he also said this:
I'm about to double the length of my cold side IC pipe and add 180 bend in it. So I'll see what kind of pressure drop I get.

i've more than doubled the pre-throttle tubing length on my car. didn't notice anything.

however i'm not sure I'd agree with "another country" not having an effect. air IS compressible unlike water. there would be pressure waves, however fast, that would do something in 4000 mile long tubing.

At least going north into Canada to air is nice and cold :)

@y8s, he said "the next county" not "the next country".

but he didn't say which county :gay:

oops. but yeah, what if the next county is across an ocean.

how big is the turbo?

Again, depends on where the throttle plate is.

If it's in the stock location then the tube leading up to it can stretch all the way to Laos for all it matters. But if the throttle plate is in Laos, then there will be problems.

new cold side pipe installed
 

Got the new "longer" cold side pipe installed and no noticeable difference in throttle response. Pics below show the old short pipe that came by the narrow rad, the old short pipe (already cut) and the install.

I ordered the ebay pipes from "just intercoolers" (aka cxracing) and paid the extra $5 for black hoses to go with my black pipes. So the box arrived and everything was black except the elbows, which were blue. I shot them an email and the response was "oh, we don't have black elbows, just black straight hose"... wtf...:vash: Just a warning to those wanting "all black".

http://i158.photobucket.com/albums/t...ldsidepipe.jpg
http://i158.photobucket.com/albums/t...wcoldpipes.jpg
http://i158.photobucket.com/albums/t...installed2.jpg
http://i158.photobucket.com/albums/t...installed1.jpg

According to same Japanese builder at mnet, the more the volume between the throttle body and the turbo, the quicker the turbo spools up when you open the throttle.
He claims that's the reason the WRC teams go with big chambers in front of the throttle body ...

Here is what he was talking about - check the big chamber in the IC pipe just before the throttle body. He is claiming that this chamber (the extra air volume before the throttle body) leads to quicker spool and quicker boost. This is the 2007 Subaru WRC rally car:

http://www.ultimatecarpage.com/images/large/3195-6.jpg

I think I can see the logic in that. Though no room for big cans right before my tb.

maybe someone could go from 2" to 3" back to 2.5" just before the throttle body would that work? i may try seeing as i'm about to start my build :dunno:

Not sure what you mean there. Flow and pressure drop go hand-in-hand. Geometry comes into play too of course like you mentioned.

Conservation of mass.

Oh OK yeah I agree. For steady-state flow conservation of mass does apply. There will be periods of time when conservation of mass does not apply, such as during quick transients, like going from part throttle to WOT, or going from WOT to closed throttle. During those periods there will be brief instances where the volume in the induction system (after the compressor) will be packing and unpacking, including in the intercooler.

You guys have heard of the squire or STS turbo systems? If that works, I doubt throttle response is a concern.

Bull shit they have the patent on remote mounted turbos.

Were you thinking of going into business?

I don't see the logic. Larger volume means more volume that needs to be compressed before the entire system sees whatever boost you're looking to achieve. Right? Why does the WRC Subie have that large pipe? I don't know. If I ever talk to one I hope to remember to ask.

Of course on the other extreme 1" intercooler piping would be a tiny volume and too much of a restriction. Smaller volume means more velocity which makes those bends more of an importance to flow restriction too, right?

So you want a balance of large enough pipes so flow isn't harmed but small enough that it spools the quickness.

In reality you do whatever fits easiest cause you won't notice any difference anyway.