I S4 I - Hilton

Recently i have noticed quite high intake temps with vag-com, even with normal driving... and extreme intake temps during spirited driving...

50 deg C normal intake temp
70-80 deg C spirited intake temp

Ok.... now all repeat after me "HEAT SOAK"

Now i have a thermo couple multimeter i used while doing this testing. I monitored different parts of the engine bay and intake tract surfaces... verrrrrrrrry interesting!!!!

I wont bore you with all the figures... suffice to say a lot of heat buildup is post intercooler.... intake manifold gets very hot!! (75-85deg)
The entire intake tract (including the airbox) gets quite hot too.. (from 50 to 70 in various places)

So i figured i can make the factory intercoolers much more efficient just by eliminating pre/post intercooler heat buildup..

How? With high temp ceramic coatings on the intake manifold (inside and out) plus a ceramic intake manifold gasket. Will probably get the intake flowed and ported while its off, before it gets coated.

External ceramic coatings on the rest of the intake tract including airbox, to keep the nasty power robbing heat out!!!

Im also toying with the idea of internally ceramic coated dump pipes to help get the heat away from the turbos and keep the hot gases flowing.

To further improve things ive thought about water sprayer for intercoolers or maybe 2nd hand water/air intercooler replacements.

Why go to all this trouble??
This should get me on or below ambient temp even while still running a good dose of boost!
I can run slightly more boost and more timing, while also gaining more power from the lower intake temp.

Ive read somewhere that you lose 1 HP for every couple of degrees on your intake. In a chipped S4, thats a significant power loss from heat soak!!

So over to you guys for comments!!
H.

VonK :: Retired

--->they take that much longer to cool down. :-(

I wish somebody would come up with an aftermarket hood that sports three elegant NASA inlets scoops (like the center one on the engine belly shroud) just aft of the front edge. That would combat the extreme under-hood temperatures of the S4.