L31 based 383 running on a 2005 GMT800 Export L31 based tune.

[Fast355]

First startup of the 383 in the Express with the factory L31 based manifold and ignition. Running on a Green/Blue P59 out of a 2004 DBC 6.0L van. So far I have segment swapped the 4L85E, turned the VATS off, set the injector flow rate to match the AUS Injection 48 lb/hr spider and copied the MAF table from a 2002 L31 van into the 2005 Mexican tune. Had to populate the idle tables that were not used with the manual trans. Other than that the mexican cal is relatively stock GM issue.

https://youtu.be/FzEDpuSIwJc

[Fast355]

I spent a couple of hours messing with it today. Hooked up a water hose to the heater return on the water pump and dumped the waste water out of the shop to really get all the heater core, and lines really flushed out today. I don't want any pf that crap in my new radiator. I got it dialed in pretty good after adding a 4" MAF into the mixture. Also figured out the bog off-idle when first starting to open the throttle. Transmission abuse mode was kicking in even in Park and cutting the ignition timing to negative 15 or 15 after top dead center. Disabled abuse mode and it rips now. Its taken on some nice exhaust crackle and popping going into decel fuel cut as well. On throttle snap up to fuel kill at 5,200 it leaps up the RPM band. To hit the air/fuel ratio target the MAF is reading 410 gms/sec at 5,200 rpm. Given the formula of 1 gm/sec is 1.2 hp, that means I am feeding it 492 hp worth of fuel. Predicted torque on the torque model is reaching 512 ft/lbs at about 3,700 rpm. The cyl/air reading holds pretty flat at 1.03-1.09 gms/cyl from about 3,000-5,200. It is moving a ton of air through the engine and the exhaust just booms because of it. I have the base idle timing now programmed at about 34 BTDC and it seems to idle best around that. Idle compensation spark has been reduced. Both really seemed to help stabilize the idle.

https://youtu.be/iEn1Ht6Ta-s

https://youtu.be/1xXFPoS3Y2Y

https://youtu.be/w_JzvJ7lZLQ
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