Lean spool qestions....

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May 27, 2007 | 06:25 PM

#16

gtpumps

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From: Sydney

Quote:

Originally Posted by mrfred

They should be pretty close, but maybe not lined up. If you haven't disassembled your ROM, send it to me, and I'll find the tables for you. PM me if you are interested.

Ok thanks.

May 28, 2007 | 01:41 AM

#17

rob82

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Quote:

Originally Posted by mrfred

Here are the lean spool tables for the Evo 8 94170008:

------------
<table name="Lean Spool Load Threshold" category="Misc" address="39A2" type="2D" level="1" scaling="Load8">
<table name="input value" address="63DA" type="X Axis" elements="14" scaling="RPM"/>
</table>

<table name="Lean Spool Trailing Time (Rich Side)" category="Misc" address="397A" type="2D" level="1" scaling="uint8">
<table name="input value" address="63DA" type="X Axis" elements="14" scaling="RPM"/>
</table>

<table name="Lean Spool Trailing Time (Lean Side)" category="Misc" address="398E" type="2D" level="1" scaling="uint8">
<table name="input value" address="63DA" type="X Axis" elements="14" scaling="RPM"/>
</table>

<table name="Min Temp for Lean Spool" category="Misc" address="167E" type="1D" level="1" scaling="Temp"/>

<table name="Lean Spool Enable Load Hysteresis" category="Misc" address="167C" type="1D" level="1" scaling="Load16"/>

<table name="Lean Spool AFR Mapping" category="Misc" address="39B6" type="2D" level="1" scaling="AFR">
<table name="base AFR" address="6400" type="X Axis" elements="7" scaling="AFR16"/>
</table>
------------

You'll also need to add this line to the "evo7base.xml" file:

------------
<scaling name="AFR16" units="AFR" toexpr="14.7*128/x" frexpr="14.7*128/x" format="%.1f" min="8" max="20" inc="0.1" storagetype="uint16" endian="little"/>
------------

There is also what looks like a lean spool igntion adder right before the lean spool AFR map. i dont see what all the fuss is about though with regards to mixtures. My understanding is that a certain amount of air is introduced post combustion. So your not actualy changing the thermal loading within the chamber. I assume there is a fan pump duty vs lambda table as well so that the leaner the desired mixtures within "Lean Spool Map" the higher the fan duty and the morel introduced air.

Last edited by rob82; May 28, 2007 at 03:24 AM.

May 28, 2007 | 06:57 AM

#18

mrfred

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From: Tri-Cities, WA // Portland, OR

Quote:

Originally Posted by rob82

I went back and found that I had overlooked some entries relating to AFR, so I updated my post. However, I don't see any items in the ROM relating to timing. If you are looking at the 94170008 ROM assembly, can you tell me what lines you are looking at?

Also, it sounds like you are thinking of the SAS system rather than lean spool. SAS uses air introduced into the exhaust manifold to keep the turbo on-spool during throttle lift. Lean spool appears to lean out AFR during initial throttle to encourage faster spool-up of the turbo.

Last edited by mrfred; May 28, 2007 at 07:01 AM.

May 28, 2007 | 02:48 PM

#19

gtpumps

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From: Sydney

Quote:

Originally Posted by rob82

Yes you ARE changing the thermal load because the AFR is changing. There is no way you can get an optimal hi power tune with this lean spool stuff happening.
The effect seems be be more dramatic on some ROM's.
If it only moved 0.3 AFR (like jcsbanks example with EVOIX) maybe that would be workable I guess it's just a matter of understanding (and finding) what all the parameters are.

I am not saying Mitsubishi is stupid it's just that when you run a lot more boost than factory obviously some parameters may need tweaking to keep everything happy.

Last edited by gtpumps; May 28, 2007 at 02:58 PM.

May 28, 2007 | 03:31 PM

#20

rob82

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From: .

Quote:

Originally Posted by mrfred

If you introduce air into the exhaust post combustion it will add to the oxygen content which is essentially enleaning mixutes as measured at the tailpipe. To me it would make alot more sense to introduce air into the exhuast then lean the mixtures pre spool. I'm wondering wether the lean spool table is a function of fan duty cycle and the SAS system is used for lean spool.

Also if air is introduced post combustion there is no change in thermal loading of the chamber it just your measureing device or O2 sensor that is skewed.

May 28, 2007 | 04:03 PM

#21

gtpumps

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From: Sydney

Quote:

Originally Posted by rob82

Also if air is introduced post combustion there is no change in thermal loading of the chamber it just your measureing device or O2 sensor that is skewed.

I know what you mean but this is not the case the AFR's are definately changing. You can see the milliseconds change in the EVOscan log which is confirmed by the UEGO sensor.

Jun 8, 2007 | 01:41 PM

#22

Jeff_Jeske

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From: On the track

Back to the lean spool talk....

On some dyno's you see a drop off in power after 7k rpm and this is blamed on lean spool. Is that an EVO9 only thing or is it common to find that on the 8s as well?

I'm still torn about this hack. I don't like seeing 12.5:1 at peak torque but I'm not seeing knock either so how bad can it be?

Jun 8, 2007 | 01:57 PM

#23

mrfred

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From: Tri-Cities, WA // Portland, OR

Quote:

Originally Posted by Jeff_Jeske

8s and 9s both have lean spool with the disable set to 7000 rpm. So I would expect to see a richening at 7000 rpm on an 8 also. If you're not seeing knock, maybe you don't need to worry about it. My issue is that if I spool up the car at 4000-5000 rpm in 4th or 5th gear, I get a bit of a boost overrun, and with lean spool enabled, then I get knock.

Jun 8, 2007 | 02:25 PM

#24

Jeff_Jeske

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From: On the track

I wish I could simply lower the OFF rpm of lean spool. I dont want to turn the option off entirely I simply want it to stop dicking with my fuel after 4500 rpm. That way I would get great spool up and non-changing high gear AFRs.

Jun 8, 2007 | 03:43 PM

#25

mrfred

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From: Tri-Cities, WA // Portland, OR

Quote:

Originally Posted by Jeff_Jeske

Nothing to stop you from setting the stop rpm to 4500. You'll get get a step up in richness at 4500 rpm. Should be possible to tune away some of the step.

Jun 8, 2007 | 09:06 PM

#26

Jeff_Jeske

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From: On the track

What number would need to be entered to have the end point be 4500 rpm?

Jun 8, 2007 | 09:20 PM

#27

Jorge T

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From: Houston, TX

if you changed the stop rpm to 1684, just change the rpm value to 4500

Jun 8, 2007 | 09:24 PM

#28

Jeff_Jeske

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From: On the track

I thought the stop value isn't actually an RPM.

Jun 9, 2007 | 09:26 AM

#29

mrfred

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From: Tri-Cities, WA // Portland, OR

Quote:

Originally Posted by Jeff_Jeske

I thought the stop value isn't actually an RPM.

Correct, the anti-lag stop rpm is not an rpm value. The previous poster is saying that you can change the address of that entry to point to the lean spool stop rpm. Or instead of doing that, you can paste the following two lines into you ECUFlash 94170008.xml file:

<table name="Lean Spool Start RPM" category="Misc" address="1680" type="1D" level="1" scaling="RPMStatLimit"/>

<table name="Lean Spool Stop RPM" category="Misc" address="1684" type="1D" level="1" scaling="RPMStatLimit"/>

Then you'll have explicit lean spool start/stop entries.

Jun 9, 2007 | 10:27 AM

#30

Jorge T

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From: Houston, TX

Quote:

Originally Posted by mrfred

Is there an advantage to doing this other than having explicit values? I'm trying to understand that if by changing the stop values in the boost enhancement from 1682 to 1684 changes (or disables)the AFR value of the lean spool and your method is prefered to maintain that and add stop rpm control.

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