[Cake Eater]

Just literally did this yesterday lol. Dremel, step bit, and touch up paint you will need.
Here's the pics.
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The vents do get pretty warm after a drive just make sure you remove the paper/fiber trims on the top of the fenders to allow air flow to the vents. You can even see the opening of the side vents after you removed the trims.


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What size hole saw, it looks the business, did you clean out the swarf, Im worried about leaving swarf in the inner guards and creating rust spots.

My lip kit arrived today, I may need to buy a hole saw and some tubing to conect to the vacuum cleaner to clean out inside before I start working on it..

So far yours is the best job I've seen at enlarging the flow path.

Again, good work.

 

[usefulidiot21]

You gotta pop off the front part of the side skirts to get the plastic fender vents off. The beginning of this video shows you how it's done: How-To Remove Side Badges on 2015 Subaru WRX/STI - YouTube

Some time with a dremel is needed to remove the plastic that is blocking the vents. Then you'll want to drill some holes in the fender with a stepped drill bit, that's the easiest way. Clean up the edges of the holes and touch them up with some paint. Put everything back together and you're done.

 

[Lumbergh]

Given that they were either covered with a little flap or simply open from 2008-2014, I'm curious why Subaru saw the need to make the vents permanently non functional and cover the airflow path in the engine bay. It's obviously very intentional. You guys have any ideas why?

 

[usefulidiot21]

It likely had to to with airflow under the hood.

Testing would need to be done to see what effects the changes have on radiator and intercooler airflow at speed.

Here's some good reads from a while back:
AutoSpeed - Undertrays, Spoilers & Bonnet Vents, Part 1
AutoSpeed - Undertrays, Spoiler & Bonnet Vents, Part 2
AutoSpeed - Undertrays, Spoiler & Bonnet Vents, Part 3

 

[Lumbergh]

It likely had to to with airflow under the hood.

Testing would need to be done to see what effects the changes have on radiator and intercooler airflow at speed.

Here's some good reads from a while back:
AutoSpeed - Undertrays, Spoilers & Bonnet Vents, Part 1
AutoSpeed - Undertrays, Spoiler & Bonnet Vents, Part 2
AutoSpeed - Undertrays, Spoiler & Bonnet Vents, Part 3

Nice. Thanks for the reading info.

I have been really thinking about opening up the vents. It just seems that if Subaru went through the trouble closing them they must have had a reason. I like the idea of venting heat, but there is almost certainly going to be a negative effect to air flow where we want it. Otherwise, why close them in the first place.

 

[usefulidiot21]

Nice. Thanks for the reading info.

I have been really thinking about opening up the vents. It just seems that if Subaru went through the trouble closing them they must have had a reason. I like the idea of venting heat, but there is almost certainly going to be a negative effect to air flow where we want it. Otherwise, why close them in the first place.

I agree, but they are open and vented on the 2015 nurburgring car.

 

[Cake Eater]

I would say cost as being the reason, much cheaper to fabricate.

 

[xyzyx00]

lets look at the facts. main problems with underhood temps deal with intake temps and intercooler heat soak.

anyone who has an accessport can monitor intake temps and will see that a stock STI actually does pretty well under normal cruising conditions (50mph+) with intake temps not 15dF+\- or so above ambient. crusing 70dF ambient @ 70mph intake temps hardly reach 80dF. the real problem lies when we slow down or come to a stop. those numbers jump very quickly! we have no way to monitor intercooler temps but I have seen graphs showing similar results. I beleive Grimspeed has done reasearch with their TMIC.

this is what ive noticed under normal driving conditions, i dont see a need for it on a stock car. granted if your tracking ect, we are talking about a whole other world. maybe if your rotated and your filter is up in the engine bay, or you have a non cold air aintake ect. also food for thought, i think it was mentioned earlier, if you have a filter that sits down in that wheel well, will this have negative effects during wet driving conditions?

why did subaru decide to block this off? dunno. i just went out and checked my 2017 and ya, its completely sealed off - no give.

 

[Nikko619]

What size hole saw, it looks the business, did you clean out the swarf, Im worried about leaving swarf in the inner guards and creating rust spots.



My lip kit arrived today, I may need to buy a hole saw and some tubing to conect to the vacuum cleaner to clean out inside before I start working on it..



So far yours is the best job I've seen at enlarging the flow path.



Again, good work.

Thanks!

Yes I had rags to catch the shavings when I was drilling the holes, plus blew out the rest with an air compressor.

I used a step-bit so the largest hole it can make is 1 3/8".


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[Lumbergh]

lets look at the facts. main problems with underhood temps deal with intake temps and intercooler heat soak.

anyone who has an accessport can monitor intake temps and will see that a stock STI actually does pretty well under normal cruising conditions (50mph+) with intake temps not 15dF+\- or so above ambient. crusing 70dF ambient @ 70mph intake temps hardly reach 80dF. the real problem lies when we slow down or come to a stop. those numbers jump very quickly! we have no way to monitor intercooler temps but I have seen graphs showing similar results. I beleive Grimspeed has done reasearch with their TMIC.

this is what ive noticed under normal driving conditions, i dont see a need for it on a stock car. granted if your tracking ect, we are talking about a whole other world. maybe if your rotated and your filter is up in the engine bay, or you have a non cold air aintake ect. also food for thought, i think it was mentioned earlier, if you have a filter that sits down in that wheel well, will this have negative effects during wet driving conditions?

why did subaru decide to block this off? dunno. i just went out and checked my 2017 and ya, its completely sealed off - no give.

Interesting. I do not have an Accessport and plan to leave it that way for a bit haha. Too far down the mod rabbit hole on my last car. So we are only able to monitor actual pre-turbo intake temps with the Accessport? I would be much more interested in cold side temps to actually see if there is an observable effect on intercooler function. Between that and water temp, that's what I would be really curious to see with the engine vents.

I would say cost as being the reason, much cheaper to fabricate.

I agree. One solid piece, no little add on rubber flap. Likely much cheaper. We have to factor in that they added the little piece in the engine bay on both sides though. That definitely added cost to the equation.

 

[Cake Eater]

After some driving around in the rain I found that when the side dress/block off stuff are removed, there was a lot of dirty water entering the engine bay, I had a look at the back of the block off thingies and they had some dirt and sand particles on the inside of them.

I'm thinking that somehow the crap from the road is coming in through the inner guards and when the block offs are removed and it comes into the engine bay.

I pretty anal about keeping the car clean, if this happens every time it rains Im going to be spending a lot of time cleaning the engine bay.

Anyone had this issue?

 

[SpeedHoles]

Anyone else tackle this and have any more input?
Or more long term feedback now that it's been a couple of years?


Like Cake Eater mentioned, I'm also slightly concerned with getting more debris into areas I can't reach to get it out, so I may put some backing foam (cut up dirt bike air-filter) behind the mesh vents.

 

[forsey01]

Just literally did this yesterday lol. Dremel, step bit, and touch up paint you will need.
Here's the pics.

The vents do get pretty warm after a drive just make sure you remove the paper/fiber trims on the top of the fenders to allow air flow to the vents. You can even see the opening of the side vents after you removed the trims.


Sent from my iPhone using Tapatalk

Just literally did this yesterday lol. Dremel, step bit, and touch up paint you will need.
Here's the pics.

The vents do get pretty warm after a drive just make sure you remove the paper/fiber trims on the top of the fenders to allow air flow to the vents. You can even see the opening of the side vents after you removed the trims.


Sent from my iPhone using Tapatalk

hey do you think if you had air piped to the wheel well for the breaks and then a pipe to the vets. that they would pull out the incoming hot air from the breaks ?