View Full Version : injector with S/C
Rcoug
12-12-2005, 07:57 PM
I want to put a S/C on my 99 cougar, v6 returnless, and I want to know which injector I need. I read a lot of post and it alway said 24# injector are enouhg but my friend give my a formulate to calculate the sive of injector but with this the 24# are not enough. I don't want to put larger injector if I don't need it because thay are more expensive. The kit I put is based on the vortech kit for return system.
(260hp * 0,50)/(6*0,80) = 27,1lbs
Thank you, Sorry for my english!!!
Francis
Buckshot77
12-12-2005, 10:04 PM
24's will be a bit on the light side, I'd rather see you have a 30# injector in there which are pretty readily available as well so the cost shouldn't be too much more.
Rick
AtomicInternet
12-12-2005, 11:57 PM
Better to run rich than lean with an S/C. Spend the extra $$ up front so you don't run lean and detonate.
Rcoug
12-13-2005, 02:07 PM
where could I find 30# injectror? Which car use this?
24's will be a bit on the light side, I'd rather see you have a 30# injector in there which are pretty readily available as well so the cost shouldn't be too much more.
Yes, but where's the chip that knows about the larger injectors??? Gotta have the ECU injector constant changed to match what you put in, or you'll drown in fuel at idle and during normal driving. Your ECU expects 17#/hr injectors - The SVT ECU, 19#. Other than ADC, who can give you an out-of-the-box running chip? $400 for that one...
DemonSVT
12-14-2005, 01:58 AM
24lb injectors will support about 300 wheels.
The Vortech on a normal 2.5L is not going to reach 300 wheels.
Buckshot77
12-14-2005, 11:45 AM
Yes, but where's the chip that knows about the larger injectors??? Gotta have teh ECU injector constant changed to match what you put in, or you'll drown in fuel at idle and during normal driving. Your ECU expects 17#/hr injectors - The SVT ECU, 19#. Other than ADC, who can give you an out-of-the-box running chip? $400 for that one...
Considering he is all ready planning on 24's and assuming that he knows the kit MUST have an aftermarket chip as is, I figured this was a given.
Rick
Considering he is all ready planning on 24's and assuming that he knows the kit MUST have an aftermarket chip as is, I figured this was a given.
Rick
Not necessarily a foregone conclusion- Just thought I'd throw that out there.
Rcoug
12-14-2005, 08:48 PM
24lb injectors will support about 300 wheels.
The Vortech on a normal 2.5L is not going to reach 300 wheels.
Why when you use a program to calculate the sive of the injector you need, it's say you need 28lbs?
Considering he is all ready planning on 24's and assuming that he knows the kit MUST have an aftermarket chip as is, I figured this was a given.
Yes, I know it, but I wait to know what sive of injector I need before to call it.
Thank you
Francis
DemonSVT
12-14-2005, 11:31 PM
Why when you use a program to calculate the sive of the injector you need, it's say you need 28lbs?
Because most calculators do two things:
They err on the side of caution. (max duty cycle 80% and calculate for a stupidly rich A/F ratio)
They are setup for the "typical" engine efficiency and the Duratec far exceeds that.
Rcoug
12-15-2005, 08:16 AM
Because most calculators do two things:
They err on the side of caution. (max duty cycle 80% and calculate for a stupidly rich A/F ratio)
They are setup for the "typical" engine efficiency and the Duratec far exceeds that.
Thank you Demon!!! :bowdown:
Buckshot77
12-15-2005, 10:27 AM
Demon, while I agree in most respects, I don't think that 80% duty cycle is a bad thing to figure. If you should happen to have something cause the injector to go wide open due to need for fuel, I'd rather have a 20% cushion than a 5% cushion on an engine that's extremely expensive to build. As far as engine efficiency, as long as you plug in a more efficient multiplier into the equation, you can pretty much take care of that issue right off the bat. I calculated my engine particulars about 20 different times and ways when picking out 42's and usually came up with needing around 39# injectors when looking at 350-400 whp and 80% duty cycle.
Unless you get massively oversized injectors, why shouldn't he leave himself a little room for expanding his power capability should he ever decide to go with a smaller pulley, nitrous, etc where he could concievably break the 300 wheel mark? As someone who has bought, upgraded and bought again, I can tell you it gets f'in expensive doing it that way rather than starting out a little on the overkill side. My $.02
Rick