I just happened to stumble upon the following web page for injector sizing
http://www.overboost.com/story.asp?id=1358
All of the boosted tib's have a pretty good idea as to when they need upgraded injectors but i've never seen the math done for the N/A guys
So i figgured i'd work everything backwards and see when it'd be time to swap up to my bigger injectors that i've got sitting around waiting and share my results so everyone knows when its time to switch em up.
Here's what i came up with using their formula's:
Stock injector's:
stock duty cycle: roughly 83% (a little high if you ask me but seems ok)
stock injector's will support roughly 160 crank HP @ 90% duty cycle. ( the web site reccomends not going over 90% duty cycle for longjevity and reliablility) Thats roughly 136 WHP assuming roughly 85% of the power gets to the ground. (stock trim gets about 80% to the pavement and i figgured a good grippy clutch and wheels would up that to about 85%)
That means its time for evan and a few others to swap em up. anyone running I/H/E and a few other goodies is right on the edge of needing larger injectors.
larger 290cc injectors:
Max Hp supported at 90% duty cycle: roughly 220 hp at the crank.
that's roughly 185 WHP assuming 85% gets to the wheels

Most of the N/A V6 tibs are looking to upgrade to the 290cc injectors right around 200WHP which works out with the math i laid down above.
if anyone would like to check my math just to be double sure on this one it'd be muchly appreciated. Other than that the guidelines is about 135 whp its time for bigger injectors.
Booya

im good man...car needs to lean out a bit as it is. im probably right around 160 to the crank

Its the ecu that's making you run rich. you need a controler to change that. my point is your running on the edge of 90% injector duty cycle or perhaps beyond. past the 90% duty cycle you may start to run into reliability issues. Just meant as something to think about before ya do too many more mods.

So...

Are you telling me that I will get more power with bigger injectors, and just that alone?

Here's what I have:

CAI
SR BBTB
OBX Headers
EVO Cat-Back
Plugs/Wires/Misc.

Would I notice a difference our would the ECU pulse them shorter to the same fuel load as the smaller ones.

What size's (Stock and Replacement) are we talking about?

You wont notice a power increase. The problem is if you run your injectors too hard (basicly anytime they are open more than 90% of the time) they tend to become unreliable. This could lead to an expensive motor replacement. the stock size is 210cc/min and the upgraded units are the ones available from kspec.com and sharkracing.com they are 290cc/min. I belive they come from the sonata or somehting like that. unfortunatly our ecu will not adjust for the new injectors so they will have the be used with some kind of fuel controler such as a SAFC NEO or a mafterburner. Larger injectors will just allow you to support more HP. they will not produce any.