Just checked my logs and "MAP AFR" indeed seems to be capped at 12.88 from 100 load until 160 load on my car but the resulting "Actual Wideband AFR" is 13.0-13.1 and then after that it's 12.62 tapering to 11.40 "MAP AFR" which results in 12.9 tapering to 11.5 Actual AFR at full boost.

When looking at my high octane AFR map it's it's 13.7 tapering to 12.9 in that same 100-160 load region so something is definitely clipping AFR during spool here! I guess I'm lucking out since MAP and actual AFR are almost identical due to my scaling/latency combo and current mods. It's one reason why I haven't done the +10% MAF calibration to my car to account for the AMS 3" intake yet because it works so well the way it's set now.

Now how to get around that limit when your MAP AFR is capped at 12.9 and results in low 11's high 10's is going to be tricky.

 

did you enable lean spool in ecu options ?

 

Where is the option to disable and enable lean spool?

 

ECU Options -> ECU Options Set #3 -> bit.0: Lean Spool Off/On

Might be worth seeing if it will improve the situation, although you will want the LTFT disable to make it more predictable.

 

there is no such function on the 2008 ECU .. don't waste the effort

 

ORLY?

I had no idea it was off and non-useable which makes a 2010 ECU a little more flexible. I wonder if there is any other way to lean out the spoolup parts of the map then.

 

Ooh .. of course

On the JDM they actually did use another function to generate leanspool .. I noticed its not used on the USDM sadly ..

but its quite scary .. in stock form .. you're at 13AFR at 26psi .. I guess thats also the reason why the JDM spools a tad quicker .. and the reason why we need to run colder plugs than standard once yo get it tuned..

 

i saw it in my ecu options ... so does that means even it is in my ecu options and it wont work ? mine is off might consider to turn it on ... hang on , just to confirm . . .

ECU Options -> ECU Options Set #3 -> bit.0: Lean Spool Off/On this is by default does it means it's off ?

or when it is set to bit.1 then it is on ?

thx

 

Are you 100% sure on that?

- Bryan

 

200% ..

Wanna see the subroutines where it just goes FF on you ?

 

Alright so if we do not have this option turned on...

Then why is the ECU forcing that the map not go above 12.9 MAP AFR... but the actual wideband AFR is 10's or 11's...

Is there a map or subroutine that is forcing the 08 ECU to limit spool to 12.9 and not go richer?

 

I am having the same problem:

Stock turbo
Lots of bolt-ons
DW 1000's
100 OCT

LTFT idle -0.39
LTFT cruise -1.5
Scaling 636 (weird for DW 1000's, but the trims are great!)
New green relay

I even though my target AFR's are set to 13's-14's in places on the High Octane fueling table, I'm still getting 12.88 AFR during spoolup and actual ARF's in the 10's, and even 9's around 6-7k!

No matter how much I lean the map out, it still becomes very rich during spool up. Is this due to the injector scaling perhaps? Can I increase scaling and let the trims go positive; will this lean out the x in open loop WOT conditions?

 

Your scaling is way off. I've achieved +/- 3% idle and cruise LTFT with the following:

Scaling: 886

Latencies:

6.12
5.328
2.808
1.824
1.464
1.08
0.816

Try those. If that puts you way too lean, then you have a fueling issue (fuel pump, fuel pump relay).

 

The problem isn't his scalings, the issue is that the ECU limits the spool to 12.9... when you have lower scalings with large injectors it forces you to use 12.9 MAP AFR spool, but actual afr's are much lower.

There has to be a way to allow a leaner spool.

 

Read his post again

His injector scaling is causing extreme rich conditions throughout the power band.

And I'm not quite certain why you're so interested in lean spool. The Evo X already spools WAY quick with bolt-ons, MIVEC tuning and the stock turbo. How much more is there to gain except more wear and tear on your turbo?

But somebody mentioned a lean spool flag from the 2010 ROM. Maybe that's something to look into. It's pretty obvious the ECU has a check routine during spool-up (or maybe even all open loop operation) that keeps target AFR's from going leaner than 12.9.