HOW TO - Control boost using ECUFLash and 3 port GM boost solenoid
Jul 1, 2008, 02:08 AM
#334
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Man I am so friggin confused, it's not even funny.
I wanted to know, is the JDM map necessary when tuning/setting up the GM 3 Port? I was hoping i could just eye-ball my boost gauge and use that to tune the 3 Port.
I wanted to know, is the JDM map necessary when tuning/setting up the GM 3 Port? I was hoping i could just eye-ball my boost gauge and use that to tune the 3 Port.
Jul 1, 2008, 07:10 AM
#337
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Like Tephra said, I dont think you it matters, but just for the sake of it, I soldered mine in on the GM pigtail on the grey wire b/c that is what I saw in one of the original write ups of how to install the GM 3 port. So does yours work or not work at all?
Jul 1, 2008, 09:23 AM
#338
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Does it become harder to dial in?
Jul 1, 2008, 09:33 AM
#339
With direct boost control, the ECU follows a boost curve that you can set. So the ECU will stick to the same boost no matter what weather conditions. Of course just as with load-based control, there are physical limits on how much boost a turbo can achieve, and the direct boost control system cannot overcome that, e.g., the target boost can be set to 25 psi at 7000 rpm, but if you have the stock turbo, you'll never get there.
Direct boost control is not more difficult to dial in than load-based, but both methods do take time. I spent several weeks dialing in mine (a few runs a day), but now I don't think about it or tweak it all. It does exactly what I want.
Last edited by mrfred; Jul 1, 2008 at 12:02 PM.
Jul 1, 2008, 09:36 AM
#340
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Thanks for your help mrfred, that clarifies a little.
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
With load-based control, the ECU will adjust boost to try to follow your target load curve. With completely stock boost control settings, the boost can vary quite a bit depending on the weather because the ECU tries to follow a load that is very weather dependent. I've devised several ROM mods that greatly minimize this, but there still can be a bit of variation in boost from day to day.
With direct boost control, the ECU follows a boost curve that you can set. So the ECU will stick to the same boost no matter what weather conditions. Of course just as with load-based control, there are physical limits on how much boost a turbo can achieve, and the direct boost control system cannot overcome that, e.g., the target boost can be set to 25 psi at 7000 rpm, but if you have the stock turbo, you'll never get there.
Direct boost control is not more difficult to dial in than load-based, but both methods do take time. I spent several week dialing in mine (a few runs a day), but now I don't think about it or tweak it all. It does exactly what I want.
With direct boost control, the ECU follows a boost curve that you can set. So the ECU will stick to the same boost no matter what weather conditions. Of course just as with load-based control, there are physical limits on how much boost a turbo can achieve, and the direct boost control system cannot overcome that, e.g., the target boost can be set to 25 psi at 7000 rpm, but if you have the stock turbo, you'll never get there.
Direct boost control is not more difficult to dial in than load-based, but both methods do take time. I spent several week dialing in mine (a few runs a day), but now I don't think about it or tweak it all. It does exactly what I want.
Jul 1, 2008, 10:06 AM
#341
Thanks for your help mrfred, that clarifies a little.
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
Yes to your other questions. Several modifications need to be made to the ROM before the JDM MAP sensor can be installed. These mods are described in two threads. You'll have to search for them.
Jul 1, 2008, 10:37 AM
#342
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TouringBubble and I had been fooling with mine for a few weeks. Either it would only boost to wastegate psi or it would boost WAY too much 33+ We tried rerouting the way the vac lines were connected, tried switching the 2 electrical wires, replaced the BCS with another new one, tried changing the duty cycles and such in the ecu. And nothing changed.
So I connected a MBC and I can manipulate psi, currently at 15.5-16.5psi
So I connected a MBC and I can manipulate psi, currently at 15.5-16.5psi
Jul 1, 2008, 11:56 AM
#345
Thanks for your help mrfred, that clarifies a little.
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
Isn't the 3bar map (JDM) only good for around 26psi though? What happens after that?
So without the JDM map the car will determine boost based on the load cell right where as with the jDM map it will bosot the same during winter, summer, fall regardless if whether the car hits different load cells making it more stable right?
With direct psi control, it's just more intuitive to tune and it's nice to always see the same boost on the gauge, no matter the weather or season.
With load control, you are always putting the same amount of air in your engine, which i would call "more stable" but because of the weather/season changes, same amount of air will come at different psi readings, so it just doesn't "feel" right to see different psi on the gauge, while technically it's probably a better way to achieve consistency.
My 0.02. I btw use direct psi control... Last time i changed my turbo, i spent approx 2 hours tuning it (run on the highway, exit, park, tweak the map, repeat) and haven't touched it ever since. The ambient temp would go down to 30F then and up to 90F now. Same psi all the time.
Last edited by mplspilot; Jul 1, 2008 at 12:13 PM.