Bought a CC Dually 454 Whipple

[Supercharged111]

Truck is MAF only right now and the starts are money! It's always fired right up, then hesitated a bit and sometimes stalling before falling into a rhythm and being good to go. Seems calculating VE with VE is not the way to go. My 1500 does this but worse. I may have found the flaw in what I was doing wrong on that one. For this one, the 3% I need to add up top will take me from the 11.9:1 I saw to the 11.5:1 that I want. I'm super stoked. Both trucks had reasonable LTFTs so I always figured I'd gotten VE pretty close, and maybe I did but not at an idle. This is completely dependent on the procedure I elected to use to tune with, I've done it successfully other ways in the past.

 

[OutlawDrifter]

Glad to hear you're getting it lined out!

 

[Supercharged111]

Glad to hear you're getting it lined out!

It's a relief to have that refinement back. I also discovered I can break the VE map down into a bunch of 2D lines that I can basically drag and drop. I find that MUCH easier to visualize the change in VE with respect to RPM and load, at least when it comes to changing stuff by hand to blend it.

 

[Supercharged111]

Looks like I forgot to plug my hanger fix. I had something like a 1" bead holding the exhaust hangers to the thin walled exhaust piping. It was not a permanent solution. I decided it would be easier to bend some 3/8" rod around the pipe and I was right, but it still took some ass to get it to bend. I then simply welded that to the 1/2" hanger because that part fits the stock rubber mounts properly. A little hit and miss on the welds, but I don't think it's coming unstuck any time soon.

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Now I don't live in fear of the pipe tearing itself apart.

 

[Christian Steffen]

Hey @Supercharged111 how much boost do you see at elevation?

Just curious really. I took my truck out for a highway run for the first time since moving here and a spirited pull (80-90% tps) yields 110-120 kpa. So based off of station pressure that's 4.5-5.5 psi. I should have went to WOT to see what it could get to.

FWIW I saw about 30* over ambient on the IATs on the couple pulls I did.

And here is where it was running for timing.

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[Supercharged111]

110kpa in CO, but strangely only 125kpa at lower elevations. I suspect the bypass valve is opening.

 

[Christian Steffen]

110kpa in CO, but strangely only 125kpa at lower elevations. I suspect the bypass valve is opening.

Wouldn't that just be the difference from elevation?

 

[Supercharged111]

Wouldn't that just be the difference from elevation?

The difference was more significant in the 1500.

 

[Christian Steffen]

The difference was more significant in the 1500.

Ah okay, I guess it should be more than a 15 kpa difference.

 

[Supercharged111]

Ah okay, I guess it should be more than a 15 kpa difference.

Yeah 125kpa at 2500' and 125kpa at 700'. Something is up. Even so it hits hard at 125. It blows the lid off of the timing table, so that boost timing puller is handy on the custom operating system.