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Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 4:26 pm
by hsv08
Ok so i have done a comparison on the vt v8 and vs v8 pcm pinouts.
basically to swap out the vt v8 pcm for the vs v8 pcm to to convert from maf to map and take full advantage of $11p code.
attached is the excel spreadsheet i have made that compares pin functions between the two pcms
So what i am wanting to is convert my vt v8 manual (getrag) to map.
other then the pin swapping from my loom into the plugs of a 672 and adding the map sensor and associated wiring, what else will i need to do?
So far:-
Repin loom to 672 plugs and pcm
vs v8 dizzy and plug and repin plug end
Map sensor and associated wiring
Vs v8 memcal
add vs v8 IAT sensor (somehow adapt this into the pipe to TB as the vt manifold is blanked off at that location)
What other things am i missing here?
I take it the 672 will pickup the getrag vss signal as its the same as auto?
Can i disregard all the auto loom?( assuming my manual loom is already missing all the auto stuff already)
Re: Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 8:25 pm
by vs ss
First off before you go any further the pcm 0672 is a vs v6 so no good for what you want.
You will use the vsv8 pcm 424 for the mafless conversion.
The getrag speedo sensor will work fine on the 424 pcm as the getrag and the auto both used reluctor sensors.
Also you should be able to use the vt dizzy and just hook up the one sensor as you won't need the other sensor in the dizzy cause you won't be using sequential injection with the vs pcm.
Edit: The injectors will need to be connected in two banks of four so injectors 1,3,5,6 go to terminal c15 and injectors 2,4,7,8 go to terminal c16.
Re: Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 9:55 pm
by Jayme
vs ss wrote:
Edit: The injectors will need to be connected in two banks of four so injectors 1,3,5,6 go to terminal c15 and injectors 2,4,7,8 go to terminal c16.
nah not essential.... 424 v6 is banked injection and can do this due to the cam sensor, 424 v8 is full on batch fire.
Re: Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 10:14 pm
by vs ss
Sorry I just copied that from the manual as a guide on where to put his injector wires just incase he went looking for extra spots like on the vt.
While looking at that,do you know why holden wired the two injectors on opposite banks?
Cheers.
Re: Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 11:01 pm
by Jayme
ease of wiring maybe? There are two injector drivers. One injector driver wire to each bank of 4 is the simplest way to wire it.
Re: Converting MAF to MAP v8
Posted: Fri Nov 20, 2015 11:21 pm
by vs ss
Yeh I relise dual drivers etc but what I'm trying to say is according to the wiring diagrams they don't wire it in banks left and right 1,3,5,7 and 2,4,6,8 ,they have 3 injectors on one bank then a wire running round to one injector on the opposite bank. ( if that makes sense )
Nothing important just curious maybe it's just a misprint in the diagrams or I've lost my mind and just confusing myself.
Sorry hsv08 I shouldn't be clogging your thread with my mumbling crap.
Re: Converting MAF to MAP v8
Posted: Sat Nov 21, 2015 12:21 am
by hsv08
Nah that no worries. I was thinking the same thing on why they would fire 2 injectors on opposite cylinders. I forgot the vs v6 was also a maf based motor.
Atleast requiring dizzy won't need to be done. I thi k there's a spare port on the back of the mani for the map sensor aswell? Or that maybe the fuel reg one I'm thinking of.
Also I can't remember if the knock sensors were different based on the knock filtering being based on the PCM on vt and being on the memcal on the HSV map engines?
Re: Converting MAF to MAP v8
Posted: Sat Nov 21, 2015 12:56 am
by vs ss
You are right with the knock sensors as they are different resistance so grab the black plug type from an earlier model 6 or 8 it doesn't matter as it's just the knock board that has to be v8 only.
With the manifold the map hose normally plugs on up front next to the fuel reg hose,the booster and hvac pipe is on the back but due to being a vt the map hose fitting is welded up.
Re: Converting MAF to MAP v8
Posted: Sat Nov 21, 2015 4:12 am
by yoda69
In regards to injector wring you also need to look at firing order, here is a post from another thread that hopefully makes sense.
Look at the grouping, v6 is in groups of 3 and 3 as per firing ordering.
2,3 & 4 and 1,5 & 6 which is 3 firing cylinders followed by the next 3.
Given that firing order only by convention starts at 1, if you off set the v8 by 1 to 27845631 you get 2 groups of 4 grouped as per the wiring 2478 and 1356. Batch fire may have been a consideration for the v8 but never implemented, but more than likely was copied from some chev wiring.
yoda69
Re: Converting MAF to MAP v8
Posted: Sat Nov 21, 2015 5:42 am
by hsv08
vs ss wrote:You are right with the knock sensors as they are different resistance so grab the black plug type from an earlier model 6 or 8 it doesn't matter as it's just the knock board that has to be v8 only.
With the manifold the map hose normally plugs on up front next to the fuel reg hose,the booster and hvac pipe is on the back but due to being a vt the map hose fitting is welded up.
Early model 6 or 8. So are you talking ecotec pre vt or Buick (unsure if Buick ran them?)
Don't really want to drill the manifold with it on but don't want to take it off either so may throw the vacuum up there and drill if I have too.