OK, so the Subaru WRC car has a Front Mounted Intercooler. Cool.

The Mitsubishi Lancer EVO has a FMIC on the WRC car. But it ALSO has one on the street car. Fine, all well and good, they need not change any design.

Now, the WRX (the original, not the new one). Why is there a hood scoop and Top Mounted intercooler?

And why is there a hood scoop on the WRC car?

The Impreza was created solely for the WRC. So, OK, they create it and turbo it...were the early models equipped with a Top Mount? Did I miss that?

Why couldn't they just leave them ALL FMIC and then leave the scoop out? I know it wouldn't look as cool, but I'm thinking in terms of functionality...

A front mounted intercooler is more efficient than a top mounted intercooler since it is placed directly in the air stream. However, a front mounted intercooler is more susceptible to damages from flying debris at high speed.

A top mounted intercooler is less prone to damages from flying debris. However, it is less efficient because at high speed, a portion of the air flowing over the hood doesn't even enter the hood scoop.

The hood scoop on a car with a front mounted intercooler allows underhood heat to escape when the car is not moving and lowers underhood temperature when the car is moving.

My Typhoon has a front mounted intercooler. The engine bay feels like an oven everytime the hood is opened after a boosted run. I'm going to get either a cowl induction hood or a louvered hood to reduce underhood temperatures.

--
Richard
http://www.whitetyphoon.com/impreza/

On the wrc car, the intercooler is front mount, and the hood scoop is used to take in cold air for the intake.

If you look at the NEW WRC car (not the old one for this example) the hood scoop serves the funtion of providing intake air. But the hole in the front of the hood has a small lip on it. That lip pushes air over the hole (and into the scoop) and creates a vaccuum. This vaccuum pulls air through the front mounted intercooler. On the older model the two vents in the side of the hood were used for the same purpose.

Richard, if you want to lower underhood temperatures and increase the efficeincy of the front mount intercooler you need to pull air THROUGH the engine compartment, not push air into it. Take an old body WRX and add a front mount to it. Now drive it around, take some underhood temp. measurements. Works great, but the scoop is still pushing air into the engine compartment. Now turn the scoop around and drive again, measure again. The underhood temperatures are lower and you've increased the effectiveness of the intercooler. With the scoop reversed you're pulling air through with a vaccuum effect. Take a look at CUSCO's JTCC car. Just a thought.

Correct me if I'm wrong, but isn't a cowl induction hood like a WRX hood with the scoop reversed? I know they don't really look the same since on the cowl induction hood the raised area is the full length of the hood instead of a small part like on the WRX. Plus cowl induction hoods have the cool little open/close thingy (yes, that is the technical term), or at least the old chevelles did.

Drakos

Why not have both? It would be a little heavier but damn it would be cool.(haha I think that was a pun)

Cowl induction hoods take in the high pressure air from in front of the windshield.

ok, I guess it makes sense now... :)

Richard,
This is off-topic and I'm not a fan of GMs, but SWEEEET Typhoon! I loved those things!

Sean

Another reason the WRC cars have FMIC's instead of TMIC's is simply because its BIGGER. You can put a pretty big IC in the nose of the car, compared to the relatively small one found in the WRX. You cant put a HUGE intercooler on top of the engine, theres no room.

The standard WRX IC is more than enough for a street car (IMHO), pushing less than 350 hp.

that wasn't my question though.

it was more two seperate questions.

1. Why does the WRC car have a hood scoop?

2. Why did they make the WRX with a TMIC instead of FMIC?

Originally posted by JGard18
2. Why did they make the WRX with a TMIC instead of FMIC?

Here's a couple of possible reasons.

1. Less prone to debris damage.

2. Less turbo lag.

3. Imagine the cost of repairs if you had a FMIC and got into a
fender bender!:eek: A Nec IC and new IC piping isn't cheap.

4. It has become a Subaru signature thing over the years... just
like how all Vettes always have the same rear lights.

5. Cost of production probably cheaper too (goes along with 3)

:alien:

JGard18,

The Subaru WRC car had a top mount intercooler from the beginning through to 1999. In 2000 they updated the whole car, except for the exterior(only minor changes there) and they moved the IC to the front between the headlights. They moved the airbox/filter and positioned it directly under the hood scoop. They have not yet changed the production version, but remember that everything trickles down from Racing, so they may in the future.

Is that what you were looking for?

disco

YES! :) that was exactly what I was looking for!! Thank you! :)

I know they based the road car on the rally car...and I figured there had to be a point where the rally car had a TMIC. Because they wouldn't have made it special for the road version. Thanks man! :)

Originally posted by Irvine Subaru
Richard, if you want to lower underhood temperatures and increase the efficeincy of the front mount intercooler you need to pull air THROUGH the engine compartment, not push air into it. Take an old body WRX and add a front mount to it. Now drive it around, take some underhood temp. measurements. Works great, but the scoop is still pushing air into the engine compartment. Now turn the scoop around and drive again, measure again. The underhood temperatures are lower and you've increased the effectiveness of the intercooler.

True. However, you are still sucking air in even if you reverse the hood scoop. This is how a cowl induction hood works. Both the hood scoop and the cowl induction hood would let underhood heat to escape while you are sitting still, however. This is why a louvered hood is on the top of my list. It allows air to pull through the engine compartment while the vehicle is moving and it also allows heat to escape while the vehicle is sitting still.

Here is an example of a cowl induction hood:
http://www.whitetyphoon.com/cowl_hood.jpg

Here is an example of a louvered hood:
http://www.whitetyphoon.com/louvered_hood.jpg

--
Richard
http://www.whitetyphoon.com/impreza/

I forgot to mention that a FMIC is perpendicular to a smooth stream of air. Thus, more surface area of the FMIC is exposed to the oncoming air, increasing its efficiency. A TMIC, on the contrary, sits more or less parallel to the air stream and takes turbulent air in the hood scoop. This is less efficient. I don't know about the design in the WRX, but would the TMIC get cooked by the engine heat if you are sitting still?

--
Richard
http://www.whitetyphoon.com/impreza/

Originally posted by JGard18
I know they based the road car on the rally car...

Ummm, ya. :rolleyes:
I really doubt they designed the WRC car and said, gee, that would make a good road car. I think it's the other way around.
And the term 'based' is used lightly, they look similar on the outside but under the skin there have been a helluva lot of changes (at the WRC level anyways).

I know it was explained above but I wanted to make note of the fact that the Subaru WRC does not have the FMIC in the same place a Lancer Evo does.

In the bottom large hole is the radiator. In the front grill(between headlights) is the FMIC. I'm pretty sure under the hood scoop is the oil cooler based on some british race car technology magazine I read that had an article on the new(current) Subaru WRC car.

hey Kevin, way to cop an attitude....that was cool.

but the intent of the Impreza was for Rallying. The Legacy existed, and was being rallied, but they wanted something better. so they built the Impreza purposely so it would be good at it. Sorry, I guess I misinterpreted that fact? :confused:

Originally posted by JGard18
Why did they make the WRX with a TMIC instead of FMIC?

Cheaper, easier to work on (more engine space, less parts), less volume to compress by not having long tubing.... meaning less lag. Also, of course more safe from items flying at it. Not to mention our AC would be even LESS cold having a big intercooler in front of the condenser ;)

I really think they designed it well.... an up pipe will help get the under hood temps down to help more.