Guys, I have a question about the analog input for HPT.
Unfortunately my boost gage does not have a dedicated output like a wide band - but has anyone tried to just tap into the sensor wires themselves to get a feedback signal for hpt? The boost/vac sensor has three wires so i though I could tap into 1 wire (if it's the feedback voltage).
Open to suggestions if anyone has tried this...
Well - I think it will work - tapped into a wire and have 1.508V at 0 gage psi. It varies if I put pressure or vacuum on it but need to calibrate it on hpt. Any other comments or insight is welcomed.
You can use any 0-5V signal to interface with HPTuners, so the boost gauge wouldn't be any different. I'm just curious why you would even bother with something like this. There is no way to change your VE tables to "Analog input vs RPM", so all you would be getting is a copy of your boost gauge in HPTuners. Are you just wanting it to datalog with?
I have no signiture
Why can't you use the MAP sensor again?
Whalesac wrote:You can use any 0-5V signal to interface with HPTuners, so the boost gauge wouldn't be any different. I'm just curious why you would even bother with something like this. There is no way to change your VE tables to "Analog input vs RPM", so all you would be getting is a copy of your boost gauge in HPTuners. Are you just wanting it to datalog with?
I know you can't use the analog input for tuning the tables. I wanted it for logging purposes for a comparison and learning.
Today 11:20 AM
Wagonwes
Quote Reply
Why can't you use the MAP sensor again?
MAP will only tell me boost onset since I only have a 1 BAR, so unless I do the 2 BAR fake or something I don't see how using the MAP can help me tune on boost.
If you don't do the fake 2 bar, you can still install a 2 bar map. They are only like 45 bucks or so shipped.
Why use a 2BAR MAP then my off boost idle and cruise has lower resolution. I think only the S/C guys use the 2.0 and 2.5 BAR MAP sensors.
I think most use VE or TPS and RPM based tuning instead of MAP based in closed loop PE mode. I have an FMU too that I can use if needed anyway so I don't think I need to know my actual MAP when in boost (except on my boost gage).
heavyclutch wrote:Why use a 2BAR MAP then my off boost idle and cruise has lower resolution. I think only the S/C guys use the 2.0 and 2.5 BAR MAP sensors.
I think most use VE or TPS and RPM based tuning instead of MAP based in closed loop PE mode. I have an FMU too that I can use if needed anyway so I don't think I need to know my actual MAP when in boost (except on my boost gage).
I believe the term you're looking for is "Alpha-N." Every fueling algorithm tunes for VE.
I think you misunderstood what Wagonwes was saying. He was suggesting to run 2 map sensors. You can leave the original 1 bar hooked up as is and wire the 2 bar or 2.5 bar map sensor the same way you want to wire the boost gauge.
I have no signiture
Whalesac wrote:heavyclutch wrote:Why use a 2BAR MAP then my off boost idle and cruise has lower resolution. I think only the S/C guys use the 2.0 and 2.5 BAR MAP sensors.
I think most use VE or TPS and RPM based tuning instead of MAP based in closed loop PE mode. I have an FMU too that I can use if needed anyway so I don't think I need to know my actual MAP when in boost (except on my boost gage).
I believe the term you're looking for is "Alpha-N." Every fueling algorithm tunes for VE.
I think you misunderstood what Wagonwes was saying. He was suggesting to run 2 map sensors. You can leave the original 1 bar hooked up as is and wire the 2 bar or 2.5 bar map sensor the same way you want to wire the boost gauge.
Yup. You can piggyback your 5V and ground from the existing MAP, just run the output to HP Tuners.
Wagonwes wrote:Whalesac wrote:heavyclutch wrote:Why use a 2BAR MAP then my off boost idle and cruise has lower resolution. I think only the S/C guys use the 2.0 and 2.5 BAR MAP sensors.
I think most use VE or TPS and RPM based tuning instead of MAP based in closed loop PE mode. I have an FMU too that I can use if needed anyway so I don't think I need to know my actual MAP when in boost (except on my boost gage).
I believe the term you're looking for is "Alpha-N." Every fueling algorithm tunes for VE.
I think you misunderstood what Wagonwes was saying. He was suggesting to run 2 map sensors. You can leave the original 1 bar hooked up as is and wire the 2 bar or 2.5 bar map sensor the same way you want to wire the boost gauge.
Yup. You can piggyback your 5V and ground from the existing MAP, just run the output to HP Tuners.
Thanks for clarifying guys - I didn't understand that you were talking about two individual sensors. I did get the boost gage to wire up and read fairly accurately. I may need to make some fine adjustments since it uses 70% of the voltage for boost and 30% for vacuum .
So if I were to wire in a separate 2 or 2.5 bar sensor how can I better use it to tune over what I have wired now? If using Alpha-N as the primary tuning scenario it's not MAP based......
It might be more accurate, I guess I thought you were looking for other alternatives. It sounds like you got everything figured out.
Wagonwes wrote:It might be more accurate, I guess I thought you were looking for other alternatives. It sounds like you got everything figured out.
I agree the full 5 volts on the extra MAP would be more accurate but for what i'm doing I think I'm ok.
I wouldn't say I have everything figured out by any means - that's why I'm asking. I really appreciate your feedback and insight while I continue learning and trying to apply this stuff.
Go here:
http://www.hptuners.com/help/
Expand: Working with VCM Scanner > Enhanced IO > Configuration
I am guessing this is what you are asking about? This is how to configure the slope/graph for you custom defined 0-5 volt input, which in your case is the boost gauge output.
I forgot to add, your boost gauge might come with a page that has the default graph of volts versus pressure. You then put those numbers into HP Tuners. If it didn't come with a graph, then maybe it came with some software in which you could change it to what you want (I know my LC1 wideband is like that). My boost is gauge is not digital though, sorry.
Thanks Wes - I think I got it here. Like I was saying - i have it configured in the gages and as an input correctly. It does work but may have to tweak just a little. I have greddy boost and all the directions originally were in Japanese so I had to download the english version.
The AEM wideband definately came with the calibration pages but there is a default AEM in HPtuners for it too. I'll have to check it's calibration too when I actually get to start the car :-)
Edited 1 time(s). Last edited Tuesday, March 30, 2010 6:10 PM
- Attachments
- boost_io.jpg (36k)
Check your PM box.
Looking at your graph there, I notice one thing off the bat. Your scale is in PSI, and at 0 volts you are reading -25. Atmospheric pressure is -14.7 PSI. So I would look into that.
Oops! I mean full vacuum is -14.7 PSI.
That looks perfect to me!
