Did you leave your grill shutters installed? If so I would check to see if they are stuck close. Not sure if mountune requires you to remove them for fitment.

 

No, they are completely removed, fortunately.

 

That looks like what my stock IC temps ran. I have a different IC than you but same weather you do and I am seeing about 2 degrees above what my dash shows for ambient. What was interesting was for about 10 minutes after I did my IC install my charge temps were about 20 degrees below ambient, then they rose up to normal and have been a couple degrees above ambient for the most part ever since.


Page 2 these guys are talking about the same temps with the Mountune

http://www.focusst.org/forum/focus-st-discussions/6861-mountune-intercooler-2.html

 

When you're idling or cruising the IC doesn't have much of an effect on anything and your charge temps should be about the same as IAT. Under boost is when you should see a difference compared to stock. Idle temps will usually be higher than cruising since you're not getting any fresh air into the intake and the temp will be influenced by engine heat under the hood.

Edit: Also, I don't have an access port but I'm assuming there's a way to monitor IAT? If so, you'd want to monitor IAT and charge temp. The difference between them would be a good measure of the job your IC is doing.

 

Yes idle you will see a rise. However seeing he was driving it, the low end should be right about ambient.

 

On the way to work a few hours ago my IAT was around 92F and my CT was around 110 to 113F.

 

Was that stop and go traffic, or hiway? If that was cruising on the hiway, something is wrong, charge temp should be very close to intake temp. If it was stop and go and little air was passing through the intercooler fins to cool things down, then temps should be further apart.

 

That was cruising at about 55MPH, the lowest it got was maybe 106.

 

I'd do some logs of 4th gear pulls starting early in the powerband until redline and see if things cool down a bit.

 

I have the same IC on my '14 and live close to you. I am usually seeing about 2-5 over ambient cruising on city streets, highway cruising is usually more like 8-10 over. When I am stopped for an extended time at a long light, it will rise to 100-110. A 3rd gear pull will bring a 20-25 deg rise over ambient.

 

Since the mountune ic for the 2015 focus st doesn't have the air guides, could that be some of it?

 

And/or is the 2015 bumper cover more restrictive? Are 2015 owners w/ an aftermarket FMIC (other than Mountune) seeing 2-5 degrees above ambient?

 

Keep us up to date with your findings.

This was the IC that I wanted to buy.

 

Not sure what the issue is & I'm certainly not unhappy with the intercooler but from what I've heard about other brands it's not working quite as efficiently. My temps are around 15-20 above IAT when cruising. It also cools off very fast after a hard WOT. It seems others have 5-10 above IAT at most.

It was still worth the extra money to not give Ford any reason to void part of my warranty.