Marine Intake

[L31MaxExpress]

Man, if my truck is making 320whp up here it's making more juice than I thought. Probably a little lower than that as I have 33s, but still. I would have figured 400 at the crank at sea level tops. I always find it odd the way airflow can sometimes fluctuate throughout the range. Why the hesitation to take it past 5300? Seems if there is a definitive gain yet to be found, that's where it'll be. Kinda like the LS6 heads and intake. At stock and lower (my race class) power levels there really isn't much of any difference, but get a motor that happily pulls past 6000 and suddenly a cam does so much more with the LS6 stuff than the LS1 stuff.

It was just a first pull to check for knock and air/fuel. I was also on a small side road, it is also night and there are a lot of deer around. 5,300 is already 50 mph in 1st gear and it's a 60-mph zone where I kicked it in the pants.

 

[Supercharged111]

Deer? You mean rats with antlers? Gotta get you a deer smasher up front. I plan to build some before I move back to MI. There it's a matter of when, not if, one of them is gonna F up your truck. I have a similar struggle near home, 80 in 2nd is a bit much leniency to ask of the cops in a 50.

 

[L31MaxExpress]

Deer? You mean rats with antlers? Gotta get you a deer smasher up front. I plan to build some before I move back to MI. There it's a matter of when, not if, one of them is gonna F up your truck. I have a similar struggle near home, 80 in 2nd is a bit much leniency to ask of the cops in a 50.

It is actually a DPS Trooper that lives close by that hangs out in town here nabbing speeders. One blinking yellow light town with a necessary slow down through the center of it so its expected.

 

[L31MaxExpress]

I took what I learned with the EOIT spread sheet then tweaked the values a bit. Discovered I am able to make close to a 20% difference in the fuel trims with injection timing alone at idle with no other changes. Using those higher numbers I was showing nearly +10% after it warmed up at idle. Decreasing both values 0.1 at a time I found it is burning fuel most efficiently with a 6.5 Boundary and 6.3 Normal. Fuel trims went to roughly -10%

 

[L31MaxExpress]

Nearly finished with any luck.

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[PlayingWithTBI]

That looks like a lot of fun working down in there

 

[L31MaxExpress]

That looks like a lot of fun working down in there

It is not much fun, lol. About to have to fight my way in there to get the PCV vent tube back on. I went back to a sealed system when I put it all back together. I knocked the vent tube off just before taking the pictures, trying to get my hand back in there with a Torx bit screwdriver to adjust the Minimum Air Rate screw on the throttle body. It was set a bit low as I had over 100 IAC counts at hot idle.

 

[BeXtreme]

I took what I learned with the EOIT spread sheet then tweaked the values a bit. Discovered I am able to make close to a 20% difference in the fuel trims with injection timing alone at idle with no other changes. Using those higher numbers I was showing nearly +10% after it warmed up at idle. Decreasing both values 0.1 at a time I found it is burning fuel most efficiently with a 6.5 Boundary and 6.3 Normal. Fuel trims went to roughly -10%

This is good info... I'm learning a lot from watching this. I'm hoping to be able to really dial in this L29 when I finally get it stuffed into my squarebody. Still working through the stock wiring harness and all the modifications, removals, and additions for the changes I made. From what I've gathered so far, the order of initial tuning should be:

1. Make sure injector data is correct
2. Initial EOIT settings from spreadsheet into tune
3. Start up and do initial dial in of VE
4. Tune MAF tables
5. Rough adjust of timing tables
6. Start iterating logging and fine tuning everything

On a side note... I think I finally figured out how to get oil pressure into the 0411. The 99-2006 corvettes had an oil pressure sending unit and I found the pinout into the 0411 harness. I'm keeping the original L29 oil pressure switch/sensor for the fuel pump bypass and as the sender to my gauge. Then I am installing the corvette sensor with an adapter from ICT billet into the port above the oil filter. I'm hoping to be close to running it outside the truck this weekend, so I should get to see if the ECM reads oil pressure or not at that point.

 

[L31MaxExpress]

This is good info... I'm learning a lot from watching this. I'm hoping to be able to really dial in this L29 when I finally get it stuffed into my squarebody. Still working through the stock wiring harness and all the modifications, removals, and additions for the changes I made. From what I've gathered so far, the order of initial tuning should be:

1. Make sure injector data is correct
2. Initial EOIT settings from spreadsheet into tune
3. Start up and do initial dial in of VE
4. Tune MAF tables
5. Rough adjust of timing tables
6. Start iterating logging and fine tuning everything

On a side note... I think I finally figured out how to get oil pressure into the 0411. The 99-2006 corvettes had an oil pressure sending unit and I found the pinout into the 0411 harness. I'm keeping the original L29 oil pressure switch/sensor for the fuel pump bypass and as the sender to my gauge. Then I am installing the corvette sensor with an adapter from ICT billet into the port above the oil filter. I'm hoping to be close to running it outside the truck this weekend, so I should get to see if the ECM reads oil pressure or not at that point.

I think I may have found an oil pressure sensor for a Gen1. Mercruiser and Volvo both have a listing for a 0-5v transducer with a 1/8" NPT fitting. Probably the same one that was used on the Mexican GMT800 trucks. I have not been able to figure out that part number yet to cross check it.

 

[L31MaxExpress]

FWIW I just found the GM equivalent to the $$$$ marine sensor. Looks like it was used on some of the 3.8L and 2003+ 4.3L engines.

12677837

More Information for GM GENUINE 12677837