Hey Guys in planning for my turbo setup in which I would like to my my A/C I think the best routing for the IC pipes would be to have it come from the turbo around to the passenger side bottom and then go through the intercooler and have it come out the top of the passenger side of the I/C and then up to the TB. Is there a problem with running it this way or performance loss running it like this? The one thing that confuses me is the IC divided in the middle or is it just 1 core with a closed off endtank on one end? Does having it like this not cool the air as much since its just going in the inlet and the outlet is right above/below?

Thanks for any input

 

Ive heard they arent as good but Im not sure why. Would like to know also.

 

Tony1 was mentioning something about this, he has alot of insight if i remember.

tony, chime in!

 

Check my post in the peak boost ultimate thread...

 

there he is.... yea that thread you guys is where i saw tony talking about it. its a huge messy thread about the peak boost turbo kit and trying to compare this to that, and that to this.... yada yada

tony, is it march yet, time for a little vacation?

PS dont forget to make that manifold i told you about on myspace

 

The majority of heat exchange takes place in the first couple inches of the IC core, after that the rest of the IC really just acts as a heatsink.

Best bet is to have as tall and thick a core as possible... a dual pass setup is merely "long" and doesn't do as great a job.

 

I don't understand that logic.

If your intercooler is long and skinny, most of the cooling would just take place over a longer distance rather than "the first couple inches". That part has to be relative.

Second tall intercoolers don't get any airflow when they are covered up by the bumper. They can't possibly be more effective than an equal amount of surface area on a long, skinny intercooler that's completely exposed to moving air.

And same with thick intercoolers. Would wide, tall and skinner be more effective? - ie more surface area.

Surface area exposed to moving fresh air seems most desirable to me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">I don't understand that logic.

If your intercooler is long and skinny, most of the cooling would just take place over a longer distance rather than "the first couple inches". That part has to be relative.
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Take 2 different intercoolers with exactly the same internal and external surface area. First intercooler has many channels because its tall or it is a top to bottom design intercooler. The second intercooler has less channels but is much longer.

Theoretically they should both perform the same right? Wrong.

Reason:
One of the major driving forces between heat transfer is the amount of temperature differentiation. The greater the difference the more efficiently the hot air will be absorbed into the intercooler. This plays such an important role that 95% of the heat transfer happens in the first few inches of the intercooler and the rest of the intercooler merely acts as a large heat sink desperately trying to release the heat into the outside air which is a horrible at absorbing heat.

What happens when you use a dual pass intercooler or short long intercooler is that you are increasing the amount of pressure lost and not taking advantage of the fact you can have much shorter channels and still get the job done better by exposing really hot air to as much surface area as possible immediately when entering the intercooler.

This larger pressure drop makes your turbo work harder and thus increases charge air temperature and pumping losses.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">
Second tall intercoolers don't get any airflow when they are covered up by the bumper. They can't possibly be more effective than an equal amount of surface area on a long, skinny intercooler that's completely exposed to moving air.
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Their are 2 things happening in an intercooler you need to be aware of:

1) the hot charge air transfers heat internally into the aluminum intercooler.

2) the intercooler desperately tries to release this stored heat into the atmosphere.

The thing you must understand is that the first step is so much more important to be done properly than the 2nd step because the important driving force for heat transfer is temperature differention. The outside surface area is really poor at transferring the warm(not hot) intercooler heat into the atmosphere because air is an insulator. So essentially you must view an intercooler as a large heat sink which slowly tries to dissipate the heat over a large surface area.

Sure it is important to not have too thick of an intercooler (most of the exterior heat release happens in the first 1/2 inch of the thickness of the core). Sure it is important to expose the whole core to fresh incoming air. Yet, it pales in importance to the benefits of exposing the internal charge air to as much surface area as possible as soon as possible.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">
And same with thick intercoolers. Would wide, tall and skinner be more effective? - ie more surface area.
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This depends on how thick because with a really thick core you get the benefit of more immediate surface area but the trade off is that the heat being released from the intercooler to the atmosphere is done inefficiently for the amount of exterior surface area and you have to consider other issues such as the amount of air passing through the intercooler to cool your radiator.

So the thickness should be balanced properly. I would not recommend a 4" core for a street car.

 

Looks like dasher got the long explaination, so I'll just attend to some fiddling small ****.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Second tall intercoolers don't get any airflow when they are covered up by the bumper. </TD></TR></TABLE>

Which is okay, because short intercoolers don't get any airflow, either, even when completely exposed by the bumper.

For your average 2.5" thick core, with vehicle travelling at 100 mph and good IC exposure, airspeed coming through the backside of the IC will be in the 15-18 mph range depending on core type. Most of the air deflects over and around the IC... a taller IC would grab onto some of it. And the extra core height gives both more surface area @ max temperature differential as well as more core mass to grab onto heat and stave off heatsoak.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stealth1 &raquo;</TD></TR><TR><TD CLASS="quote">Hey Guys in planning for my turbo setup in which I would like to my my A/C I think the best routing for the IC pipes would be to have it come from the turbo around to the passenger side bottom and then go through the intercooler and have it come out the top of the passenger side of the I/C and then up to the TB. Is there a problem with running it this way or performance loss running it like this? The one thing that confuses me is the IC divided in the middle or is it just 1 core with a closed off endtank on one end? Does having it like this not cool the air as much since its just going in the inlet and the outlet is right above/below?

Thanks for any input</TD></TR></TABLE>

If you need to have the inlet and outlet charge pipes on the same side than just go with "top to bottom" intercooler instead of a dual pass one. The charge air will travel vertically rather than horizontally.

Another problem with dual pass inter-coolers is the fact the air has to make a sharp transition half way through the core which increases pressure losses.

 

Ideally, the only significant pressure losses the charge should undergo is friction from rubbing against the inside of a well designed IC... which is why a good tube/fin with a pressure drop does better than any bar/plate with hardly any pressure drop.

Aside from that...

 

Ok I read that 3 times to take it all in. It clears up alot but one thing I still dont get is why the heat transfer has to happen in the first few inches of the intercooler? It seems to me it would happen as soon as it could --- until that area heated up and the heat differential isnt there anymore, while that area was cooling down exchanging heat to the atmosphere, the hot charge air would transfer its heat further downstream in the intercooler that wasnt heat soaked yet.

 

hmmm sounds like the dual-pass idea isnt ideal so I guess I will just have to route the piping back across the engine bay and do a "normal" style intercooler setup. Thanks for all the info.

 

so is my intercooler big enough? some people say its to big

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">so is my intercooler big enough? some people say its to big

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how does your bumper fit on there ?

 

it fits..... hahahaha it took alittle bit of cutting to get it to fit but its on there

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Ok I read that 3 times to take it all in. It clears up alot but one thing I still dont get is why the heat transfer has to happen in the first few inches of the intercooler? It seems to me it would happen as soon as it could --- until that area heated up and the heat differential isnt there anymore, while that area was cooling down exchanging heat to the atmosphere, the hot charge air would transfer its heat further downstream in the intercooler that wasnt heat soaked yet.</TD></TR></TABLE>

Heat transfers well inside the aluminum intercooler because aluminum has a high thermoconductivity. The heat absorbed in the first few inches of the intercooler quickly dissipates throughout the whole aluminum intercooler.

Sure the hot side of the Intercooler will be warmer than the coldside of the intercooler after a hard run, but what we are concerned with is temperature differentiation.

The air entering the intercooler at 280 F is exposed to Aluminum which is maybe 100 F, while the air on the cold side of the intercooler has already cooled to 130 F and the Aluminum is 85 F. The temp differentiation on the hotside is 180 F and on the cold side its 45 F which is a huge difference.

The air will continue to cool as it travels down the channels but extremely inefficiently. You can effectively have the air travel only 6 inches in a 28" tall intercooler work better than the air traveling 28" in a 6" tall intercooler.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">You can effectively have the air travel only 6 inches in a 28" tall intercooler work better than the air traveling 28" in a 6" tall intercooler.</TD></TR></TABLE>

Thats just hard for me to wrap my head around. Thanks for explaining this to me buddy!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">
You can effectively have the air travel only 6 inches in a 28" tall intercooler work better than the air traveling 28" in a 6" tall intercooler.</TD></TR></TABLE>

.. provided the distribution of air is balanced. Thats why top to bottom intercoolers which have many channels but the air only travels a very short distance(6") have endtanks which gradually decrease in width to provide better distribution.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">so is my intercooler big enough? some people say its to big

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It's fine

 

It would work better if the end-tanks were tapered or the pipes entered in the middle to disperse the air more evenly.

 

seems to be working fine the way it is now......... I have low IAT's, so I think its doing its job... I might change it up later down the road but with a core this big its hard to get endtanks that will fit on there with a bumper

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">seems to be working fine the way it is now......... I have low IAT's, so I think its doing its job... I might change it up later down the road but with a core this big its hard to get endtanks that will fit on there with a bumper </TD></TR></TABLE>

im sure you can always make it a bit smaller with some welding/fab.

 

Curious, what are your IATs?

On a friend's car with an IC a little smaller than yours, on his old T3/T04E @ 20 psi, ~70-80 degree ambient temps, we were logging low to mid-90's at WOT. Pretty pimpy. The end tanks on his IC are also not "ideal," but it is what it is.

 

The ic I built for Allen's SFWD car, garrett core, 24x12x3.5 with custom end tanks, picked up 8deg. C through a full pass. From before the burnout to the end of the track at 35psi! We-todd is down or i'd put the pics up.