my question is really more of a lesson i need in tuning, ive never done anything that has to do with PCM's. I have a '02 silverado 1500 5.3l
mods:
Shorty headers
Full exhaust
powerdyne centri S/C with FMU
E-fans
180 thermo

Now online it says that the powerdyne is set up to run stock injectors with the FMU installed with its own custom tune(which i do not have)
I have both the stock injectors and a full set of 8 out of the chevy 8,1L (non marine)a little bigger

would it be worth it to put in those new injectors with maybe a 255 walbro?
what would i have to do to get it tuned with the new injectors?
or with the stock ones?
i dont want to try and start it with all this stuff installed
also the computer was for a 4.8 i swapped in the 5.3
tuning options?
steps?
---thanks much appreciated Michael

 

As far as I can tell......If you don't have access to the original tune file from Powerdyne (which used the original 5.3 injectors),it complicates things.... you might as well start the tune over from scratch. If that's the case, then you might as well use the larger injectors. You'll need access to the injector data from the 8.1 tune. Then, you'll need to take the vehicle to a competent tuner, or rent dyno time and tune it yourself..if you're able.

I'm not familiar with the Powerdyne FMU....but get the impression that it would be a useless piece in a situation where you had to have a custom tune done....as long as you have a FPR with a boost reference port on it.