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OAR Value

Messages
75
Likes
18
Location
Toronto
#1
I loaded Stage 0 and have had 2 tanks of gas and OAR never made it to -1.00.
I've always gone to this station and filled up with Shell 91.

On the same second tank of gas, I loaded Stage 1 91 Cobb OTS and within about 10 mins of driving OAR reached -1.00.

Is this normal? Has this happened to other owners?
 


Messages
350
Likes
116
Location
Austin
#3
So I have been experiencing the same thing.

Most people won't really experience this. I will, because I am competing in HS AutoX regularly, but like to run E30 during the week because well.. the torque is awesome!

Back to the point..

I have to reload the Stage 0 tune (which I recently CONFIRMED is IDENTICAL to the stock tune from Cobb staff at a local test and tune day) every time before an event so as to be within class regulations. Well when I switch to Stage 0, I am also finding that it takes much much longer to near -1.00 OAR. In fact, I cannot get it to -1 completely!

It leads me to two questions:
1) There is obviously something different going on with the OAR between tunes. What is changing between these tunes in terms of OAR?
2) How in the heck do I get it to -1.00?? I have gotten it to -0.87. I did this best by performing a combination of full throttle fourth gear pulls and half throttle sixth gear pulls.

If anyone knows any tricks on how to get it to -1 faster that would be awesome. As of now, I am having to re-tune to stage 0 2 days prior to an event just to be able to get the OAR back to a reasonable level, which IMO is -0.50 or less.
 


Messages
276
Likes
207
Location
Beltsville
#4
So I have been experiencing the same thing.

Most people won't really experience this. I will, because I am competing in HS AutoX regularly, but like to run E30 during the week because well.. the torque is awesome!

Back to the point..

I have to reload the Stage 0 tune (which I recently CONFIRMED is IDENTICAL to the stock tune from Cobb staff at a local test and tune day) every time before an event so as to be within class regulations. Well when I switch to Stage 0, I am also finding that it takes much much longer to near -1.00 OAR. In fact, I cannot get it to -1 completely!

It leads me to two questions:
1) There is obviously something different going on with the OAR between tunes. What is changing between these tunes in terms of OAR?
2) How in the heck do I get it to -1.00?? I have gotten it to -0.87. I did this best by performing a combination of full throttle fourth gear pulls and half throttle sixth gear pulls.

If anyone knows any tricks on how to get it to -1 faster that would be awesome. As of now, I am having to re-tune to stage 0 2 days prior to an event just to be able to get the OAR back to a reasonable level, which IMO is -0.50 or less.
Answers to your questions:

1) Oar response is MUCH more aggressive in taking out OAR in the OTS tunes and less aggressive bringing the oar down (towards -1). OR to go back to directly answer your question: there are tables in the ECU that change the OAR listening range (when ignition corrections actually change the OAR) ,how its responds to ignition corrections, and the timing changes made based on OAR. There is an RPM, load and coolant temp range where this is done.

2) There are alot tables and factors that in the end, will effect your OAR. Think of it as your long term fuel trims for ignition and ign corrections as your short term fuel trims. If your OAR isnt reaching -1 at all, that may be reflective of your octane of the gas relative to your tune(or for the fuel trim analogy, how accurate your base fuel tables are). I would only really worry about this if you are constantly maxing out the positive ignition corrections and its not going to -1. Basically, your OAR might be where it needs to be.

or you an just make your default OAR -1. Cobb lets you do it either the stock way (will go back to that OAR on resets) or their way which allows you do put it at your chosen value every time the car is started.

Without tuning changes, there's really no "tricks" to getting the oar where it needs to be. Drive the car at temp and don't be cruising (IGN corrections and OAR are not used under a certain load)

At the end of the day, even if your OAR is -0.5 and the fuel quality would reflect an OAR of -1, your ignition corrections should be making up at least some difference for the timing added by OAR. So your not really loosing power unless your OAR is way off from what it supposed to be.
 


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