high egts with new turbo

cosmo22nov

cosmo22nov

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Jun 11, 2007
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ok so i installed the new turbo i have in my sig and i can still peg the 1600* pyro. it definitely doesnt get there as fast as the stock turbo but i would think with stock sticks it souldnt be over 1200*. it is non-gated and i can push it to about 55-60 psi, and it spools fairly quick for a 66. let me know if you can help me out.

thanks,
tanner
 
Tanner, the injection event duration is hurting your performance and making it hot. The II pump is trying to push a higher volume of fuel through the stock injector. The event starts wherever you have it timed but it ends far later than it should.
 
carfichris said:
Tanner, the injection event duration is hurting your performance and making it hot. The II pump is trying to push a higher volume of fuel through the stock injector. The event starts wherever you have it timed but it ends far later than it should.
Click to expand...

Chris, is the idea that it will take the small nozzles and smaller lift of a stock injector a longer time to evacuate the fuel into the combustion chamber hence keeping the injector open longer?
 
carfichris said:
Tanner, the injection event duration is hurting your performance and making it hot. The II pump is trying to push a higher volume of fuel through the stock injector. The event starts wherever you have it timed but it ends far later than it should.
Click to expand...

oh ok i think i get what you're saying. its basically like a traffic jam in my injector, the is so much fuel trying to get into the engine but the injector is only letting so much fuel in at a time that the fuel left over comes in to ate and causes excess heat.

is this correct?
 
Yes the pump puts out a dose of fuel the injector has to inject. If the dose is too large given the flow rate of the stock nozzle the duration has to increases to dispense the entire amount. You would have to run a pile of timing to attempt to have it done in time. Put a good set of injectors in it and make more power while running cooler. Give me a shout if you have more questions about it.
 
thanks chris that REALLY helps. i totally understand now. so as soon as i get the bed on my truck ill be calling you for that wastegate and injectors :D
 
Wouldn't the uncovering of port by the lower helix in the pumping plunger dictate the end of injection? I could understand high line pressures in what you are describing, but I'm a little lost at how the fuel would continue to be injected after the port is uncovered.
:what:
 
It would dictate the end of the injection cycle from the pump. The inability of the injector to process what the pump has dispensed is what causes the delay not a lengthy cycle time in the pump itself.
 
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well guys i got the new injectors in and i still have the egt problem. it sounds like the timing is off. i have a good low end with pretty good spool up, high egts, then a some what lazy top end. what do you guys think?
 
Im afraid its just something you will have to get used to. I havent seen a 12 valve or any good running single turbo cummins yet that couldnt get past 1500* easy enough. I have stock injectors, a 4k, 0 plate, 191's and an HX40 and i can send my EGT gauge getting it towards the peg with just my little bit of fuel. Its just the nature of the beast. You'll just have to back the fuel off a decent bit if you want to keep EGT's down some. Other than twins, that is the only way its going to happen i imagine.

Eric
 
As long as you're not towing or running 120+ MPH in a standing mile, 1500 is nothing for these motors. You're fine till you start getting up in the 1800+ range.
 
Wouldn't hurt to check what your timing is set at, and maybe bump it up. What plate are you running? Whats your AFC setup like? Whats the smoke like on top when it gets lazy? If its still smoking on the top end, but laying over, I'd either look at your GSK (although I imagine yours is a 4k in the DF pump?) or timing.
 
Im afraid its just something you will have to get used to. I havent seen a 12 valve or any good running single turbo cummins yet that couldnt get past 1500* easy enough
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Mine sure changed from this when I put DDP 4's in, my EGT's dropped about 150......the gauge is really overrated now.

Jim
 
low timing will definately be lazy up top with high EGT's

didn't I tell you those DDP4's are a nice street stick, Jim? :D
 
well hopefully ill get the timing checked out this week and let you guys know what i come up with
 
well hopefully ill get the timing checked out this week and let you guys know what i come up with
 
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