View Full Version : Changing fuel injectors 5.4 L


kaboom10
12-30-2007, 11:48 AM
Has any one changed injectors from the stock flow to a higher flow rate? From what I gather the stock rate is 19lbs/hr. The extra horsepower I expect to make calculates out to about 26-28lbs/hr for the flow I need. Can I expect any horsepower gain/throttle crispness from just replacing the stockers before the mods start? How about tuning the engine with a tuner?

Bulldog Stang
01-03-2008, 12:23 PM
Dont change injectors unless you are supercharging and only do that once it is supercharged. Do your fuel system and injectors at the same time as an install with the s/c

kaboom10
01-03-2008, 01:10 PM
Dont change injectors unless you are supercharging and only do that once it is supercharged. Do your fuel system and injectors at the same time as an install with the s/c

In searching and reading what I was told the stockers should be fine till the power level goes up from mods (heads/cams/etc.). Found a lot of math to calculate sizes. An increase in pressure would be mre help now. I'm gonna get a reprogrammer for an axle change so I'll add a bit of fuel too. obtw no supercharging is in the future. Never have and never will.

Bulldog Stang
01-04-2008, 01:16 PM
then u will be fine with the stockers .. maybe, and i mean maybe change out to 24 lb when u do a heads/cam swap with a ported intake ...

kaboom10
02-14-2008, 03:23 PM
then u will be fine with the stockers .. maybe, and i mean maybe change out to 24 lb when u do a heads/cam swap with a ported intake ...
I've started taking the inlet/exhaust restrictions out and max tuned it on 93 octane. I've done 0-60 times using stock A/F @ W.O.T. then went to 10% richer setting and no diff at all. Am I reaching the stockers limits? I'd like to change to 24's for the better spray pattern at least. obtw the mpg's went up 20% (2.0mpg) with my foot in it.

kaboom10
06-08-2008, 09:21 AM
I switched to 21lb. units for the heck of it. I thought I'd try Accel and it has a crisper throttle response than before. Might just be the spray pattern? It was worth it to me for the money spent. I changed the values in the tables to match them also.:pimp:

autosay97
06-09-2008, 04:34 PM
There are no gains to be made with fuel injectors alone. Kaboom, what are your plans for the truck? Is it a pi or non pi motor?

kaboom10
06-09-2008, 07:45 PM
It's a PI engine being a 2002. I've been tuning on the MAF transfer function table to bring F/As in line.:bomb:

autosay97
06-09-2008, 08:39 PM
Had much luck?

autosay97
06-09-2008, 08:39 PM
oh and what are you using for tuning? Tweecer? SCT?

kaboom10
06-09-2008, 08:59 PM
SCT LiveWire with Pro Racer Package.

autosay97
06-09-2008, 09:48 PM
That live wire looks nice, does it work well? shift light looked like a joke in the pics. For the money its really hard to beat the sct stuff.

kaboom10
06-10-2008, 06:49 AM
It works great. I have the alert light setup for a few PIDs. Shift light gets my attention too. I can datalog real time onto my laptop. Just select what you want to see.

kaboom10
12-13-2009, 06:48 AM
I've tuned in the injectors over time since I put them in. They are now at peak performance. The tires break loose on dry pavement and all I need is 1/3 throttle. That's enuff to get into 60%+ on load and 9-10" of vacuum. Incredible throttle response also. :pimp: