need for 24# injectors?

[Stage 2 Dan]

Hello everyone,

Have had my 1999 ranger sport, w/ 2000 Explorer 5.0 on the road for about 3-4 months now.
No major issues other than EGR control module. But starting to look for a couple performance upgrades.

I picked up a NOS set of Ford motorsport explorer headers recently, that are going to be installed soon.

One of my Mustang buddies said that I need to swap out the 17# injectors and MAF, and move up to 24# injectors along with the correct MAF. I realize that this will probably mean that I will have to get the ECM
re tuned for the larger injectors. Will this mod still allow the vehicle to pass the OBD2 smog test? I have heard some conflicting stories.
The engine is all stock for now with a K&N air filter in the stock air box.
I have a free flowing catalytic converters 2 1/4 mandrel bent primaries, to a 3" single with a walker ultra flow muffler.( I feel my biggest bottle neck is the exhaust manifolds.)

Been having a lot of fun surprising the chevy s10 boys, just want to get a little better at it.

Dan.

 

[Turdle]

I think the stock injectors are 19lb, and if you do not get any sort of p0171 or 172 codes your injectors will flow fine. You do not need the 24s which will just cause tuning headaches. You arent going over 5800 rpms with the stock valvetrain anyway. It will not take this.
I think the rev limiter is 5300 for your protection. You might bump it up to 5600 but that is kinda pushing the pedestal rockers.

 

[Stage 2 Dan]

HI Turdle,
I thought that I was told that starting with the 2000 model year they downsized the injector size to #17 lbs, and #13 for California emissions?
I'm not that well versed on this information.
It just seems that it will lay down a little bit if I stab the throttle wide open once the truck gets up near the end of 2nd gear and farther up. If I back the throttle up it just seems a little bit happier. I have replaced the TPS sensor, thought that that was the culprit.
I have a walbro 190 liter per hour pump in the tank with a new fuel filter also.
I don't want to go the way of bigger injectors if I really don't need em.

Dan.

 

[Centaurus5.0]

You'll only need bigger injectors (and fuel pump) than stock if you:

-spends a lot of time at 6,000rpm (road racing) Not happening with a stock cam as Turtle said.
-Get bigger heads (with cam)
-Increase Displacement (331-347)
-Install power-adder. (turbo, supercharger, nitrous)

 

[VR4]

I have cam, headers, full exhaust with a borla, and a little intake work. No problems at part or fill throttle with stock fuel