BLOWNJROCK

I'm stumped on this one...
The opening on the blower is 3 inch and the opening on the throttle body is 2 1/2 inch. Now I bought an intercooler and the opening on the pass side of the intercooler is 2 inch and the opening on the driver side is 2 1/2 to match the throttle body. Now the question is should I redo the pass side to make it 3 inch to go along wih the s/c or should I make the pipe smaller after coming out of the blower down to 2 inch? Now which would be more beneficial? will i lose psi if i stick with the 2" pipe? considering its a blower and that the boost is constant. Thanks for the help!

Overboostvr4

The inlet should always be one size smaller than the outlet on the IC, this helps with pressure drop and throttle response.

Gernby

This question would probably be better answered in "Under the Hood".

BLOWNJROCK

so going from 3 - 2 won't hurt it.

i've posted under the hood no one said anything.

BLOWNJROCK

does this sound right??

toayoztan: you won't lose psi
toayoztan: wouldn't adding an IC increase your volume, thus already decreasing your psi b/c you have more volume to cover for a set amount of pressure? yup, you would
toayoztan: and i would make the pipe 2" before going into the IC
toayoztan: you won't have that drastic of a bottle neck
toayoztan: versus keeping a 3" pipe and jamming it in the end to a 2" inlet
toayoztan: remember...if boost is constant/set and is determined by your pulley (not actuators), you technically would have more psi w/ less volume
toayoztan: so a 2" pipe would be more beneficial in higher psi than a 3" pipe
toayoztan: in terms of "how much psi is created"
toayoztan: in terms of performance, that can be a-whole-nother story
S2KJerome: well what of performance
S2KJerome: brb again
toayoztan: ok
toayoztan: well, it depends
toayoztan: you don't want to have too much psi for such a small amount of volume (in this case, the pipe size)
toayoztan: that would just cause restriction
toayoztan: so you see, it's kind of a trade off
toayoztan: how much psi would you lose in having a 3" pipe versus 2" pipe? I don't know, it could be .5 psi, or up to 2psi (highly doubt it)
toayoztan: that's just where dyno figures or first hand experience from others come in
toayoztan: but it may be better losing .5 psi b/c of a 3" pipe to get rid of a restriction on airflow that a 2" pipe MAY cause
toayoztan: and you have to remember
toayoztan: the other side of the IC is using only 2.5inch piping
toayoztan: if you do indeed use a 3" pipe for the inlet...that would create another bottleneck, technically speaking
toayoztan: 2" to IC to 2.5" may be bottlenecking it (depends)
toayoztan: i mean, it wouldn't be
toayoztan: 3" to IC to 2.5" would be bottlenecking (technically speaking)