i had a few questions that i hoped someone here could help me understand regarding upgrading your fuel injectors. i have seen several forms where other members were giving recommendations for upgrades on relatively lightly modded evos to upgrade the fuel pump and put some 1000cc injectors with a tune on their vehicle.

Now i could be wrong but would upgrading your injectors to 1000cc kinda be overkill unless your running like 500 hp? If your evo doesn't require that kind of fuel consumption wouldn't it just be a waste of money? Also i know the fuel pump drops voltage when just idling to slow the rate of fuel going to the engine but wouldn't such large injectors still cause the car to idle rough and way to rich?

Also i have a few of the equations to figure out what size injectors would be right for your set up but requires dyno numbers to figure it out and a awd dyno is something that i have no access to for a couple thousand miles... Does anyone have a recommendation for a logical size of injectors for light modded evos (that's if i am completely wrong and 1000cc would be the way to go)

 

You can use this to help you pick injectors based on goal airflow and/or whp: http://rallyevo.com:8080/injectors.php

But anyways, many people go with "oversized" injectors for 2 reasons:

1. They plan to upgrade to a larger turbo in the future
2. They need 20-30% more fuel for E85

You are correct that very big injectors can introduce drivability problems, but most name-brand injectors behave nicely if latencies are dialed in correctly.

1000cc injectors are common because they are suitable for small turbo + E85 (up to about 46 lb/min), or for a medium sized turbo + gasoline (up to about 60 lb/min)

 

^ +1

If you are planning on upgrading to a bigger turbo(FP Green/Red/3076 later on, I would go 880's and a walbro 255lph fuel pump, then get them scaled correctly with a tune..

If your gonna go E85 or BIG turbo, then 1200+ or so would be good along with a bigger FP setup..
Whoever you decide to tune the car could give you recommendations for your build path..
Key is choosing a good tuner.
good luck..

 

Thanks for the advice guys, but does anyone know on average how rough the idle is with the 1000cc injectors with a tune? Also will it cause my evo to run really rich while just idling? That's my main concern with upgrading the injectors

 

I have 880's so i cant speak from experience on 1000's..

But I would think if they are scaled correctly when you get it tuned, they should drive/idle just like any other Inj's...
Scaling them right is the key..