Turbo barking at lock up.

Big Blue24 said:
I think your lift pump is not keeping up, 2800 rpm is right where the stock lift pump starts to struggle when you have big injectors. I'd try modifying the overflow valve and see if it temporarily fixes the surge.

If you want to make as much power as possible with your setup, you need to maintain adequate lift pump pressure. For your truck with 180 HP pump, I'd try to maintain at least 30 psi.
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Damn, where were you 6 months ago when I was trying to figure out why my truck falls on its face at 2600-2800 rpm? It ended up being my FP. As soon as it gets to 2800rpm, my FP dropped to about 15psi and it wouldn't rev any higher. It would still accelerate slowly, but the rpm's wouldn't climb at all.

Is it safe to just add pressure permanently via the ofv? Or is best to get a pusher pump?
 
madmikeismad said:
Damn, where were you 6 months ago when I was trying to figure out why my truck falls on its face at 2600-2800 rpm? It ended up being my FP. As soon as it gets to 2800rpm, my FP dropped to about 15psi and it wouldn't rev any higher. It would still accelerate slowly, but the rpm's wouldn't climb at all.

Is it safe to just add pressure permanently via the ofv? Or is best to get a pusher pump?
Click to expand...

It is just fine to modify the overflow valve, on a daily driver that might sit in hot Las Vegas/Phoenix traffic, you probably don't want to set the idle pressure higher than 40-45psi, that way you still get some flow through the pump since the "Dodge" factory service manual states that fuel flow through the pump aids in cooling.

Kickaha said:
Mine will run right up to 3800 rpms in 3rd with no problems.
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My Junker drag truck would free rev right up to 4200 rpm and run to 3900 rpm with 0-5psi fuel pressure, it just didn't have any power. Believe me, when I added a pusher pump to maintain pressure when running WOT, it pulled a lot harder above 2700 rpm, calculated to increase of 83 HP at the drag strip from increased MPH.
 
Big Blue24 said:
It is just fine to modify the overflow valve, on a daily driver that might sit in hot Las Vegas/Phoenix traffic, you probably don't want to set the idle pressure higher than 40-45psi, that way you still get some flow through the pump since the "Dodge" factory service manual states that fuel flow through the pump aids in cooling.
Click to expand...

I don't know that would be a big issue, being that the lift pump is an engine driven positive displacement pump, I can't see if loosing much if any volume at higher pressure assuming the lift pump is still in good shape.
 
The afc looks good and has full fuel at 40 psi of boost. Fuel psi never dropped below 30 going up to 4000 rpms with 48 pounds of boost in 3rd gear with an ending egt reading of 1500 at about 3200 rpms in 4th gear.
 
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