I converted my OS in hptuners to 2 bar SD and saved it under a new name. I didn't write it to the vehicle or make any other changes.

I looked at my VE table to verify it does go to 210 kpa now. I had read a book on this as well as watched a tutorial video and noticed a difference in my VE table compared to theirs after making the switch so I did not write to vehicle.

My VE now starts at 30 kpa and jumps more numbers to fit the 210 kpa into the same number of vertical columns as it had before switching the OS. In the book and tutorial video their VE didn't lose resolution going to 2 bar it actually added vertical columns to extend the kpa to 210.

Is there a way to change the resolution on the kpa axis of the VE table or is something wrong with what I did?

 

It should NOT start at 30! Did you rescale your MAP sensor settings? What year/model PCM?

 

Yup, limited space in the OS means a lower resolution VE table. Don't worry, it won't hurt a thing.

 

yep I talked to hptuners support the 04 got screwed with limited space so they had to lower resolution. I still should be able to copy the areas that do match up with my old tune below 105 kpa to have a good starting point.

 

You can switch to a different OS to get a better VE table, just FYI

 

And which OS would that be that makes everything continue to operate normally on an 04 GTO?

 

I suppose whatever OS it is would be without the lean cruise option that ONLY 2004 GTO owners have.

 

The 04 GTO is like the red headed step child of the LS community...

I went ahead and converted to the 2 bar SD OS and ordered the ac delco 2 bar map sensor.

 

I wanted to give a little update after converting to 2 bar Sd...

I converted my OS to 2 bar sd, installed a dw300c fuel pump, and daetschwerks 60 lbs injectors ahead of the procharger install. I wanted to go ahead and check idle/driveability with just those changes before doing the procharger.

I did all the normal stuff when tuning sd...fail maf, disable fuel trims, force open loop, etc. I also entered the data for the injectors that daetschwerks provides.

At first idle quality was poor and timing at idle was jumping from 5 to 30. I noticed the idle timing table didn't match the main timing tables in those areas so I matched those up and that made a small improvement. I then decided to play with the primary VE. I'm new to tuning and I didn't mess with any of the idle airflow stuff when converting OS so that seemed like a good place to start.

It was idling in the 800 rpm 50 kpa cell so I changed that number from 44 to 47 and bam near perfect idle and driveability in stop and go driving. The commanded idle speed is 850 rpm.

So last night I decided to compare the new tune to the old tune. I noticed in the old tune it was idling in the 800 rpm 55 kpa cell. Well I no longer have a 55 kpa cell with the loss of resolution. The VE number in the old tune in that cell at 800 rpm and 55 kpa...47.

 

The Deatschwerks injector data is off. Therefore, everything in the VE table will have to change relative to the previous combo. Also, check your fuel pressure. I bet it's over 60psi now and overtaking the stock FPR. That will also change everything if you have more fuel than the PCM expects requiring you to lean things out.

Also, what cam are you running? I'm in the 30s in that same area. But I also set the EOIT correctly so the car doesn't reek of fuel and that drops the lower end of the VE into the toilet. My old cam (big cam) was in the 20s.

 

I'd be willing to bet that I could get a factory OS to run just fine.

2bar SD is NOT an absolute requirement just because you have boost. I would much rather have a MAF with a stable signal and sufficient range when running boost, but I would also prefer to have a VE table that properly matches the engine's pumping behavior in all the transient areas like GM intended.

Properly calibrated, you won't see a ton of change to actual VE above 105kPa. The ECU does still need a 2bar MAP sensor in order to feed the SD calculation numbers higher than 105kPa though. If you map it right, it will still calculate a g/cyl number that is appropriately high during boost.

Of course, with all this said, you'll still likely need to scale the tune for both injector flow greater than 8.0g/s and airflow greater than 512g/s. Luckily, the scaling process can cover this without any significant loss of resolution in the calculations. (I showed this on my GM Advanced tuning DVD)

 

Still waiting on that OS ID.

 

I think you missed my point. I almost always use the stock read (and hence, OS) from the car as my starting point. I perform a stock TCS reflash based on the VIN if necessary. I can count on one hand how many times I have had to resort to using a custom OS. The last one I remember had stacks/ITBs with no plenum volume, so we were forced to go alpha-N instead of traditional MAP-based speed density. If it's just a head/cam/blower combo, I don't see any need to use something other than the factory strategy with carefully built calibration values.

 

Ahh so you are in the wrong thread, got it.

 

Sorry I've been real busy and just saw this. I'll tell you what I can about my setup and where I'm at with it currently.

Cam is 228r with long tube headers no cats. Daetschwerks 60 lbs injectors and dw300c pump. I have a fuel pressure gauge mounted to the stock rails. At initial startup after the D1x install it showed right at 58 psi at idle. It now shows more like 65. I've read they aren't that accurate. It stays steady while idling but is a little different now then it was on the initial fire up.

Plugs are tr6 gapped as they come I just checked to verify they are all the same.

Procharger is installed with a 7.65 crank pulley and 4.25 blower pulley. The bung they sent with the kit for the bov is 1.5" and doesn't work with the race valve I have. I ordered a 1.5" to 2" elbow because that is what is required to make it fit the space. I will weld a 2" pipe to the bov flange and mount it to the elbow with hose clamps to get it drive able.

So with that in mind all I've done is start the car to fill fluids completely and purge the air from the system. I've also verified the thermostat is opening. I have a 160 thermostat and first fan on at 179 off at 174. Second fan on at 185 off at 180. The second fan never comes on because the first fan drops temp immediately as soon as it comes on so it never reaches 185.

I also wanted to prime and purge air from the power steering fluid so I drove it back and forth in the driveway while turning. That is as far as it's gone. I didn't want to drive it with the open bung after the blower.

It fired up and finds idle speed perfectly. With a small rev it comes done and finds idle speed again in just a second no hanging idle. When going to neutral or reverse/drive it doesn't change idle speed or surge while pulling ahead. The wideband is an aem located in rear exhaust bung. It's reading about 15.5 at idle, but does smell rich. I've read they aren't accurate at idle. The boost gauge is showing 14-16 vacuum at idle and the scanner is showing about 49 kpa.

I havent decided yet if I want to take it to a tuner for wot tuning yet, but I will do some part throttle logging when I get the bov installed. The scanner is showing about 79 lb/hr flow rate at idle. According to the deatschwerks data at 58 psi fuel pressure and 49 kpa that is about what I should expect if I'm reading it right.

Im still learning. I've had faster cars in the past, but always had shops do most of my work and all the tuning so I'm taking it slow and being real careful. Any input is greatly appreciated.

ETA: One thing I did before the procharger install just for practice was setup a histogram for idle airflow and log that through as many ECT as I could. I put that data in the tune and idle was improved, but startup was just a bit of a struggle. I then added a little to the initial startup airflow and set the delay at 4 camshaft revs. After that it fired up and idled much better. I will log that again when I get the bov installed. I also have a histogram setup for logging AFR error with the correct rows and columns to match my VE table.