So I know that stock injectors are pretty much maxed out from the factory. I havent been able to get a good amount of information about what is a good upgrade from teh stock 540s. I was thinking about 780s but I keep seeing 640 and so on popping up. Im looking at getting about 80 ~ 85% duty cycle under WOT conditions while running 21 ~ 22 PSI . I'd like to keep the stock turbo as long as possible since I enjoy the quick spool of the stocker.


Thanks!
Terry

 

stock injectors are fine for the stock turbo. You won't need to upgrade injectors until you outgrow the stock turbo.

 

^^ +1+^^

 

reason why I asked is because I'm seeing 90 to 97 % duty cycle at WOT. I havent done anything with the stock fuel map. Im just mainly concerned with over running my injectors.

 

do you have a walbro fuel pump? and what is the AFR at WOT? both of those can make a big difference on your duty cycles.

 

Yup

 

Well even with a walbro pump I was seeing IDC's of about 96+ and once even hit 102 with afr's in the low 11's high 10's at full throttle around 7k+...I went ahead and did the upgrade, it doesn't really cost much and can add a lot of room to grow for future mods/upgrades.

 

I dont have a Walboro, I'm picking one up soon, however when I order one Id like to get the injectors at the same time so I can get my fuel system out of the way for the time being. Inprogress, has about the same idea, I dont want to just get the fuel pump and have to wait to retune for larger injectors.

 

StlEVO: Weird that you should be maxing out the stock injectors on the stock turbo. What is your complete modlist and how much boost are you running? Also, what method are you using to arrive at your IDC numbers.

 

I know you