injector size .. ?
50psi of fuel pressure. RC Engineering 440cc injectors.
Car made 310whp 220tq. Customer was reccommended to change to injectors a little bigger.
Car had full ac, ps and other things. Setup was basically a revhard kid.
If all you want is 300, get 440s. If you are buying new, I'd recommend for you to get some 550s.
Car made 310whp 220tq. Customer was reccommended to change to injectors a little bigger.
Car had full ac, ps and other things. Setup was basically a revhard kid.
If all you want is 300, get 440s. If you are buying new, I'd recommend for you to get some 550s.
.... i would provide the kit but after looking at inline's prices ... never goina happen i can put the kit on myself thats no biggy. but im going to have to have someone tune it... anyone know if i can just use the chipped pr4 ecu i got.. has xenocron chip in it..?
Just gets some 850's or something and tune them down. My buddy had 1000's on his setup and he made barely 300hp. He just had to tune them down so the car would run. Not that hard to do.
+1 On going overkill.
I left that out in my earlier post for the sake of simplicity.
I have some 780's and i don't make 300hp (until the retune) gas mileage is fine. But realize that you cant be too concerned with it in this hobby.
I left that out in my earlier post for the sake of simplicity.
I have some 780's and i don't make 300hp (until the retune) gas mileage is fine. But realize that you cant be too concerned with it in this hobby.
That has nothing at all to do with injector size.
The gas pedal is completely mis-named, because it only lets in air, not fuel. The ECU decides how much fuel you need based on the amount of air you let in. For any given injector size, the ECU will adjust (and tuning has a lot to do with this) depending on the amount of fuel you need. So if you have a turbo, and 330cc injectors, at some throttle opening you may be putting out 75% of what those injectors can flow, versus putting out maybe 40% of what a 550cc injector can flow.
Put another way, if you "womp" on the gas, you'll put out more power. If the injectors can't flow enough for the max power you put out, at some point you'll max out the injectors, go very lean and bad things will happen. So more throttle opening with injectors that are too small doesn't really give you more fuel, it makes you run more lean.
If the setup has been tuned, you will have a safe air/fuel ratio at wherever you are in the throttle range. This assumes that you have the large enough injectors to to the job correctly.
The larger you go, the harder it is to tune for idle and off-boost conditions. That's not to say it can't be done (and it is done all the time), it just takes more time and work because of the decreased resolution that comes with having a huge injector and a limited range of duty cycle adjustment. So I wouldn't recommend going much larger than you need. If a 5xx cc works for the power output that you want, doubling the size isn't going to do anything but add a lot of tuning headaches. Basically, if you don't need all that extra headroom, don't willingly take on the complications the extra headroom will cause.
If you want to make a lot more power later, and need the flow of 1000cc injectors, the price of 1000cc injectors is going to be small compared to the money spend on the rest of the supporting mods/parts. Plus, you can sell your 5xx injectors later, there will always be a market.
The gas pedal is completely mis-named, because it only lets in air, not fuel. The ECU decides how much fuel you need based on the amount of air you let in. For any given injector size, the ECU will adjust (and tuning has a lot to do with this) depending on the amount of fuel you need. So if you have a turbo, and 330cc injectors, at some throttle opening you may be putting out 75% of what those injectors can flow, versus putting out maybe 40% of what a 550cc injector can flow.
Put another way, if you "womp" on the gas, you'll put out more power. If the injectors can't flow enough for the max power you put out, at some point you'll max out the injectors, go very lean and bad things will happen. So more throttle opening with injectors that are too small doesn't really give you more fuel, it makes you run more lean.
If the setup has been tuned, you will have a safe air/fuel ratio at wherever you are in the throttle range. This assumes that you have the large enough injectors to to the job correctly.
If you want to make a lot more power later, and need the flow of 1000cc injectors, the price of 1000cc injectors is going to be small compared to the money spend on the rest of the supporting mods/parts. Plus, you can sell your 5xx injectors later, there will always be a market.
Last edited by Fabrik8; Sep 27, 2008 at 11:35 AM.






