At what point is the stock intercooler maxed out / heatsoaks? I have a stock 05 turbo, injen piping, 3" tbe, 1000cc injectors and hks 272s tuned at about 25 psi. We are seeing 3-6 counts of knock at higher rpms in 4th gear only. Tuner has tried playing with timing and afr but knock always shows up towards the end of 4th. I'm assuming this to be a heatsoak issue since it's fine in 1, 2 and 3rd gears. I don't mind spending the money on a new intercooler if needed, I just want to be sure I'm at that point where it needs to be upgraded or if something else is the problem.

 

your already heatsoaking the fmic. running 25psi on a stock turbo your are over speeding the air compounded with the psi and with the stock tiny cooling tube passages on stock fmic....

just throw some sensors in the in & out side of the core and you will really see whats going on.

good luck

 

I was always curious to get an educated and tested answer on this question. I have read on previous posts that the stock FMIC is good for up to 350 whp, though again the idea is airflow.

If you are road tuning then it is getting adequate and realistic airflow whereas if you are on a dyno the fans dont really push realistic air to the intercooler thus necessitating a larger intercooler. Correct if I'm wrong, I'm always ope to better interpretations of this topic.

 

well if you really want to get down to it :

Throw temp and pressure sensors both just before and after the in/outlets. record a pull from 3rd, 4th, and 5th and you will really get the answer your looking for. This way you will get the overall picture/efficiency of the cores.

as for rule of thumb... that probably works for most applications without any data or facts. it's like using the butt dyno... feels faster therefore must be faster.

 

Id say 35 to 400hp max you should be running stock IC.

When I had my evo, i was making 350hp/380tq on stock IC, stock exhaust and 23psi I believe.

Now i gave the 350-400hp range only because I have a few mates and have seen videos of people making 400hp on stock IC and wonder why wihile tuning, why their horsepower only goes up 3hp per psi after that point.
For the most part, you should see around 10hp gains per PSI increase.

BTW how much are you making with your current setup?

 

As soon as it comes from factory

 

If you're experiencing knock in the upper RPM range and it isn't tune related, it's most likely due to stock unit being heat soaked.

Our 3.5" unit is perfect for cars in the 400-650whp range if you're looking for an affordable upgrade:

http://www.vr-speed.com/vrsf-evo-8-9...evolution.html

 

I have VRSF intercooler on my car and love it.