tales from the hood

[BenO]

ha... In many member's rides threads I have seen that they do not have the heat padding stuff on the underside of their hood. Is this safe to do? won't the hood get very heated and be unsafe to touch?

Is removal just pulling the black circles that seem to hold it on and is it reinstallable after removed?

Also, the hood scoop... the plastic thing that pretty much blocks much air travel from the scoop to the engine bay, if that is removed are there any disadvantages? I see more air traveling in to the engine area to cool the under hood temperature.

Teach me the thoughts and hard facts on this concept

[2.5GT]

Most car's don't have any heat covers under the hood.

The tabs are holding the piece to the hood.

The hood scoop plate is basically aesthetic piece. Since our car's not turbo'd. Taking it off will increase more air flow into the engine bay. Only when you're moving. You will get water in the engine bay.
I took mine off and the rain water trap into the little cubby hole down where the knock sensor sits, it somehow manage to mess up the sensor.

I say leave everything be, it won't do you no harm or good by taking it off. I took mine off, and notice no temperature change (I monitor it with my scan gauge). And if any change, it'll be very minuscule.

[Huffer]

I've had the heat padding on and off in both my GTs - no discernable temp difference. It's really for fire protection but anyone that's had an underhood fire knows that some asbestos padding isn't going to do squat.

The hood scoop plate - don't remove it unless you have an intercooler to put in its place otherwise you WILL mess up your knock sensor. If you do remove it, you should fab up something that will drain water away from the knock sensor.

[impreza_GC8]

The knock sensor is under the intercooler on a turbo car anyway so having it open on an NA car makes no difference, either way water will get in there. If you are worried then don't do it. Personally, I've had the vents and scoop uncovered on my 2.5RS for two years now with no problems. I do put the vent covers back in for heavy rain though, but the scoop has been open for a long long time now. The one on my Outback is open as well, in fact, I removed the plastic scoop insert assembly entirely leaving the largest hole in the hood that I could get to aid airflow. I have an intercooler under there though.
I believe that if you have a hood scoop, you should use it. Otherwise you are like every stock Mustang that comes with a lame useless scoop. Subarus are meant to have scoops, wear them with pride.
You can see the larger opening from removing the scoop insert in this photo. I modified a WRX scoop splitter to fit in the gab and funnel air directly onto the TMIC.
https://sl-i.net/FORUM/images/imported/2009/06/subaruoutback003_JLD-1.jpg

[anothernord]

This is old, but; could we get a view of the modified WRX splitter on your hood? I'm trying to do a setup that is similar.

[Reason]

And the problem with the knock sensor is getting wet is if itLs cracked it will throw a code and put the car in limp mode. So if you remove you scoop plate and its raining or you hit a car wash and then your car drives like shit, its time for a new knock sensor and you didn't now it till now.

[anothernord]

And the problem with the knock sensor is getting wet is if itLs cracked it will throw a code and put the car in limp mode. So if you remove you scoop plate and its raining or you hit a car wash and then your car drives like shit, its time for a new knock sensor and you didn't now it till now.

Correct. The only things in the engine that weren't designed to get we are the air filter, alternator, and battery. Driving in the rain is better for us FI guys running TMIC's; the rain gets into the scoop and lowers IAT's like crazy!