Large injectors or Staged injectors

[GuilhermeBuonfiglio]

Hello,

I'd like to discuss two scenarios that I'm not sure if staged injectors are needed or not.

The first one is a C20XE turbocharged with a GT28RS, 9.5:1 C/R, stage 1 head running on E100, fully sequential. 360hp+ is the goal, and based on a B.S.F.C. of 0,91 I've calculated:

• 4 injectors: 992cc/min (94.5lb/h)
• 8 injectors: 496cc/min (47.25lb/h)

In case of going for big injectors, I have a few concerns:

• Would I have trouble setting idle, getting decent fuel economy and good emissions?
• I've found "Trick Flow 95lb/h" and "Standard Motor Products 96lb/h (on Racetronix website)" low impedance injectors. Are they the same injector (they look exactly the same). Are they good injectors?

Is there anything else to worry about?

In case of going for small staged injectors, I have a few concerns:

• How would be engine response when staging injectors?
• Is it better to use 8 equal size injectors or asymmetrical injectors?

Is there anything else to worry about?

The second one is VW Golg MKIII 2.0 8V turbocharged with a KKK16, 12:1 C/R, stage 1 head running on E100, fully sequential. 200hp+ is the goal, and based on a B.S.F.C. of 0,91 I've calculated:

• 4 injectors: 551cc/min (52.5lb/h)
• 8 injectors: 276cc/min (26.25lb/h)

This car will spend two hours a day on heavy traffic (!), and owner desires lowest possible idle rpm and the best possible low rpm driveability.
Too big injectors are not a problem in this case, as 52lb/h injectors are easy to find and "easy to idle".
Do small staged injectors  give any advantage on these conditions?

Thanks and Best Regards,
Guilherme

[lugnuts]

I don't know if anyone is actually using the staged injection function. I can't risk trying it until I get some documentation. Full boost isn't the time for a mistake.


About the injectors, your best bet for E85-E100 fuel is either Bosch 1600cc (cheap, no resistor needed, but not great driveability on the street) or the Injector Dynamics injectors available here in the USA.
The ID2000cc injector will drive like a stock car on E100, and provide more fuel than the Bosch 1680 as well.

Check out this flow graph of the ID2000cc vs. the Bosch 1600 :


See the big dip in the Bosch 1600cc at low pulsewidth? that's why they drive like crap at low loads.

Both the ID1000cc and the ID2000cc injectors are high impedance, (easy to use with VEMS ECU) and are the highest quality injectors available with dynamic testing that is done by no other companies.

[NOTORIOUS VR]

^^^ tho's injectors look sexy!

I don't have much to add other then I doubt the OP needs to stage injectors even on a 4cyl with the size injectors he's planning.  Especially for the Golf, that should be a piece of cake.

I just finished doing a street tune tonight for my friends 24V VR6T...

930cc injectors (low-z), idles @ 14.5 AFR @ 850rpm.... cruise 15.5 AFR no problem steady as a rock.  PW @ idle is approx 1.4-1.5.

[MWfire]

i made 6-7 cars with 900-1000cc injectors, and idel is perfect(lambda is steady 1.03).
On one car i tried 1570cc injectors and idle was good( lambda jumping 0.95-1.03).

[GintsK]

Guys, when you write "perfect idle with 1200cc injectors" please ident your injectors.

Why: I have the case with fairly good idle on siemens 2400cc. But at same time i gave up with Denso 660 or 640 Low impedance ones. Labmda 0.8 and no leaner... I tried everything with no luck (peak-hold, resistors, different flyback voltages...)

[GuilhermeBuonfiglio]

For the C20XE, it looks like the Siemens D4 870cc/min (P/N FI114961) would be a good option. The fuel delivery system can easily handle more pressure if needed...

For the Golf, what about the Siemens Deka 478cc/min (P/N FI11351)?

[]s!

[MWfire]

on my car(c20xe) i have siemens deka IV 890cc. Tried bosch high impendace 900cc and lucas 1200cc low z, but with active flyback.

[NOTORIOUS VR]

Guys, when you write "perfect idle with 1200cc injectors" please ident your injectors.

Why: I have the case with fairly good idle on siemens 2400cc. But at same time i gave up with Denso 660 or 640 Low impedance ones. Labmda 0.8 and no leaner... I tried everything with no luck (peak-hold, resistors, different flyback voltages...)

No idea what the injectors are or who makes them... I will try to find out though...