I will S/C my truck in a few days , it's a Mark Lt with a 5.4 3v engine. I bought the new Whipple S/C but i don't want to install it with the stock injectors, i don't think they are strong enough to the new fuel delivery needs. My question is, can i install 48lbs injectors for now and for future boost upgrades ? Can i keep my stock fuel pump ? My truck will be tuned by JDM with a Xcal2. If so, what are the best injector brands that will fit in a 5.4 3V engine ? If i have to replace the fuel pump too, which one you guys recommend ? Thanks for your time guys, i will appreciate any comments.

 

I'm assuming the 5.4 3V's still come with 19# injectors. FRPP 42# injectors would be a good upgrade. As far as the rest of the fuel system I don't know what the 04+ trucks have as far as fuel pumps. You can always wire in an in-line pump to supply the extra fuel though.

 

I think those trucks have the new style injector, I forget the actual technical name, but its smaller with a different plug (was on the 99-02 cobras) The 42# is all you really need, and you can run your stock ones with the stuff in the kit most likely. I haven't upgraded my Lincolns fuel pump and run the 42# injectors, so you'd most likely be fine.

 

98NAVI, i was thinking about 48lbs injectors just in case i get a second tune for 15psi. What do you think ?

 

No such thing as having too much fuel system capacity. Too much is tuneable, too little is a road block.

 

Does the 06 have a return system, or a returnless system? If it has a return system, you can't have to much as it will send unused fuel back to the tank. I know the mustang changed, in 99 I believe to a returnless system and the guys who wanted serious power were spending over a grand to convert to a return system. A friend of mine was running a 93 with a 5.0 that was bored to 306, with a vortech s trim pushing 16 psi and had the 42# injectors on it (the ones that are on mine now!) She had a dyno proven 510HP to the rear and was capable of over 600. I don't think you'd need them, but bigger is usually better. You'd have to get a MAF that was programmed for them, I think that'd be the biggest pain (more expensive, whereas a 42# MAF is $100 shipped to you off ebay in the Ford Racing version)

Some basic fuel injector info I found from a racing site

It takes about .6 pounds/hour of fuel to make one[1] Horsepower. (edit:this was for a 6 cylinder buick regal turbo, I read alittle deeper afterwards....The amount for your truck may be higher or lower slightly)
Example: Fuel Req'd. = 527 HP x .6 #/hr = 316 #/hr
Example: Injector Size = 316#/hr / 8 = 39.5 #/hr

We have determined that it takes 316#/hr to generate 527 HP and that at least 39.5#/hr injectors are required to deliver that amount.

Based on that, and mind you I didn't make those someone else did so I am assuming that .6# an hour per HP is correct, you could push 500 RWHP with the 42# injectors no problem. But they would be close to their max, so if you wanted more then the 48# may be a good idea. Remeber also, thats the maximum output for the injector, so the 42# would have little room for error.

http://www.megasquirt.info/v22manual/minj.htm
That site has slightly different numbers, but alot of good info

Hope this helps

 

Great post 98NAVI. On ebay i coudn't find any 48lbs injectors, i found a lot of 42lbs, after reading your post i will go with 48s, do you know where can i buy 48s including the Maf sensor you mentioned . I am looking for a reliable brand and i don't mind spending more money for a good known brand. Thanks a lot.

 

http://cgi.ebay.com/ebaymotors/VENOM...QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/86-95...QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/Unive...QQcmdZViewItem

http://cgi.ebay.com/ebaymotors/Accel...QQcmdZViewItem

You need to know if you have high or low impedence, and if its the thin or fat style injector.

 

The "venom injector" i don't know if it's a reliable brand and that accel won't fit in my engine 5.4 3v, but anyway i appreciated your time Navi, you are always very helpful, thanks for your time.

 

You've sparked my interest in your project, I'll help you search for parts as best I can find. As I have always said, this is my first mod motor so most of my experience came in the past from the 5.0 Fortunately, since the stang has the same mod motor setup (although I'd rather it still had the 5.0) lots of the names that I know can help us with your motor too. One of the premier but lesser known names is Sean Hyland. He has a place up in canada, but his stuff is second to none. I have seen cars he built, balanced 50/50 front/rear and even as far as to factor in the weight of the person who would be driving it, that pushed well over 800HP and looked like a factory direct car.

THis is is web site http://www.seanhylandmotorsport.com/...b3e361fd480780

I am sure he can provide whatever you need. He isn't however, the least expensive out there. Some of his stuff is about in line, some is extremely high IMO. He doesn't have a listing for the MAF or injectors on his site, but I am sure if they are available he'll be able to supply you with them. Give'em a call on Monday and I know you'll be satisfied.

 

I will call him for sure dude, probably he will have some good 48lbs injectors and maf sensor. I let you know what happen on monday, thanks again.

 

I would just get a maf extender.

 

rafa, not sure if you knew this or not, but the whipple kit comes with a larger MAF sensor. I'm not sure of the size however.

 

That's interesting. I wonder what it comes with.

Someone with a whipple post up.

 

Stock injectors are 24lb/hr and with the fuel pump, they have no problem maintaining 11.5:1. We control the fuel psi which increases to 65lbs @ WOT. I would not recommend installing such a large injector, as cold starts, transient and decel will be compromised. If you truly have to change the injectors, you need something in the 34-39lb range. The Ford GT injector is a 34lb/hr but there too short to fit without machining the fuel rail mounting boss down. The 39lb cobra injectors would be my next choice. With the larger injector, you can safely make 500rwhp before the pump is maxed out, as long as you decrease the fuel psi.

The MAF is 75mm and we also have a 95mm that we can use, although it does not fit with the same air inlet tube because of the diameter. Were working on something for that, but it will be a bit before we release that as a bolt on addition.

Thanks,
Dustin
Whipple Superchargers