pileofparts

Is this normal? A log that I do in 4th gear hits 11.2-10.8. In 6th gear I hit 12-11.6. Is there any easy way to account for this with an MBC?

Fuel trims are pretty dialed in on 1000cc injectors with a MBC.

I can provide much more detailed info if needed. Any help is really appreciated.

Evoryder

iTrader: (55)

Lean spool disable.

Typically the higher gear is supposed to be richer. Due to load cells you're hitting. It also depends on your tune(r)

nonschlont

iTrader: (3)

sounds like u have "Lean spool" enabled. The first link is to learn about it, and second is how to tune w/ it...
I just enabled it (again) today, after a year or so, and I will say, that the car feels a bit snappier, between shifts, w/ it enabled...
GL

https://www.evolutionm.net/forums/ec...l-dummies.html

https://www.evolutionm.net/forums/ec...s-enabled.html

pileofparts

I currently have the lean spool start/stop set to 1500. From my understanding this should diable lean spool and should not be my problem correct?

nonschlont

iTrader: (3)

ya thats the "old" method of doing it, but Priphery FBA bit 00, set to "0" is the proper way to disable LS. So, check your periphery bits...

pileofparts

oh cool. I will set those and give it a shot. Thanks.

Boosted Tuning

iTrader: (12)

You can get that snapper feeling with lean spool off, just gotta tune for it.

Evoryder

iTrader: (55)

I do both myself.

Mellon Racing

iTrader: (38)

I think you have something else going on if you're getting leaner in higher gears, typically it's richer. How's the IDC's looking in 4th compared to 6th?

personally I don't think high horsepower pulls in 6th gear is a good idea anyway

nonschlont

iTrader: (3)

looks like reading pwned me... as mellon suggested, check ur IDC's...

and when I enable/disable LS, I do both as well.

ace33joe

iTrader: (2)

I second Mellon's suggestion, even with LS enabled, higher gears usually show richer AFR, and LS even makes the difference bigger (richer) because LS works as a timer.

For example, if you go WOT from 3k rpm at 2nd gear, LS decays AFR by 0.5 point by 5k rpm, and if you do the same thing at 5th gear, LS decays AFR by 1 point by 5k rpm. (Just an example, actual decay rate can be different)

Boosted Tuning

iTrader: (12)

And me too

I concur, LS makes it richer in higher gears. I just read different AFRs in different gears and spat out "lean spool".

Mellon Racing

iTrader: (38)

if the idc's aren't any higher then it could be hitting a different load column that may not have as much fuel (tune issue)

Appauldd

iTrader: (22)

Running richer with LS enabled in the higher gears has to do with several factors.

First, there is more time spent in the higher gears, so it takes LS longer to affect the tune. You can easily see this if you have the "Trailing time" tables. It mostly happens in the mid range of the pull.

The second factor that affects it is the "Decay Step size". Again in taller gears you are in the gear longer so LS has longer to work. The large decay allows LS to do it's job longer.

The 3rd factor is the Load as others have said. You are at a much lower load (depending on the incline you are on) in higher gears because the car is already moving. This different load puts you in different cells on your timing and fuel tables....of which are usually richer and less timing anyhow and are often not ones you would hit on a normal tune pull.

Finally comes the "AFR mapping" I found, that for consistency, that the LS AFR table is not logical for it's stock values (with the help of others Thanks!). You have to look at the base value it is hitting and then set it logically to what you would like. For example, setting all of the values to only be about 0.5 afr different give the "snappy" feel, without going to the extreme that happens with the stock values.

LS is a bear to understand and tune for, thus most people just turn it off and be done with it. There is so many variables to tuning it to be consistent from one gear to the next and from one pull to the next which will never truly be 100% consistent.

One last note...."Lean Spool" is a bit of a misnomer for a title as this "feature" does not really affect turbo spool much at all. It does affect AFR though DUH.

I recommend tuning with LS off until you can get consistency in your pulls. Then, if you want to turn it on, change the AFR values to only be a couple 10th off of what you have in your base settings. This will be a safe starting point. Then as you get used to the feature and understand the intricacies, then you can lean the values a little more to get that "snap" back. Just know that as long as you have LS enabled, you will not have consistency from pull to pull or from gear to gear.

Hope this helps.

Paul

pileofparts

Thank you all for the input. I have set the periphery00 bit and also set the lean spool start/stop to the same. I am still leaner in 6th than 4th.

On a pull from 2400 - 4000 rpm:
injector duty % is between 24 and 34.
ipw 11.2ms - 12.02ms

I reach peak boost of 22psi at 2600rpm. At this point my afr is at 12. Boost and afr decay as the rpms incresase.

So after being at 100% throttle from 2400rpm in 6th gear I reach an AFR of 11.4 with boost at 21.6PSI @ 3500.

I did notice that my Low LTFT is at -7% right now. I think that it may be the gas.

Low LTFT: -7.743%
Mid LTFT: .101%
High LTFT: .101%

Is this acceptable? Or could this be the source of my issue?