when do MSP injectors max out?

kicker22705

Member
:
03.5 Ti MSP
at what level of boost will the msp max out its injectors and will need extra or larger ones?

i've heard of people running 13-15psi w/o maxing em out.

i'd like to run 14psi after i get forged internals on stock fuel injectors, pump, and rail if its okay.
 
10psi with a good tune is pushing them to their limits. a few guys have datalogged IDCs with stock injectors at various fuel and boost pressures and on the MSP's t25r 10psi is as far as I reccomend. depending on the tune you can probably squeeze them to sustain 12psi but at that point they will be very close to 100% IDC if not already static, plus the tune isn't going to be ideal

edit- heh, see orangezoom's post :)
 
mspeed101 said:
no you would need to either upgrade to larger injectors or add injectors
If the injectors look at mspeed101's avatar, they would prabably squirt very well.
 
Ok... so this is a dumb question. If you get larger injectors, could you use the stock ecu maps with them? I don't really understand how they could be maxed out at stock psi when our cars show that it is running very rich at 10psi? Maybe someone could explain that.
 
Yeah I max mine out at around 8-9psi now. Before I was running 13psi on the "stock" setup, however I never monitiored my a/f except through the WDS. You need something to control bigger injectors, however I suggest running extra instead. That way your car will run like stock until you turn them on.
 
BlkZoomZoom said:
Yeah I max mine out at around 8-9psi now. Before I was running 13psi on the "stock" setup, however I never monitiored my a/f except through the WDS. You need something to control bigger injectors, however I suggest running extra instead. That way your car will run like stock until you turn them on.
I agree.
 
i have the splitsecond psc1 (dsmconvert afc) which can control any size injectors but not more. so i'd rather go bigger for now.

so if i were to get the wrx 440cc and tune it for my car will i be okay for 14psi, or will i still also need a fuel pump & rail to supply enough fuel?
 
the fuel rail will be ok but you may want to get a walbro255lph pump if you plan to run 440's. you'll also need a new motor with 14psi ;)
 
i have the split second aic1 which is the xtra injector controller. anyone can use this, as it does NOT need to be calibrated for the msp ecu. the list cost is 283, i got mine for 80 :)

i plan on running 1 extra low impedence 720cc injector or 1600cc if i feel crazy, or three high impedence 440cc injectors.

check it out. www.splitsec.com

does anyone know what size the extra injecotrs are on the mpi setup? i know there are 2 but i dont know how many cc they are.

is running 1 extra at 1600cc better than 3 smaller 440s or does it even really matter. i just need to know because my aic can control 1 low impedence injector, or three high impedence ones.

anyone?

-B
 
It depends on how far you are pushing them. One 1600cc injector at 10%DC isn't as good as 3 440cc injectors at 50%DC. I think injectors have an operating range, but don't quote me on that. Plus with 3, an injector failure isn't nearly as catastrophic.
 
well, i have three low impedence 720 cc injectors in my pipie right now, but i will only be able to use one of them since my aic only controls one low impedence.

720 cc extra fuel per minute should be plenty extra fuel i believe.

any other thoughts?
-B
 
a 720cc is fine IMO, i think a 1600cc would be too big to use to its potential. no rotaries here lol.
 
Unichip tuned my car based on the amount of injector (or lack of I should say) the cars have. That's why those units go from 10-12psi (where it's safer.).

With the tune I have (or any Unichip user has), the car is running safe at 10-12psi.

I've recently installed a BEGi FPR and have RC Engineering 440cc that will be installed soon (then tuned for those).


-Don't forget there is more to adding boost than just injector size-
 
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