Injectors

[Supreme Cutlass]

Would you get a performance boost from larger injectors? or would you just run too rich?

[Aaron]

No, it won't add horsepower or make it run rich, it will do nothing but cost money.

[Prospeeder]

yea, now if ur doing forced induction, then yes, it definatly will help, but scince ur not, then no

[Robby1870]

you need internal modifications or boost to warrant larger injectors

[Aaron]

you need internal modifications or boost to warrant larger injectors

 

You can need an upgraded fuel system with just bolt ons.

[Robby1870]

lots of bolt ons

[Prospeeder]

what do u mean by bolt ons? like turbo/s/c or like WAI and CAI?

[Aaron]

Either, all are bolt ons.

[Guest TurboSedan]

No, it won't add horsepower or make it run rich, it will do nothing but cost money.

 

i would think it would run too rich? maybe i'm wrong but....why wouldn't they? you could add an AFPR and turn down the pressure to make the injectors seem smaller, but with the stock FPR i would think larger injectors would make the engine run too rich (on an otherwise stock engine of course).

[Prospeeder]

well, the computer will limit the amount of fuel, so if it detects is running rich, poof, cuts fuel, so its worthless

[Aaron]

well, the computer will limit the amount of fuel, so if it detects is running rich, poof, cuts fuel, so its worthless

 

Exactly.

 

It's better to run bigger injectors than smaller ones, the optimum number is about 70-75% of what the inejctor's max flow is. The DOHC is right on this number, I'd assume the pushrod moors are as well. But the power difference will be minimal, and it could screw up your idle if they are too big.

[Guest TurboSedan]

well, the computer will limit the amount of fuel, so if it detects is running rich, poof, cuts fuel, so its worthless

 

i realize that, but the computer can't do anything about the injectors themselves being mechanically different (bigger).

[Prospeeder]

well, the computer will limit the amount of fuel, so if it detects is running rich, poof, cuts fuel, so its worthless

 

i realize that, but the computer can't do anything about the injectors themselves being mechanically different (bigger).

 

im not seeing what ur saying, ur asking if it will run rich, or give u performance if you just have that and nothing else like boost, the answers NO, because of the computer, yes, it can do somthing about the bigger injectors, make less fuel come out, ur not making much sense, duh it cant do anything about its actual physical size, but it can cut fuel when theres too much going in

[Aaron]

well, the computer will limit the amount of fuel, so if it detects is running rich, poof, cuts fuel, so its worthless

 

i realize that, but the computer can't do anything about the injectors themselves being mechanically different (bigger).

 

Yes it can, it opens them for a much shorter amount of time, thus letting less fuel in.

 

But even if you did add fuel, it'd take away power, as running rich makes less power than lean. This is quite evident in my white car's dyno, whenever the A:F went lean (Above 12), there was a power spike. People are under the impression that FI is like carbing, where back in the 60s, they added a bigger carb, and picked up like 20-30hp. But they think carb is just for fuel, when in fact, a bigger carb is like a bigger throttle body--It also adds more air, which is why they picked up power.

[Guest TurboSedan]

duh it cant do anything about its actual physical size, but it can cut fuel when theres too much going in

 

DUH that was my point. thank you for understanding.

[Prospeeder]

well what the fuck were u asking? i told u that the computer chancged fuel, and ur saying "but the computer can't do anything about the injectors themselves being mechanically different (bigger)"

 

no shit, it can cut fuel tho, derrr, thus how fuel injection works, even if there bigger than stock, if it detects its rich, it will make less and less fuel till its just right

[Guest TurboSedan]

just because you don't understand doesn't mean you need to get nasty

 

so according to your logic you can throw 30lb injectors in your TGP and the O2 sensor will see this and the ECM will cut duty-cycle down to where everything is running fine? i just don't see it. you can try it if you want, good luck!

[Prospeeder]

aaron just said that if u could read, it doesnt just say, oh its this much rich, turn it down just as much as the stock injectors, no, it puts less fuel till its just right, then when it goes lean it gives more, thus how fuel injection works

 

theres TGP guys that run bigger injectors, like 24-28 and they dont run rich at all

[Guest TurboSedan]

aaron just said that if u could read, it doesnt just say, oh its this much rich, turn it down just as much as the stock injectors, no, it puts less fuel till its just right, then when it goes lean it gives more, thus how fuel injection works

 

if i can read? what the hell is that? i don't think you fully understand you fuel injection works. sure the ECM will adjust to some extent, but it depends on how big you go. you can't just throw bigger injectors in and expect everything to be fine. it may work when going to a slightly larger injector, but that's about it. there is only so much the ECM can do about it.

[Prospeeder]

Well you tell me how it works then, from what i understand

 

the injector sprays fuel into the cumbustion chamber, and if its running rich, the o2 tells the ECM, that cuts fuel, if its running lean, it gives it more fuel, or like the TGP, that has Fuel Tables for the X amount of boost when boosting

 

so ur saying an outragous size of injector will run rich, i guess that would make some sense if it was HUGE, cause the computer wouldnt be ablse to close it off fast enough and way to much fuel would get in

[Guest TurboSedan]

so ur saying an outragous size of injector will run rich, i guess that would make some sense if it was HUGE, cause the computer wouldnt be ablse to close it off fast enough and way to much fuel would get in

 

that's what i've been saying all along, i'm sorry it was so difficult to understand. and the injector doesn't have to be outrageously big for the computer not to be able to compensate.

[Aaron]

so ur saying an outragous size of injector will run rich, i guess that would make some sense if it was HUGE, cause the computer wouldnt be ablse to close it off fast enough and way to much fuel would get in

 

that's what i've been saying all along, i'm sorry it was so difficult to understand. and the injector doesn't have to be outrageously big for the computer not to be able to compensate.

 

Yes it does, the ECU has amazingly high amounts of control on injector pulses. But, I guess if you welt to like 60 or higher, you could make it to where the ECU couldn't control it, but you'd also be losing high amounts of power, even if the ECU could control it.

[Guest TurboSedan]

But, I guess if you welt to like 60 or higher, you could make it to where the ECU couldn't control it, but you'd also be losing high amounts of power, even if the ECU could control it.

 

so are you saying it could control it or not? the first part of the sentence you say it couldn't and the second half you say it could. also, why would you be losing high amounts of power if the ECM could control it? because it would be running way too rich!

 

i don't believe the ECM has that much control. not even close.

[Prospeeder]

Well didnt Aaron go to like Colledge on this stuff? I think he would know

[Guest TurboSedan]