Cobb v103 93 Octane Log = Rich?

[iso100]

I finally got around to recording a log or two and thought it was interesting that my AFR is about 14.99 at the leanest and goes as rich as 11.61 higher in the RPM once the pressure bleeds off.

I'm assuming this is normal and is there to make sure we really don't detonate?



Link to online viewer:
http://datazap.me/u/iso100/test-log?log=0&data=2-4-7

 

[lessard.dcj]

that is what you want to see in the higher rpm ranges. nothing over 11.99 AFR. safer to go rich and piss extra fuel than go lean and melt things.

 

[rodmoe]

Yup 11.61 is what I see when in the upper rpm too

 

[iso100]

Cool. Good to know.

 

[SpooledUpST]

V.103? Am I missing something? Is there a new revision out and if so I haven't heard anything about it yet!

 

[iso100]

Crap, sorry. I got messed up between "accessport v3" and 93. This is 102.

 

[MOFiestaST]

Crap, sorry. I got messed up between "accessport v3" and 93. This is 102.

Haha, I was hoping you were doing some testing, Lol. I was looking for a dyno result with the new 93 102v3 map. I think all I could find are older maps.

I'm Not looking for bigger gains on it but curious to see as I'm really trying to go with a tuner I'm going to be happy with.
Thanks

 

[HaveBlue83]

I'm seeing 12.5 WOT and I just installed the AP before my drive home, 93 oct stage 1. I know tuning and I know that 1. I am not on E85 and 2. this engine has about 10sec left of 12.5 WOT before it melts and blows up for running lean. 11.7 is the Leanest you want to see, regardless of motor. I'm not happy and I want answers.

 

[iso100]

HaveBlue, are you sure you don't have things backwards? A lower # is richer, not leaner. If 15 is essentially stoichiometric barring any MTBE or other additives then 12.5 is on the rich side, not lean.

You can verify this yourself by making sure AFR is displayed on the AP. Then while driving, leave it in gear and coast at speed with your foot off the gas. You'll see it shoot up to 45 or so when the ECM cuts fuel to the injectors for economy.

 

[iso100]

Additionally, Naturally Aspirated engines make best power in the 12-13.5:1 range under load. Turbo engines are typically safer in the 11.5-12.0:1 range under load.

 

[HaveBlue83]

no, I meant leanest. over 11.7 things start melting. I want 11.2-11.7 optimal AFR. 12.5 will melt pistons unless I am running Ethanol, and then 12.5 is perfect. Trust me I know tuning, I have a 4g63 and those cars make anyone a mechanic and tuner LOL. I usually like to see 10.8-11.2 on my cars to be safe when i run a custom tune.

edit: if i see 12.x on a boosted car on pump 93 i lift!

 

[iso100]

Hmm, if it's not detonating then I'd imagine nothing's being damaged, no?

Also remember the 4g63 is 90's tech. This engine is the latest tech with direct injection and comes factory with a quite large FMIC. I'm betting there's plenty of fuel in there to prevent detonation when running 93 and then if it *did* detonate, the knock sensor would pull ignition before any damage occurs.

When I've been watching my AP during spirited driving I haven't yet seen it pull timing. It's always added timing... sometimes as much as 6 degrees.

I think you're safe.

 

[HaveBlue83]

Hmm, if it's not detonating then I'd imagine nothing's being damaged, no?

Also remember the 4g63 is 90's tech. This engine is the latest tech with direct injection and comes factory with a quite large FMIC. I'm betting there's plenty of fuel in there to prevent detonation when running 93 and then if it *did* detonate, the knock sensor would pull ignition before any damage occurs.

When I've been watching my AP during spirited driving I haven't yet seen it pull timing. It's always added timing... sometimes as much as 6 degrees.

I think you're safe.

detonation and running lean is two different things. you can run lean and melt it all with zero knock. it will run until it melts pistons.


ideal combustion afr doesn't change. 11.7 is ideal for boost. I am updating the AP, going to reflash and see what it does. If it stays at 12.5 I will not be able to go WOT. just innate to any car guy that high 11's-12's is BAD under boost with pump..

 

[iso100]

Run Stage 0 and let us know what the stock AFR looks like. I'd do it but my car is at Ford getting a bum transmission replaced. 😢

 

[iso100]

Also check out this PDF with some tips the Miata turbo guys put together for AFRs at various load levels:
http://www.miataturbo.net/attachments/ecus-tuning-54/20150-lean-burn-engine-afr-pdf

 

[HaveBlue83]

Stage 0 is the same. I am so loat on how this is possible. I might not be able to use this thing. I dunno wtf to even think now. Engines blow at this ratio. Why is this functioning?!

Edit: according to that chart the stock and cobb stg1 93 is dead on. i just dont get how its ok. Sorry but since 05 its been 11.7 for me and anything that tunes.....its just blowing my mind.

 

[iso100]

Stage 0 is the same. I am so loat on how this is possible. I might not be able to use this thing. I dunno wtf to even think now. Engines blow at this ratio. Why is this functioning?!

So if Stage 0 is the same then I don't think the Cobb tune is doing anything wrong or dangerous. Heck, they don't even adjust the requested boost values to be more than stock requests. I've had many VW turbo cars in the past and all the aftermarket software greatly increased boost. I'm amazed Cobb is getting these gains without increasing boost.

Not trying to be a dick or anything but perhaps your idea of ideal AFR doesn't apply to the modern EcoBoost engine?

Maybe Braden from Cobb can chime in on this thread. He's their tuner.

 

[HaveBlue83]

I could not find or log timing, so im not really sure what is going on inside the engine. Sorry to hijack the thread. Im kinda freaked out.

 

[iso100]

Check out the log link in the first post. I believe it's IGN Corr Cyl X.

 

[COBB Tuning1]

Stage 0 is the same. I am so loat on how this is possible. I might not be able to use this thing. I dunno wtf to even think now. Engines blow at this ratio. Why is this functioning?!

Edit: according to that chart the stock and cobb stg1 93 is dead on. i just dont get how its ok. Sorry but since 05 its been 11.7 for me and anything that tunes.....its just blowing my mind.

Welcome to Direct Injection! The 1.6L Sigma ecoboost motor is a fantastic piece of engineering. In stock form the tune runs 12.7:1 through most of the powerband and only begins to inject fuel when the catalyst temps near their peak. Our calibrations bring the fuel in a little earlier due to the increased low end boost and advanced ignition timing. If you were to run 11.0 the engine would run poorly as the combustion chamber would be saturated with unusable fuel. The days of port injection are becoming more and more limited with the rapid advancement of DI.

Cheers,
Braden@COBB