I'm aiming for anything over 500hp but want my car to be able to accept it if it is able to produce more. I was thinking of 55lb injectors but I dont know the max hp of these injectors. I will be running a Vortech V2 and probably about 15psi. I don't understand the math behind injectors and engines but can someone tell me how far the 55lbs can go? The max ill ever want is 600hp, but if my car made that i would want the injectors to be able to reach that. The reason im asking is the 60lbs are $100 more and i dont want to spend the money on injectors that i wont need. Thanks
55lb injector question
- Thread starter mat82284
- Start date
CobraRed_96_GT
Active Member
I hear ya man, have been looking over the same things. 42lb injectors have a max of 500hp. 55's should be solid past 600hp, 60's and 62's are more in the 650-750hp range me thinks.
Hopefully someone can chime in on this subject. I dont want to get to the dyno to find out i maxed at say 580hp because my injectors are tapped and only to find out i could have had 610 if i had the extra injector. I also head that the tuner can up the psi to get them to flow more and some injectors can flow up to 80+psi so im guessing if your adding 16psi you would be flowing 60psi and you could still up it another 20psi more for some extra fuel. Is this correct or do i have it all wrong lol.
CobraRed_96_GT
Active Member
You don't need to trust me, read this page:
RPM Outlet.com - 1996 to 2004 FORD MUSTANG GT Fuel Injectors
All hp figures are at the engine (multiply by .85 or .80), and a bit high if you ask me as you dont want to run near max flow of an injector at that power range for fear of leaning out.
RPM Outlet.com - 1996 to 2004 FORD MUSTANG GT Fuel Injectors
All hp figures are at the engine (multiply by .85 or .80), and a bit high if you ask me as you dont want to run near max flow of an injector at that power range for fear of leaning out.
Flghtmstr1
Member
I think what your tuner is talking about is increasing the voltage to the fuel pump, which is similar to how a Kenne Bell Boost-A-Pump works. The stock fuel pressure in most cars (including ours) is 43.5 psi. By bumping the fuel pressure up to 60 psi, your 55 lb injectors would be flowing 64.59 lb per hour. If you don't want to increase the fuel pressure (there are good reasons not to), you can use an online calculator such as: Fuel Injector Calculator from WitchHunter Performance in order to determine your injector needs.
I was originally planning on only making ~ 500hp too. That soon turned into 600 on pump gas and hopefully 800 on race gas. I went with the 60's at first just so i had some room to grow (you always want more) and now i'm worried those 60's might not be enough.
As a rule i always go a little bigger than i need (as long as it isn't going to really hurt anything) so i have some room to grow. Better to do it once and pay a little more than do it twice and spend even more.
I wasnt saying i dont trust you. I'm just trying to see if 55lbs would be enough.
Whats a BSFC? What would that be for a supercharged engine? Does it change with ported heads and cams and 8.5 compression?
Ok after some calculations it looks like 55lbs will be to short for 600rwhp or did i calclate this wrong. I think the max at 43.5 psi was 650 crank hp. I want rwhp. Honestly i Think ill buy the 55's and just swap them out when i swap my blower, I dont think ill even be able to get 600rwhp from a Vortech V2 or am i wrong?
CobraRed_96_GT
Active Member
You are correct, 600rwhp wouldn't be easy to reach on most any vortech. 55's should be plenty for now.
Stan Weiss
Member
With a BSFC of .55 and a duty cycle of 85% I get 680 HP from 55 lb injectors. At 90% duty cycle that is 720 HP. Remember when you run boast you should a a boast reference fuel regular. What that mean is as boast pressure increases you have to increase fuel pressure by the same amount to get the same 55 lb flow.
Don 95Vert
Founding Member
Pay the extra $$ abnd get the Siemans-Deka 60's. Keep in mind that 42's are rated to flow at Ford's spec of 39.5, but 55's are rated at the industry spec of 43.5. When you factor that in, the 42's are not that far away from the 55's (46ish). Plus the flow patterns on the 60's are so much better than any 55's and the value files SCT has - if you are using SCT to tune - are really a whole lot better. It'll idle and drive much nicer, even if you are not near maxing them out.
Or if you think you'll make killer power someday, the new Ford Racing 80's are said to be pretty good - they are so new I have not yet seen them on any cars.
Or if you think you'll make killer power someday, the new Ford Racing 80's are said to be pretty good - they are so new I have not yet seen them on any cars.
Stan Weiss
Member
Old Fuel Pressure 39.5 psi flow 42 lb/hr New Fuel Pressure 43.5 psi flow 44.075 lb/hr
If anyone needs to do these calculations I have this and other Automotive calculators on my web site Automotive Performance Software / Interactive JavaScripts Calculators
I second what Don 95Vert said about getting the bigger injectors as long as they will idle and drive much nicer, even if you are not near maxing them out.
If anyone needs to do these calculations I have this and other Automotive calculators on my web site Automotive Performance Software / Interactive JavaScripts Calculators
I second what Don 95Vert said about getting the bigger injectors as long as they will idle and drive much nicer, even if you are not near maxing them out.
Similar threads
