SPFI vs MPFI vs HPFP vs Bigger Injectors

[jeffreylyon]

We've got a number of options for those who are running out of fuel with their turbo upgrades. I'd like to hear what we all think about the various options and have listed everything that is available and a good start of pros and cons.

I know that there are lots of people running a 5th injector or MPFI with good results but I find the simplicity and pure-DI of the larger injectors and HPFP appealing.

Anyways, here's the list. Flame on!

Option 1: Auxiliary Single Port Injector
Cost: $
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a throttle body spacer
Cons: Additional plumbing and brain box, possible uneven fuel delivery

Option 2: Auxiliary Multi-Port Injectors
Cost: $$
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a intake manifold spacer
Cons: Additional plumbing and brain box

Option 3: Higher Pressure Fuel Pump
Cost: $$$
Pros: Easy (?) installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

Option 4: Bigger Fuel Injectors
Cost: $
Pros: Easy installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

 

[koozy]

Option 1 and 2
I don't think these have a built in fail safe, which is a bit of a concerning in the long run, one must rely on another hardware like a Guardian Angel. The way it is wired in is less then elegant without a plug and play harness.

Option 3 and 4
Cost $$$ and relatively new to tuners to iron out.

 

[MitchsFiesta]

We've got a number of options for those who are running out of fuel with their turbo upgrades. I'd like to hear what we all think about the various options and have listed everything that is available and a good start of pros and cons.

I know that there are lots of people running a 5th injector or MPFI with good results but I find the simplicity and pure-DI of the larger injectors and HPFP appealing.

Anyways, here's the list. Flame on!

Option 1: Auxiliary Single Port Injector
Cost: $
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a throttle body spacer
Cons: Additional plumbing and brain box, possible uneven fuel delivery

Option 2: Auxiliary Multi-Port Injectors
Cost: $$
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a intake manifold spacer
Cons: Additional plumbing and brain box

Option 3: Higher Pressure Fuel Pump
Cost: $$$
Pros: Easy (?) installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

Option 4: Bigger Fuel Injectors
Cost: $
Pros: Easy installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

Option 1: What benefits of a throttle body spacer are you seeing on a turbocharged car?
Cons: If your running high boost levels, you dont get great atomization because there is a low differential pressure across the injector
long distance to intake valve can cause fuel to turn into liquid, moves location of throttle body
no failsafe, current controller solution is finicky at best

option 2:
What benefits of an intake manifold spacer on a turbocharged car?
Cons: Adding extra gaskets, potential failure points.
no failsafe in most currently implemented solutions, current controller solution finicky at best

option 3:
This really only benefits the fuel pressure drop at lower rpms (torque limits). The stock high pressure fuel pump does fine at redline, you go lean because the injectors run out of available pulsewidth. These work, and pretty much allow full e85 on the stock turbo. The manufacturers are working with tuners to get all the parameters to make it more "plug and play". However, it really only raises your max torque that much higher. These seem to be very expensive and really only a full solution when paired with the larger injectors.

option 4:
raises your max HP level achievable on direct injection. Still only going to raise it so much.

The thing about option 3+4 is you are paying a large amount to marginally raise your fuel levels for both HP and torque. With option 2 and an in-tank pump upgrade, the sky is the limit.

Is there a good reason all the OEM's are going with option 2? (Euro GTI, 3 Cyl ecoboost, ecoboost raptor, coyote, and more). I think so.

 

[Hijinx]

We've got a number of options for those who are running out of fuel with their turbo upgrades. I'd like to hear what we all think about the various options and have listed everything that is available and a good start of pros and cons.

I know that there are lots of people running a 5th injector or MPFI with good results but I find the simplicity and pure-DI of the larger injectors and HPFP appealing.

Anyways, here's the list. Flame on!

Option 1: Auxiliary Single Port Injector
Cost: $
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a throttle body spacer
Cons: Additional plumbing and brain box, possible uneven fuel delivery

Option 2: Auxiliary Multi-Port Injectors
Cost: $$
Pros: Can revert to a stock tune, claims of cleaning residue off of intake valves, benefits of a intake manifold spacer
Cons: Additional plumbing and brain box

Option 3: Higher Pressure Fuel Pump
Cost: $$$
Pros: Easy (?) installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

Option 4: Bigger Fuel Injectors
Cost: $
Pros: Easy installation, retains pure DI
Cons: Can't use a stock tune, new to tuners

Larger injectors and an HPFP sound simple, but there will be far more headaches than aux-port injection. As you mentioned it’s more costly, the installs are more involved, and then there’s the tuning... You don’t hear a whole lot about DI injectors for a reason. Because there is a lot to consider, a real, truly compatible upgrade would require much more R&D than cross-checking fit, and a higher output. We’ll see those difficulties come into play when someone buys them and no one can get the car to run right.

Edit - Pumaspeed says they spent weeks testing the injectors, but all they have to show for it is one dynograph with two HP plots (as far as I know), so you be the judge.


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