Plugs, fuel pump and horsepower.

[Barracuda]

I continue my serious of stupid questions. Does inferior plugs have direct effect (harmful) on engine's output, if we rule out knock?

And how about inferior fuel pump? Like a stock rewired pump with a 50-trim turbo blowing 20psi. I know the pressure drops the more revs the engine has, but if AFRs were compensated adding more fuel?

Sorry, I couldn't find answers on these ones anywhere

 

[DSMboostin15]

When it comes to fuel, it's not so much about pressure, but more about flow. A stock rewired pump will only flow "X" amount, whereas a Walbro 190 or 255 will flow "Y" and "Z" respectively. That's why when you start to increase the volume of air in the combustion chamber, you need compensate with more fuel to prevent running a lean condition. This is where the flow becomes important. When you increase the flow of air, the flow of fuel has to increase as well.

 

[Barracuda]

so unstable fuel flow hurts power output (as it's dangerous) , even if A/F ratio seems to be in check?

 

[Calan]

so unstable fuel flow hurts power output (as it's dangerous) , even if A/F ratio seems to be in check?

If your fuel flow is "unstable" and not flowing enough fuel intermittenly, then your AFR won't be stable either...unless your fuel requirements are below the threshold of whatever "unstable" is.

The bottom line is that you need enough continuous pressurized fuel in the fuel rail to supply the injectors with whatever the ECU thinks they need.

 

[Barracuda]

thanks, the reason I asked these was that I'm trying to figure out low engine power and jumpy dyno graph..

Mods are in the profile. that's a bep 50trim set to 15psi, creeping steadily to 19psi@7000rpm.
No boost leaks.

 

[the_mork]

http://www.dsmtuners.com/forums/tuning-engine-management/244522-injectors-fuel-pumps.html

A rewired stock fuel pump will barely outflow stock injectors.

 

[habitatguy187]

If it's your spark plugs you would most likely feel it while boosting, but the fuel pump could be flowing less than what's needed but still enough to create a small explosion, but if you're not getting enough fuel then it's probably knocking, therefore pulling timing.

What are you using to control your 650s? I saw that your profile says, "engine management", what is that?

 

[Barracuda]

It actually says ECU+ Engine management. or piggyback to be more accurate

According to logs. there's no timing pull and no knock either.