its hood scoop time

drift a 944 · 07-26-2007, 10:53 AM

got a 924CGT hood scoop shipped to my house for $17.50

anyway, my question is... is there a tech article on installing these? I know its relatively easy, just cut a hole in the hood and bolt it down... but i want to at least find a way to get the placement right so it lines up right where an original CGT scoop would be.

here's how the scoop will look!

if anyone has a scoop on thier car, i want to seeeee!!

thanks guys.

mr. dude · 07-26-2007, 11:09 AM

Do you want it for looks or for functionality? If you want it for functionality I wouldn't mount it where the 924CGT has it located, but if you're just trying to replicate the look then that's cool.

blk924s · 07-26-2007, 11:15 AM

NOOOOO I want one of thoes scoops so bad! Any idea of where to get more for cheap?

MPitt · 07-26-2007, 11:36 AM

Didn't someone say somewhere (sorry for the specifics) that a hood scoop actually messes up the airflow under our hoods?

drift a 944 · 12:55 PM

Quote:

Originally Posted by mr. dude

Do you want it for looks or for functionality? If you want it for functionality I wouldn't mount it where the 924CGT has it located, but if you're just trying to replicate the look then that's cool.

Yea I have thought about that over and over.

I do like the the original passenger side mounted look, but yet i am no purist and would be fine with the driver side mounted look, if it looked just as good.

As far as functionality... Im not sure if mouting it on the drivers side will be close enough to the air filter to really make a difference, unless it really pulls air from behind. I do have the cone, but still I would think not enough.
On the other hand, mouting it on the passenger side could help push heat from the headers down and out right...?

in either case reading the quote below has me just a tad bit worried....

Quote:

Originally Posted by MPitt

Didn't someone say somewhere (sorry for the specifics) that a hood scoop actually messes up the airflow under our hoods?

*worried* hopefully someone will prove that wrong!

Quote:

Originally Posted by blk924s

NOOOOO I want one of thoes scoops so bad! Any idea of where to get more for cheap?

hehe i dont know how i got so lucky with this deal.... i signed up on a bmw forum and posted a pic of my 944, and a guy says here, take this hood scoop for free, just pay for shipping.

couldnt pass that up...

Schumi · 07-26-2007, 01:16 PM

If you want it anywhere near functional it is going to have to be on the right side and further frontwards, over the airbox, and you will have to make a duct from it into the top of the airbox.

drift a 944 · 07-26-2007, 01:50 PM

Quote:

Originally Posted by Schumi

If you want it anywhere near functional it is going to have to be on the right side and further frontwards, over the airbox, and you will have to make a duct from it into the top of the airbox.

makes sense.

do you happen to know if installing the scoop will disrupt air flow under the hood in any way?

blk924s · 07-26-2007, 04:47 PM

If you feed all the scooped air into the airbox it wont change the air flow in the engine bay at all. I don't know this for sure, but I don't think there is any airflow path designed into the engine bay. Most of our cars have some sort of belly-pan that I think helps keep the underside aerodynamics smooth, but air that passes through the radiator and other orafaces is going to be so turbulant anyways that forcing more air with a scoop *probably* wouldn't make a huge difference. Of course any scoop will cause more drag on the car's exterior though.

Eldorado · 07-26-2007, 05:06 PM

the 9x4 series is designed with the belly pan under the car to scoop air up into the engine bay, and let it pass back down and out the back of the car. The design was later improved by the Turbo spoiler underneath the back of the car to deal with this air and make it less turbulant when it hits the air passing *over* the car at the back... A scoop in the hood will surely disrupt this airflow, and possibly create a vacuum under the hood, which is an area void of air, which allows for more heat to accumulate.

If you put it over the air filter, especially if you duct it directly into the filter, then say goodbye to driving in the rain, or washing your car without plugging that hole. It's design is to scoop air - and if water is in that air it will get scooped as well - and we all know the dangers of having water sucked into the intake.

drift a 944 · 07-26-2007, 05:25 PM

right right, i see where you guys are getting at i think.

but what do you suggest though.

if installing the scoop to just openly dump air into the engine bay is going to disrupt important airflow and create vacuum, and making a duct straight to the filter will potentially cause problems with water getting in, then what is the best solution?

......and dont say to not put the scoop on! this sucker is def. going on somehow, with a hole in the hood, maybe duct'd to somewhere else though.

Eldorado · 07-26-2007, 05:45 PM

I believe, although I could be wrong, the hood scoop on the 924 went above the intercooler to keep it chilled.
Personally, I dont see a benefit of really adding it anywhere, so I dont really want to suggest a place to put it.. not to mention that i dont really think it follows any of the car's lines or really looks like it 'belongs'.. but that said, to each their own.... if you're hell bent on it, which you seem to be, I'd just put it in the "stock" 924 position.

drift a 944 · 07-26-2007, 06:03 PM

yep it went over the intercooler.

I want to put it on simply because its something different, its still porsche oem, and at least doesnt look heinous.

In the end, if i dont like it, i'll just replace the hood all together.

I think I may just mount it on the passenger side with just open scoop, run it, and see if i feel any positive or negative differences, perhaps during events as well, and then go from there.

sound decent?

Eldorado · 07-26-2007, 06:41 PM

does to me.. it's your car, dont ask for approval

924RACR · 07-27-2007, 04:45 AM

There's enough flavors of "original" that you can pretty much do whatever you feel like.

The 931 has the NACA duct, sole purpose is to dump cool air in the general area of the turbo.

The CGT had the scoop as noted to feed the IC over the cam cover.

The CGTS had the scoop in the same location as the CGT, but the IC was in the same location as the 951, so it was just for cool air, again.

The CGTR (the racecars) had them all over the place. Some teams even mounted them backwards to try to remove heat from under the hood! But there's a few pics floating around of some GTR's with the scoop low on the driver's side, suitable for feeding in cold air to the intake. I intend to do this when I get around to building up my car. It' looks pretty sharp, more agressive IMO than the CGT location.

For example:

blk924s · 07-27-2007, 12:59 PM

Quote:

Originally Posted by Eldorado

the 9x4 series is designed with the belly pan under the car to scoop air up into the engine bay, and let it pass back down and out the back of the car. The design was later improved by the Turbo spoiler underneath the back of the car to deal with this air and make it less turbulant when it hits the air passing *over* the car at the back... A scoop in the hood will surely disrupt this airflow, and possibly create a vacuum under the hood, which is an area void of air, which allows for more heat to accumulate.

Eldorado- I don't understand how exactly airflow is directed in and out. The early belly pans have louvers that look like they'd let air out from the radiator/ aux belt area, and the later pans have larger rectangular holes that again look like they let air out that is forced in the radiator. It also seems to me that a scoop force feeding air into the engine bay would create a high pressure zone, not a vacuum... Just my thoughts from visual observation.

But yes the rain especially heavy rain would pose a problem to your intake...

drift a 944 · 07-27-2007, 04:58 PM

^ interesting point... i would love to hear more about this if anyone knows.

seems like it would create high pressure to me too, but i dont really know whats best for the motor?

blk924s · 07-27-2007, 05:27 PM

No Belly Pan - Should 944 na have one?

In this thread a couple people say the belly pan helps to extract hot turbulant radiator air from the engine bay, and that without a pan installed the car runs hotter because the air doesn't exit. Definitely something going on with heat and pressure under the hood

I've never had a pan on but im gonna put on an early pan and then a late pan next week and if i notice anything ill post about it.

I also really want to find out about the rain issue from people who have fed their intakes with hood air.

Eldorado · 07-27-2007, 05:50 PM

Gabe - it's simple. if you feed your intake from a hole in your hood, and you drive in the rain, you will suck in water. there's not really much else to hear about it.

drift a 944 · 07-27-2007, 05:54 PM

Interesting. I have the plastic pan on mine, and I drove around for about a week with it off and didnt notice any difference in temp.

I am curious though, if the pan was off, and the hood scoop is on, wouldnt the air entering the scoop be pushing the dead air down and out? What about if the pan and scoop are both on?

the rain thing im not worried about, i wont be driving it much in the rain. and, if i did put the scoop over the intake i would have a roll of duct tape handy in case i was caught in the rain.

blk924s · 07-28-2007, 10:57 AM

Who knows what is going to happen. We can only guess until someone tries it and ties a bunch of strings to different things in you engine bay, puts a huge fan in front of the car, and video tapes it from inside the bay to see what the threads do.

It doesn't take "much" water to hydrolock an engine, but I want to know if anyone has done it with a hood scoop.-- A friend just hydrolocked his engine by really soaking the intake in a large street-lake, and thats the only way ive ever heard it has happened. Ive also heard of people pouring a little water at a time into the air cleaners of an old engine and not damaging it. Guess it depends on your compression ratio, and how high it can go without destroying the weakest link.