Legality of cutting front to mount intercooler..

[mic*]

d-shiznit,

If you want short plumbing, go the barrel cooler. I would try to stop thinkin about this top mount.

To put it very bluntly when your car goes forwards the air hits it that way. If you want your cooler on another angle it takes excellent plumbing / air dams etc which in turn takes research, & testing.

If you do wana do all of that, hopefully your research will show you that putting a 90deg bend on the outlet of you IC (or anywhere) should be avoided.

[RONA]

the scoop

[Draven]

The main reason I'm thinking of doing it is to minimise piping length...
To front mount my intercooler would mean long piping.
The intercooler I currently have is 270x300x75... while this might be a bit small, piping would be a 90deg bend connecting intercooler to intake - VERY SHORT length, should make for really good response.

IC size and piping length has a tiny impact on response... front mount it and whack on a well-matched turbo for what you want - this will get you much better results. Where's Norbie to explain the volume of air pumped out by a turbo compared to the total volume of the inlet system? I'm way too hung-over to explain it concisely

[oldcorollas]

dunno about turbo.. but with SC

say you are running 1 bar boost on a 1.6L motor...

that means, even at idle, you are pumping 1.6L per engine revolution..

at idle (say 600rpm.. 10 revs per second) thats 16L per second.

lets say you have 2metres EXTRA of 3" tubing = that 8.8L (ie to move to front mount)
so it will fill in half a second (no air consumption).... or in 1 second with no boost (this is assuming it is vacuum to begin with)

say you are doing 2400rpm... thats 64L/sec, or 0.25seconds before the tubing fills and there is no boost....

of course a turbo will take a little longer, but thats just the time for the compressor to spool.. once it is moving air, the time to fill IC tract

or something like that.. it's buggerall, but you can calculate it...

[mic*]

I beleive there is a bit more to it than just volume. The effective inertia of a greater volume is obviously more than that of less volume. I think thats where a big misconception about shorter pipe = responsive comes from.

The ability of the turbo to effect an impulse or change in inertia on the air flowing is where your response comes from. As shown, the volume flowing is massive so has little impact whatsoever on response, except when that volume is made to edure additional "frictional losses" that would otherwise not be there. Note that increasing flow (boost) increases frictional or static loss in a pipe of constant diameter.

Frictional loss in piping increases exponetially with a reduction in diameter. 1/2Dia = Fric.Loss squared.

Bends and joins attract heavy loss. Similarly to diameter, as the radius of a bend reduces, loss increases exponetially.

Oversized AND undersized intercoolers. IC cores are a matrix of small dia tubes. Forcing too much flow through a small tube creates obvious loss. Splitting the volume more times than is necesary (oversized) does the same thing.

All this assumes you have a correctly matched turbine / compressor combination to suit your engine flow or you wont get response anyway.

So the moral of my story is, if you shove pipes in randomly to fit, then the general rule would be, longer = laggy. If you look at the limiting factors properly you will see designing for your intended purpose/parameters has way more effect on performance than does length of your pipe.

For those who are lazy - less pipe means less chance of fucking up their project with things they dont understand. To those ppl i say dont use an intercooler, and preferably not a turbo either. Or else write a cheque to the ppl who get paid to care.

[Squid]

dunno about turbo.. but with SC

say you are running 1 bar boost on a 1.6L motor...

that means, even at idle, you are pumping 1.6L per engine revolution..

at idle (say 600rpm.. 10 revs per second) thats 16L per second.

lets say you have 2metres EXTRA of 3" tubing = that 8.8L (ie to move to front mount)
so it will fill in half a second (no air consumption).... or in 1 second with no boost (this is assuming it is vacuum to begin with)

say you are doing 2400rpm... thats 64L/sec, or 0.25seconds before the tubing fills and there is no boost....

of course a turbo will take a little longer, but thats just the time for the compressor to spool.. once it is moving air, the time to fill IC tract

or something like that.. it's buggerall, but you can calculate it...

That's a good rough calculation, also based on the fact the pressure of a fluid in a non restrictive container is constant throughout that container, this estimate is time to reach maximum boost, but it grows to this level so the effect of the boost would be seen almost immediately and the full effect would be in 0.25 seconds.

Also any time that you are worried about how fast your turbos is spooling I dare say you are probably doing more like 4800rpm than 2400 so the effect is even less!

[4DaDrift]

Edited post!

[cycleofabuse]

wouldnt heat soak be a problem cosnidering heat rises ?

Great point.
Also, since the IC is on such an angle I'm not sure air much air would be flowing though it, most of the air would go through the radiator. I don't see anything wrong with putting an intercooler infront of a radiator, the IC needs airflow more than the radiator for sure. I removed my AC condensor and put a front mount in and my radiator is getting far more airflow than before, operating at a significantly lower temp.
I don't think you'll notice much more turbo lag mounting it on the front. I went from a top mount to a front mount with MUCH more piping and didn't notice much difference in lag. I actually have way less lag with my front mount that my mate with an st185 with the stock top mount.

My 2c...