does this support boost? like, how do I make it read boost, without throwing an error code because its speed density.. Im doing this on a 2200...
are there any more in depth posts about how to start tuning with HPT?
JooDrivinHondaKilla wrote:does this support boost? like, how do I make it read boost, without throwing an error code because its speed density.. Im doing this on a 2200...
are there any more in depth posts about how to start tuning with HPT?
Well the J-Body ECU's do not really read boost (unless you have the GM reflash for the 2.4 charger kit, or Ecotec charger kit). Thing is on the 2.4 reflash can be edited by HPT. Someone on here flash a 2200 c ar with a 2.4 gm reflash and they said it worked. If that is the case you can do that. DO a search you should find the post in this forum.
FU Tuning
Did you read the sticky at the top: How to tune with hpt the easy way..? very informative and is basically a step by step.
I did.. I cannot find my answer...
if I turbo and tune a 2200, what do I need to do to the map sensor or ecu to effectivly tune the car at ~12 psi or more...
yeah.. haha.. I just read that..
JooDrivinHondaKilla wrote:I did.. I cannot find my answer...
if I turbo and tune a 2200, what do I need to do to the map sensor or ecu to effectivly tune the car at ~12 psi or more...
Science
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Mitsu TD06-20g |3" Downpipe w/ Cutout | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
j-bodies aren't speed density.
try hpt forums.
explanation only goes so far, tuning is best learned through experience
try looking at the FAQs at the top of the forum
tuning a 1 bar jbody for boost can be done but it takes a good tuner
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
J- bodies are speed density
Speed Density
Speed Density systems accept input from sensors that measure engine speed (in rpm) and load (manifold vacuum in kPa), then the computer calculates airflow requirements by referring to a much larger (in comparison to an N Alpha system) preprogrammed lookup table, a map of thousands of values that equates to the engine’s volumetric efficiency (VE) under varying conditions of throttle position and engine speed. Engine rpm is provided via a tach signal, while vacuum is transmitted via an intake manifold-mounted Manifold Air Pressure (MAP) sensor. Since air density changes with air temperature, an intake manifold-mounted sensor is also used.
Production-based Speed Density computers also utilize an oxygen (O2) sensor mounted in the exhaust tract. The computer looks at the air/fuel ratio from the O2 sensor and corrects the fuel delivery for any errors. This helps compensate for wear and tear and production variables. Other sensors on a typical Speed Density system usually include an idle-air control motor to help regulate idle speed, a throttle-position sensor that transmits the percentage of throttle opening, a coolant-temperature sensor, and a knock sensor as a final fail-safe that hears detonation so the computer can retard timing as needed.
Why did you bring this back from the dead?
Jamie S wrote:J- bodies are speed density
Speed Density
Speed Density systems accept input from sensors that measure engine speed (in rpm) and load (manifold vacuum in kPa), then the computer calculates airflow requirements by referring to a much larger (in comparison to an N Alpha system) preprogrammed lookup table, a map of thousands of values that equates to the engine’s volumetric efficiency (VE) under varying conditions of throttle position and engine speed. Engine rpm is provided via a tach signal, while vacuum is transmitted via an intake manifold-mounted Manifold Air Pressure (MAP) sensor. Since air density changes with air temperature, an intake manifold-mounted sensor is also used.
Production-based Speed Density computers also utilize an oxygen (O2) sensor mounted in the exhaust tract. The computer looks at the air/fuel ratio from the O2 sensor and corrects the fuel delivery for any errors. This helps compensate for wear and tear and production variables. Other sensors on a typical Speed Density system usually include an idle-air control motor to help regulate idle speed, a throttle-position sensor that transmits the percentage of throttle opening, a coolant-temperature sensor, and a knock sensor as a final fail-safe that hears detonation so the computer can retard timing as needed.
Hey smartass, we all know what speed density is. Problem is.... you're wrong.
1) What's "N Alpha"? I've never heard of it.
2) Uhhh... Just about every production engine requires those sensors. They have nothing to do with an engine adjusting fuel via Speed Density (MAP vs. RPM) or Alpha-N (TPS vs RPM). A narrowband o2 sensor doesn't look at the actual ratio, it only checks if the ratio is above or below 14.7:1. Since you felt it necessary to even mention a coolant sensor and idle-air controller, I can tell right now that you don't have a clue how a fuel injected engine even works. You might as well have mentioned that a speed density tuned engine needs an intake and exhaust as well. So to address your other claims is pretty much mute...but I'll do it anyways.
3) A given MAP and IAT at a given RPM or a given MAF has a set VE and Throttle position does not change VE. The only thing throttle position does is change your map per RPM or your maf (which is why ALPHA-N pcms work well for NA and some supercharged engines). Yes, engine load will change based on TP or delta TP as the computer will decide if the current event is constant part throttle, constant WOT, positive delta TP (such as off-idle), negative delta TP(such as off-WOT), etc. and remove/add more fuel and/or timing as necessary, but VE is VE and it will only change by physical changes made to the engine (i.e. I/E manifold design, cam selection, head geometry etc).
but most importantly....
4) All J-bodies are Alpha-N except for the 97' pcms (I believe the 95' and 96' as well) and 00-02 2.4L GM supercharger reflashed pcms. The only thing your J-body map sensor is there for is spark tables, automatic transmission control, and I believe some decel tables. Apart from the previously mentioned exceptions, ALL J-BODY pcms are Alpha-N and NOT SPEED DENSITY.
Thanks webster
So what are the X and Y axis on the VE table, because the systems I have worked with and researched use MAP and RPM for the X and Y axis, where VE is use as a variable.
You said it yourself
A given MAP and IAT at a given RPM or a given MAF has a set VE. Oh wait, the MAP sensor is used for more than spark, auto shift and decel.
So, you want to retract this statement?
Uhhh... Just about every production engine requires those sensors. They have nothing to do with an engine adjusting fuel via Speed Density (MAP vs. RPM)
Look at Megasquirt for example their VE table uses a MAP value and RPM as the axis. And guess what, people from GM wrote and designed the system.
I have not gone inside the J-body ECM so I dont know what their tables look like and maybe you do and they may have a different strategy. So, in your defence I could be wrong saying that J-bodies are speed density. But, in my defence the systems I have used do use MAP sensors to determine engine load.
I am not even going to get into your mature statement about me not knowing how fuel injection works, but I have tuned a lot of engines brother. All which have used MAP as an axin in a fuel table.
Regards
Jamie S wrote:
So what are the X and Y axis on the VE table, because the systems I have worked with and researched use MAP and RPM for the X and Y axis, where VE is use as a variable.
If every pcm is speed density to you, then how do you even know of the existence of Alpha N?
Jamie S wrote:
You said it yourself
A given MAP and IAT at a given RPM or a given MAF has a set VE. Oh wait, the MAP sensor is used for more than spark, auto shift and decel.
So, you want to retract this statement?
Uhhh... Just about every production engine requires those sensors. They have nothing to do with an engine adjusting fuel via Speed Density (MAP vs. RPM)
Look at Megasquirt for example their VE table uses a MAP value and RPM as the axis. And guess what, people from GM wrote and designed the system.
Your pretty good at quoting part of what I said to help your defense. Are you a lawyer or lobbiest on the side?
1) No I don't want to retract it. I guess I have to quote myself now,
whalesac wrote:A given MAP and IAT at a given RPM or a given MAF has a set VE and Throttle position does not change VE. The only thing throttle position does is change your map per RPM or your maf (which is why ALPHA-N pcms work well for NA and some supercharged engines).
And that was in response to you saying a TPS changes VE in a speed density tuned pcm, which is pointless to say, because a throttle's purpose is
TO CHANGE MAP, which of course will change VE. All a throttle position sensor does is change engine load on a speed density pcm, whereas on an Alpha-N pcm, VE is a variable of the TPS. The very point of an Alpha-N tuned pcm is to simulate a speed density system, except it is impossible to simulate speed density correctly in a turbo engine, because mass air flow is not a close relation to throttle position like in a NA engine. The only real benefit to an Alpha-N pcm is to help idle on an engine with long duration cams with a great deal of overlap where map will fluctuate greatly.
2) What does that have to do with mentioning an o2 sensor, idle air controller and coolant sensor. The fact that you felt it necessary to mention devices that every engine requires for warmup enrichment and closed loop operation (and in the case of the IAC, operation at all) in defense for your claim that J-body PCM's are speed density was simply absurd, hence my firm reaction.
And how does Megasquirt prove that the J-body pcm has speed density tables. Megasquirt and MS-II both can be tuned as Alpha-N, Speed Density or a blend of both. I installed MS-II and have tuned with it myself, so I know first hand. Also, I didn't say that every GM pcm is Alpha-N. There are plenty of GM pcms that are set up for speed density, the majority of J-body pcms however just happen to not be. So your statement was false.
There is absolutely no reason to debate this further. I already told you which pcms have VE tables based on MAP vs RPM and which are strictly TPS vs RPM. If you don't want to believe me, fine. I don't care anymore. I'll let others assure you otherwise. Or you can search for the hundreds of threads about this already.
Jamie S wrote:Thanks webster
Your welcome.
