12200411 PCM swap for 1996 to 2000 GMT400 trucks

[Scottm]

Ok thanks yevgeni.. um, yev. I ask because even an emissions legal 454 with good heads, headers and dual cats should be able to make 400 crank hp. But the stock L29 manifold is really bad. The air comes around the runner in the top half, then is forced straight down past the injector, then has to turn a sharp 45 into the head. I see room for minor smoothing and blending, but no way to straighten the path enough to make it really flow. So if the 0411 can run speed density, then maybe it can run any direct port setup, like an Edelbrock 29045 manifold/injector setup.

 

[yevgenievich]

Ok thanks yevgeni.. um, yev. I ask because even an emissions legal 454 with good heads, headers and dual cats should be able to make 400 crank hp. But the stock L29 manifold is really bad. The air comes around the runner in the top half, then is forced straight down past the injector, then has to turn a sharp 45 into the head. I see room for minor smoothing and blending, but no way to straighten the path enough to make it really flow. So if the 0411 can run speed density, then maybe it can run any direct port setup, like an Edelbrock 29045 manifold/injector setup.

Will need a custom tune and a workable throttle body, but intake it self should not be much of an issue. I was thinking of using pro flo xt intake

 

[Ksniem]

What’s up guys,

recently finished my swap, truck runs and drives but when I go to communicate via scan tool I can’t connect with the pcm. Serial data is in correct port and my powers and grounds check out. Anyone have some sort of familiar issue?

 

[SS Performance]

I received the pinouts from Lextech he was very prompt with the delivery.

I am now looking to purchase the 411 ECM.

I'm wondering if I should purchase one off eBay or is there someone I can purchase from that can install the initial tune? Do I need to have my VIN programmed into the ECM? Is there any other issues I need to be aware of?

Thank you
Craig

 

[REM777]

1998 transition year computer is an adequate computer supported by HP Tuners - not sure the value there for swapping it out for the 411 computer - pre-1998 yea ..

 

[MAC_Built]

What’s up guys,

recently finished my swap, truck runs and drives but when I go to communicate via scan tool I can’t connect with the pcm. Serial data is in correct port and my powers and grounds check out. Anyone have some sort of familiar issue?

Did you figure out your problem??

 

[Ksniem]

Did you figure out your problem??

Not yet. Waiting to hear back from my tuner. I can connect with the auto function on my autel, my other scanner has been acting up. it will read the vin and recognize the vehicle. I can also read and clear dtc’s. But as far as live data, functional tests, it’s a no go. I’m thinking maybe he did something on his end to lock it?

 

[L31MaxExpress]

1998 transition year computer is an adequate computer supported by HP Tuners - not sure the value there for swapping it out for the 411 computer - pre-1998 yea ..

Not really, have had all 3. The 97 computer I first tweaked with TunerCats OBD2. Then swapped in a 98 with simple changes to the pinouts so that I could take advantage of HP Tuners better datalogging software. With better datalogging I was able to get it dialed in better. Then swapped to an 0411. 0411 was leaps and bounds better, ran smoother, had better trans shifting, more power and better driveability. Now I run an 05 DBC Green/Blue on a Mexican GMT800 L31 based tune. GM had nearly 10 years of refinement in the 2005 stock tune. Even with the stock tune modified for startup prior to dialing everything in, each progression has run better. Only thing I miss on the Green/Blue is the custom HP Tuners MAF enhanced operating system for the 2002 0411 that allows real time tuning of various parameters like fuel and timing. Green/Blue allows for an easier way to setup E85 and it just works better than the 0411.

 

[Scottm]

L31, is it possible to run the 0411 in speed-density mode? I would like to eliminate the MAF sensor on my l29 build.

 

[L31MaxExpress]

L31, is it possible to run the 0411 in speed-density mode? I would like to eliminate the MAF sensor on my l29 build.

It is possible, but why would anyone want to unless it was getting a turbo. They make an inexpensive 4" MAF.