hpfiend

iTrader: (4)

Hey all- I have an LQ4 out of a Silverado 2500 4x4 truck. I have the entire harness that I am going to convert to standalone. As I plan out the firewall pass through/fuse box/relay box locations I had a few questions... 1) Does hptuners flash the pcm through the obdii port? I will be getting hptuners pro once I get the engine in place. 2) can I use the existing map sensor output to show boost level to activate my water injection system by tapping the wire or will That interfere with the pcm and I need to run a separate map/boost switch? 3)I assume I neeed room to run wiring from the hptuners box to various sensors/my innovate wideband? 4) do I need to know the actual fuel pressure in the cabin or will the pcm Know this somehow?
I will be using a boost referenced aeromotive fpr and Bosch 044 so will
It matter or am I only concern d about air/fuel ratio?

I hate this mobile app- will be using Siemens 80lb injectors.

Thanks

rpturbo

iTrader: (47)

Yes, HP Tuners uses the OBD-II port to tune. For boost, you will need to change to a different map sensor, via either a 2 bar, 2.5 bar or 3 bar, depending on how much boost you want to run. As far as a wideband goes, you will simply take a output wire, and it taps into the little green "plug" on the HP Tuners box. You can simply unplug that from the box. I tuck mine under my center console in my truck, and pull it out when I tune or log.

Base fuel pressure is what it is. You can just put a gauge on the rail or fpr, and set your pressure as you want it. The AFR isn't going to change based on the pressure, you just need to make sure it stays in check as your tuning, and consistently stays there.

hpfiend

iTrader: (4)

Thanks for your help! So the only wire I need to feed into my hptuners is one wire from my wideband? So you leave your wideband in all the time?

I was going to try to run off the MAF first and see how that goes and maybe get an ls7 card MAF.

I have a 3 bar gm map I purchased but have read it's more difficult to tune and obviously I am a complete newbie.

gametech

iTrader: (1)

Running your water/meth injection off the one MAP sensor used by the PCM is workable, but not the best idea. I experimented once with multi-using one MAP sensor. It obviously works fine with the PCM, and it even worked with meth injection, but once I piggybacked a boost gauge, there was too much load for the 5v output to handle. The fact that one additional sensor fubared the whole thing leads me to believe that MAPs are best left to supplying one sensor at a time.