2003 4.2 I6 GMC Envoy P10 to P12 conversion

[eclipse5302]

Ok, so this appears to be the ticket for putting boost into a 2005 and older Trail Blazer or Envoy.

For those of you who aren't aware, the 2002-2005 don't use a MAF...they have this mish-mosh of an Alpha-N and SD setup. The primary VE table is based on Load, and not based on actual VE values. This simple fact makes it nearly impossible to rescale the tables for boost, and when the PCM sees boost it goes into Reduced Power mode. No fun.

So, everyone has said that you could go to a P12 PCM and you gain a MAF along with proper tables. With a MAF, a simple MAF-rescale should take care of the boost, and the other tables can be rescaled / modified as needed.

The biggest problem for this swap has to do with the suspect change to the CANBUS data bus in 2006. From the research I've done, this change only appears to affect the 5.3 V8...the 4.2 stayed Class 2 Serial. I've compared wiring diagrams between the 2003 and 2006 Envoy, and everything suggests that with a pinout change, the 2006 PCM should run the truck.

Anyone have any thoughts or experiences with this type of issue?

[jimbos'ss]

something to consider is that the p12 pcm was used on boosted applications as early as 2004, might wanna look into one of the 2005 or prior ones to avoid the canbus changes. idk if it will work or if this helps, just a thought though.

[eclipse5302]

I ended up getting one from a 2005 Colorado - but the bigger problem now is that the connectors are different. If they were the same, I could just re-pin them...but now I've got to cut and splice new connectors on there.

[scotte]

i'm planning on doing it to my jeep (has 03 4.2 swapped in

the only effect a bus change can have on my application is i may have to switch speedometer clusters

i have most of the parts to do it and i have the pcm pinout pritouts from gm esi

i also have the turbonectics tune for a h3 hummer i5 (p12) w/turbo kit

operating system appears identical

its interesting how they tuned it

[ronnyek]

Ok, excuse me for being a bit in the dark... could somone clarify this?
I've got a 2005 4.2l motor with stock ecu, and woudl very muchlike to run some boost on the motor. I've got everything pretty much worked out, except how to get the ecu to run it without freaking out and grenading the motor.

if p12 is an ecu from a i5 colorado, how exactly does it run 6cyl (vs 5)?

My options are full standalone ($$$), piggy( just not sure if thats how I want to do it) or like other people have said maf scaling. I'd prefer to go that route... as it'd be like stock, but more power.

I'd appreciate any input as this is the route I'd prefer to go.

[scotte]

Ok, excuse me for being a bit in the dark... could somone clarify this?
I've got a 2005 4.2l motor with stock ecu, and woudl very muchlike to run some boost on the motor. I've got everything pretty much worked out, except how to get the ecu to run it without freaking out and grenading the motor.

if p12 is an ecu from a i5 colorado, how exactly does it run 6cyl (vs 5)?

My options are full standalone ($$$), piggy( just not sure if thats how I want to do it) or like other people have said maf scaling. I'd prefer to go that route... as it'd be like stock, but more power.

I'd appreciate any input as this is the route I'd prefer to go.

th p12 is also the stock ecu on 06 trailblazers

the p12 is boost compatible with a little work( i have the stock turbo tune for an h3 turbo kit w/ a p12 and copying the tables over will make a great starting point

[bruhaba]

I am starting an m112 supercharger project on an 06 trailblazer and the first thing I notice is that the MAF sensor is very limited in flow capability. I've acquired the supercharger and injectors and will be getting an engine pull so that I can place the whole thing in my shop and work out the mounting, drive, etc.

Scotte, would you care to share that turbo tune on the I5. I'd be very interested to see how it was done. Do you know what injectors were used? One thing I am questioning already is the MAF sensor on the trailblazer. Appears to be limited to a pretty low flow. Do you think a MAF swap would have to be in order?

Thanks

[scotte]

i'll email the file to anybody that sends me a pm with a request for the file "07 h3 turbontics tune" and their email address

it may take a day to respond (busy schedule,flaky internet, etc....)



as for the maf if i remember right on the h3 they take the sensor out of the housing and mount it a chunk of tubing (i'm not sure as to the difference in diameter (if any)

i would assume that they would have to recalibrate the maf table if so

it's been awhile since I looked at it

[senthilmar]

i need gmc envoy complet wiring diagrams any one have or were i find