: Running a 2005 N* on a 2006 N* PCM



NorthStarGXP
01-22-09, 09:29 AM
Anybody looked into this? There have been threads about using an LS1, but what about using the 2006 N* PCM since it is tunable?

Geez, I missed being able to tune my car by one model year.

AJxtcman
01-22-09, 07:17 PM
Anybody looked into this? There have been threads about using an LS1, but what about using the 2006 N* PCM since it is tunable?

Geez, I missed being able to tune my car by one model year.

You can't run the 05 on a 06 PCM. The 06 only has 1 Crank Sensor and it is up by the starter.

Now back to the 04 & 05. What is it you want to tune?

NorthStarGXP
01-23-09, 09:42 AM
Thanks AJ. What would I like to tune? Definitely Ignition timing, and possibly AFR. I don't know exactly what advance and AFR these engines like for max power (maybe you or the sand rail guys do), but I do know that tuned LSx motors benefit from up to 28 degrees of advance at WOT, and AFRs of 13.0 and sometimes even leaner.

I run nothing but 93 octane, or if I am traveling in the mountains 91 if that is all that is available.

I datalogged timing and AFR using my Dashdyno SPD. 2nd gear WOT pull, no heat soak, IAT was at 59 at the beginning of the run. Here are some data points for timing:

RPM / Degrees
3500 / 12.0
4000 / 13.0
4500 / 13.5
5000 / 14.0
5500 / 19.0
6000 / 24.0
6300 / 24.0

AFR at WOT typically runs from 12.0 in the midrange to 12.6 above 5000rpm. There is probably some power available there, but really that is not too bad. An aggressive timing curve would work well with those AFRs.

Also, a bunch of timing is pulled during shifting, presumably to protect the trans and keep the car going straight. I'm seeing about negative 10 degrees during the 1 / 2 shift. I'd be willing to stress the trans a bit more and have timing just go to zero, or maybe slightly advanced.

AJxtcman
01-23-09, 02:18 PM
Have you ever wondered why the 99 and priors ran harder?

This Datalog was on my Fiero with a stock 99 PCM & without an ABS module. This will cause the PCM to remove a set % of timing. Lets say 10%.
http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/99%20Data%20Logs/99-1.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/99%20Data%20Logs/99RPMVSMAP.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/99%20Data%20Logs/99RPMVSMAF.jpg

Get the picture on the Timing?

NorthStarGXP
01-23-09, 03:22 PM
I didn't know anything about how the 99's ran one way or the other. But based on the above, the 99 N* had much more aggressive timing tables, so as I suspected, there is probably a lot of torque and power being left on the table with my PCM.

Makes me wonder if GM went conservative on ignition timing in 2000 to keep the headgaskets from failing, even though that was not the root cause.

Submariner409
01-23-09, 04:14 PM
THAT set of tables makes sense. I've never seen the total advance above 34 degrees in my 2002 VIN 9.

Now, how do we recover the "lost timing" in a 2000 - 2004 PCM ?

AJxtcman
01-23-09, 06:14 PM
THAT set of tables makes sense. I've never seen the total advance above 34 degrees in my 2002 VIN 9.

Now, how do we recover the "lost timing" in a 2000 - 2004 PCM ?

This is what I logged 0n Highlines 2003 DHS. This took us about 1 hour to collect
http://i224.photobucket.com/albums/dd25/AJxtcman/PCM%20Stuff/Tables/Noname.jpg


This is another type of log from a WOT run. This took about 15 second to collect
http://i224.photobucket.com/albums/dd25/AJxtcman/Bert/VDR/NoN2O80frame7-4-08.jpg