I want to buy a ETS intercooler but don't know what size I should get.Do you think I will benefit more from a 4" or 3.5".I have a exhaust,intake,uicp,mbc.With me having such little mods do you think I need a 4" intercooler.What I really want is the bigger size but I just want a little advice from everyone.

 

I'm also curious as most vendors like to push bigger cores and overall size but I care more about efficiency, drivability and turbo response. I was looking at ColtSpeed / ARC and they have stock size 2.5" IC's with supposed higher flow fins and faster spool up so I would like some experts to chime in. I'm under the impression that a higher flowing more efficient stock size IC will improve turbo response and not cause any pressure drops - compared to the huge 3.5" to 4" cores.

 

There are a lot of factors to pressure drop, do a search on it and you will see some interesting things about it. Personally, I like to do mods that can grow with me. I will be buying the buschur ic which is 4.5" core. I have always run larger intercoolers than I needed, and the largest drop I ever saw was 2psi. I have doubts that with the x, I would see a full one psi drop (time will tell). I will also be going big turbo in the future, but it still won't reach the cfm limitations of the buschur ic.

 

Recommend you read this thread for all your questions have been addressed previously:https://www.evolutionm.net/forums/ev...tercooler.html
To the OP regarding size, some of the FMIC that are larger than 3.5" thick have had some fitment issues; not to say that it cannot be installed, just that it is easier when they are <4". Using the hard pipes coupled with FMIC you get your largest whp gain. In general the larger the intercooler the better; how you get large is also important.

Later, Ken

 

You may need consider upgrading the radiator/fan when going with a large intercooler. HKS recommends it for their 4" Type R I/C as the thickness of the core blocks off a good amount of cool air from entering the radiator, I`m surprised that no other vendors address this for their large core intercooler, it would suck if your engine overheats because of high water temp.

ARC is the only intercooler that would aid cooling of the radiator due to their special fin designs, testing have showned around 3 degrees drop in water temperature from stock intercooler. It may not give you the most whp gain right out of the bat, but for sure one of the most efficient intercooler available.