3 Bar Map Sd Questions.

[WS6HUMMER]

Well I was looking at swapping the os over to a 3bar MAP OS and clicked the button not realizing that it would go into effect immediatly. I thought it would ask are you sure or something, no big deal though. I'm in the midst of building a hotside for the car so I'd have to do it sooner or later. I have a few questions though.

1. My new (single) VE table has defaulted every cell to 152, I'm assuming this is because the new table has more cells so it didnt carry over the applicable part of my 1bar stock OS's VE table. Can I copy and paste the values that do apply and tune from there?

2. I plan on running the car to move it around the shop at some point, can I do this with the 1bar MAP sensor still in place?

3. If this OS is SD only then why is my MAF table still there?

4. Can I get rid of the narrowband sensors now?

Thanks in advance.

[Bill@HPTuners]

1. My new (single) VE table has defaulted every cell to 152, I'm assuming this is because the new table has more cells so it didnt carry over the applicable part of my 1bar stock OS's VE table. Can I copy and paste the values that do apply and tune from there?

As per the help file (This step for 2bar and 3bar enhancement only) The VE table will be full of invalid data. You *must* create a valid VE table before writing the file to the PCM. It is a good idea to copy your previous VE table into the non-boost region and then copy and increase the last row of the VE table to the new boost area. It is important to start tuning on the rich side (higher numbers) and then work back to your desired AFR.

Theres also our 2 bar demo which shows you a quick way to create a new VE table which is also in our help file www.hptuners.com/help under demos

2. I plan on running the car to move it around the shop at some point, can I do this with the 1bar MAP sensor still in place?

Probably but there are a few values that will need to be changed to reflect what map sensor you are running.

3. If this OS is SD only then why is my MAF table still there?

I assume there was space in the code to keep the table there so rather than making more work for ourselves we left it

4. Can I get rid of the narrowband sensors now?

Sure

[WS6HUMMER]

As per the help file (This step for 2bar and 3bar enhancement only) The VE table will be full of invalid data. You *must* create a valid VE table before writing the file to the PCM. It is a good idea to copy your previous VE table into the non-boost region and then copy and increase the last row of the VE table to the new boost area. It is important to start tuning on the rich side (higher numbers) and then work back to your desired AFR.

Theres also our 2 bar demo which shows you a quick way to create a new VE table which is also in our help file www.hptuners.com/help under demos



Probably but there are a few values that will need to be changed to reflect what map sensor you are running.



I assume there was space in the code to keep the table there so rather than making more work for ourselves we left it



Sure

Bill, as aways thank you for the help!!! Bill

I appreceate!

[WS6HUMMER]

As per the help file (This step for 2bar and 3bar enhancement only) The VE table will be full of invalid data. You *must* create a valid VE table before writing the file to the PCM. It is a good idea to copy your previous VE table into the non-boost region and then copy and increase the last row of the VE table to the new boost area. It is important to start tuning on the rich side (higher numbers) and then work back to your desired AFR.

Theres also our 2 bar demo which shows you a quick way to create a new VE table which is also in our help file www.hptuners.com/help under demos



Probably but there are a few values that will need to be changed to reflect what map sensor you are running.



I assume there was space in the code to keep the table there so rather than making more work for ourselves we left it



Sure

1 more question, can I leave the DFCO enabled while running in OLSD? I would think you could but was looking in the VE tune instrucions submitted by you and it says to turn it off. I'm guessing thats for just while you are tuning to keep from getting lean spikes right?

[5_Liter_Eater]

You're correct. It just says to turn it off for tuning. Afterwards it can be turned back on.

[WS6HUMMER]

You're correct. It just says to turn it off for tuning. Afterwards it can be turned back on.

Thanks, I just wanted to make sure. What about disabling the LTFT's & STFT's? I guess these are used or their data is collected from CL and if I'm always running in OLSD there would be no point in them being left enabled. Am I close?

Man I havent messed with my tune in a year so I'm pretty rusty.

[5_Liter_Eater]

The OL in OLSD is "open loop" so thats saying that you have disabled STFTs and LTFTs. Just because your running a 3 bar SD tune doesn't mean it has to be open loop. On a gen3 you just max out the closed loop ECT VS IAT table and make sure "SFTF in open loop" is disabled. On a gen 4 you also to max out the O2 readiness table to prevent STFT.

[WS6HUMMER]

The OL in OLSD is "open loop" so thats saying that you have disabled STFTs and LTFTs. Just because your running a 3 bar SD tune doesn't mean it has to be open loop. On a gen3 you just max out the closed loop ECT VS IAT table and make sure "SFTF in open loop" is disabled. On a gen 4 you also to max out the O2 readiness table to prevent STFT.

Thank you, I understood what the abbreviatoin OLSD (open loop speed density) means but wasnt sure if the LTFT & STFT's were part of CL or OL. When I tuned my car's VE table I only watched the amount of AFR error% and didnt ever pay attention to the LTFT's to see if they were +/- after. Thanks again for clearing everything up for me though. I think I got it now, LTFT & STFT's are part of closed loop, right?

[5_Liter_Eater]

Right, fuel trims=closed loop. Once they are disabled be sure to clear the old learned ones out using VCM Controls to they are not affecting open loop.

[WS6HUMMER]

Right, fuel trims=closed loop. Once they are disabled be sure to clear the old learned ones out using VCM Controls to they are not affecting open loop.

Thanks! Glad I understand now. I'll remember to clear the fuel trim learn too,