Schpenxel- is the manifold boost patch the preferred approach? I did some searching after your message the other day and I was unable to find the patch or any instructions of how to implement it. Is there a link to both? Thanks.
Schpenxel- is the manifold boost patch the preferred approach? I did some searching after your message the other day and I was unable to find the patch or any instructions of how to implement it. Is there a link to both? Thanks.
- Ken
2014 Chevy SS, LS3 6.2L, auto, Whipple Supercharged, 8 psi on 91 octane.
Should be under the OS menu. It's called manifold vacuum boost or something like that. Have to do a write entire to enable it.
I've never used the SC options so not sure what differences there are vs this way
Obviously fuel delivery issues are #1
So my issue ended up being as follows:
My tuner put one of the ID injector data tables (offset v. Volts) into a injecter offset v. voltage modifier. schpenxel found that most lS3 motors have that table set to 1. Because I have varying voltage (not sure why) when the voltage would rise, the engine would go fat (9.9:1) and when voltage would lower the motor would go lean. Whatever the voltage was when the engine was tuned was where everything was set. so when it goes up or down from whatever that was, the injectors would take or add fuel.
I ended up quick fixing by modifying that table to near 1 but it needs to retuned with the entire table set to 1.
2011 Camaro LS3 - Whipple 10lbs, ID850's, ADM FPCM, 222/239 114 .610, 2" TSP's, ZR1 Map, MSD BAP (not currently hooked up), ZL1 Pump, 91 Octane 640/550 rear wheel
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
I finally swapped out the factory FPCM with the ADM-programmed FPCM, which allows setting 3 fuel pressure setpoints that are selected based on fuel flow rate (no 400kPa upper limit). My understanding is that this FPCM has the same functionality as the ZL1's. [My car, a 2014 Chevy SS LS3 with Whipple @8psi, supposedly comes with the ZL1 fuel pump but NOT the ZL1 FPCM]. I have attached 3 screenshots from hptuners log. (1) File "20160803 tune01L before 3-bar factory map, delta-pressure injector flow control and ADM FPCM" was my starting point that still used factory stock 1.2 bar MAP sensor, (2) "20160903 tune04D after 3-bar factory MAP and delta-press Injector flow control, before ADM FPCM" with the proper ZL1 3-bar MAP sensor and "supercharger fitted" option selected such that "Injector Delta Pressure" now reads proper pressure drop across injector, and (3) "20160909 tune05G1 after 3-bar factory MAP, delta-press Injector flow control, ADM FPCM" after new FPCM and proper programming. In each case I retuned (MAF-only, using LTFT closed loop for part throttle, WB AFR open loop for WOT). On the display, the upper-left large round gauge is aftermarket MAP, to the right of it is factory MAP (1.2-bar in pic 1, 3-bar in pics 2 and 3) both measuring manifold pressure below sc intercooler brick, and directly below those gauges are SAE fuel pressure and injector delta pressure. Case 1 and case 2 fuel pressure setpoint is fixed at 400kPa (58psi), while in case 3 w/ new FPCM fuel pressure is set at 400kPa for "low" flow, 415 kPa for "normal" flow and 460 kPa for "high" flow. FPCM voltage ("fuel system min voltage" setting was 14.5V in case 1,2, and 15.5V in case 3. In previous tests running case 1 conditions, FPCM voltage selection didn't have significant effect on fuel pressure drop.
Results:
In case 1, at peak hp and indicated 7.7/2.9 psi boost, the SAE fuel pressure drops to 38.4 psi, and the injector delta pressure erroneously reads 43.5 psi due to saturated MAP (and incorrect ECM delta-P calc). In case 2, at peak hp and indicated 8.3/7.7 psi boost, the SAE fuel pressure drops to 40.6 psi, and the injector delta pressure reads 33.8 psi, about right for the boost level. Finally in case 3, at peak hp and indicated 8.3/8.3 psi boost, the SAE fuel pressure drops to 53.2 psi, and the injector delta pressure reads 42.9 psi. 20160803 tune01L before 3-bar factory map, delta-pressure injector flow control and ADM FPCM .jpg20160903 tune04D after 3-bar factory MAP and delta-press Injector flow control, before ADM FPCM.jpg20160909 tune05G1 after 3-bar factory MAP, delta-press Injector flow control, ADM FPCM.jpg
- Ken
2014 Chevy SS, LS3 6.2L, auto, Whipple Supercharged, 8 psi on 91 octane.
So it was better then with the different FPCM or not until you did some other stuff?
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
What did you change in the tune between runs 2 and 3?
The FPCM was changed last, and it allowed me to increase the fuel pressure, which was my goal. I also wasn't satisfied with the "hokey" way injector duty cycle was selected by ECM without it knowing injector delta-P, due to factory 1.2 bar MAP sensor. For a given target AFR, the actual AFR always increased as rpm and load (flow rate) increased. This first thing I changed was to replace the factory 1.2 bar --> 3 bar MAP sensor so that I wouldn't tune "blindly" and so the fuel injector (delta) pressure drop Vs flow transfer function could be properly utilized. But the ECM algorithm doesn't use the manifold pressure once in boost unless its told. I selected the "supercharger fitted" option which told the ECM to reference MAP both in vacuum and in boost to calculate delta-P across injector and obtain flow rate. So with the proper sensor and "supercharger fitted" option I had to retune (adjust MAF) and AFR was more stable across operating range. I then tried increasing FPCM voltage to drive fuel pump harder but didn't achieve significant difference in fuel pressure. Finally I changed FPCM which allowed me to increase fuel pressure at higher flow rate. There is still a large pressure difference between setpoint and actual fuel pressure, but it is very repeatable, and fuel pressure is 10 psi higher than with stock FPCM and single 400kPa (58psi) setpoint. I had to retune (MAF) for operating over a new, higher pressure portion of the injector fuel pressure Vs flow curve. Overall I am satisfied with the result.
I am at 53 psi SAE fuel pressure at 6K rpm and 66.x% injector duty cycle with kit's 63 lb/hour injectors
Last edited by Mach Schnell!; 09-10-2016 at 01:41 AM.
- Ken
2014 Chevy SS, LS3 6.2L, auto, Whipple Supercharged, 8 psi on 91 octane.
Realsquash - I had to bump up the MAP curve at lower range (3000-6000Hz, especially at lowest end) and also in 8000-10000Hz range. This was all using LTFT closed loop tuning. The adjustment at high end, over the 10KHz-12kHz range, using wideband AR error @ WOT open loop, was small, about 0.5%.
- Ken
2014 Chevy SS, LS3 6.2L, auto, Whipple Supercharged, 8 psi on 91 octane.
Ken - just humor me here - set all the flow modes to 58psi in your tune and go out for a rip, with the new FPCM installed. Then see what the fuel pressure does.
Realsquash - OK I will have to try that. By the way, I originally tried to set up the ADM FPCM like the CTS-V's 3 pressures, with the low flow region at 350kPa setpoint. With my injectors this didn't produce stable operation or repeatable results - so I couldn't calibrate. Moving the low pressure setting back up to 400 kPa (58 psi) fixed that.
- Ken
2014 Chevy SS, LS3 6.2L, auto, Whipple Supercharged, 8 psi on 91 octane.