| lettucemanatee | 04-01-2005 10:36 AM |
efficiency of STi hood scoop?
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i recall reading somewhere in the past that the factory hood scoop on an 02 wrx loses efficiency at ~ 90 (i think) miles per hour. what i mean by that is that is when air just starts to flow over the scoop instead of into it.
does anyone know when the STi hood scoop loses efficiency in this manner?
does anyone know when the STi hood scoop loses efficiency in this manner?
| BriSalig | 04-01-2005 12:14 PM |
pretty sure that air never needs to flow into it....
| pityr | 04-01-2005 12:16 PM |
[QUOTE=BriSalig]pretty sure that air never needs to flow into it....[/QUOTE]
and why do you think that?
and why do you think that?
| VSGTS14 | 04-01-2005 12:17 PM |
i would hope it doesn't lose efficiency considering it's size, but obviously it does not get as much air as a fmic and it's also close to the engine
| BadTrip | 04-01-2005 12:25 PM |
[QUOTE=BriSalig]pretty sure that air never needs to flow into it....[/QUOTE]
And so.......on the STi, the intercooler is larger......AND the hood scoop is larger.........but.........no air needs to flow over the intercooler at all.
...............I see.
It's an air-to-air intercooler....but it needs no air flow.
..............I see.
The front-mount units are used when the situation demands more air flow on the intercooler.....but.....it doesn't need air flow at all.
..............I see.
*wonders when Davenow or Uncle Scotty will see this post.* :devil:
And so.......on the STi, the intercooler is larger......AND the hood scoop is larger.........but.........no air needs to flow over the intercooler at all.
...............I see.
It's an air-to-air intercooler....but it needs no air flow.
..............I see.
The front-mount units are used when the situation demands more air flow on the intercooler.....but.....it doesn't need air flow at all.
..............I see.
*wonders when Davenow or Uncle Scotty will see this post.* :devil:
| conker69 | 04-01-2005 12:42 PM |
[QUOTE=BriSalig]pretty sure that air never needs to flow into it....[/QUOTE]
:lol:
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.
:lol:
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.
| lettucemanatee | 04-01-2005 12:46 PM |
[QUOTE=conker69]:lol:
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.[/QUOTE]
in a world where everyone else is a "guru," he is still a "newbie." that should speak volumes.
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.[/QUOTE]
in a world where everyone else is a "guru," he is still a "newbie." that should speak volumes.
| kpmatt00 | 04-01-2005 12:55 PM |
[QUOTE=lettucemanatee]in a world where everyone else is a "guru," he is still a "newbie." that should speak volumes.[/QUOTE]
I think that has some validity, however I'm sure there are newbies on here with some knowledge......but that is pretty funny never-the-less, he'll learn when to read and see what other people with a little more experience has to say after getting being flamed uncontrolably.
On a side not, I put the USDM sti hood scoop on my wrx for increase air flow over the tmic. It works!!
I think that has some validity, however I'm sure there are newbies on here with some knowledge......but that is pretty funny never-the-less, he'll learn when to read and see what other people with a little more experience has to say after getting being flamed uncontrolably.
On a side not, I put the USDM sti hood scoop on my wrx for increase air flow over the tmic. It works!!
| BadTrip | 04-01-2005 12:55 PM |
Manatee....I was just looking in Unabomber's manifesto to see if he'd gathered any info with respect to your question and didn't see any real numbers or figures......other than the logical idea of more flow would be better than less flow....and cooler is better.
I tend to think that by the time you're up around 90mph you've probably got a fairly substantial amount of positive pressure forcing air down past the engine....but I'm not an engineer or an expert.
I guess if it's a real concern either go FMIC or install a IC sprayer/N-tercooler system.
I tend to think that by the time you're up around 90mph you've probably got a fairly substantial amount of positive pressure forcing air down past the engine....but I'm not an engineer or an expert.
I guess if it's a real concern either go FMIC or install a IC sprayer/N-tercooler system.
| kpmatt00 | 04-01-2005 12:59 PM |
Damn, when did I become a Guru, though I was still a newbie, huh...
Check with KTR, i think they may have some info regarding diff larger hood scoops make, some real life examples with the dyno.
-Matt
Check with KTR, i think they may have some info regarding diff larger hood scoops make, some real life examples with the dyno.
-Matt
| BadTrip | 04-01-2005 01:00 PM |
[QUOTE=kpmatt00]I think that has some validity, however I'm sure there are newbies on here with some knowledge......but that is pretty funny never-the-less, he'll learn when to read and see what other people with a little more experience has to say after getting being flamed uncontrolably.
On a side not, I put the USDM sti hood scoop on my wrx for increase air flow over the tmic. It works!![/QUOTE]
I've also installed the STi version on my WRX with STi IC. I like to think it helps...but I don't havething to really substantiate the claim. Kinda hard to do a comparison on the dyno, as it doesn't really give you realistic flow. Maybe we can find someone to rent us a wind tunnel or something. :)
By the way....I didn't really intend that response as a flame. Just kind of a gentle warming sensation. If you don't KNOW....then don't pretend you do.
On a side not, I put the USDM sti hood scoop on my wrx for increase air flow over the tmic. It works!![/QUOTE]
I've also installed the STi version on my WRX with STi IC. I like to think it helps...but I don't havething to really substantiate the claim. Kinda hard to do a comparison on the dyno, as it doesn't really give you realistic flow. Maybe we can find someone to rent us a wind tunnel or something. :)
By the way....I didn't really intend that response as a flame. Just kind of a gentle warming sensation. If you don't KNOW....then don't pretend you do.
| kpmatt00 | 04-01-2005 01:06 PM |
[QUOTE=BadTrip]By the way....I didn't really intend that response as a flame. Just kind of a gentle warming sensation. If you don't KNOW....then don't pretend you do.[/QUOTE]
Tru...
Tru...
| Siper2 | 04-01-2005 01:26 PM |
[QUOTE=conker69]:lol:
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.[/QUOTE]
Watch it, punk, my RS came with a non-functional hood scoop.
:D :D
Please explain this. I am very curious how you came about such superior knowledge. I think you are confusing real hood scoops with just for looks scoops. In other words ricers.[/QUOTE]
Watch it, punk, my RS came with a non-functional hood scoop.
:D :D
| mcowger | 04-01-2005 01:34 PM |
GACK! You're a RICER!
| Drayton | 04-01-2005 01:58 PM |
When I bought my STi scoop a did some rough math as to how much the STi would flow vs. the stock one. I can't remember the result, but I do remember saying to myself that the money spent was justified. In my figures, I assumed 55mph.
| Siper2 | 04-01-2005 02:02 PM |
[QUOTE=mcowger]GACK! You're a RICER![/QUOTE]
Technically not, since I took the backing plate off....
...but since that's blowing on an airbox, then again.... :D
Technically not, since I took the backing plate off....
...but since that's blowing on an airbox, then again.... :D
| kpmatt00 | 04-01-2005 02:07 PM |
What if you put some sort of splitter or small antennas on the front of the hood or top of the bumper, get more turbulent flow over the hood?? I wud think more air wud get into the scoop as a result...even those splitter the evo mr has on the roof, that might work really well too....just a thought
| CalcVictim | 04-01-2005 02:20 PM |
[QUOTE=Drayton]When I bought my STi scoop a did some rough math as to how much the STi would flow vs. the stock one. I can't remember the result, but I do remember saying to myself that the money spent was justified. In my figures, I assumed 55mph.[/QUOTE]
I understand you calculated the airflow, into the scoop but have you done any calculations in regard to the actual temperature of the surface of the intercooler?
I understand you calculated the airflow, into the scoop but have you done any calculations in regard to the actual temperature of the surface of the intercooler?
| Drayton | 04-01-2005 04:57 PM |
[QUOTE=CalcVictim]I understand you calculated the airflow, into the scoop but have you done any calculations in regard to the actual temperature of the surface of the intercooler?[/QUOTE]
Not at all. I was just interested to see just how much more air could flow into this bigger opening at a certain speed.
My .02 concerning actual temp is this: After a short drive of considerably less than 90mph, my IC feels cooler than I remember it feeling after the same short trip when I had the normal USDM one on.
Not at all. I was just interested to see just how much more air could flow into this bigger opening at a certain speed.
My .02 concerning actual temp is this: After a short drive of considerably less than 90mph, my IC feels cooler than I remember it feeling after the same short trip when I had the normal USDM one on.
| scoobdude | 04-01-2005 07:53 PM |
subscribe
| CalcVictim | 04-01-2005 09:17 PM |
[QUOTE=Drayton]Not at all. I was just interested to see just how much more air could flow into this bigger opening at a certain speed.
My .02 concerning actual temp is this: After a short drive of considerably less than 90mph, my IC feels cooler than I remember it feeling after the same short trip when I had the normal USDM one on.[/QUOTE]
I guess it would be interesting to find out if the bigger scoop actually has a performance gain. Even if the intercooler is lower temperature on the exterior how much effect it has. The reason I say this is because I think a bigger scoop is ugly as **** and only would be worth puting on if there an actual performance benefit.
My .02 concerning actual temp is this: After a short drive of considerably less than 90mph, my IC feels cooler than I remember it feeling after the same short trip when I had the normal USDM one on.[/QUOTE]
I guess it would be interesting to find out if the bigger scoop actually has a performance gain. Even if the intercooler is lower temperature on the exterior how much effect it has. The reason I say this is because I think a bigger scoop is ugly as **** and only would be worth puting on if there an actual performance benefit.
| Drayton | 04-01-2005 10:41 PM |
Asking the question "[does] the bigger scoop actually has a performance gain?" is like asking "is the STi wing functional?" Response is mixed on the latter question, but I will stand behind the sentiment that if it did not have [I]some[/I] beneficial effect, then STi would not use it. I recognize that we could be seeing brand identification and differentiation, but my mind says �bigger hole, more air, cooler IC�.
We could even go so far as to ask if the increased drag is worth the increase in IC cooling efficiency. (And likewise regarding the wing, is the increase in down force justified by the increase in weight?)
We could even go so far as to ask if the increased drag is worth the increase in IC cooling efficiency. (And likewise regarding the wing, is the increase in down force justified by the increase in weight?)
| gjhsu | 04-01-2005 11:24 PM |
If you're worried about efficiency at high speed, get yourself a splitter and call it a day.
| flicky30 | 04-02-2005 10:41 AM |
[QUOTE=gjhsu]If you're worried about efficiency at high speed, get yourself a splitter and call it a day.[/QUOTE]
What is a splitter?
What is a splitter?
| CalcVictim | 04-02-2005 12:03 PM |
[QUOTE=Drayton]I will stand behind the sentiment that if it did not have [i]some[/i] beneficial effect, then STi would not use it.[/QUOTE]
The STI has a different and bigger intercooler hence I don't think you can really make the assumption.
The STI has a different and bigger intercooler hence I don't think you can really make the assumption.
| toke513 | 04-02-2005 09:03 PM |
The splitter is a metal piece that goes inside of you scoop and itdirects the airflow more evenly over the whole intercooler. Supposedly more air flows over the top half than on the bottom.
| adam_m_mcinerney | 04-17-2005 12:23 AM |
A friend of mine is an aeronautical engineer on some crazy turboturbine crazy jet engine thing (and yes that is the very technical name for it). He works with wind tunnels all the time. I posed this question to him, and he said that the jump in speed would have to be considerably faster (read 80-85mp higher) than the 90mph on the jdm hodd scoop to make the slipstream jump another 3/4" to go over the higher sti scoop. He said that would be his guess as to what the excess windspeed would have to be, it is not a technical answer for you because he hasn't put the car with both scoops in there, so it is just his guess. On the other hand, he does have a lot of experience with this type of thing, so I think he adds some weight to the discussion. And he would also guess that the drag coefficient opposed to the cooling effect would probably not slow the car any, He says it wouldn't create nearly enough drag because the air is technically still flowing. So that is an outside professional opinion, but not definitive fact. And he doesn't really care which way it looks big or small so no bias there.
| Balr14 | 04-17-2005 02:15 AM |
There's really no way to tell without wind tunnel testing. One assumes Subaru is doing things for a reason, though you have to wonder about that STI wing.
| BriSalig | 04-17-2005 03:55 PM |
sorry, i totally forgot about this thread.
i am aware that the hoodscoop is functional, but i thought it was there to help drain the heat from the intercooler. i knowits not an intake, i was under the impression that it was a source of discharge.
brian
i am aware that the hoodscoop is functional, but i thought it was there to help drain the heat from the intercooler. i knowits not an intake, i was under the impression that it was a source of discharge.
brian
| Jpapania | 04-17-2005 05:15 PM |
It is actually a little bit of both (intake/exhaust). Your intercooler works much like your radiator, for it to work air must flow through it hitting the IC and cooling it. You will also notice a small area on the passanger side. that the IC is not using. That flows down to the turbo hitting it with some cool air at speed. When you slow down, in theory mind you, a small porition of engines heat can flow out the scoop. After driving park your car outside on a hot summers day and you can see the heat flowing out.
| slowscooby | 04-17-2005 05:34 PM |
Yeah a cool thing to get is the heat shield with a chimney on it that goes directly to that opening in the scoop, it should in theory direct most of the hot air from the turbo out and away from the intercooler...i want one, but they are pricey.
Oh and i dont think a splitter is the answer to the problem of no air flow over 90mph....being as if your getting no air flow into the hoodscoop, the thing inside the hoodscoop cant do its job. Although the splitter does help direct more air over the intercooler.....like what a few people on here said, we can never really know what scoop is better at a certain speed without a controlled test.
Oh and i dont think a splitter is the answer to the problem of no air flow over 90mph....being as if your getting no air flow into the hoodscoop, the thing inside the hoodscoop cant do its job. Although the splitter does help direct more air over the intercooler.....like what a few people on here said, we can never really know what scoop is better at a certain speed without a controlled test.
| Nikko | 04-17-2005 11:31 PM |
[QUOTE=Balr14]...though you have to wonder about that STI wing.[/QUOTE]
The wet noodle...
The wet noodle...
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