stock injector hp limit?

[ImpulseBlue06]

i have the lpe walbro kit but i was wondering with the walbro and the stock injectors what hp is my combo good for?

[New Era Performance]

475ish give or take a few things.

[Shift_GRIND]

crank hp i take it?

so somewhere around 400whp?

[ImpulseBlue06]

So in other words I'm near maxing out the injectors on what I have done to the car?

[Devinsgn]

I have a cam and my stock injectors are maxed out. so probably somewhere between 375 and 400 wheel on a A4

[ImpulseBlue06]

So u would reccomend I get some larger injectors?

[btorres0770]

Dumb question but when do you know you need to upgrade your injectors? Does your performance decrease? what are the signs that let you know time to upgrade

[Shift_GRIND]

when you scan you look at your IPWs (injector pulse widths) IIRC 20+ is static @ 6000rpm

[mistermike]

So u would reccomend I get some larger injectors?

I would recommend you buy two more letters to complete the word "you." ;)

[mistermike]

Dumb question but when do you know you need to upgrade your injectors? Does your performance decrease? what are the signs that let you know time to upgrade

You want to look at a combination of fuel pressure and injector duty cycle. Duty cycle, while derived from pulse width, is a more useful yardstick, because it is independant of injector size.

Much over 80% duty cycle, and you're running out of fuel and/or injector. The GTO typically drops a fair amount of pressure at peak demand. Fixing that can get more out of a given set of injectors and simplify tuning. 60Lb injectors can compensate for a sagging fuel system, up to a point. Persons using forced induction should seriously consider a boost referenced, return style fuel system.

[GTO1_OHIO]

When I first got my h/c combo my rwhp was in the low 430s and the duty cycle did go above 90% when it was dynoed. I ran a full year like that without any problem before going to Ford Racing 30# injectors (red tops)

[Stone Cold Goat]

I was making 458/419 on stock injectors. FAST 90/90, C-Cam, LTs etc and my injectors were at a little over 75%. But it surely wont hurt to change them.

[gjellis]

I discussed this with a couple vendors before I purchased my cam and was told that the basic rule for a LS2, was that the stock injectors would work fine - cam only; including supporting mods such as headers / intake etc... and if I were to upgrade both the heads & cam - then the injectors would need to be upgraded accordingly.

I was also told that I should never see > %80 on the injector duty cycle (cam only) even with a large cam.
I'm currently at around %70.

[Shift_GRIND]

whats the limit of the pump and the rest of the system? Sounds like injectors are the weakest link though.

[Konnie the Goat]

My pump gets un happy @ 100 shot (wet). drops to 55PSI. 125 drops it to 50.