I have been tuning off and on for long time, and often thought that my van just doesn't have the top end power I know it should have. On another thread (http://www.turbo-mopar.com/forums/sh...ome&highlight=) I posted my thoughts on that, and Juggy commented about needing more timing.
So over the last 2 days i studied lots of different templates, looking at the timing curve and the calculated total timing.
This is the 'Advance from RPM2' or '00GOVNER'
In this pic the Light Blue= T-smec G-head cal, Green= swirl head (both 2.5) I noticed that as the RPM goes up the swirl cal adds timing and the G-head does not.
So i assume that the "swirl" curve is closer to the factory engineered curve of timing needed dependnet on RPM. So instead of using the G-head curve I took the Swirl curve and added 10* of timing to every point so it is the same Shape but more timing. Like this
Dark blue=Swirl head cal, Green=G-head template, Light Blue= What I did.-
Result= WAY MORE POWER! the van is now on 4 psi less (12 instead of 16) and according the the Butt Dyno the current low boost cal would smoke the old one.
That only makes sense to me, that as the engine spins faster it needs more timing Just like the swirl cal. I am not done tuning it yet but now it runs so much better and smoother across the RPM range, but Especially has significantly more power over 4000 RPM.
IDK but i would suggest that maybe Rob can update the G-head template in T-SMEC. From what i remember that was based off a cal that someone else did. I like some of the drive-ability issues it helps with but its is lacking its potential.
What are your thoughts everybody?