Tuning with LS enabled
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Tuning with LS enabled
The question comes every once in a while about how to tune the car with Lean Spool (LS) enabled. Most are aware that LS will, in fact, lean your AFR by approximately 1 full ratio point. This can cause issues when trying to get consistant results. This thread is an attempt to debunk the myth that you cannot tune with LS enabled.
Myself and a few others in the EcuFlash forums have LS enabled with great results. These results certainly did not come easy. LS has a tendency to not be consistant from pull to pull until you get the settings dialed in.
With the help of 03whitegsr I was able to effectively tun my car with LS enabled.
WARNING.....If your car is tuned with LS disabled and you go ahead and enable it you will cause severe lean conditions that may result in engine damage.
Injectors and MAF must be scaled prior to enabeling LS.
There are several tables that must be set up properly for LS these are....
LS Start RPM
LS Stop RPM
LS AFR Mapping
LS Load Threshold
Start RPM:This should be 2500. This is the stock value and does not need changed because no one has a turbo that can spool below 2500.
Stop RPM: Depending on your setup (redline, turbo, cams, build, etc.) this value can be raised. A common occurance with LS enabled is that you will see a drop in HP at about 6800 RPM. To resolve the drop in power I found raising the Stop RPM to = my redline setting move the loss in top end power to where I shift. Keep in mind that LS will shut down quicker than your logging will show so you still may see a slight decrease in top end HP.
LS AFR Mapping: This is the critical setting. When you open the table you will see that the values are approximately 1 full point leaner than the AFR Base. The stock table is a bit leaner than me or 03whitegsr cared to play with so the table was adjust as such....
__________________________________________________ ______
base AFR (AFR)
14.7 13.0667 11.7600 10.6909 9.80000 9.04615 8.40000
14.7 13.0667 12.4609 11.6870 10.5708 9.90316 9.31485
AFR
------------------------------------------------------------------------------------------
These settings help to gain consistant resuts and as you can see they are approximately 1 full point leaner than the base AFR.
LS Load Threshold: This table sets the load that the ECU will use in conjunction with the Start RPM and trailing time to enable LS and lean the AFR. In my case the upper RPM values of 40 were too low becasue of my setup. I raised them to 50 and consistancy increased quite a bit. I beleive that the load value was too low where, in my case there was too much timing and I would have way too lean conditions. Of course the only time I was in this transition area was when driving down hill on the highway in 4th, so yes I had to initiate it. Reguardless, I raised them to 50 and the minor problem was resolved.
Other than settings in the LS tables the rest of the tuning session should go as you normally would. You have to change your train of though from the fuel table being exact AFR values to more of reference points.
Over all, I like having LS enabled. I find that the car is much more responsive while at the same time I can maintain mild manners if I so choose. For those of you that daily drive your car it is nice to have tons of power when you want it, and usefull only when you need it.
Paul
Myself and a few others in the EcuFlash forums have LS enabled with great results. These results certainly did not come easy. LS has a tendency to not be consistant from pull to pull until you get the settings dialed in.
With the help of 03whitegsr I was able to effectively tun my car with LS enabled.
WARNING.....If your car is tuned with LS disabled and you go ahead and enable it you will cause severe lean conditions that may result in engine damage.
Injectors and MAF must be scaled prior to enabeling LS.
There are several tables that must be set up properly for LS these are....
LS Start RPM
LS Stop RPM
LS AFR Mapping
LS Load Threshold
Start RPM:This should be 2500. This is the stock value and does not need changed because no one has a turbo that can spool below 2500.
Stop RPM: Depending on your setup (redline, turbo, cams, build, etc.) this value can be raised. A common occurance with LS enabled is that you will see a drop in HP at about 6800 RPM. To resolve the drop in power I found raising the Stop RPM to = my redline setting move the loss in top end power to where I shift. Keep in mind that LS will shut down quicker than your logging will show so you still may see a slight decrease in top end HP.
LS AFR Mapping: This is the critical setting. When you open the table you will see that the values are approximately 1 full point leaner than the AFR Base. The stock table is a bit leaner than me or 03whitegsr cared to play with so the table was adjust as such....
__________________________________________________ ______
base AFR (AFR)
14.7 13.0667 11.7600 10.6909 9.80000 9.04615 8.40000
14.7 13.0667 12.4609 11.6870 10.5708 9.90316 9.31485
AFR
------------------------------------------------------------------------------------------
These settings help to gain consistant resuts and as you can see they are approximately 1 full point leaner than the base AFR.
LS Load Threshold: This table sets the load that the ECU will use in conjunction with the Start RPM and trailing time to enable LS and lean the AFR. In my case the upper RPM values of 40 were too low becasue of my setup. I raised them to 50 and consistancy increased quite a bit. I beleive that the load value was too low where, in my case there was too much timing and I would have way too lean conditions. Of course the only time I was in this transition area was when driving down hill on the highway in 4th, so yes I had to initiate it. Reguardless, I raised them to 50 and the minor problem was resolved.
Other than settings in the LS tables the rest of the tuning session should go as you normally would. You have to change your train of though from the fuel table being exact AFR values to more of reference points.
Over all, I like having LS enabled. I find that the car is much more responsive while at the same time I can maintain mild manners if I so choose. For those of you that daily drive your car it is nice to have tons of power when you want it, and usefull only when you need it.
Paul
Great stuff! So it seems like the most difficult part is getting the load thresholds and trailing time properly adjusted.
I am looking at the tables now and am still a little confused. What does the trailing time affect and how does adjusting it affect the car? So changing the threshold for load lower would cause LS to come on earlier, or in cruise areas?
I am looking at the tables now and am still a little confused. What does the trailing time affect and how does adjusting it affect the car? So changing the threshold for load lower would cause LS to come on earlier, or in cruise areas?
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Mike,
The load thesholds are not all that difficult to adjust really. My car idles very high because of my hard pipes and revolver cams. Thus, my cruise load is higer too. Because of this I was sitting in the lean spool territory at cruise. Yes I raised the values that are above cruise, but the result was it worked to make the car a bit more drivable.
SmikeEvo,
I am not certain that changing to a smaller value for the stop would work as well. The reason i think it wouldn't work is because the LS is really more for quick on and off throttle transitions to keep the turbo spooling thus avoiding a loss in power. By reducing the stop to a value below the upper RPM levels will make the car very difficult to tune and will most certainly affect drivability because of the on and off effect a lower stop will cause. None of this is proven, but I strongly believe that these events will occur.
The load thesholds are not all that difficult to adjust really. My car idles very high because of my hard pipes and revolver cams. Thus, my cruise load is higer too. Because of this I was sitting in the lean spool territory at cruise. Yes I raised the values that are above cruise, but the result was it worked to make the car a bit more drivable.
SmikeEvo,
I am not certain that changing to a smaller value for the stop would work as well. The reason i think it wouldn't work is because the LS is really more for quick on and off throttle transitions to keep the turbo spooling thus avoiding a loss in power. By reducing the stop to a value below the upper RPM levels will make the car very difficult to tune and will most certainly affect drivability because of the on and off effect a lower stop will cause. None of this is proven, but I strongly believe that these events will occur.
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I agree with you on the accel enrichment stuff. Many "tooners" simply max out the accel enrichment table creating horrible rich conditions between shifts and when first accelerating. I believe the reason they do this is to be able to run a leaner fuel table.
Personally, I don't like this. Changing one table to affect another for athe purpose of trying to make more power when all that really happens is drivability suffers.
I leave my accel enrichment table stock. This is one table that if it ain't broke...don't fix it certainly applies.
Personally, I don't like this. Changing one table to affect another for athe purpose of trying to make more power when all that really happens is drivability suffers.
I leave my accel enrichment table stock. This is one table that if it ain't broke...don't fix it certainly applies.
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I agree with you on the accel enrichment stuff. Many "tooners" simply max out the accel enrichment table creating horrible rich conditions between shifts and when first accelerating. I believe the reason they do this is to be able to run a leaner fuel table.
Personally, I don't like this. Changing one table to affect another for athe purpose of trying to make more power when all that really happens is drivability suffers.
I leave my accel enrichment table stock. This is one table that if it ain't broke...don't fix it certainly applies.
Personally, I don't like this. Changing one table to affect another for athe purpose of trying to make more power when all that really happens is drivability suffers.
I leave my accel enrichment table stock. This is one table that if it ain't broke...don't fix it certainly applies.
Back on the topic of LS, what is the trailing time? What does it do - what are the units? Why is there a rich and lean side?
Last edited by MR Turco; May 20, 2009 at 10:27 AM.
I think before anybody tries and tunes this feature, they should understand how it actually works.
https://www.evolutionm.net/forums/ec...-question.html
JCSBanks with post 47 pretty much wraps up the entire function of this feature but it is worth reading it all to gain an understanding of how this feature actually works.
I say feature, because I think we should rename it because it really has nothing to do with "spool." This feature is a timed enleanment as JCSBanks described. The longer you are on the throttle and above the activation load, the less effect this feature has and the closer you get to the main fuel map AFRs.
The Trailing Time tables are actually decay rate/reset adjustments, maybe JCSBanks or Mrfred can better explain these settings.
As far as tuning, I tuned the main fuel maps to what I would describe as a "Best Conservative" tune with the feature disabled using the periphery bits. This is a tune that still makes good power but is going to be safe under any condition, be it a 20 minute road race or cruising around on the street.
Once I had my main fuel table completely tuned, I then activated the feature and started tuning the "lean spool AFR Map table." I set all the values to conservative numbers, only leaning out about 0.2-0.3 AFR at first and then leaned out more and more based on how the car was performing.
I am actually able to run the car mid 12:1 AFRs on 91 octane which then tapers down to low 11s based on how long I am on the throttle. It makes a HUGE difference on how responsive the car feels and yet I still have a very safe tune that I never get knock with. It would not have been possible to run this lean had I not used this feature though as I would get knock after about 5 second of boost trying to run leaner then mid 11s.
https://www.evolutionm.net/forums/ec...-question.html
JCSBanks with post 47 pretty much wraps up the entire function of this feature but it is worth reading it all to gain an understanding of how this feature actually works.
I say feature, because I think we should rename it because it really has nothing to do with "spool." This feature is a timed enleanment as JCSBanks described. The longer you are on the throttle and above the activation load, the less effect this feature has and the closer you get to the main fuel map AFRs.
The Trailing Time tables are actually decay rate/reset adjustments, maybe JCSBanks or Mrfred can better explain these settings.
As far as tuning, I tuned the main fuel maps to what I would describe as a "Best Conservative" tune with the feature disabled using the periphery bits. This is a tune that still makes good power but is going to be safe under any condition, be it a 20 minute road race or cruising around on the street.
Once I had my main fuel table completely tuned, I then activated the feature and started tuning the "lean spool AFR Map table." I set all the values to conservative numbers, only leaning out about 0.2-0.3 AFR at first and then leaned out more and more based on how the car was performing.
I am actually able to run the car mid 12:1 AFRs on 91 octane which then tapers down to low 11s based on how long I am on the throttle. It makes a HUGE difference on how responsive the car feels and yet I still have a very safe tune that I never get knock with. It would not have been possible to run this lean had I not used this feature though as I would get knock after about 5 second of boost trying to run leaner then mid 11s.
Just for consolidation of information i quoted JCbanks in here:
03whitegsr thanks for the information this clears up a lot of stuff. I think having "spool" in the name really causes confusion.
I notice you dont mention anything about tuning the trailing times. Do you leave those pretty stock? I like the idea of the car going lean and gradually going rich but i am not sure why it would want to go lean again. I would also think that if you wanted to get aggressive you could make the car as lean as possible and shorten the time to getting rich to avoid knock when beating on the car.
The lean spool system does move its interpolation starting from lean towards rich as you are above the load threshold, and then leans again gradually as you have time below the lean spool load threshold. The rate at which it moves towards rich is controlled by the rich trailing time, and the rate it moves towards lean is controlled by the lean trailing time.
Unfortunately, I can't put units on the timers (indirect reference that modifies them no doubt, that I can't find) and it will need empirical testing. We should have all we need to full control it though, I still quite like the system. Keeps it crisp when you just want a quick pass, but richens when you are beating on it.
Unfortunately, I can't put units on the timers (indirect reference that modifies them no doubt, that I can't find) and it will need empirical testing. We should have all we need to full control it though, I still quite like the system. Keeps it crisp when you just want a quick pass, but richens when you are beating on it.
I notice you dont mention anything about tuning the trailing times. Do you leave those pretty stock? I like the idea of the car going lean and gradually going rich but i am not sure why it would want to go lean again. I would also think that if you wanted to get aggressive you could make the car as lean as possible and shorten the time to getting rich to avoid knock when beating on the car.
not sure to put it here, but can someone know the addresses of the
LS AFR Mapping
LS Load Threshold
for a 96260009 rom. I am quite intrested in LS and would prefer to keep on using it as i agree.
LS AFR Mapping
LS Load Threshold
for a 96260009 rom. I am quite intrested in LS and would prefer to keep on using it as i agree.
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I have always maintained that its function was not intended as a Leaning function, but rather designed as an Anti-Abuse function. The longer you are on the throttle, the richer it gets. I like it and I also keep it active on my car and is especially valuable for the auto, so as it loads up through the gears it gradually gets richer and safer.
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<table name="Lean Spool Load Threshold" category="Fuel Lean Spool" 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 Load Threshold" level="2">
</table>
<table name="Lean Spool AFR Mapping" category="Fuel Lean Spool" address="39b6" type="2D" level="2" scaling="AFR">
<table name="base AFR" address="6400" type="X Axis" elements="7" scaling="AFR16"/>
</table>
<table name="Lean Spool AFR Mapping">
<table name="base AFR" address="6654"/>
</table>
These are for the 94170015 ROM.
<table name="input value" address="63da" type="X Axis" elements="14" scaling="RPM"/>
</table>
<table name="Lean Spool Load Threshold" level="2">
</table>
<table name="Lean Spool AFR Mapping" category="Fuel Lean Spool" address="39b6" type="2D" level="2" scaling="AFR">
<table name="base AFR" address="6400" type="X Axis" elements="7" scaling="AFR16"/>
</table>
<table name="Lean Spool AFR Mapping">
<table name="base AFR" address="6654"/>
</table>
These are for the 94170015 ROM.