Intercooler Piping

nmcbchief

nmcbchief

Registered User
While I have searched and searched this subject I would like to know the best size intercooler piping to use. Some use 2 2/2 while others use 2 3/4 up to 3 inches. I have even seen some that were 2 7/8 to the intercooler and 2 1/2 out of it to the return plenum. Getting ready to buy an intercooler and piping and just need some input. Running a 1.7L AR.
 
I understand that 2.75 in and out is optimal for the majority of blowers available...3" is a little big for pipe routing purposes...I've heard people having no problems with 2.5", but Dave Dalke recommended 2.75" in/out for me with an MPx blower
 
I just want it to be enough without going too big or too small. I would like to purchase the materials within the next couple of weeks so any other input would be greatly appreciated.
 
the best size is the one that is the right size.... helpful huh?

look at the components you have to work with and optimize the size for them. For some, the intercooler inlet and out let will dictate a size. For most of us the intake manifold and inlet plenum for the manifold are the main restriction. In general the most CFM's the best intake/head combo on our car will flow (at ambient pressure) is ~400CFM. http://www.sccoa.com/forums/showthread.php?t=104246&highlight=2.75

2.75" is fine. 2.5" may even be fine. intake charge velocity will go up (as well as increased friction/heat, and head pressure at the blower) as tube size goes down. charge velocity goes down, heat goes down, and head pressure goes down as tube size is increased. There is a balance somewhere between too big and too small. I don't know that anyone has done any testing to find the optimum combination (partially because everyones combination is different).

Fitting 3" is tough so if you don't need it due to any other reason, smaller makes life easier. 2.75 seems to fit up well with most intercooler cores. Check yours to make sure.
 
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The intercooler I am going to use (I think) is somewhat like Ryan Zimmerly's. Entry and exit on the same side with the pipes going through where the factory cooler would sit.
 
2.75 is what I used. Mine works well as it was custom built from a quality core and I also run alky injection
 
They may not be ideal, but I've have dyno runs from +90 deg. outside temps and with the Snow my intake temps were 68-70deg.
 
rzimmerl said:
They may not be ideal, but I've have dyno runs from +90 deg. outside temps and with the Snow my intake temps were 68-70deg.
Click to expand...

68-70 is good enough for me. The MP is really not an actual FMIC in my opinion. More like a mid-mount. Besides, I don't have the big bucks to purchase one. I have the skills to piece one together and if it doesn't turn out then I will look to doing something else. I may not be ready for the shootout this year but come next year I will be there with my car.
 
i ran 3" pipng and it seems to have worked out so far for me although i get a popping in the intake side right before it enters the stock intake piping that runs under the ps pump
 
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