I wonder why the subaru intercooler is on top of the engine? has a better flow of air ????? but it has worse cooling !!!!!!! but the evo intercooler is in the bumper and there is no problem with that! so which one is better ??????

 

u have answered ur own question.
if the evo setup is great, and the sti setup is bad, therefore, placing the ic upfront is a better choice!


ps. subaru ic is on top maybe cause of packaging constrains. u need space to place that ic and route all the piping. it might have been more cost effective to just place it on top.

 

Somewhere between Stage I and Stage II, a larger intercooler is recommended?but may not be absolutely necessary until stage II.

The intercooler sits between the turbo charger and the engine. Its job is to cool the compressed/charged air that comes from the turbo. By cooling this charge (remember cold air takes up less space than hot air and is therefore "denser"), it is theoretically possible to fill the cylinders with a denser air/fuel mixture.

What really means is that you may be able to safely run with an extra pound of boost (say 16 psi vs. 15 psi)?and you will loose less power on those hot summer days?a larger intercooler on its own will make little power difference.

The debate over a top mount versus a front mounts intercooler rages on?which is better. It probably all comes down to preference and how far you want to take your ride. You see, while it is true that a front mount has a greater cooling potential, the questions remain "Do I want to have a body shop tear the front end of my car up?" or "Do I want to lose my driving lights?" or "Do I lose any chassis, structural rigidity, or crash worthiness?"

Other questions a front mount intercooler brings to the table stem from the fact that you will be adding approximately 5 feet of tubing that the "turbo charge" will have to pass through before reaching the engine (contrasted with 6-10" for a top mount intercooler).

With that much tubing, are there significant pressure losses that will require you to run the turbo hotter? Many vendors say there is little or minimal pressure loss...Therefore, make your own decision...

Just one thing...if you plan on making BIG POWER (more than 400 hp)...you will need a front mount intercooler

 

yeah a lot of STI owners end up getting a FMIC anyway. there's not a lot of room to go with a bigger top mount intercooler.

 

Heat soaking is the major issue of top mount, hence why you can sell alot of bags of ice to sti owners on race day lol and if they have the means they go front mount.

Advantage of top mount is the space saving as mentioned but I would also expect the shorter piping to maybe contribute to less heat dissipation from the IC, is this an accurate assumption?

 

The STI was designed so that during a rally a small front end impact would not damage the intercooler.

 

TMIC gets you lower power levels, but it doesn't have as much of a lag issue...

It's already been stated that the more tubing there is the more time it's going to take for it to get to the turbo...

Faster spool, less power...

 

That was just the approach that Subaru decided to take with the WRX and STI. Like some people have said, packaging is a bit easier, plus it requires MUCH less piping, since the turbo and intercooler are very close to each other, compared to the more complicated and longer-running piping of a FMIC setup like the Evo's. Another benefit is slightly less lag compared to the exact same engine and turbo but with a FMIC, theoretically speaking, since the air going through the piping travels a shorter distance overall.

The shortcoming is that due to its location, TMICs tend to be relatively small (compared to a FMIC), so its cooling abilities aren't as effective when you are on the hunt for more power, which is why a lot of the higher hp WRXs and STIs make the switch to FMICs. Due to the size and shape of your typical hood scoop, less air reaches the intercooler, and hits it an an angle. FMICs are facing oncoming air head-on and in a very even fashion. Also, even for the Subaru owners who switched to larger TMIC units that still fit, aftermarket units can only get so large. Evo FMICs are a good size and are very effective for cooling in most applications, even when going for more hp.