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Mapping AFR 1200 Turbo


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#1 bjerrang

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Posted 22 May 2012 - 03:41 AM

Hi guys.

I'm making a new fuel map for the 1200.
Got the new 180hp map from mcx and it uses a lot of fuel (afr 11.5 to 13 max) so iam now modifying this.

Does anyone know why the 1200 is map`d to 11.5-12 AFR from ski-doo in the 3500-4500 rpm low speed (30-40kph)unboosted. (values in this area is untouched by mcx)
Is it just for high torque ?

So my target it unboosted 14.7 transition to boosted 13.5 and 11.5-12 wot. Any recommendations here ?

The photo is the new map for the 180hp

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#2 SKIDOOCHRIS

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Posted 22 May 2012 - 05:52 AM

if you run that lean now and when it gets cold it wont run
also when you are very lean off boost when you go to boost quick it may miss or backfire
you do not need to be super lean. lean motors need more octane

09 1200, renegade ,precision 5128, powderlites header/IC/ intake, Motec, Tapp, ID1000,  DD floating qrs
16 1200, renegade red/white edrive-3g, pilot ts and quick adjust 

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#3 bjerrang

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Posted 22 May 2012 - 10:18 AM

if you run that lean now and when it gets cold it wont run
also when you are very lean off boost when you go to boost quick it may miss or backfire
you do not need to be super lean. lean motors need more octane



14.7 is the best afr fuel economy. I know cars running at 16 ultra lean.
Why run under 13 afr unboosted?
I have i also a nytro with custom map it runs 14.7 off boost, with no faults 2 season now.
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#4 desperado

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Posted 28 May 2012 - 12:03 AM

This is an interesting topic and one where we did extensive tuning work on turbocharged Doo's over the last 12 months, both on the dyno at MoTeC in Australia, on various race tracks this past winter and finally on the trail using pump gas.

Let me provide some basic information.

First, most people assume an engine is not under boost when the analog boost gauge shows 0psi at low load cruise speed. This is a false assumption. A typical NA engine will cruising at low load will usually show a MAP value of around 75kpa (vacuum)if the throttle is held steady and constant. The same engine fitted with a turbocharger and cruising at the same speed and load will show a higher MAP value of perhaps 95kpa (still vacuum). Anytime MAP value is below 100kpa, a typical analog boost gauge will not register any boost value. However, it has to be undertood that 95kpa is a very high load value for an ECU mapped for a naturally aspirated engine, actually it is basically a WOT MAP value.

What the above means is if the engine is indeed operated at low load and low speed but the MAP value reads above 90kpa..... then the oem ECU will interpret that condition as low speed & high load because the engine load channel is in fact the MAP channel as opposed to the throttle position channel. This is a 2 edge sword: on one hand, it will promote timing retard which is fine because you have more air mass being ingested into the engine..... but it will also increase the injector duty cycle beyond what is actually required because the ECU "thinks" the engine is highly loaded at low rpm, while in fact it is not at all.

Ok, so that is out of the way in terms of understanding that 0psi boost pressure on the gauge does not mean the engine is not getting additional air mass flow volume.

There was a comment made earlier about engine popping when running lean. Actually, this is more a function of the acceleration enrichement setting not being rich enough to allow for the rapid opening of the throttle body. The reality is the 1200 Doo has a high volume intake plenum that slows down the MAP signal. This is fine for the NA version of the engine, but in a forced induction application, the oem ECU does not have sufficient acceleration enrichement to account for the sudden manifold pressure rise when the throttle is quickly blipped and the turbo is already spinning quite fast. The oem ECU uses a TP based acceleration enrichement that should be further enriched to get ride of the occasional odd popping when accelerating quickly.... it does not matter how lean or rich the engine is setup to begin with, it has to do with rpm rate of change suddenly climbing up to a maximum value of around 12,000rpm per second and the fact the MAP signal is not fast enough to catch up with that sharp rpm rise which lasts only a few miliseconds and has a an acceleration and deceleration bell curve -- therefore TP is a better channel to tune fuel enrichement by anticipation of the fuel requirement rather than by sensor feedback.

Fuel calibration can not be optimized without a good understanding of ignition timing and fuel octane. While it is common knowledge that the 1200 turbocharged Doo will make best power at AFR's well above 12.3 -- this should only be attempted by people who understand what the proper ignition timing advance curve should be for any given boost level and fuel octane. When in doubt, it is obviously much safer to settle to a fat fuel setting around 11.5. When having no clue about what the ignition timing should be, then going for 10.5afr can be one option to move on the safe side but at the same time, it is a testimony the tuning is poor.

One other aspect that is often neglected after an injector change to higher flow units is the injection timing relative to the available 720* degrees injection time as well as the dead time calibration. Since most people are using the oem ECU, whenever the oem injectors are changed and/or modified.... the whole low duty cycle accuracy goes south and the engine becomes very difficult to tune for consistency at duty cycles below 30%. This is because modifying injectors changes the dead time values and these are locked into the oem Siemmens/VDO ECU and can not be altered. Matters become worst when replacing injectors as the oem ECU Dead Time tables relative to battery voltage does not and will never match the requirements of the new injectors. So the bottome line is you move into a situation where your engine no longer run as good as when it was totally stock. Again, when this happens... it is better to tune on the rich side to avoid lean issues as the whole system can not be predictable and repeatable anymore.

Ok, back to the topic... there is no reason why a properly tuned 1200 turbocharged Doo could not be very safely tuned to 14,2-14,4 low load cruise AFR, 13.6-13.9 normal cruise afr, 13.0-13,3 high load AFR and 12.3 WOT AFR. If in doubt about the timing curve versus the fuel octane and boost load..... then enrich one full point from the above figures. If you really do not know what you're doing and you're very concerned about your tune not being right, then enrich 2 full points.

The sad reality is the fact the oem ECU was never designed to support a forced induction to begin with. The timing curve is very inapropriate and there is no air charge temperature compensation to properly trim ignition timing and fuel. Air temperature getting into the engine in the NA version rarely exceeds 35F degrees.... Air tempereture getting into the engine on a turbo setup always exceeds 85F degrees.... that's a massive difference that throws ignition timing and fuel calibration off.

My $0.02 on the subject. I hope it provides a useful perspective.

#5 canam800

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Posted 30 May 2012 - 02:20 PM

I WAS WONDERING HOW DO I TELL MY TP AND ECU TO FURTHER ENRICH THE FEUL IS IT DONE BY THE BUDS SYSTEM OR SOME OTHER WAY? ANY HELP WOULD BE GREATLY APPRECIATED.

#6 bjerrang

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Posted 30 May 2012 - 02:28 PM

I WAS WONDERING HOW DO I TELL MY TP AND ECU TO FURTHER ENRICH THE FEUL IS IT DONE BY THE BUDS SYSTEM OR SOME OTHER WAY? ANY HELP WOULD BE GREATLY APPRECIATED.


Please push you caps-lock button....
Piggyback or standalone fueling devices. Rapidbike,vi-pec and so...
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#7 bjerrang

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Posted 30 May 2012 - 02:42 PM

This is an interesting topic and one where we did extensive tuning work on turbocharged Doo's over the last 12 months, both on the dyno at MoTeC in Australia, on various race tracks this past winter and finally on the trail using pump gas.

Let me provide some basic information.

First, most people assume an engine is not under boost when the analog boost gauge shows 0psi at low load cruise speed. This is a false assumption. A typical NA engine will cruising at low load will usually show a MAP value of around 75kpa (vacuum)if the throttle is held steady and constant. The same engine fitted with a turbocharger and cruising at the same speed and load will show a higher MAP value of perhaps 95kpa (still vacuum). Anytime MAP value is below 100kpa, a typical analog boost gauge will not register any boost value. However, it has to be undertood that 95kpa is a very high load value for an ECU mapped for a naturally aspirated engine, actually it is basically a WOT MAP value.

What the above means is if the engine is indeed operated at low load and low speed but the MAP value reads above 90kpa..... then the oem ECU will interpret that condition as low speed & high load because the engine load channel is in fact the MAP channel as opposed to the throttle position channel. This is a 2 edge sword: on one hand, it will promote timing retard which is fine because you have more air mass being ingested into the engine..... but it will also increase the injector duty cycle beyond what is actually required because the ECU "thinks" the engine is highly loaded at low rpm, while in fact it is not at all.

Ok, so that is out of the way in terms of understanding that 0psi boost pressure on the gauge does not mean the engine is not getting additional air mass flow volume.

There was a comment made earlier about engine popping when running lean. Actually, this is more a function of the acceleration enrichement setting not being rich enough to allow for the rapid opening of the throttle body. The reality is the 1200 Doo has a high volume intake plenum that slows down the MAP signal. This is fine for the NA version of the engine, but in a forced induction application, the oem ECU does not have sufficient acceleration enrichement to account for the sudden manifold pressure rise when the throttle is quickly blipped and the turbo is already spinning quite fast. The oem ECU uses a TP based acceleration enrichement that should be further enriched to get ride of the occasional odd popping when accelerating quickly.... it does not matter how lean or rich the engine is setup to begin with, it has to do with rpm rate of change suddenly climbing up to a maximum value of around 12,000rpm per second and the fact the MAP signal is not fast enough to catch up with that sharp rpm rise which lasts only a few miliseconds and has a an acceleration and deceleration bell curve -- therefore TP is a better channel to tune fuel enrichement by anticipation of the fuel requirement rather than by sensor feedback.

Fuel calibration can not be optimized without a good understanding of ignition timing and fuel octane. While it is common knowledge that the 1200 turbocharged Doo will make best power at AFR's well above 12.3 -- this should only be attempted by people who understand what the proper ignition timing advance curve should be for any given boost level and fuel octane. When in doubt, it is obviously much safer to settle to a fat fuel setting around 11.5. When having no clue about what the ignition timing should be, then going for 10.5afr can be one option to move on the safe side but at the same time, it is a testimony the tuning is poor.

One other aspect that is often neglected after an injector change to higher flow units is the injection timing relative to the available 720* degrees injection time as well as the dead time calibration. Since most people are using the oem ECU, whenever the oem injectors are changed and/or modified.... the whole low duty cycle accuracy goes south and the engine becomes very difficult to tune for consistency at duty cycles below 30%. This is because modifying injectors changes the dead time values and these are locked into the oem Siemmens/VDO ECU and can not be altered. Matters become worst when replacing injectors as the oem ECU Dead Time tables relative to battery voltage does not and will never match the requirements of the new injectors. So the bottome line is you move into a situation where your engine no longer run as good as when it was totally stock. Again, when this happens... it is better to tune on the rich side to avoid lean issues as the whole system can not be predictable and repeatable anymore.

Ok, back to the topic... there is no reason why a properly tuned 1200 turbocharged Doo could not be very safely tuned to 14,2-14,4 low load cruise AFR, 13.6-13.9 normal cruise afr, 13.0-13,3 high load AFR and 12.3 WOT AFR. If in doubt about the timing curve versus the fuel octane and boost load..... then enrich one full point from the above figures. If you really do not know what you're doing and you're very concerned about your tune not being right, then enrich 2 full points.

The sad reality is the fact the oem ECU was never designed to support a forced induction to begin with. The timing curve is very inapropriate and there is no air charge temperature compensation to properly trim ignition timing and fuel. Air temperature getting into the engine in the NA version rarely exceeds 35F degrees.... Air tempereture getting into the engine on a turbo setup always exceeds 85F degrees.... that's a massive difference that throws ignition timing and fuel calibration off.

My $0.02 on the subject. I hope it provides a useful perspective.


Good info desperado.
ive mapped the megatune below 100kpa farly good now.
This was also the biggest issue.
Will alter the 0 psi(100kpa) and up mapping now.
The mcx mapping is at 11.4-11.5AFR wot , so i will try and change this in my next runs.
Adjusted the idle afr also , its 11.5 before. At 13.5 it idles nice , but on 14.5 its not that smooth running. Guess this is normal.
Had to do some research to the megatune rpm columns i did not make any sense for me. (used to the rapidbike) , the "5000" rpm column is actually from 4500-5500rpm.

When the fueltable is completed i will post it here.
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#8 BlueMax

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Posted 31 May 2012 - 09:03 AM

desperado

Great info. Kind of explains why the members running turbos with stock ECU and piggyback controllers can get mixed results. A couple of questions.

The dead time is the amount of time it takes a fuel injector to start injecting fuel once it receives a signal from the ECU. Correct?


The dead time is determined by the manufacturer (lets say SkiDoo) through tests with a given injector, electrical system operating voltage, and fuel system standard pressure. Correct?

The lower the system voltage or higher fuel pressure the larger the dead time. Correct?

High impedance injectors (like the 1200s) have longer dead times typically. Correct?

The lowest injection open time for an injector is roughly 1 msec (.001) and the maximum injection time on the 1200 at lets say 8500 RPM is 14 msec so that leaves a window of roughly 13 msec to inject fuel in the 1200.

So if I get what you are saying, changing or modding the injectors changes this dead time and the amount of fuel injected more than likely will not be correct. Since this dead time change is fairly constant, the effects will be greater at lower engine RPM than at lets say WOT. Now throw in that the stock 1200 ECU adjusts this dead time with changes in electrical system voltage (adds additional time for lower voltages) but these rates of changes due to voltage fluctuation can vary greatly with different injectors.

The same problem goes for the turbo systems that have increased fuel pressure to compensate for boost since the increase pressure also increases this dead time which the stock ECU has no compensation.

A couple of final questions.

Does the stock electrical system on the 1200 require changes to minimize voltage fluctuation???? What are some options???

Would a 1200 turbo system be easier to tune if you ran 2 injectors per cylinder? Could a Motec 800 be used for this 6 injector operation or would this be too expensive?

#9 SKIDOOCHRIS

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Posted 31 May 2012 - 04:21 PM

Desperado,

I only disagree on one point that being the ecu was not designed for boost
the Siemens ecu is almost identical to the seadoo Siemens ecu
just in the skidoo ecu all the extras are turned off
I have heard the seadoo ecu is mapped to 15psi

09 1200, renegade ,precision 5128, powderlites header/IC/ intake, Motec, Tapp, ID1000,  DD floating qrs
16 1200, renegade red/white edrive-3g, pilot ts and quick adjust 

14 900 ace renegade for daughter 

 


#10 desperado

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Posted 02 June 2012 - 06:22 AM

Good info desperado.
ive mapped the megatune below 100kpa farly good now.
This was also the biggest issue.
Will alter the 0 psi(100kpa) and up mapping now.
The mcx mapping is at 11.4-11.5AFR wot , so i will try and change this in my next runs.
Adjusted the idle afr also , its 11.5 before. At 13.5 it idles nice , but on 14.5 its not that smooth running. Guess this is normal.
Had to do some research to the megatune rpm columns i did not make any sense for me. (used to the rapidbike) , the "5000" rpm column is actually from 4500-5500rpm.

When the fueltable is completed i will post it here.


If your AFR is around 11.5 WOT at the present time and you know what the timing advance should be relative to your normal boost pressure and fuel octane... then you can enlean. If you are unsure about your ignition timing advance and/or if your IAT is above 50C degrees at WOT, then I would suggest you leave your fueling at 11.5.

Idle will be best between 13.4 to 14.0 AFR. It is true that anything over 14.5 AFR will make the engine not run as smooth. Idle AFR while warming up should be between 12.7 to 13.2 for best results and to avoid fouling plugs on warmup.


desperado

Great info. Kind of explains why the members running turbos with stock ECU and piggyback controllers can get mixed results. A couple of questions.

The dead time is the amount of time it takes a fuel injector to start injecting fuel once it receives a signal from the ECU. Correct?


The dead time is determined by the manufacturer (lets say SkiDoo) through tests with a given injector, electrical system operating voltage, and fuel system standard pressure. Correct?

The lower the system voltage or higher fuel pressure the larger the dead time. Correct?

High impedance injectors (like the 1200s) have longer dead times typically. Correct?

The lowest injection open time for an injector is roughly 1 msec (.001) and the maximum injection time on the 1200 at lets say 8500 RPM is 14 msec so that leaves a window of roughly 13 msec to inject fuel in the 1200.

So if I get what you are saying, changing or modding the injectors changes this dead time and the amount of fuel injected more than likely will not be correct. Since this dead time change is fairly constant, the effects will be greater at lower engine RPM than at lets say WOT. Now throw in that the stock 1200 ECU adjusts this dead time with changes in electrical system voltage (adds additional time for lower voltages) but these rates of changes due to voltage fluctuation can vary greatly with different injectors.

The same problem goes for the turbo systems that have increased fuel pressure to compensate for boost since the increase pressure also increases this dead time which the stock ECU has no compensation.

A couple of final questions.

Does the stock electrical system on the 1200 require changes to minimize voltage fluctuation???? What are some options???

Would a 1200 turbo system be easier to tune if you ran 2 injectors per cylinder? Could a Motec 800 be used for this 6 injector operation or would this be too expensive?


Blue....

Deadtime is basically a time measurement of the period required for a particular injector to fully open and fully close. Let me explain. Let's take the example of a 1000cc injector. The injector will obviously flow 1000cc per minute when fully opened. However, it requires a certain amount of time for the injector to go from fully closed to fully open position. During that time, the injection volume is a fraction of the rated output. Same thing for when the injector closes. Now, if you take the example of a low injection time of 1.5ms, the injector may require 0.35ms to open and close and during that period, the full 1000cc will not be available. Further, if you lower voltage, opening time and closing time take longer because there is less current to activate the injector. In addition, if you increase fuel pressure, the injector has to fight internal pressure when opening and closing which again has an impact on deadtime. Deadtime is specific to each injector based on its design and operation characteristics. Deatime is calculated using 2 main channels that impact the net opening and closing time: battery voltage and fuel pressure. Deadtime calibration for battery voltage between 8vdc to 15vdc is usually part of any good ECU calibration. Deadtime calibration mostly impact low duty cycle operation as when duty cycle exceeds.... say 20%.... then full injector opening time vastly offsets whatever the opening and closing deadtimes are. I hope this makes sense?

If the only concern is WOT fuel calibration, then most people can get ok results by changing injectors or modifying stockers. If good idling and low speed fuel accuracy is required.... then the only way to accomplish that is by using injectors that have similar deadtime characteristics than the stock ones.

It does not make any sense to use 2 injectors per cylinder when using a standalone ECU. Outstanding injectors are readily available that will allow to use as much boost as you want and still retain idle smoothness as good as stock. For example, a good set of 1000cc injectors will allow up to 32psi+ boost at 58psi fuel pressure without any problem.... and idle quality will be identical to stock. For people wanting to run up to 45psi boost.... well there is always 2000cc injectors that will get you there at barely 65% duty cycle and with outstanding idle quality.... the only downside is idle speed needs to be raised to 2000rpm to maintain an acceptable injection time above 0.9ms. The M800 can indeed support two injectors per cylinder.... but I would not recommend that as other less expensive and equally good solutions and designs are available.


Desperado,

I only disagree on one point that being the ecu was not designed for boost
the Siemens ecu is almost identical to the seadoo Siemens ecu
just in the skidoo ecu all the extras are turned off
I have heard the seadoo ecu is mapped to 15psi


Chris...

Yes they both use similar Siemens ECU's, but in addition to the mapping, the firmware is likely different. This is the case with all more modern Bosch ECU's used by Rotax and other manufacturers. Forced induction applications normally use a different firmware... which can mean Hex addresses and reference are not the same, maps are located in different areas in the Eeprom memory and functions in the firmware are different. A quick example would be absolute pressure fuel map: in the case of the Seadoo ECU, that map exists and is calibrated to double fuel for every 100kpa increase... up to perhaps 250kpa (not sure here) -- in the case of the Skidoo ECU, that map does not exist and the ECU has no way of adding fuel for every 100kpa increase...... which is essential and very basic on any forced induction engine. Another example would be the intake air temperature compensations on fuel and ignition: Seadoo's have it to charge temps well over 110F degrees -- Skidoo's don't. The list goes on and on. Bottom line is yes the ECU can support a forced induction application.... but the firmware has to be the correct one and the Eeprom maps have to be tuned for the engine and operating environment.

#11 Need for Speed 2

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Posted 02 June 2012 - 07:40 AM

Looks to me that we have a great wealth of knowledge from Desperado aka Martin. Thanks for sharing Martin, I hope you can keep educating us all here on this site. Please dont get turnrd off by a few keyboard peckerheads, they will try to dicourage you from sharing info, again thanks Martin.Kevin

#12 Rotax!

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Posted 02 June 2012 - 08:43 AM

Well said speed.... I don't even own a turbo sled, but thought that was a great read.... Awesome..

#13 1050REV

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Posted 02 June 2012 - 09:52 AM

I have to agree with Speed as well....great information not only with great knowledge, but obviously countless hours working with the boosted 1200!
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#14 rrrenegade1000X

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Posted 13 October 2012 - 07:21 PM

I feel more intelligent just from reading this... Thx




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