id like to install a blow through turbo setup on my 12A using an s4 or s5 turbo and im just doing a little homework. ive read that the fuel lines need to be replaced with bigger ones, does this mean the rubber ones or the hardlines under the car? also why should the oil return line for the turbo be bigger than the feed line? thanks in advance.

 

That's a good question. I am putting a turbo motor into my car now and not thought about it.

And if you need to increase the line size would you need to weld in bigger intake tubes in the gas tank as well?

 

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The rubber fule lines have the same internal diameter as the metal lines that run to your tank, so if you have to replace one I would asusme you have to replace them both.

 

There is no need to replace the stock hardlines with bigger ones (AJC13B made over 500rwhp on the stock ones).

You can never have a big enough oil return line. If the line is to small it will restricts the flow and make oil seep past the seals in your turbo (it will smoke). A -3 or -4 oil feed and a -10 return works nice.

 

yeah, return is low to non-pressure, so it has to be larger than the feed.... otherwise, like frode said, you'll get oil weep past the seals, and it will burn off in your hot exhaust manifold and make it look like your car has a mAdD oIL lEaK y0!1! which isn't very cool....

 

thanks guys, im sure ill come up with some more turbo questions soon. man, i miss driving my car so much, its been sitting in my garage for 7 months so far, my goal is to get it done before i go to college.

 

stock fuel lines will work fine, the oil dump tube should be at least 5/8 or bigger.........cant have a return oil line too big..