aZnjCC

I AM NOT TRYING TO TUNE MY CAR

So can someone explain to me, when you are tuned with Crome, that is only for WOT or open loop right? Is there still closed loop, or partial throttle? Does the ecu still adjust the a/f by itself using the o2 sensor? If not, then it's highly possible that at partial throttle you could be running very lean or rich right?

Just trying to maximize my gas mileage, and trying to get a further understanding of what being "tuned" means.

MikeySpec

All those different tables you see are for different loads. Adjust them until you reach the desired a/f.

aZnjCC

Sorry I wasn't the one who did the actual tuning, so I dont really know the GUI of Crome.

So you're saying that Crome provides different tables for different loads? What if the tuner only tunes for WOT, and no partial throttle? Does the ECU still run in closed loop when it's not at WOT?

SkankyEJ7

yeah i was wondering this too, but i figured that, that was what all those different levels of graphs meant

jeffsciv23

on my last car i tuned out the part throttle just by cruising around for awhile and logging. drove and idled liek a stock turbo car.

98vtec

screen shot from crome

aZnjCC

so since most dyno tuning done is only at WOT, and for those of us that dont' have the luxury of getting partial throttle tuned, our gas mileage may suffer just daily driving?

98vtec

thats why you do street tuning for partial throttle adjustments. Or you can get on a dynapac hub dyno. It can hold the engine at certain loads and allow you to tune for part throttle.

aZnjCC

sorry if i'm confused, but I'm not sure if I understand fully.

Doesn't the ecu run in closed loop at partial throttle, so why would you need to tune partial throttle. Shouldn't the ecu be making adjustments on it's own to get the ideal a/f?

When I look at that map, it makes me think that closed loop doesn't exist anymore, since aren't leftmost columns of that map essentially the numbers used for partial throttle situations, and the rightmost columns are closer to WOT?

I guess I'm just wondering why it's possible to have closed loop, yet still able to define your partial throttle maps.

98vtec

yes it runs closed loop at part throttle, if you have it set that way. But you arent going to want to run the part throttle maps that come with the starting basemap. Especially if you are like me and run an p28 which is NOTHING like an h22 ecu. You are going to want to tune your part throttle to ~14.7:1

basemaps are far from being able to run around and get good gas mileage.

aZnjCC

haha thanks for bearing with me.

i see the light now

98vtec