Max HP stock injectors can take??

[98blueGTNPI]

hello, im new to the mustang crowd, ive mostly worked on imports as that was my budget would allow. i recently bought a 1998 GT that has a few typical modds, or so im told they are typical. my goal is to keep it through my college years but i want to be able to keep up with the camaros around town, which right now it runs 14.3's and they run 13.9's. i know the year i bought has limmited intake and heads cmpaired to newer ones, but my goal is still 320hp to the wheels.

will its stock injectors and MAF sensor be able to support this power level?

i have purchased a plethura of parts that i am told should net me about 250-260HP and then my plans are to use a nitrous system i currently own on it untill i can save up for a supercharger.

im just getting mixed answers from my friends that both have mustangs, and wanted to know for sure before i install everything without upgrading those too.

 

[speedfreak98r]

Yes, your stock injectors will support 320hp.

 

[Stan Weiss]

There are calculator on the internet which will give you an idea of how much HP a give injector will make. I one factor is BSFC which is normally measure on a engine dyno. This will change based on mods and if the engine is N/A or FI. What I am getting at here is in two differently setup engines the same will yield a different Max HP.

 

[mrvax]

An engineer named Mr.Chip or something like that came here and carefully explained how the stock injectors will support about 300rwhp max. And even at that, you would be running at 100% duty cycle at WOT. So, to be safe, if you are approaching the 300rwhp mark, spring for the larger fuel injectors & tune.

 

[Crzyhrse]

I'd definitely get a set of 24lb. injectors. The stock 19lb are only good up to about 300RWHP.

 

[Stan Weiss]

I am going to use 18 lbs/hr as my base -- engine HP
.36 BSFC 80% DC 320 HP
.36 BSFC 95% DC 380 HP
.42 BSFC 80% DC 274.3 HP
.42 BSFC 95% DC 325.7 HP
.50 BSFC 80% DC 230.4 HP
.50 BSFC 95% DC 273.6 HP

 

[BooWFO]

Is it a dry kit or wet kit?
300rwhp out of a 4.6 sohc N/a can be acheived but it ain't cheap or easy.
If it was my car I'd go with PI cams or some aftermarket ones, Pi intake, possible swap head while the rwhp increase may not be great the trq seems to really pick up. get a good tune, and spray it.

 

[98blueGTNPI]

its a dry universal kit i was running a 40 shot but with the volume of a v8 im thinking of running an 80 shot.

coincedently with the stock 98 GT's injectors fit on a 98 V6 with the split port intake and head swap performed?? a friend wants to buy my stock ones if they will fit in his v6 cause his current injectors are limmited to 160rwhp and hes got close to 200 now

 

[LaserRed01GT]

From what I've seen these NPI motors usually are around a .44-.46 BSFC. When calculating fuel system requirements you have to talk about the HP at the crank, the fuel system has no idea what kind of drivetrain loss we have and doesn't care. It only knows the current load on the motor and the pulsewidth that is being commanded.

With a average .45 BSFC, 80% duty cycle and 48 PSI at WOT, the stock injector will support around 300 HP at the crank.

Now of course you can squeeze more out of the injector and push it up to 100% duty cycle where it will handle around 370-380 HP at the crank, but anything over 80% is not a good idea. When you go over 90% the injectors will tend to lose control. As you approach 100% duty cycle the injecors will start to go static.

 

[whyask]

does that follow in line with the 5.4, I have stock injectors and with my spray im getting worried there not enough...in line with your caculations , should I upgraded....

Good thread by the way, been meaing to ask this ? for a while..Thanks !
(sorry to steal it for a quick ?)

 

[Stan Weiss]

How many lbs/hr are your injectors? What pressure are you running them at and how high can you adjust it to?

 

[98blueGTNPI]

does that follow in line with the 5.4, I have stock injectors and with my spray im getting worried there not enough...in line with your caculations , should I upgraded....

Good thread by the way, been meaing to ask this ? for a while..Thanks !
(sorry to steal it for a quick ?)

hells yeah i wanna know befores i blow this thing up i just put about all the money i have into the parts i can aford a blow up LOL


anyone know about the 19lb/hr injectors for my friends V6???