AFR #s for Cruising

[whiplash willy]

I just installed an AEM Wideband and it shows I am running about 11.5-12.5 AFR when I am cruising. I know this is a little rich for cruising, but is it so rich it will do damage if I run it for a prolonged period of time? Im running a stock SR with stock boost settings.

[Mouse6933]

im no expert but i waqs told cruising #'s should be like 15's (like 5th gear highwat cruise) light throttlw should be like 13's and wot should be like 11.6 ish, Ideal... I was running rich too soo i was woried bout detonation, so i order emanage ultimate should be here this week .. Hope this helps...

[safin]

how would all those numbers would translate into lambda?, im planning on going the cheap way by just using a bosch wideband O2 sensor with the autometer air/fuel gauge that i have

any ideas?

[oki_bum]

any ideas?

dont go cheap...

[cheapscheisst]

14.7 is the ideal a/f ratio when cruising

[safin]

dont go cheap i guess yeah, all the wideband gauges are like 250ish do you know what would be the ideal options among the ones available? ngk, aem, etc etc? this is just based on whatever you are running, how has that been working out for you

[doridori23]

Ideally you would go with an AEM as it has both 1v output (for stock ECM)and 5v output for your Emanage Ultimate. IF you are just using it as a monitor and not going into a fuel management computer then the Bosch 5v O2 sender and Autometer gauge will be fine. Go with the proven sender and any gauge that looks prettiest as the gauge is only as accurate as the sending unit. Keep in mind that BOSCH is what ALL aftermarket a/f meters even Innovative Motorsports, they took a Bosch unit and reboxed it to not look like a Bosch.

[safin]

great info man, thanks im probably going to use an safc 1, but i want something somewhat accurate to know how the car is running.i already have the autometer gauge but is not numerical, it only has lights.

so i can get a regular wideband bosch O2 sensor, do i have to do any splicing or the connector will automatically substitute my old sensor?

thanks!!

[Blown240sx]

14.7 is the ideal a/f ratio when cruising

Cruising you can actually go leaner than that as long as your under vaccum. When we tune we tune for 15.5 A/F cruising for gas milage. At 0 pressure we aim for 12.5-13 A/F and under load we tend to aim for 11-11.5 and use timing to make the power. Safer A/F is more important than trying to make power by leaning it out to far.

[whiplash willy]

Is 11.5-12.5AFR safe for cruising though? Will prolonged running of this rich condition do any damage to my engine? This is what I am most concerned about.

You can get an AEM Wideband O2 sensor from horsepowerfreaks.com for about $280 BTW.

[oki_bum]

I have the AEM Wideband. It works great. I've been cruising with ~12.5 ration for months and my motors fine....i really wish i knew if that was bad or not, lol. But for the past week i leaned it out a little so cruising on the highway is around 13-14.7.

[hpmachine]

Cruising between 11.5 and 12.5 shouldn't do anything harmful (except to your wallet at the pump). Anything richer than that over prolonged periods and I would be worried about gas getting by your rings and into your oil. Not cool

[stewie8apie]

how would all those numbers would translate into lambda?, im planning on going the cheap way by just using a bosch wideband O2 sensor with the autometer air/fuel gauge that i have

Lambda 1 for gas is 14.7 A/F, so 12.0 A/F would be 12/14.7 = 0.82 Lambda

For best gas mileage I tune for around 15-16 a/f. It's not lean enough to hurt anything. You could actually go leaner than that under highway "cruising" conditions.

Safer A/F is more important than trying to make power by leaning it out to far.

This is true. Also leaner is NOT meaner as most people would think. Their is an acceptable "window" of lean-ness, after that you start losing power and hurting your motor. I usually tune for 11-11.5 a/f (on boosted applications of course). You'd be surprised as to how rich you can actually go without losing power. I've seen af's as low as 10.5 before ANY power was lost.

To answer your question though, you should be fine cruising with the af's that you are, but your wallet must hate you!

[Blown240sx]

Lambda 1 for gas is 14.7 A/F, so 12.0 A/F would be 12/14.7 = 0.82 Lambda

For best gas mileage I tune for around 15-16 a/f. It's not lean enough to hurt anything. You could actually go leaner than that under highway "cruising" conditions.

This is true. Also leaner is NOT meaner as most people would think. Their is an acceptable "window" of lean-ness, after that you start losing power and hurting your motor. I usually tune for 11-11.5 a/f (on boosted applications of course). You'd be surprised as to how rich you can actually go without losing power. I've seen af's as low as 10.5 before ANY power was lost.

To answer your question though, you should be fine cruising with the af's that you are, but your wallet must hate you!

The loss of power or pushing it beyond the limits is also true with Ignition timing. What people dont understand when they tune is Power falls off way before knocking occurs and thats what gets people in trouble with tuning. Thats why a Dyno is necessary. You can get a good A/F on the street but true tuning requires some dyno time.

[Istilldo]

I have 11-11.5 on boost 14.5 on cruising afr, with my ca18det, I'm using emanage bluebox,but when I depress gas at a gear, my afr goes to 11-11.5 ,, something wrong here but I could not find the problem

[hpmachine]

When you say 'depress', do you mean take your foot off the gas? If so, are you running an uncirculated bov? That could be the problem. Mine is doing that, and I plan to recirc it soon.

[Istilldo]

yeah I mean that, sorry for my bad eng.but also I do not have a bov

[S14-NEO]

11.5 -12.0 AFR will not only cause you to lose your behind at the pump but it can also wash your rings down and thin out your oil over a prolonged time....not advisable

[Istilldo]

I know that, but I can't find when I'm not pressing gas(on a gear) why does my injectors still open? anyone got an idea?

[Seishuku]

Bad/leaky lower o-rings, bad injectors.

I know that, but I can't find when I'm not pressing gas(on a gear) why does my injectors still open? anyone got an idea?

[Istilldo]

no problem with internals, rings or pistons nothing wrong, and I have 9 comp. ratio

[Seishuku]

I mean the rubber o-ring that seals the injectors...

[luv2spedup]

Cruising you can actually go leaner than that as long as your under vaccum. When we tune we tune for 15.5 A/F cruising for gas milage. At 0 pressure we aim for 12.5-13 A/F and under load we tend to aim for 11-11.5 and use timing to make the power. Safer A/F is more important than trying to make power by leaning it out to far.

dude that's great info thanks do you tune aem