3.5 bar MAP
10-17-2004, 04:07 PM
#11
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My point exactly. If I have not done one thing to the e-manage, and the cars runs OK, then my theory above seems to be working. 2.9v on the 3.5 bar sensor will alow me to run 21psi before the PCM starts causing problems. This is much better than the 10/11psi the factory sensor will allow at max (only 6psi at 2.9v). How will the ECU throw codes? If I am running the 3.5bar MAP and 720cc injectors, I need to lean out the e-manage only ~10%.
Basically I am thinking of the e-manage like the AFC (which is what it is, with finer adjustments). The PCM needs to see the MAP voltage along with TPS to determine what amount of fuel to run the car. Normally if only the injectors were changed, I would have had to intercept the Map voltage with the e-manage and decrease it so much (50%) just to keep the 720cc from squirting un-godly amounts of fuel. However, with the 3.5bar MAP, the voltage is much lower (40% lower) than what would have been sent to the PCM. Now with the e-manage, I can control this 10% change in voltage and the plus side is that I can keep the volts below 2.9v as long as I keep it below 21psi!! If this works, which it will, e-manage users will have many more options.
Basically I am thinking of the e-manage like the AFC (which is what it is, with finer adjustments). The PCM needs to see the MAP voltage along with TPS to determine what amount of fuel to run the car. Normally if only the injectors were changed, I would have had to intercept the Map voltage with the e-manage and decrease it so much (50%) just to keep the 720cc from squirting un-godly amounts of fuel. However, with the 3.5bar MAP, the voltage is much lower (40% lower) than what would have been sent to the PCM. Now with the e-manage, I can control this 10% change in voltage and the plus side is that I can keep the volts below 2.9v as long as I keep it below 21psi!! If this works, which it will, e-manage users will have many more options.
10-17-2004, 04:13 PM
#12
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Originally Posted by Slows2k,Oct 17 2004, 02:14 PM
If you can get it to work, more power too ya. I've fooled enough with my emanage and Little 440cc's to know what kind of changes the PCM will react to, and which ones don't make it happy. I'd get prepared to start pulling and clearing DTC's if I were you.
1st gen DSM PCM's are a little more forgiving than this one.
i'm not giving you a hard time, you just have a bunch of work cut out for you. Good luck.
1st gen DSM PCM's are a little more forgiving than this one.
i'm not giving you a hard time, you just have a bunch of work cut out for you. Good luck.
10-17-2004, 10:46 PM
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I've been playing with the emanage for some time now. Here are some notes that might help.
1. Stock map sensor should be clamped at 2.85 across the rpm range. You can verify this figure by turning the key without hitting the start button, turn on the emanage support tool, import the map, open real time and choose the sensors you need. You will observe the voltage at atmosphere which is about 2.84v. For that matter you can do the same and observe what your aftermarket sensor reads at 0 psi too. This gives you the clamp but you should clamp using the stock sensor as that is what the stock ECU will read. Your map sensor will be used by the emanage (assuming it's a 5 volt, which is what the GReddy Pressure sensor is)
2. The stock map sensor will be used by the stock ECU. The emanage can use your map sensor if you like. I am running the GReddy Pressure sensor which is good for 3 bar and is a 5 volt unit. It plugs right in. But I can't see why you can't use yours. Just be sure to select it when creating your tables in the "additional injection map". If you wire it in place of the GReddy Pressure sensor, select that. You can also determine the max. boost level you will run, find the matching voltage and set one step above that as your limit so you can have a finer resolution on your Y-axis of the table. Just set your high at the bottom of the column, set your low at the top then use the extrapolation button, it will do the rest.
3. I believe the 720cc is too big as I am running 550cc and hardly see 20% duty cycles running between 5-6 psi of boost. The duty cycles are so low that it makes on/off boost transitions difficult because the "squirt time" of the injector is either too little or too much even though we're talking about the smallest increment change of 1 ms. I would suggest something around 440cc or running an adjustable RRFPR with stock injectors (which have a better pintle design and spray pattern for better atomisation), but set the RRFPR at somewhere reasonable, perhaps 2:1 then use the emanage to add just a little fuel instead of large percentage increases. The mechanical nature of the RRFPR will always yield a much better and smoother transition from off/on boost. It will also save you the work of tuning part throttle.
4. You can use the "adjustment airflow map" to remove fuel needed, and you can add fuel once you are higher than 30% TPS. I have observed the factory computer triming fuel in it's short term fuel upto 30%. Once you hit 30% TPS, the computer stops triming fuel, goes to 0% fuel trim. This was determined using an OBD II software and it seems irrelevant of gear or load. I would highly recommend you get your hands on a good OBD II software so you can see and log in realtime what the factory ECU is doing and how it's dealing with the changes.
5. I found in general that leaving the stock computer to do what it likes in vaccum results in a good clean driving car. At a point just below boost you can start adding fuel to smooth the transition into boost. Once on boost you should be safe to tune without too many issues because at that point the stock computer is reading atmosphere and you are able to run in open loop.
I hope this helps.
cheers
W
1. Stock map sensor should be clamped at 2.85 across the rpm range. You can verify this figure by turning the key without hitting the start button, turn on the emanage support tool, import the map, open real time and choose the sensors you need. You will observe the voltage at atmosphere which is about 2.84v. For that matter you can do the same and observe what your aftermarket sensor reads at 0 psi too. This gives you the clamp but you should clamp using the stock sensor as that is what the stock ECU will read. Your map sensor will be used by the emanage (assuming it's a 5 volt, which is what the GReddy Pressure sensor is)
2. The stock map sensor will be used by the stock ECU. The emanage can use your map sensor if you like. I am running the GReddy Pressure sensor which is good for 3 bar and is a 5 volt unit. It plugs right in. But I can't see why you can't use yours. Just be sure to select it when creating your tables in the "additional injection map". If you wire it in place of the GReddy Pressure sensor, select that. You can also determine the max. boost level you will run, find the matching voltage and set one step above that as your limit so you can have a finer resolution on your Y-axis of the table. Just set your high at the bottom of the column, set your low at the top then use the extrapolation button, it will do the rest.
3. I believe the 720cc is too big as I am running 550cc and hardly see 20% duty cycles running between 5-6 psi of boost. The duty cycles are so low that it makes on/off boost transitions difficult because the "squirt time" of the injector is either too little or too much even though we're talking about the smallest increment change of 1 ms. I would suggest something around 440cc or running an adjustable RRFPR with stock injectors (which have a better pintle design and spray pattern for better atomisation), but set the RRFPR at somewhere reasonable, perhaps 2:1 then use the emanage to add just a little fuel instead of large percentage increases. The mechanical nature of the RRFPR will always yield a much better and smoother transition from off/on boost. It will also save you the work of tuning part throttle.
4. You can use the "adjustment airflow map" to remove fuel needed, and you can add fuel once you are higher than 30% TPS. I have observed the factory computer triming fuel in it's short term fuel upto 30%. Once you hit 30% TPS, the computer stops triming fuel, goes to 0% fuel trim. This was determined using an OBD II software and it seems irrelevant of gear or load. I would highly recommend you get your hands on a good OBD II software so you can see and log in realtime what the factory ECU is doing and how it's dealing with the changes.
5. I found in general that leaving the stock computer to do what it likes in vaccum results in a good clean driving car. At a point just below boost you can start adding fuel to smooth the transition into boost. Once on boost you should be safe to tune without too many issues because at that point the stock computer is reading atmosphere and you are able to run in open loop.
I hope this helps.
cheers
W
good info!
10-18-2004, 02:47 AM
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Thanks for the good info! I think I can manage using the 3.5 bar sensor and still get the 720's managable. As it sits right now, it idles perfect and the only problem is now and then when I transition to boost too fast, it will stumble a bit. This is what I hope to tune out with the e-manage. With my rough calculations, I am going to try and cut 10% fuel out today and see if the stumble goes away. This small of a change should not cause any problems within the PCM I hope. If this works, I think I will be going the right direction and will be able to give more info when the car is tuned with a WB.
The 720's are required because it will be running 18psi on pump all the time. Higher boost will be added on race gas and we are going to ned injectors that size to provide the fuel needed. These same injectors were run in a friends eclipse and we got them under control with only an AFC and a hacked MAS.
I guess the only way to really find out is to try it. I have not seen anyone say that they have ran 720's with a larger (3.5) MAP and could not get it to work.
Thanks again for all the useful info and if anyone has anymore ideas, please reply.
The 720's are required because it will be running 18psi on pump all the time. Higher boost will be added on race gas and we are going to ned injectors that size to provide the fuel needed. These same injectors were run in a friends eclipse and we got them under control with only an AFC and a hacked MAS.
I guess the only way to really find out is to try it. I have not seen anyone say that they have ran 720's with a larger (3.5) MAP and could not get it to work.
Thanks again for all the useful info and if anyone has anymore ideas, please reply.
10-18-2004, 02:51 AM
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Originally Posted by Wael El-Dasher,Oct 17 2004, 10:46 PM
I've been playing with the emanage for some time now. Here are some notes that might help.
1. Stock map sensor should be clamped at 2.85 across the rpm range. You can verify this figure by turning the key without hitting the start button, turn on the emanage support tool, import the map, open real time and choose the sensors you need. You will observe the voltage at atmosphere which is about 2.84v. For that matter you can do the same and observe what your aftermarket sensor reads at 0 psi too. This gives you the clamp but you should clamp using the stock sensor as that is what the stock ECU will read. Your map sensor will be used by the emanage (assuming it's a 5 volt, which is what the GReddy Pressure sensor is)
2. The stock map sensor will be used by the stock ECU. The emanage can use your map sensor if you like. I am running the GReddy Pressure sensor which is good for 3 bar and is a 5 volt unit. It plugs right in. But I can't see why you can't use yours. Just be sure to select it when creating your tables in the "additional injection map". If you wire it in place of the GReddy Pressure sensor, select that. You can also determine the max. boost level you will run, find the matching voltage and set one step above that as your limit so you can have a finer resolution on your Y-axis of the table. Just set your high at the bottom of the column, set your low at the top then use the extrapolation button, it will do the rest.
3. I believe the 720cc is too big as I am running 550cc and hardly see 20% duty cycles running between 5-6 psi of boost. The duty cycles are so low that it makes on/off boost transitions difficult because the "squirt time" of the injector is either too little or too much even though we're talking about the smallest increment change of 1 ms. I would suggest something around 440cc or running an adjustable RRFPR with stock injectors (which have a better pintle design and spray pattern for better atomisation), but set the RRFPR at somewhere reasonable, perhaps 2:1 then use the emanage to add just a little fuel instead of large percentage increases. The mechanical nature of the RRFPR will always yield a much better and smoother transition from off/on boost. It will also save you the work of tuning part throttle.
4. You can use the "adjustment airflow map" to remove fuel needed, and you can add fuel once you are higher than 30% TPS. I have observed the factory computer triming fuel in it's short term fuel upto 30%. Once you hit 30% TPS, the computer stops triming fuel, goes to 0% fuel trim. This was determined using an OBD II software and it seems irrelevant of gear or load. I would highly recommend you get your hands on a good OBD II software so you can see and log in realtime what the factory ECU is doing and how it's dealing with the changes.
5. I found in general that leaving the stock computer to do what it likes in vaccum results in a good clean driving car. At a point just below boost you can start adding fuel to smooth the transition into boost. Once on boost you should be safe to tune without too many issues because at that point the stock computer is reading atmosphere and you are able to run in open loop.
I hope this helps.
cheers
W
1. Stock map sensor should be clamped at 2.85 across the rpm range. You can verify this figure by turning the key without hitting the start button, turn on the emanage support tool, import the map, open real time and choose the sensors you need. You will observe the voltage at atmosphere which is about 2.84v. For that matter you can do the same and observe what your aftermarket sensor reads at 0 psi too. This gives you the clamp but you should clamp using the stock sensor as that is what the stock ECU will read. Your map sensor will be used by the emanage (assuming it's a 5 volt, which is what the GReddy Pressure sensor is)
2. The stock map sensor will be used by the stock ECU. The emanage can use your map sensor if you like. I am running the GReddy Pressure sensor which is good for 3 bar and is a 5 volt unit. It plugs right in. But I can't see why you can't use yours. Just be sure to select it when creating your tables in the "additional injection map". If you wire it in place of the GReddy Pressure sensor, select that. You can also determine the max. boost level you will run, find the matching voltage and set one step above that as your limit so you can have a finer resolution on your Y-axis of the table. Just set your high at the bottom of the column, set your low at the top then use the extrapolation button, it will do the rest.
3. I believe the 720cc is too big as I am running 550cc and hardly see 20% duty cycles running between 5-6 psi of boost. The duty cycles are so low that it makes on/off boost transitions difficult because the "squirt time" of the injector is either too little or too much even though we're talking about the smallest increment change of 1 ms. I would suggest something around 440cc or running an adjustable RRFPR with stock injectors (which have a better pintle design and spray pattern for better atomisation), but set the RRFPR at somewhere reasonable, perhaps 2:1 then use the emanage to add just a little fuel instead of large percentage increases. The mechanical nature of the RRFPR will always yield a much better and smoother transition from off/on boost. It will also save you the work of tuning part throttle.
4. You can use the "adjustment airflow map" to remove fuel needed, and you can add fuel once you are higher than 30% TPS. I have observed the factory computer triming fuel in it's short term fuel upto 30%. Once you hit 30% TPS, the computer stops triming fuel, goes to 0% fuel trim. This was determined using an OBD II software and it seems irrelevant of gear or load. I would highly recommend you get your hands on a good OBD II software so you can see and log in realtime what the factory ECU is doing and how it's dealing with the changes.
5. I found in general that leaving the stock computer to do what it likes in vaccum results in a good clean driving car. At a point just below boost you can start adding fuel to smooth the transition into boost. Once on boost you should be safe to tune without too many issues because at that point the stock computer is reading atmosphere and you are able to run in open loop.
I hope this helps.
cheers
W
What problems do you think this will cause. This is what I was saying about how it has very decent driving manners now with no manipulation from the e-manage. The lower voltage reading from the sensor is causing the factory PCM to dose out smaller doses of injector pulse width...less fuel.
10-18-2004, 04:07 AM
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I think it doesn't matter what map sensor you use, as long as the voltage your sensor sends to the stock ECU is accepted. I would follow step 1 and read what voltage the emanage support tool displays at 0psi. If it's close to the stock unit's 2.84v then you are fine, but if it is less, which is what I suspect it will be since it's a 3.5 bar unit vs. 1.4 bar, then the stock ECU might never recognize that you're near 0 psi.
If it's reading something like 0.9v, and say that correlates to say -20"vac. then that's what it will try to run for fuel. That's why I was suggesting re-installing the stock unit back in, let the stock ECU use that unit and you can clamp it at the voltage the stock ECU understands as atmosphere, then use your 3.5 bar map sensor for the e-manage exclusively. Or you can buy the GReddy 3 bar map sensor if you don't want to fiddle with this map sensor issue for too long (I believe it's $90 with plug'n'play wiring harness) so you can get to the real work...the tuning
The truth is, I don't know how the stock computer will react to using the map sensor you have, it might work just fine, it might not. I have no experience with it. The above setup is how I am running and is what I know for sure works. If the purpose is to have sensor that can do the job, then I know the GReddy Pressure sensor is designed to plug right into the e-manage and it will solve the problem while allowing you to keep the stock unit so no need to fuss with stock ECU's calibration. My suggestion is play with it for a while (but not too long so you're not regressing with the project) if it doesn't work, then you have a clear alternative to solving the problem, but don't design the system to revolve around a map sensor, it wouldn't make any sense.
Please keep us updated, I would like to know if it works.
cheers
W
If it's reading something like 0.9v, and say that correlates to say -20"vac. then that's what it will try to run for fuel. That's why I was suggesting re-installing the stock unit back in, let the stock ECU use that unit and you can clamp it at the voltage the stock ECU understands as atmosphere, then use your 3.5 bar map sensor for the e-manage exclusively. Or you can buy the GReddy 3 bar map sensor if you don't want to fiddle with this map sensor issue for too long (I believe it's $90 with plug'n'play wiring harness) so you can get to the real work...the tuning
The truth is, I don't know how the stock computer will react to using the map sensor you have, it might work just fine, it might not. I have no experience with it. The above setup is how I am running and is what I know for sure works. If the purpose is to have sensor that can do the job, then I know the GReddy Pressure sensor is designed to plug right into the e-manage and it will solve the problem while allowing you to keep the stock unit so no need to fuss with stock ECU's calibration. My suggestion is play with it for a while (but not too long so you're not regressing with the project) if it doesn't work, then you have a clear alternative to solving the problem, but don't design the system to revolve around a map sensor, it wouldn't make any sense.
Please keep us updated, I would like to know if it works.
cheers
W
10-18-2004, 05:57 AM
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I'll keep you updated for sure. I know at the current moment the stock PCM is working well with the 3.5 and 720's with no adjustments. I know the stock 1.5 MAP is no longer in there. The PCM handles all normal driving well and only gives the problem when transitioning to boost too fast. I meant to say that the sensor gives the PCM .090v for every psi versus .200v on the 1.5 MAP. I will take the reading at atmospheric today and report back my findings tonight.
Thanks for the helpful input!!
Thanks for the helpful input!!
10-18-2004, 04:08 PM
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Just an update. I checked the MAP sensor voltage with the car off as suggested (atmosphere) and it shows 1.6v. This was not the 1.3 volts I calculated, but I had based that on assumptions about the stock sensor. So my theory is correct and it does give a lower voltage which in turn will allow me to run more boost before I hit the magic 2.9v. I used my corrected calculations and came up with something real close to factory drivability. I basically used the injector conversion and told it I was useing 100cc injectors to begin with and switched to 90cc injectors. This gave me the 10% richer scenario I was looking for. There is no more stumble and the transition to boost is very smoth. 1st and 2nd gear sprints feel incredible for this low of a boost setting. Once we have the wide band I will refine the tuning and share the results. Looks like this might work after all, but I will not jump the gun yet as tuning is much more involved than just changing one parameter.