In my datalogs Im seeing at WOT pulls im maxing at 90% IDC. Ive read other places that its a good rule of thumb not to go past 80% on a set of injectors. One pull this evening I saw close to 100%!

Im running stock pump, Perrin intake, greddy Ti-C TBE, and stock boost (granted with cold weather and small mods seeing 21psi)...

is it time to upgrade the pump?

 

Its only at 90% at around redline, correct? You are ok, just if you will get more mods, new injectors would be a smart upgrade. I ran my stocker at 110% injector duty cycle for about a year and recently upgraded.

 

Im in the same situation, but I have a whole list of things I would like to do first but was unsure of the saftey of this, I think its right in the low 90s up top maybe high 80s but Im only running 20/21 lbs also, I do see past 100 percent through the range in some cases.

 

well, i was thinking, a 255walbro is $100 and its an insurance sorta thing against the stocker kicking out. plus it should push higher pressure with a higher rate. that considered that would take a load off the injectors since they dont have to open as long to flow the same fuel with an upgraded pump.

 

I wanted to get a walbro 255 but I was worried about the install, and how hard it actually was to do cause I like to do stuff myself especially since funds are tight. In accordance I think I might have over boosted today and stretched my head studs so well see how it goes, My Fiance said she saw white smoke out the back but it was also 36 degrees then so Im thinking it might have just been the cold, her definition was terrible who what it looked like.

Sorry ive gone off topic!!

 

any more input on IDC?

 

I would try replacing your fuel pump. I have similar mods as you and saw +90% injector duty before getting the walbro. I would have needed to run a much more conservative tune without it.

My max injector duty is about 90.xx% now. I think it is a good insurance to have.

 

I have had my car At 93% for 2 years with no problems but I have a 255

 

I would say that anything over %80 isn't safe. The extra 20% is a safety margin to accommodate bad gas, changes in weather, etc...

 

A lot also depends on the type of injector. When a Denso (stock/Greddy) hits above 80% IDC they just go wide open and dump fuel, making tuning difficult. A Siemans type injector (FIC/PTE) can go a little further, up to 90% IDC, but after that they go lean.
What kind are you running?

 

stock injectors and stock pump right now...

ill be going in with the 255 soon.

 

the rule of thumb is to keep it @/under 90%, to give you a 10% safety margin. But the injectors dont go "static" till ~ 110% (in EvoScan) so you actually have a 20% safety margin...

Ive run mine @ 110% IDC, and currently keep it in the low 100's, but does not reach 100% till ~ 7000, (I shift @ 7k) running them like this for ~ 2 years...
Get a pump, and you'll be fine, till u can get some inj...