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Discussion Starter #1 (Edited)
Hey all. Finished my GenV M90 and intake swap into my 98 GS. I decided to go this route because my original GenIII that came with my Series II the coating flaked off the impellers/rotors after attempting to clean them so I lost 2-3 psi of boost by doing so. Originally the car would give me 7-8 psi before it flaked, then tops 5ish psi thereafter.

now since I swapped the GenV with the Series III intake, I am back up into the 8psi and loving it. The throttle response is so much better with this setup. I never really had a chance to compare to the original setup vs the new one so I couldn't say how much better or whatever the difference was because I was in process of a major tune up chasing issues with the car beforehand and the SC flake off happened during this time so it never ran quite right before and now the car runs great... except for fuel milage. But that may just have to do with my right foot rather than the car tune, but maybe a retune may help. I was contemplating getting the HP tuner unit for the car, as I use Torque Pro for monitoring and stuff now but would like to tinker and think that it would be a great tool. BUT before I do that, I have a couple questions and see where it goes from here.

1) Since I am using the stock ECU and tune from my 98 GS Series II set-up with the GenIII M90 and intake, my car is now a GenV M90 and intake. Is there any reason I should swap ECU's with one from an 04 GPGTP? Is there any difference in the tune? Would I benefit in any way by doing this? Will a swap even work? My Buick has that chip in key thingy. Would that be any issue? Mainly want to know if I should grab the ECU because there is one in the Pick n Pull at the moment and I could grab it now.

2) I am using the older Series II injectors that came with the car. Should I use the injectors from the 04 GTGTP instead? is there a difference with the injectors? If I use the newer injectors, could I use them on this ECU as I have it now or is it going to require the tuning map from the newer car?

I am saving my pennies to be able to purchase the HP Tuner but was wondering this as an interim until I get the HP Tuner. Any thoughts? Like I said, the car runs great as is, but wondering if it would still benefit from the swap.

Thoughts?
Thanks Chris
 

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1) no
2) no

The 05 has a completely different computer to operate with a totally different system in those cars... Not to mention electronic throttle, different transmission controller, etc.

The injectors are nearly identical flow rate, and swapping would require adapting the harness. This would only introduce opportunity to cause issues with connections for zero gain.
 

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Discussion Starter #3
Ooops it's an 04 GPGTP... Edited and corrected in the post. Would this make a difference? Sorry for the misinformation...
 

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I would stay with your current PCM. It is already set up to deal with boost. You will need to scan and plot the fueling especially in the higher boost levels. While somewhat innacurate the O2 sensor voltage will provide a good idea. It should be .85-.90V at WOT. If its not, you will need to adjust the fueling and MAF sensor table values. Not hard to do but you will need a good scanner.
 

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Ooops it's an 04 GPGTP... Edited and corrected in the post. Would this make a difference? Sorry for the misinformation...
Please re-read my reply, if you look at why it's relevant for '05, you'll realize why it's also relevant to '04.

As just mentioned, there are solutions to properly monitor and adjust your fueling available. We've gone thru all sorts of swaps for 20+yrs, and the hard parts happily swap, but it's important to apply proper methods for the electronics.
 
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