460 injectors...

[flareside_thunder]

Wanting to put 460 injectors in my truck to give it a little more OOMPH....the reason being is the factory injectors for a 460 come in ranges from 20-29 lbs....looking for a middle range like 24 or 26......Would this be a direct swap in?No machining or anything?Thanks.

 

[Bob Ayers]

Unless you increase displacement, or go to forced induction, larger injectors will just cause problems.

 

[Black150]

I'm with Mr. Ayers. You won't see any performance gains by putting in larger injectors. You'll only cause drivability issues.

 

[F 150Cobra]

yup they are right.. unfortunately it isnt like diesel.. more fuel more power..


if you use them you need to get to tune them..but it wont give you any power.. bigger injectors are used for forced induction or a highly modified engine to supply more fuel when its needed

 

[flareside_thunder]

Hmm, I figured since I've got a bigger TB that a little more poundage would get the powerband where it needs to be......still hellbent on the adjustable FPR though..thanks fellas.

 

[F 150Cobra]

i vote.. save all the money from all of those small gadgets and do a cam swap

 

[flareside_thunder]

gonna do that anyways...no one has seemingly answered my cam question on here in the smallblock forum though....

 

[conanski]

Hmm, I figured since I've got a bigger TB that a little more poundage would get the powerband where it needs to be..

Nope! It'll just make a giant mess of the powerband you have now. The computer is programmed for 19lb injectors, if you plug in something else it will constantly be correcting itself because the motor will get more fuel than it should. You don't have to force more fuel into an EFI motor, just open it up to breath better and the computer will automatically add more fuel. 19lb injectors can support 300hp so you got a ways to go before you need bigger squirters.

still hellbent on the adjustable FPR though..thanks fellas.

That can be a useful tool in some circumstances, but again it won't do what you think. The computer is constantly adjusting the fuel mixture for what it has been told(programmed) is optimal. Raising the fuel pressure will result in more fuel delivered through the injectors immediately as you adjust it, but the computer will readjust to counteract the increased fuel pressure within a fraction of a second, so the net result is no gain.

P.S. I replied to your post in the engine section too..

 

[flareside_thunder]

thanks for the highbeams on the subject Paul I always look forward to your responses...I replied back in the engine section

 

[auto02]

Raising the fuel pressure will result in more fuel delivered through the injectors immediately as you adjust it, but the computer will readjust to counteract the increased fuel pressure within a fraction of a second, so the net result is no gain.

incorrect!the computer has no control over fuel pressure on his year model truck,only the new returnless setups' pressure is computer controlled.if what you say is true there would'nt be a vaccum line to the regulator to make minor changes in the pressure depending on the vaccum the engine is making at idle,part throttle,and wot.when my truck was running 8.00's in the 1/8 i ran the 19lb injectors!you can go a long way with the 19's.

 

[Bob Ayers]

incorrect!the computer has no control over fuel pressure on his year model truck,only the new returnless setups' pressure is computer controlled.if what you say is true there would'nt be a vaccum line to the regulator to make minor changes in the pressure depending on the vaccum the engine is making at idle,part throttle,and wot.when my truck was running 8.00's in the 1/8 i ran the 19lb injectors!you can go a long way with the 19's.

I think what Paul meant was the PCM will reduce the injector pulse width to keep the A/F the same with the increased fuel pressure.

 

[conanski]

I think what Paul meant was the PCM will reduce the injector pulse width to keep the A/F the same with the increased fuel pressure.

Yes exactly, so even though the computer has no control over fuel pressure it can and does still counteract the effect the change in pressure creates.

 

[Bob Ayers]

Yes exactly, so even though the computer has no control over fuel pressure it can and does still counteract the effect the change in pressure creates.

Of course this will be true for closed loop, and until the fuel tables are changed by "adaptive control" for open loop.