when do MSP injectors max out?

[kicker22705]

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.

[mspeed101]

subscribing

[peepsalot]

They max out at 100%.


(evil)
J/p I'm curious as well.

[orangezoom]

When I started tuning mine they where pretty much at a 100% duty cycle right from the factory.

[low_psi]

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 :)

[yashooa]

They bench about 300lbs :)

[low_psi]

Mine do tree-fitty!

[CChris704]

would the perrin fuel rail fix this problem?

[mspeed101]

would the perrin fuel rail fix this problem?no you would need to either upgrade to larger injectors or add injectors

[CasopoliS]

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.

[ONRAILS]

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.

[BlkZoomZoom]

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.

[Kooldino]

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.

[kicker22705]

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?

[low_psi]

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 ;)

[azian6er]

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

[low_psi]

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.

[azian6er]

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

[low_psi]

a 720cc is fine IMO, i think a 1600cc would be too big to use to its potential. no rotaries here lol.

[UnNaturalinc]

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-

[mspeed101]

If the injectors look at mspeed101's avatar, they would prabably squirt very well.(lol)

[UnNaturalinc]

It's hard to tell in a small pic... is that Vida?

mmmmmm, Vidaaaaa............

[mspeed101]

It's hard to tell in a small pic... is that Vida?

mmmmmm, Vidaaaaa............yep since chimsp is retiring her from his sig im gonna sport her (lol2)

[mspeed101]

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-So will the unichip be offered with bigger injectors soon?

[wicked]

you can run extra injectors with the MPI,and nick also offers extra injectors with rail,and flange.

[UnNaturalinc]

So will the unichip be offered with bigger injectors soon?

Yes, I'm working on that right now actually. I've just got to get a time where everyone's schedule lines up.

[mspeed101]

Yes, I'm working on that right now actually. I've just got to get a time where everyone's schedule lines up.Nice keep us posted on that!

[mazdaspeed75]

mine arent maxed out yet at 10 psi . Volt at 4.3 in 4th gear to redline

[Focus]

mine arent maxed out yet at 10 psi . Volt at 4.3 in 4th gear to redline

Voltage ?

It's duty cycle that you need to look at.

[mazdaspeed75]

Voltage ?

It's duty cycle that you need to look at. the analog volts Nick said they would be maxed out at 5 volts

[Focus]

Your analog voltage is your Mass Air Flow voltage.


the analog volts Nick said they would be maxed out at 5 volts

[mazdaspeed75]

Your analog voltage is your Mass Air Flow voltage.so how do we know when they are maxed out when there isnt enough fuel to add because at 10 psi in 4th i can still make it pig rich of my wb .

[Focus]

When you add fuel and no changes happen, you know your injectors are maxed out.

[orng1]

Anybody try to make a fuel map with higher fuel presure?
Maybe an mpi or haltech car. Just curious as I think the fuel injectors can have more out of them.

Bob/orng1

[Brian MP5T]

10 Psi

[DSMConvert]

injectors max out at 10psi...well actually they max out at around 8-9psi but they can run 10 while still being within afr range...Shouldnt need a wally 255 till you get up around 550-600cc range...a 190 would be plenty sufficient....wallys are very very very loud on a side note....also please remember duty cycles should not be above 85% but ALSO not below 20%..below this the spray pattern is not optimum and you'll idle like crap and sputter when you first get on it even with a fuel controller...overall I'd say that the 440cc injectors should be just about perfect...I was using 450s on my old fsde turbo mx6 running 15psi on a t3/t4 turbo setup and had duty cycles averaging around 75%...

[peepsalot]

Anybody try to make a fuel map with higher fuel presure?
Maybe an mpi or haltech car. Just curious as I think the fuel injectors can have more out of them.

Bob/orng1
Can increasing fuel pressure allow you to get more out of the stock injectors without having to replace them? What would that invlove, replacing a regulator or fuel pump or something? Would increasing fuel pressure be an effective way of preventing your injectors from maxing out?

[low_psi]

no. the injectors can only flow so much. fuel pressure isn't the issue with the stock setup.