1227165 Running 12P for a GM 2.5L Iron Duke with Turbo
Posted: Tue Apr 11, 2017 4:46 am
Starting a new thread with my latest project. I've been browsing the site for a while, and now entered into the 12P zone.
Project: 1987 S10 Truck with a 2.5L 4 cyl TBI engine running at 1227165 PCM and $53 code. Pretty basic. No knock sensor. Speed density.
1227165 PCM
TunerproRT for calibrations
Craig Moates APU1 Chip reader/burner (no fancy flash tool ... just swap chips!)
Upgrades: Added Turbo and Intercooler from Volvo S50 (or something like that). Front mount side to side intercooler. Decent sized Turbo for the 2.5L.
Attempted to run Turbo on stock PCM with stock code, tweaking fuel and spark. Worked pretty well, but very limited tuning due to so few values. Was worse when you used a 2 bar MAP. 1 bar MAP worked better!
Enter in 12P!!! (insert dramatic music).
I was very surprized at how easy it was to use the 12 code on the 165 PCM. The wiring for the old S10 was almost perfect. Only the shift light was in the wrong spot. So without having to change ANY wires, I burned my first 12P version, and set to work getting it to run.
- First step was setting spark reference angle. Turns out my engine used 90 degrees. Makes no sense to me how this works, but that is how it is. I tend to ask less questions about the values, and just turn the dials until things work.
- Next was to set the fuel injection base (grams/sec). This took some time. Go up, do down, go way up, go way down. Get it to start. Then try to drive. Stall. Stall. Stall. Finally get the number close. Test drive. And with 30+ more drives, I figured out which way the value had to move to get it to run. Ok got a good base.
- Still ran so so. Go inside.
- Try again ... cold engine ... runs like a top! Cold fueling works. Warm doesn't. So tweak those values. And it starts to drive nice.
- Copy timing tables over form the old $53 version. They ran nice. Work well ... but under boost, it pings. Go to basics and remove timing in boost (BECAUSE I NOW HAVE A TABLE IN BOOST!!!).
- A bit more tweaking of the AE settings, no more dead spot.
So, with some minor work, the 12P code is AWESOME. TBI, stock fuel pump, stock injector ... runs up to 6 PSI boost and isn't leaning out. Nice to drive too.
I figure I am the limits of the stock fuel system. I knew that was going to happen, but having a working setup makes this so much nicer. Next steps are to use a larger TBI unit from a 2.8L that has two injectors. Back to basics again with fuel and see if I can get the boost up to 10 or so.
My issues thus far:
- Flex Table B. I set it up to operate a boost control valve. I have the stock Volvo relay plumbed to all the right ports. My flex table uses 100-150 KPA on the X-axis and 400-6000 RPM on the Y. I set the values to 99.61 for where I wanted the rely to be operated. Under testing it was backwards. I swapped the values to ZERO where I wanted it to be powered, and 99.61 where I don't and it kind of works. In logging, it won't operate until it gets into boost. Which is perfect. But I want it to shut off when it gets over boost ... but it stays active even though the flex table values state otherwise. It seems to get locked until you drop the throttle/RPM. Maybe using RPM is my mistake and I need to use MAP for both X and Y axis instead? Hmm ...
Well this is my project (well it's my son's ... I'm an 80's Camaro with a TPI engine sort of guy ... but his truck used the same `165 PCM.). This has been fun. So much different than other tunes.
Mark.
Project: 1987 S10 Truck with a 2.5L 4 cyl TBI engine running at 1227165 PCM and $53 code. Pretty basic. No knock sensor. Speed density.
1227165 PCM
TunerproRT for calibrations
Craig Moates APU1 Chip reader/burner (no fancy flash tool ... just swap chips!)
Upgrades: Added Turbo and Intercooler from Volvo S50 (or something like that). Front mount side to side intercooler. Decent sized Turbo for the 2.5L.
Attempted to run Turbo on stock PCM with stock code, tweaking fuel and spark. Worked pretty well, but very limited tuning due to so few values. Was worse when you used a 2 bar MAP. 1 bar MAP worked better!
Enter in 12P!!! (insert dramatic music).
I was very surprized at how easy it was to use the 12 code on the 165 PCM. The wiring for the old S10 was almost perfect. Only the shift light was in the wrong spot. So without having to change ANY wires, I burned my first 12P version, and set to work getting it to run.
- First step was setting spark reference angle. Turns out my engine used 90 degrees. Makes no sense to me how this works, but that is how it is. I tend to ask less questions about the values, and just turn the dials until things work.
- Next was to set the fuel injection base (grams/sec). This took some time. Go up, do down, go way up, go way down. Get it to start. Then try to drive. Stall. Stall. Stall. Finally get the number close. Test drive. And with 30+ more drives, I figured out which way the value had to move to get it to run. Ok got a good base.
- Still ran so so. Go inside.
- Try again ... cold engine ... runs like a top! Cold fueling works. Warm doesn't. So tweak those values. And it starts to drive nice.
- Copy timing tables over form the old $53 version. They ran nice. Work well ... but under boost, it pings. Go to basics and remove timing in boost (BECAUSE I NOW HAVE A TABLE IN BOOST!!!).
- A bit more tweaking of the AE settings, no more dead spot.
So, with some minor work, the 12P code is AWESOME. TBI, stock fuel pump, stock injector ... runs up to 6 PSI boost and isn't leaning out. Nice to drive too.
I figure I am the limits of the stock fuel system. I knew that was going to happen, but having a working setup makes this so much nicer. Next steps are to use a larger TBI unit from a 2.8L that has two injectors. Back to basics again with fuel and see if I can get the boost up to 10 or so.
My issues thus far:
- Flex Table B. I set it up to operate a boost control valve. I have the stock Volvo relay plumbed to all the right ports. My flex table uses 100-150 KPA on the X-axis and 400-6000 RPM on the Y. I set the values to 99.61 for where I wanted the rely to be operated. Under testing it was backwards. I swapped the values to ZERO where I wanted it to be powered, and 99.61 where I don't and it kind of works. In logging, it won't operate until it gets into boost. Which is perfect. But I want it to shut off when it gets over boost ... but it stays active even though the flex table values state otherwise. It seems to get locked until you drop the throttle/RPM. Maybe using RPM is my mistake and I need to use MAP for both X and Y axis instead? Hmm ...
Well this is my project (well it's my son's ... I'm an 80's Camaro with a TPI engine sort of guy ... but his truck used the same `165 PCM.). This has been fun. So much different than other tunes.
Mark.