Marine Intake

[L31MaxExpress]

Oil pressure into the ecu would be fantastic, the gauges on these trucks aren’t exactly precise-

I find that odd though. My Van and my Tahoe are both nearly spot on. I thought I had an issue with the sending unit/gauge on the van a while back. Turned out it was a real pressure problem and ended up causing bearing damage on the old 350. The pickup tube had fallen off the pump and it was starving for oil on acceleration.

 

[Reluctanse]

I find that odd though. My Van and my Tahoe are both nearly spot on. I thought I had an issue with the sending unit/gauge on the van a while back. Turned out it was a real pressure problem and ended up causing bearing damage on the old 350. The pickup tube had fallen off the pump and it was starving for oil on acceleration.

My oil pressure gauge has the notorious bouncing issue and it’s pretty regular, so it’s hard to trust consistently.

 

[L31MaxExpress]

Just got back from a short test drive. Running pretty solid now. Give it some throttle and it wakes right up and moves out nicely. Give it enough to hit PE and it moves really well. Glad I left the PE delay, with instant PE it would have knocked the tires off from a stop. It spun them a bit from a 20 mph WOT roll on in 1st.

 

[L31MaxExpress]

I have come to the realization this van needs a 6L90E in it. I am finding used ones for $1000-1,500 shipped with under 50K miles on them.

I bet if I used one, the OE driveshaft for a newer van with a 6.6L and 6L90E would fit too. I think it would have alot better get up and go with one.

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[Supercharged111]

You ain't got a hair if you don't. . . so 58X swap or use that TCM that only needs one or 2 inputs to work?

 

[L31MaxExpress]

You ain't got a hair if you don't. . . so 58X swap or use that TCM that only needs one or 2 inputs to work?

I would use the PCS controller. I do not want to go back to CNP. My van eats those coils for breakfast, lunch and dinner.

 

[L31MaxExpress]

I think it would be geared perfectly with a 6L90E and 4.10s.

Also need to get a Trailblazer PWM electric fan clutch control relay and the rpm feedback wiring on it. Using on or off instead of a PWM relay has the fan sluggish to release. I was at a point where the fan needed to be partially on to keep it cool but it really drags WOT acceleration down being fully engaged. Fan sounded like a P51 prop at full power.

 

[Supercharged111]

I've thought fondly of this swap many times. I worry the dually would shred it though. Probably be alright in the 1500.

 

[L31MaxExpress]

I've thought fondly of this swap many times. I worry the dually would shred it though. Probably be alright in the 1500.

The 80E is rated for less torque. The more I read the more I think the failures are from PWM slip of the torque converter. Get a low mileage unit, change the filter and fluid. Ditch the PWM partial lockup and it should live. My worry is lack of torque management killing it though. I think a newer shift lever would go right on after grinding a flat spot on it, giving tap shift.

 

[L31MaxExpress]

@Supercharged111

Also felt like mentioning. I drove this thing with a cold start showing 34F this morning. Never made it hesitate. With any luck the marine intake is tamed. I will say it dumps a ton of fuel though when it is cold. When it is that cold the PCM is dumping as much pulsewidth or more at 1,500-2,500 rpm under half throttle than it does hot, foot on the floor from 3,500-5,500. My open loop air/fuel adder vs coolant vs map table has values as high as 1.75. Actually borrowed the table from a LS6 Vette to richen it up. The L31 values were much lower, 1.30-1.40ish and actually had a spot where they commanded leaner than stoich from GM. Substituting the Vette table really made it happier. Commanded air/fuel ratios are in the 9s and 10s on non ethanol 93 when it is cold. Marine manifold really wants the fuel when it is cold.