Ok right now I have 3" turbo back with hi-flow cat. I have a mail in flash. I have stock intake with cone air intake filter. I'm running 20 to 21psi to redline with a profec spec b boost controller. Walbro 255 fuel pump. Other mods are not important for my question.

So my question is if I get 264/264 HKS cams do I need injectors? I want more power of course, but I can turn the boost down a little if needed. This set up would be tuned by either Dynoflash or TurboTrix.

To be more specific I want to know if injectors are only needed if you crank up the boost? One more try I want 20 to 21 psi with 264 cams and keep using stock injectors with a good custome tune, is this possible? Thanks in advance.

 

Before anyone replys I know I will be much safer with upgraded injectors, but I want to know if I can make it without them. I will not have all the funds needed.

 

I don't think you will need them. I'm not getting injectors when I get cams.

 

Your AFRs will be fine with the stock injectors but you will probably be running at 100% duty cycle beyond 6,500 rpms or so at full throttle/full boost.

 

That's what I'm thinking. I don't think that's good?

 

I think Instigator has 272's, UTEC, and a lot of other mods and he has stock injectors. They are not at 100% but they are close I think. With the 264's you could be at 90% or so. It really depends on the rest of you car, man.

 

When you say 90% what boost are you talking about? 20 to 21psi. Thanks for the help.

 

i m running AEM EMS, 3" TBE, 264/264, AEM intake,UIP, 255 fp, 23PSI .... and STOCK injectors. Mark at TurboTrix said i do not need injectors unless i m upgrading to their Turbo kit. so i think u are fine for now.

 

That is what I needed to know. Do you have idea what your duty cycle is at?

 

around 85-90%.

 

Thats the problem with stock injectors you can only boost 20-21 psi on pump gas.

But if you use Race Gas and turn up the boost to 24psi you will need a larger 660cc Injectors.

My 02. cents

 

From what everyone tells me, since I had same question, was that Inj are only needed with aftermarket Turbo. And you can boost over 20lbs on stock injectors and runs fine on pump gas.... I am told my many that stock injectors with a full setup, similar to me, other than turbo upgrade, injectors are not needed as long as you stay under the 23lbs range which the stock comp can only read to, unless you have a computer of some sort....

 

It doesnt matter what boost you would run , what matters is the injector duty cycle. The average evo needs injectors around 350-360 whp.

Mark
Turbotrix

 

No you don't need upgraded injectors yet.

Your not maxing it out . That's why you got that Walbro in there to off-set the duty cycle.

There has many evo's running low 12's with stock injectors !! Trapping 110+ mph

If you want to run more than 21psi , you'll need race gas in there just to be on the safe side ( Al suggest this ) and upraded headstuds also as a safety.

By no means your not maxing out your injectors in your current state of tune.

 

I am making 363 whp / 377 torque on race gas and 264's with stock injectors. 23 psi of boost on the stock turbo.