How to choose the right size intercooler piping 

Excellent video. Great job explaining the variables and walking us through the calculations. I'm upgrading turbos on my 300ZX to the Z1 VGX800 turbos rated at 48 lbs/min so I'm going with 2.5" piping. Thank you!

Intercooler piping length isn’t as big of a factor as the exhaust. The further the turbo from the engine the more lag the turbo will have, pressurized air through the intake moves very fast almost instantly. Check out engine masters episode on this.

Great video finally someone out there with some facts/numbers so we can make a better design system on reducing spool time .👍👍👍👍👍

If i have a ls and my power goals is 600hp@ 8 psi would the piping be same for someone running same power goal on a k20 for example 600hp @20 psi since the calcul uses only the power goal? The amount of boost does influence piping size or not?

Very helpful

Just ran into this problem with putting in my k04. It’s supposed to replace the stock turbo but my intercooler piping is too big for so I gotta figure that out

Hello, old video I know but how does intercooler size affect this? the inlet & outlet to the intercooler is pretty big and based off these calculations I should be running 2" pipes, how would that affect it?

I have 2" going from the turbo to the intercooler and 2.5" from the intercooler to the intake manifold , would this hurt power ?

very good content

What about piping size for a centrifugal supercharger???

Quick n easy

What is the best size intercooler and Pipe size? for a 2.4 diesel turbo engine stock 210 Hp the turbo is replaced to to 500 HP at the moment I have to big intercooler and doesn’t spool up quickly but after spool it very powerful , or is there something else I can do without changing the intercooler to a smaller one ? At the moment the intercooler fitted is from a Nissan skyline to big, please can you advise

I think bigger pipes are AOK for a twins crew, I'm going to experiment with 2.5in

Nice video

Congrats. U know how many people make a guess to the closest to 10mm.... boggles my mind. Ive have mechanics look at me funny when i discuss this. And exhuast diameter reductions in step with cooling exhaust gasses. Also, can u discuss the cold side specifics for BOV dynamics? Sick of people thinking this ‘tsuu tsuuu tsuuuuuuu’ sound is good.... It should sound similar to someone opening a half full bottle of coke that shaken up. An ideal venting system makes one TSeeeeeeeuuw sound.

I've put 60mm piping on my VW TDI. The guy who has done alot of projects told me that he used to use smaller piping but he noticed that if your piping is smaller than you intercooler's in/out diameter you'll have more lag and a tad bit less torque on the low end.

Nie chce mi się wierzyć bo przy prędkości rzędu 0.4 M ile trwa napełnienie się 2 metrów rury 2 cale a ile trwa dłużej napełnienie się 2 metrów rury 3 cale? Proszę podać te różnice w czasie. Z góry dziękuję i pozdrawiam👋

thanks dude

The advice in this video is pretty rough is missing some critical details about flow. Using mach number is not the correct way to determine if a fluid is turbulent or laminar. Instead, you want to use the Reynolds number which takes into account the diameter of the tubing and the density of the air, which mach number does not. I went ahead and did some analysis and found that to have laminar flow in an intercooler pipe, you would need a diameter pipe that is unrealistically small (0.05" diameter). This is assuming that the intake charge temp is 70*F and a boost pressure of 20 psi. I chose 20 psi because that is a normal boost pressure you might see post turbo in the piping. The pressure is important because it is proportional to air density, and the Reynolds number depends on density as well. In this scenario, using a 51 lb/min turbo as used in the video and a 2.5" diameter pipe, your air speed would be about 141 ft/s and you'd have a Reynolds number of 4.22*10^5, which is very turbulent and next to impossible to make laminar without an impossible pipe diameter or air speed. Also, this entire analysis is pretty much useless anyway because you wouldn't even want laminar flow in your intercooler piping. The more turbulent the flow, the lower the friction factor, and the less pressure drop you would have. You want to minimize pressure drop.

how is interior holding up? just curious lmao(i mean the black paint job)

I know this is super late but does the inlet size and size of your intercooler matter?

Cold side intercooler or pipe length and diameter make zero difference to turbo lag. Engine masters and Richard Holdener both made videos about this on an engine dyno, it’s only the hot side exhaust feeding the turbine that makes a difference.

TB = 3.5” IC outlet = 3” IC 2 inlets =2.5” 2 turbos outlet = 2” 650hp V8 What’s your solution to this problem for piping?

Hi, is this for both inlet and outlet of intercooler?

Great video, however you had my subscription strictly based on channel name alone!! FACTS!

Well looks like I need 4inch pipes

You’re incorrect

Not correct, doesn't account for boost pressure. You calculate off what the engine consumes naturally aspirated.

Yeah this is all bologna