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intercooler on 89 rx


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Yep,plenty of people on this board have done it.I know for one Caboobaroo has done it to his rx.I can't think of names of others who have used the wrx intercooler,but I know it is a good add on to do.

Another person oh the board that has a very good intercooler setup on his rx is: Drkrazy.Very good add on for a turbo car.

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i think i have the largest fmic on a rx. its a kit for an 04 sti

 

 

aeb3f5b1.jpg

 

DSCF0045.jpg

 

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nevermind that goofy bastid with the capn morgan pose. :lol:

 

and the intercooler goes to the top of the bumper skin, i think its only like 3\4" below the plastic to make room for the bolts and metal beam.

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I had a WRX and later an STi TMIC on my RX. Then I went air-water from a JDM Celica...now I am installing an Air-Water from a JDM/Auz Legacy RS.

So you prefer water to air? Why is that? I always thought they were kinda cool, but I've seen so many front mount intercooler setups on later subarus it's just not funny.

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If you do some searches you'll find tons of pics of installs. Lot's of WRX intercooled EA82T's out there. I run one off an MR2 so mine would be pretty different. Just got to get creative and it won't be a big deal. Make sure you install a recirc valve though, the EA82T's don't seem to like the straight blow off valves much from what I have read and seen.

Doesn't hurt to install an IC Sprayer, IC Fan, and Radiator Sprayer too....whoops my secret is out ;):burnout:

 

Edit: Here's the most recent picture I could find of mine (this is an MR2 IC w/Fan and Sprayer):

newic.jpg

 

Some really old ones on my old site that I haven't updated in like oh a year or more...setup has changed a bit since those old pics on that site.

http://subaru.kacsh.com/rxbuild.html

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sorry to barrow the thread, but what would it take to get the fuel rail setup that you have on that rx?

 

Simply put... about $500 and some time.

 

Fuel rails were custom made by me, from some stock I found on the net (had to buy 24" of it)... Think this was about $40 shipped

 

$100 for a decent rising rate fuel pressure regulator (i got mine used, new it would be $150)

 

Several feet of that damn braided hose, and then all the different fittings... adds up very very very quickly.

 

And, in the end... I'm not 100% it was worth it. Definately had the bling factor though.

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Seriously tho, none of this is necessary if your leaving everything stock. The only reason to install a IC is if your increasing the boost or upgrading to a bigger turbo. But even if you go to a bigger turbo, it should run fine as long as you dont increase boost.

Am I right?

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Seriously tho, none of this is necessary if your leaving everything stock. The only reason to install a IC is if your increasing the boost or upgrading to a bigger turbo. But even if you go to a bigger turbo, it should run fine as long as you dont increase boost.

Am I right?

I'd say no... cooler intake temps are always worth it... that and the addition of a BOV or BPV will increase turbo life and decrease lag time... I say you CAN(hear me out now) get more power by simply adding an intercooler. The engine will be able to run more timing on worse gas giving you a few more ECU provided ponies. There was a noticeable difference in my car... So much so that, without the hood scoop, you could feel the power drop off as the IC got heat soaked.:Flame::dead:

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Seriously tho, none of this is necessary if your leaving everything stock. The only reason to install a IC is if your increasing the boost or upgrading to a bigger turbo. But even if you go to a bigger turbo, it should run fine as long as you dont increase boost.

Am I right?

 

An intercooler can reduce the chance of predetonation (allowing for lower octane fuel), and allow more air mass to enter the engine even with the stock boost. Intercooled engines generally run cooler and last longer, and get better fuel economy. Almost all modern turbocharged engines have them. The only reason not to have an intercooler is to reduce the cost of a vehicle. Intercoolers (even front mount ones) actually do not add any measurable turbo lag either. A larger turbocharger can generally produce the same boost with less heating of the air, so adding a bigger turbo doesn't increase the need for an intercooler.

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I say you CAN(hear me out now) get more power by simply adding an intercooler.

 

I agree. If the intake pressure remains the same, and the air density is increased by the cooler temperatures, then more air molecules (and fuel) enter the engine, and more power is produced at the same boost pressure.

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Soooo, has anyone dyno'd thier rig to have proof of this?;)

Not that I dont believe what your saying, but to have the sheet to see an increase in HP from a simple install as this, maybe I will not sit on my WRX IC any longer (waiting for TD04) and do the install now.

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I haven't seen a dyno result to show how much the power is increased, but I can prove that there will be SOME power increase from basic physical principles. People who have done the modification will also tell you that it is a very noticeable increase. Air behaves approximately as an ideal gas, and follows the formula n=PV/RT where:

 

P=pressure (boost, constant due to the wastegate)

V=volume (engine displacement, constant)

R=the ideal gas constant

T=temperature

n=the quantity of air molecules

 

As you can see, if you change the temperature T by a given factor, the quantity of air molecules changes by the inverse of that factor. For example, if your turbo produces air at 450 kelvin, and your intercooler cools that air to 300 kelvin the air mass will be increased by a factor of 1.5. As your air mass meter will also detect the 50% increase in air, it will increase fuel accordingly and you will get a significant power boost, but probably not quite 50 percent (due to the actual system having additional factors that this idealized model does not include). Those temperature numbers are in the range you would expect for an engine already running a high boost, and using a very efficient large front mount intercooler. A small top mount intercooler with factory boost would result of air mass increases much less than 50%. You can measure the efficiency of your intercooler without a dynometer. All you need is to mount temperature sensors before and after your intercooler.

 

If you are considering making modifications to your turbocharger system, and would like to know which ones to make, and how they affect performance I highly recommend the book "Maximum Boost: Designing, Testing, and Installing Turbocharger Systems" by Corky Bell.

 

Soooo, has anyone dyno'd thier rig to have proof of this?;)

Not that I dont believe what your saying, but to have the sheet to see an increase in HP from a simple install as this, maybe I will not sit on my WRX IC any longer (waiting for TD04) and do the install now.

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Soooo, has anyone dyno'd thier rig to have proof of this?;)

Not that I dont believe what your saying, but to have the sheet to see an increase in HP from a simple install as this, maybe I will not sit on my WRX IC any longer (waiting for TD04) and do the install now.

 

I did dyno it. Not one HP gain. However, a 30TQ gain at the wheels. However, with more boost...the HP/TQ gain is more consistant with the IC rather than without.

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I did dyno it. Not one HP gain. However, a 30TQ gain at the wheels. However, with more boost...the HP/TQ gain is more consistant with the IC rather than without.

 

What intercooler were you using? Is it top or front mounted? A top mounted intercooler would get almost no air flow on a dyno unless it had a fan installed to force air over it, while on the road it would get considerable airflow without such a fan. Is it possible that your intercooler was simply heatsoaked from lack of airflow, and not operating at all on the dyno?

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P=pressure (boost, constant due to the wastegate)

V=volume (engine displacement, constant)

R=the ideal gas constant

T=temperature

n=the quantity of air molecules

 

As you can see, if you change the temperature T by a given factor, the quantity of air molecules changes by the inverse of that factor.

Actually, that is not the case. Once past the turbo, the amount of air molecules that will be there, are already there. Cooling of the air will not draw in a significant amount of molecules. Instead, the pressure drops. This can be observed if you hook up a boost gauge before and after the intercooler.

 

Not to say you don't gain any power, you do. However, that power gain is from a cooler intake charge.

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This can be observed if you hook up a boost gauge before and after the intercooler.

 

I disagree, the pressure drop across the intercooler is a property of the physical configuration of the intercooler, not the amount by which the air is cooled. A sufficiently large intercooler (such as a custom made Spearco intercooler that is larger than the radiator) will have both less pressure drop across it, and greater cooling. Such custom made race intercoolers have negligable pressure drop, and are able to get the intake charge cooled down to very near the ambient temperature. The wastegate on the turbo keeps the pressure before the intercooler at it's preset value, so an intercooler with less pressure drop will flow a greater mass of air. While the mass air flow is not entirely linear as in the PV=nRT equation, it is certainly not fixed as you are implying. If it were fixed, any reduction in charge temperature would need to be accompanied with a pressure reduction by an equal factor, that would be fixed for all intercooler configurations in all vehicles. This is clearly not the case. For example, My Volvo 740 Turbo has a very large intercooler from the factory (18.5x17 inches of frontal cooling area), and no pressure drop can be measured across the intercooler (a factor of under 0.05) without a very high precision boost gauge, while the temperature reduction across the intercooler is over 100 degrees C (a factor of about 0.25).

 

How could a power increase be caused by a reduction in charge temp without an increase in fuel or air mass? A reduction in charge temperature will decrease the chance of predetonation, but more air and fuel are required to create additional power.

 

Edit: It is possible for a particular intercooler to have enough restriction that the reduction in pressure equally cancels the cooling effect, resulting in the same mass of air entering the engine. Again, this would require pressure and temperature changes by an equal factor, which would require an enormous pressure drop, or very little change in temperature. This would have to be an extremely poorly (or cheaply) designed intercooler. I don't know if that is the case with the WRX intercooler or not, but it is certainly not the case with any large front mount intercoolers I am familiar with.

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