11.4 A/F ratio...is it to lean?

[boostdog]

Ok gents i just installed a aem wideband and have noticed that at wot it will dip to 11.4. I am running an OS tune via romraider w/a tbe / intake/ gm bcs as the only mods. is it running to lean? what do you think?

like i said i put it in last night. i know the map was tuned for 92-93 octane and have a tank of 91 in it because i needed to fill up and at that time it was my only choice.

thanks in advance!

edit:
I am running bullwinkle's stg2 gmbcs map..http://www.romraider.com/forum/topic3183.html

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[crampfan]

sounds about right to me, I tuned to 11.5 @ WOT have not had any problems, everyone used to tune to around 10.5, but most are tuning to around 11.0-11.5 these days. I would not go any leaner.

[2.5racer]

Have you logged any runs? That will be the only way to tell. Whats lean on one car may be rich to another. Even though technically anything under 14.7 is rich ;p

[boostdog]

yes logged some runs when i 1st flashed that map but i am going to flash his revised map this weekend and will log it then. i'll post them up. i have been running this map for a year and about 18k miles with no issues. just finally got the gauge. i don't know what i did with the logs i had though.

[2.5racer]

I wouldn't doubt if you get a little knock and retarded timing, since your car is tuned for 92-93. However, it's not a drastic change and I'm sure that map is fairly conservitive and was ment to be a base to be tweeked. Regardless, I wouldn't do any hard driving till I got some 93 in her.
I'm interested to see your log.

[boostdog]

if i can i'll log the car before/after the flash...i'll keep an eye on the af though...i should burn through this tank fairly fast as i am traveling this sunday to the race track.

[dan1587wrx]

IMHO you should be fine I am currently protuned in my 06 wrx with a vf39 and supporting mods and I hit 11.3 to 11.35 AFR on WOT. According to Cleo from Precision 11.3 - 11.4 is a safe AFR. I would keep an eye on it and if you notice the AFR going leaner I would be worried.

[2.5racer]

You can't just go by what your afr is... if that was the case my car would run pig rich at 11.4:1 (on a gas a/f monitor). Up untill my utec fried on last friday, I was tuned at 13.2:1 (on a gas a/f monitor) most people would say I was lean... they'd be wrong.

The fact is that 91 octane is more prone to early detination than 93 and being leaner in the air mixture causes the actual burn to be faster, also, if his timing is agressive... well, he may get knock because the mixture is igniting early and burning too fast. Im guessing he won't be in any trouble, but it's better to log and know, and be carefull in the mean time.

[STIBungy]

What's your AFR at spoolup and how much timing are you running then? How much timing are you running up top at 11.4 AFR?

[boostdog]

i'll log the car this weekend and report back to you all.

thanks for the help!

[Baldturbofreak]

If your having no KR and Egt's are under control it's fine. Hell I run most of my boosted motors at 12.0 under pressure until one of the above conditions command me to do otherwise.

You should see how lean DI runs, my Solstice Gxp runs 21psi at 13.1afr! and it came that way from GM!

[scutzi128]

Damn I didn't know those suckers boosted at 21psi.

[boostdog]

Originally Posted by Baldturbofreak

If your having no KR and Egt's are under control it's fine. Hell I run most of my boosted motors at 12.0 under pressure until one of the above conditions command me to do otherwise.

You should see how lean DI runs, my Solstice Gxp runs 21psi at 13.1afr! and it came that way from GM!

well that's direct inj for ya! i certianly hope subaru decides to use it in all thier vehicles.


well change of plans i am hitting the track tonight and will be putting some oct booster in the tank to get me there and put a gallon or so of 100 octane in it.

i want to add some timing into the tune since i am using the race gas but i have a ? on exactly how to do this.

from what i understand i want to use the rom raider ecu editor tool...now would it be best to advance the timing a degree or so using the base timing field or the timing advance max. field? i have read the tuning guide several times but am still not clear, obviously, on how to do this.

thanks for any advice and direction!

[boostdog]

well i compared bullwinkles tune that i am running to gabedude's stg1 tune and it looks like all the changes are being made to the base timing fields.

So what do you recommend changing as far as fields go within this tune on the base timing fields and by how many incremints(SP?)?

also when i change these fields obviously i need to log each run which i'll do - i need to look for fbnk and flkc right? as long as i see all 0's in these fields in the log i am ok right?

please forgive my newbness...thanks guys!

[yamahaSHO]

I tune my boosted SHO for about 12.5 - 13:1 A/F ratio and don't have knock issues with 26* of total advanced timing. I wouldn't consider 11.4:1 anything but rich. When I was running just under 10:1 during tuning, my car would completely cut out like there was a rev limiter at 5k RPM.

[69subaru360]

Originally Posted by yamahaSHO

I tune my boosted SHO for about 12.5 - 13:1 A/F ratio and don't have knock issues with 26* of total advanced timing. I wouldn't consider 11.4:1 anything but rich. When I was running just under 10:1 during tuning, my car would completely cut out like there was a rev limiter at 5k RPM.

That may be well and good for your car. But run a subie at 13 to 1 under boost and plan on buying new pistons.

[69subaru360]

Originally Posted by boostdog

well i compared bullwinkles tune that i am running to gabedude's stg1 tune and it looks like all the changes are being made to the base timing fields.

So what do you recommend changing as far as fields go within this tune on the base timing fields and by how many incremints(SP?)?

also when i change these fields obviously i need to log each run which i'll do - i need to look for fbnk and flkc right? as long as i see all 0's in these fields in the log i am ok right?

please forgive my newbness...thanks guys!

It really doesn't matter where you add timing in. It will work either way. If you start with a lower than maximum IAM you'll want to add it to the base map or you will have to drive it a while first before it gets added in.

Log and look for FBKC. Download and run the learning view tool (find it on the rom raider site) and you can see your whole FLKC table.

[boostdog]

i am going to flash his revised map that sorts out the overboost issues in 4th/5th gears before heading to the track...it'll learn....1.5 hr drive away. i'll log before i get to the track if i can...my battery on my laptop doesn't last very long so we'll see what i can do.

thank you 63subaru360 i'll just make the adjustments after adding some race gas and log each run. making changes along the way.


anyone want to guess what i run? FYI the time under my vehicle to the left was before the gmbcs and tune.

edit: also been using the learning tool...very useful!

[yamahaSHO]

Originally Posted by 69subaru360

That may be well and good for your car. But run a subie at 13 to 1 under boost and plan on buying new pistons.

Run a properly tuned and charged cooled Subie at 13:1 and I bet it doesn't blow up as easy as you think. I would agreed, with high boost, I would shoot for 12:1 - 12.5:1 for a safety margin. You'll have to adjust your timing accordingly, but there shouldn't be a reason you couldn't run it 12.5:1 safely.

It's still an engine... Nothing special.

[2.5racer]

Like I said earlier... I ran 13.2:1 under boost (lambda correction for gas), 22psi to be exact.

[boostdog]

nothing special?? wth it's a subaru and that's darn special! LOL.

[yamahaSHO]

Originally Posted by boostdog

nothing special?? wth it's a subaru and that's darn special! LOL.

Touche.

[the suicidal eggroll]

Originally Posted by 2.5racer

Like I said earlier... I ran 13.2:1 under boost (lambda correction for gas), 22psi to be exact.

On e85? That doesn't count, at all
I'm sure you could run 13.2:1 under boost with C16 too, but it doesn't help the OP in the slightest.

[2.5racer]

Yeah I know ... but my earlier post was to show that there's more to worry about than afr. Then, I made that last post to see if anyone would catch that I used e85. Which in reality was a afr of 8.8:1

I was getting a kick out of sho and 69's banter... tried to egg on 69 a bit (even though I agree more with his statements). I also think on 91 13+ on wot at high boost is dangerous, but it depends on timing and load too.

[yamahaSHO]

Banter? It went on for like 2 posts... I'll banter you!