110 octane with open loop

[V8KLR]

I've been trying to set up a tune on my car for 110 octane because racing season is almost here again Anywho, i've already killed one o2 sensor with leaded fuel. Would there be anyway to make the car stay in open loop so I could plug the o2sensor bung at the track and not have to worry about killing another o2?

 

[DSMopar]

If it's just for the track then unplug it, it'll be fine. There is no closed loop function at WOT anyways...

 

[turbotemper]

Be sure you have a good tune on it keeping it a bit rich for safety before you just take out your O2 sensor and floor it.
BTW are you tuning using a wideband or narrow band sensor?
Be sure you ave the proper A/F ratio.
You dont want to go boom at half track and ruin your day as well as others for oiling the track.

 

[1992awdlaser]

What are you tuning with?

 

[DSMopar]

Be sure you have a good tune on it keeping it a bit rich for safety before you just take out your O2 sensor and floor it.
BTW are you tuning using a wideband or narrow band sensor?
Be sure you ave the proper A/F ratio.
You dont want to go boom at half track and ruin your day as well as others for oiling the track.

I'm assuming he's talking about his OEM sensor, and no it will do ABSOLUTELY NOTHING to his WOT fuel maps. My head is going to pop if I have to explain this one more time on this flippin board.

 

[turbotemper]

I'm assuming he's talking about his OEM sensor, and no it will do ABSOLUTELY NOTHING to his WOT fuel maps. My head is going to pop if I have to explain this one more time on this flippin board.

I didnt say anything about what it would or would not do did I???
This is a newbie forum for the guys who dont know much so relax its Friday

 

[V8KLR]

I didnt say anything about what it would or would not do did I???
This is a newbie forum for the guys who dont know much so relax its Friday

I'm not a DSM noob just a noob to the site, that and I didnt know where to post my question. I'm tuning with a SAFC and wideband...And yes, I do have a logger before anyone asks . I know it wont affect my fuel maps above 80% throttle but I was worried that it would just die before I could go WOT

 

[DSMopar]

I didnt say anything about what it would or would not do did I???
This is a newbie forum for the guys who dont know much so relax its Friday

Yet I'm telling it to the people GIVING the advice.

Be sure you have a good tune on it keeping it a bit rich for safety before you just take out your O2 sensor and floor it.

That infers you THINK it'll make ANY difference with the O2 out...

 

[jrohner]

I'm assuming he's talking about his OEM sensor, and no it will do ABSOLUTELY NOTHING to his WOT fuel maps. My head is going to pop if I have to explain this one more time on this flippin board.

It does if your trims are off. Trims do affect WOT, I know from tuning my cars.

 

[DSMopar]

Not on a stock 1g ECM.... I can't speak for 2gs

 

[jrohner]

Not on a stock 1g ECM.... I can't speak for 2gs

They must, because the guys who run open-loop lean cruising for better gas mileage get it messed up if their high trims are off. It goes by the high trim.

Plus I've ran 1/2 E85 in my 1g with no tuning. If the trims didn't matter it would've been rediculously lean when boosting.

 

[V8KLR]

Now i'm more confused than when I posted the question .

 

[Burnett03]

If you are running dsmlink you can lock the 02 sensor feedback.

 

[tkelly27]

You've got a wideband, AFC, and I'm assuming a logger. Running 110 octane? Pull the plug, set the boost to stock and take it for a rip down the street and let us know what happens. You pretty much can't break anything at stock boost levels, I've been as lean as 14 on 87 octane with no knock.

 

[DSMopar]

They must, because the guys who run open-loop lean cruising for better gas mileage get it messed up if their high trims are off. It goes by the high trim.

Plus I've ran 1/2 E85 in my 1g with no tuning. If the trims didn't matter it would've been rediculously lean when boosting.

What 'trim' are you referring to? DSM-link? SAFC? Either of those are actually modifying the way the ECU sees air-flow data, in effect modifying the fuel maps (not really though). In any case that still has nothing to do with what we're talking about here. There IS NO closed loop operation at WOT and therefore it doesn't matter if you even have an O2 hooked up or not the ECM will still deliver the same fuel.

 

[V8KLR]

Alright as soon as it quits raining i'm gonna log a run on 10PSI with 93 octane and the o2 pulled. I letcha know what happens. And to tkelly, my car wont even run on 87 octane at stock boost without knocking. I have a 9:1CR.

 

[toofast82]

Im assuming you still have the stock 02sensor in the housing and the wideband mounted in the dowpipe. As was said, the 1g ecu only uses o2 feedback during closed loop to achieve the 14.7a/f. During leaded gas runs, you can remove the stock narrowband sensor and plug it up without an issue. If you are going to get the most out of your race gas, you will obviously be using the wideband to monitor a/f and make adjustments. hope this helps

 

[V8KLR]

Im assuming you still have the stock 02sensor in the housing and the wideband mounted in the dowpipe. As was said, the 1g ecu only uses o2 feedback during closed loop to achieve the 14.7a/f. During leaded gas runs, you can remove the stock narrowband sensor and plug it up without an issue. If you are going to get the most out of your race gas, you will obviously be using the wideband to monitor a/f and make adjustments. hope this helps

Thanks man, yes I have my wideband bung in the downpipe.

 

[jrohner]

There IS NO closed loop operation at WOT and therefore it doesn't matter if you even have an O2 hooked up or not the ECM will still deliver the same fuel.

In open loop it uses the high trim.

 

[DSMopar]

In open loop it uses the high trim.

Heh you really have no idea what you're talking about do you? You keep referring to fuel maps in terms of 'trims' which is a really a function of the aftermarket tuning device you're using.

Like we said we're talking about OEM closed loop feedback, which only happens under low load part throttle...

So far this guy (toofast82) is the only one who knows what he's talking about in this thread

 

[V8KLR]

OK here we go. I logged a 3rd gear run with 93 octane o2 installed. Then I looged a 3rd gear run with 93 octane no o2. Both runs look exactly the same.

 

[1992awdlaser]

OK here we go. I logged a 3rd gear run with 93 octane o2 installed. Then I looged a 3rd gear run with 93 octane no o2. Both runs look exactly the same.

They're going to look the same. The o2 senor has nothing to do with full throttle, just like post 15 said.

 

[DSMopar]

OK here we go. I logged a 3rd gear run with 93 octane o2 installed. Then I looged a 3rd gear run with 93 octane no o2. Both runs look exactly the same.

Shocking...

 

[V8KLR]

They're going to look the same. The o2 senor has nothing to do with full throttle, just like post 15 said.

Well that is all I needed to know in the first place. Instead 20 people get on here and argue about fuel trims being different with no o2 blah blah blah when they know nothing

 

[MY1GDSM]

Heh you really have no idea what you're talking about do you? You keep referring to fuel maps in terms of 'trims' which is a really a function of the aftermarket tuning device you're using.

Like we said we're talking about OEM closed loop feedback, which only happens under low load part throttle...

So far this guy (toofast82) is the only one who knows what he's talking about in this thread

Yes what Toofast82 said is right

1g ecu only uses o2 feedback during closed loop to achieve the 14.7a/f

but I Think that you are misunderstanding what jrohner is tring to saying
I think what He is talking about with the High fuel trim.. which if viewed in MMCD
would be any where from 81.2 to 139,. ...
is If your tuning any 1g the Hight trim is going to have to settle before you should do any WOT tunning since if it changes after Word it would change the open loop maps..