ok i thought picking up some 2.5" piping for my d16y7 with a small t3 was a good idea.... until some guys said that 2" would be better with the smaller turbo and stock motor... is this true? should i have opted for the 2" instead of the bigger 2.5?

 

mine is 2.75"

 

think air flow. bigger pipes will have more flow capacity(volume). smaller pipes will pressurize quicker reducing lag because of less volume. you should *try to have the turbo and pipes matched to how much your head will be able to flow.

anywhere from 2 - 2.5" is good. if you're going big horsepower like weir^^ go like 3" or so

 

Small T3 on a D16, your friend is right. 2" is better. Make sure it's mandrell bent though.

 

i got 2" from turbo to fmic then 2.5" to the throttle body

 

2" is the way to go

look at the area of these pipes
A of a 2" circle is 3.14*1^2 = 3.14
A of a 2.5" circle is 3.14*1.25^2 = 4.90 (thats a lot more area)
A of a 3" circle is 3.14*1.5^2 = 7.06 (thats huge by comparison)

i wouldn't use anything over 2.25" unless i was shooting for 350+ whp.

 

And 2" and 2.25" is cheaper. 2.25 for me.

 

Imo any tubing larger than the outlet of your compressor will hurt charge velocity and increase lag.

 

hmm, i have a t3 60/63 and 2.5" piping all the way around and i hit 10psi at 4000... not real bad i think

 

my personal rule is that i match pipe from the turbo to the cooler to the size of the turbo outlet.

and i match the pipe from the cooler to the TB to the size of the TB