Air fuel ratios

[70Buick464]

What air fuel ratios are good for cruising and wide open?

[MikeW]

riding around / idle should be 14.64

wot should be 11.5-12 on a FI and 13.1 on NA car.

m

[70Buick464]

Not sure what it it idling, but cruising around its usually 12 to 13. Sometimes it goes to 11 but i give it a little more gas and it goes back up.

Not sure what it is wot cause too fast to look around at all the guages but it always stays in the green on the guage.

Even if the ratios are not perfect, as long as i stay in the green is the motor still ok? Just not getting the most out of it.

[MikeW]

Is it a true wideband or one of those autometer a/f gauges that does not have a sensor on it?

[Disney Lincoln]

"The Green" really depends on what gauge you're reading off of. I'd make sure that it's around 11.5:1 at WOT.

[ReefBlueCoupe]

Rig up a digital camera to record a movie of your gauges while you drive.

Narrowband gauges are teh gay.. you should get a wideband with a seperate O2 sensor if you want a true reading... assuming that's not what you already have.

It sounds like you ratios are a little fat but that's not necessarially a bad thing with a supercharger.. nice and safe. Any chance you could get it on a dyno to do some tuning?

[2burnouts]

narrow bands stink,i have one in my car said was running lean, when i goose it.it blow raw gas out the back.id say that wasnt lean xd-16 wideband can keep you up to date.

[LINELOCKSRUS]

riding around / idle should be 14.64

wot should be 11.5-12 on a FI and 13.1 on NA car.

m x2 :up:

narrow bands stink, x2

[70Buick464]

I have the aem eugo. wideband

[ErinC@CPE]

Under cruise its better to run a little leaner than stoich. You will get better gas mileage running in the mid 15s. Since there is no real load on the engine during cruise you will not hurt it by running it leaner. 12-13:1 under cruise is way too fat. Are you running a blow through or EFI?

Erin

[70Buick464]

blowthrough

[393Bird]

When I was using gas, mine idled around 13.0, then as it went into the transfer slot (tslot) leaned to the 14s. When I started feeding from the boosters, around 2500 rpms, it went to high 12s - low 13s . I run my primary jets a tad lean, and the power valve channel restricters enlarged to fatten it up as it sees a load, which runs 12s to high 11s to be safe under boost. My double pumper has the linkage for the secondarys that starts to come in about 1/2 throttle, which matches up pretty close to when the power valve starts to open.

When setting mine up, I start with setting the Tslot on the primary to show as a square, then control the idle speed using the secondary idle adjuster. I disconnected the secondary linkage, and plugged the power valve hole, and drove it to see what exactly the idle, transfer slot, and boosters were doing, and when. Once this was the way I wanted it with out going into boost, I watched to see at what vacuum I needed the power valve to come in at. On gas, I was running 74 primary, with 76 PVCR holes and a high flow 4 door 4.5 power valve . My secondarys were 86.

On E85 I am running 80 primary, with 94 PVCR, and 96 secondarys. Here is some information I put together while converting mine to E85, but the procedures are the same.

http://members.tccoa.com/392bird/carbtech.htm