer, 1st gen DSMs with the STOCK fuel map in stock form can run in the high 9 range

That's pretty much what I would do, run in the low 11 high 10 range until you tune the spark table, once that's safe can bump the AF back to the low-mid 11 range

 

[Mach828]

Each combo is different. With a PD blower or turbo your IATs are higher, which will aid in a more complete ignition with overly rich mixtures. Especially if you have hot plugs and a higher coolant temp, and high underhood temps.

With a A2A centri you're going to have low IATs, running cold plugs (I've got BR7s), and low coolant temps (I see 170s during pulls), then you aren't going to have a clean, consistent ignition and the car is going to have a choppy power curve.

 

[MalcolmV8]

10.5 is way rich. My car would run like crap when I tried that. Even 11.5 is fairly rich. 12.0 is the sweet spot for a boosted motor, anything more is safety net and leaving HP on the table. Going into the 10s or 9s is just silly IMO.

 

[Posi]

I always have my Tuner shoot for 11:6 on my car. Never 12:0 anymore because my record setting days and shooting for every last hp are over.