surfer

just curious as to why people dont hook up a fifth injector in the charge pipes run from a pressure switch, so you use the standard injectors and maps for vacuum and then when it hits boost the fifth injector cuts in , then map the boost tables accordingly.

the way i see it this would be cheaper than using a set of 450's and you would get a perfect idle and vacuum driveability

Im having trouble getting a set of 450's so i think i am going to try this unless there is a good reason why i shouldnt

Sikocivic

How are you going to control that fifth injecter?

You can find 450s all over the place

Ravage70

itll cost u more to control the 5th injector
and 1 injector wont do ----

surfer

sikocivic - the fifth injector will be switched on using a pressure switch, and will run constantly whilst the car is in boost, I live in the UK so 450's are not all over the place :1

Ravage - if one injector wont do ---- then why do people run 5th injector setups, and i dont see how a 2 quid pressure switch and a relay are going to cost more than a set of 450's, I have a big problem in that we have limited supplies of them over here and when you find cars that run 450's in the breakers they dont like to break the engines.


doesnt anyone have anything decent to contribute in here anymore

spork

You want something decent contributed...alright, here you go. Just because people do the "5th injector" mod doesn't mean it actually uses a "fuel injector". You want a cold start injector. You'll burn out a fuel injector in no time flat if you keep it open at above 100% duty cycle for any amount of time at all. Fuel injectors aren't designed to be open all the time, they need to rest and thats where the duty cycle comes in. Anyways, find a cold start injector and do it that way if you want. You wanna do it right tho...go with a methanol injection kit. You lower intake temps and the methanol is fuel as well. It'll cost you around $250-275 for a nice progressive kit and you can run a lot more boost without worrying about octane issues as well. Just my worthless .02

Ravage70

well ur 2 quid switch will have 2 settings, on/off, no injector control
and ur gonna need a big injector anyways

Sikocivic

So when does this "fifth" injecter turn on? 1PSI or 3PSI or when? If it turns on at 3PSI and you run the motor up to 9PSI, won't you have the same amount of fuel all the time no matter how much boost you have?? How are you going to control that??

con

come on its simple, three cold start injectors and three pressure switchs, 1-3psi 3-6psi 6-9 psi progressive cold strart fuel managemnt, WAY easier then ordering some 450's

surfer

we finally got there, its ok saying it wont work but you need to explain why.

sikocivic, the idea was to have the injector come on at approx 1psi and then alter the control fopr the standard four injectors in boost

ravage, i have 2 550's which i was going to use one of, plus injector control wouldnt be needed for the fifth injector other than on or off. on in boost off in vacuum, then remap the bost tables for when the injector is on, the idea is simple which is why i wanted to know why people werent doing it.

thanks for the info guys

highroller you are gay, you need to read what i put before you continue to flame asshat, i explained what i was thinking of doing at the very top, TWICE. All i was asking for were ideas as to why it was not a good idea, which has now been explained to me

Cray91

They make extra injector controllers. Problem is that they are expensive, and not as easy as 450's or another stock sized injector.

If you can't get 450's, you could still get RC's or another brand shipped internationally for about the same price as an extra injector controller and the injectors.