Help with tuning an unusual turbo tbi project.

[scottyd]

Hi, my project is a 52 Chevy that I installed a 250ci inline six in. I have a 79 Buick regal turbo unit mounted on the intake for fuel delivery and a throttle body from a 4.3l v6 i figure that would be a good starting point since overall the inline six is 4.1 liters.

My harness is from a 94 pickup truck, the ECU is a 6395.

I've got it wire up and running (easier than I anticipated)

FOR MY TURBO, Can I use a turbo bin with this ecu? I purchased a 2 bar map sensor... and have been researching Tunerpro and getting myself familiar with the program. I have a aldl cable on the way...I plan on getting an ostrich 2.0 for real time tuning.

As of now the car runs surprisingly good (although i have not driven or ran it long for fear of running lean with boost) I'm using an Airtex fuel pump its rated at 135psi. If i cant tune for boost in the ECU i have tossed around the idea of getting an FMU to put on the return line to manually raise fuel pressure to push the injectors harder during boost... which is commonly done in supercharger and turbo applications but I have a hard time accepting its a safe alternative.. lol

I love this forum btw, have lurked for a while when getting all my parts and stuff put together.

[dave w]

To the forum.

I think the 16196395 is capable of doing boost with a 2 bar map. Both 1 bar and 2 bar map sensors provide 0 volts to 5 volts input to the PCM. The fuel and spark tables respond to the 0 volts to 5 volts input from the MAP. Using the 2 bar map will provide a map sensor voltage to the computer when boost is present. The overall map sensor sensitivity of the using the 2 bar map will be slightly less when boost is not present.

I think stock fuel pressures (less than 30 lbs) will work fine with the stock injectors. There might be a challenge tuning the 6 cylinder with enough fuel at WOT Boost, and possibly having to much fuel at idle? The 16196395 has the tuning advantage of having two fuel tables and two spark tables (near idle / off idle) which will help tuning the fuel at idle and WOT Boost!

dave w

[scottyd]

Thanks Dave, in the bin sticky it says

"16196395 PCM Information $OE This PCM was used in 1994 C/K Truck, Van, 5.7L & 7.4L (HD) 4L80E Auto Trans or Manual Trans.

Also the 16197427 came in these trucks as well and it will run $31, $OD, $OE, $E6 mask"

Does that mean the 6395 also uses those mask? or do both the 7427 and 6395 use them?

[dave w]

TBI computers 16197427, 16196396, 16168625, and 16156930 can interchangeably run the following Masks $31, $OD, $E6, and $OE.

$31 and $OE were usually 4L80E.
$E6 and $OD were usually 4L60E.

dave w

[scottyd]

Ok that clears up quite a bit, I am having a hard time finding much info and files on the 6395

edit*
Just found this:
16168625/16197427/16196395/16156930/16245358

$E6 16168625 93 C/K Truck, Van, 4.3L, 5.0L & 5.7L
$0D 16196395 or 16197427 94 - 95 C/K Truck, Van, S-10 LN2 (16168505), 4.3L, 5.7L & 7.4L
$0DA 16196395 or 16197427 94 - 95 Truck, Van, 4.3L L35 CPI
$0E 16196395 or 16197427 94 C/K Truck, Van, 5.7L & 7.4L (HD)
$31 16197427 or 16156930 95 C/K Truck, Van, 5.7L & 7.4L (HD) 95 - 96 Hummer H1 (Gas)
$8C 16245358 16197427 95 C/K Truck, Van, 4.3L 94 S/T Trucks, L35 4.3L
$8CA 16245358 95 Truck, Van, 4.3L L35 CPI
$63 16197427 96 - 97 C/K Truck, L05 EXPORT ONLY

[1project2many]

Sounds like a cool project.

I think you'll decide increasing fuel pressure with boost is the best option. But injector choice is important because some of the TBI injectors just don't operate correctly if pressure gets too high.There was an individual on j-body.org several years ago that built a nice TBI turbo setup. I believe his username was oneredry. He used the later, small body GM injectors which can handle higher pressure and are available in some extremely high flow rates. I have a spreadsheet saved with flow and pressure data for these injectors, and it may be available on this site somewhere.