do i need injectors

Sanad GT · 10-21-2009, 03:38 AM

Dear, All
I have heads and cams stage 3 in my 2003 mustang and will have track flow manifold intake soon , do i need to change the injectors to bigger one , thanks

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cliffyk · 10-21-2009, 04:42 AM

The pink injectors used in the '03 and '04 models are rated at 21lb/h.

Downrated for the 40 psi Ford runs makes them 20.14lb/h. 8 of them, at 80% duty cycle and 0.5 BSFC, are good for 20.14 * 8 * .8 / 0.5 = 257.8 HP...

So, if you'll be making much more than that you will need injectors--mine run at 85%+ duty cycle at WOT and 260 rwHP peak, meaning just about flat out...

mrtstang · 10-21-2009, 08:37 AM

If you are pushing over 300 rwhp (whick you should be) i would change them. Even if you get away with the stockers, i gaurantee you they are totally maxed out at that point. That is not a good thing.

0949er · 10-21-2009, 09:16 AM

Quote:

Originally Posted by cliffyk

The pink injectors used in the '03 and '04 models are rated at 21lb/h.

Downrated for the 40 psi Ford runs makes them 20.14lb/h. 8 of them, at 80% duty cycle and 0.5 BSFC, are good for 20.14 * 8 * .8 / 0.5 = 257.8 HP...

So, if you'll be making much more than that you will need injectors--mine run at 85%+ duty cycle at WOT and 260 rwHP peak, meaning just about flat out...

so... how do I make 288 wrhp w/ my 04 and stock injectors?

sainthk · 10-21-2009, 10:51 AM

Well 0949er if we both go for what Cliffy says, we should upgrade our injectors. I know I'm still running the stock injectors.

Sanad GT · 10-21-2009, 11:19 AM

Thanks guys but which one that will be good for my car

0949er · 10-21-2009, 12:08 PM

well bigger injectors wont hurt. you will of course need a re-tune. It will allow you to get more power w/ future mods like F/I and stuff.

but you say you have stage 3 head/cams.... does the car run now?

Sanad GT · 10-21-2009, 01:02 PM

yes it does run but did not take it to the dyno yet , waiting for trick heat meniflod thats why i am asking about the injectors

Sanad GT · 10-21-2009, 01:53 PM

what about 42lb guys

cliffyk · 10-21-2009, 04:14 PM

Quote:

Originally Posted by 0949er

so... how do I make 288 wrhp w/ my 04 and stock injectors?

Because the numbers I provided are the base guidelines for sizing injectors, and you are likely pushing them beyond 80% duty cycle.

At 90% duty cycle (about the highest controllable DC), they will support 290HP (20.14 *.9 * 8 / 0.5)...