elpiar

GSR motor. My open loop partial throttle is tuned fairly well 14.7-13.5 AFR. And yet my mpg is 21 highway and 18 city. I only do WOT pull probably 3-4 times a week

I troubleshoot everything you can think of:
ultrasonic cleaned and tested injectors, new distributor cap, rotor, blaster ss coil, new sparklug and ignition wire, fuel filter, air filter, etc.

I wonder whether I should go closed loop on my uberdata.

nonvtecD

I am heavily tuned in open loop and get 35 mpg with no 02 sensor.

nonvtecD

BTW, my partial throttle is between 15 and 16:1, but sounds like something else is going wrong with your setup. I do WOT pulls pretty much everytime I drive my car and never get below 30 mpg.

elpiar

Your motor is SOHC? D16?

isn't 15 to 16 is a little lean even for partial throttle?

xyrth

i don't know the answer to your question, but i can tell you that 15-16 is NOT too lean for low load, low throttle cruising.

adseguy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elpiar &raquo;</TD></TR><TR><TD CLASS="quote">Your motor is SOHC? D16?

isn't 15 to 16 is a little lean even for partial throttle?</TD></TR></TABLE>

That doesn't matter. As long as the motor isn't hesitating or lean- misfiring then you can run as lean as you want. Once you start putting load on the engine then you have to have the correct AFRs

Gabus

Stock closed loop targets 14.7 if I'm not mistaken.

blackeg

my motor ran like **** at anything leaner than 14.5-15.1. it would pop and hesitate and basically drive shitty. my perfect a/f for driveability was like 13.9-14.5. i still managed 25-28mpg on a 200k mile ls with a gsr trans that i would do wot runs at least every time i drove it, which was probably every other day.

xyrth

pretty much any stock closed loop is 14.7:1, it's what narrowband o2's are good at, and, it's easier than making it variable based on load/gear.

as far as what ratio works or doesn't, it differs a suprising amount from motor to motor.

ie: my dsm (8.8:1 2.4L) likes 16.5:1 anytime i'm above 2,000 in 3rd, 4th, or 5th, and above 3,500 in first or second, at less than about 40% throttle. supras seem to be about a half point leaner, i'm sure there are motors that need to be richer, i just never guessed it would be a honda

what kind of wideband are you using?

elpiar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xyrth &raquo;</TD></TR><TR><TD CLASS="quote">pretty much any stock closed loop is 14.7:1, it's what narrowband o2's are good at, and, it's easier than making it variable based on load/gear.

as far as what ratio works or doesn't, it differs a suprising amount from motor to motor.

ie: my dsm (8.8:1 2.4L) likes 16.5:1 anytime i'm above 2,000 in 3rd, 4th, or 5th, and above 3,500 in first or second, at less than about 40% throttle. supras seem to be about a half point leaner, i'm sure there are motors that need to be richer, i just never guessed it would be a honda

what kind of wideband are you using?</TD></TR></TABLE>

I'm using PLX M250 w/ gauge

blackeg

using the innovate lm-1 here.

Finland

I would highly recommend running in closed loop on a street car. Sensor technology was created for this purpose, why fight it?

My car gets 28-32mpg and I drive spiritedly.

nonvtecD

Sensor technology was also created for emissions, there is a good reason to fight it if you can. I'd rather run a good bit leaner than 14.7:1 and get mor mileage because I don't really care about the Nox I'm putting out.

JDM_Risa

iTrader: (1)

i get 22-25mpg...i guess it all lies in tuning...i am running open dumptube i don't think it really matters or does it? i beat on my car everytime i drive it on 10.5psi

street tuned cars will get better gas mileage opposed to a dynotuned car which is only really tuned at WOT so at partial throttle the car is not gettin a good a/f mixture

blaze the chemi

My tuner broke in my motor on the dyno. He first set it up to where it runs closed, not sure of A/F, until I hit boost and then it is open loop. I get around 26-29 when I'm not on it, but then when I'm pulling several times a day I notice that I'm getting around 20-22 mpg. B16 @ 11 psi