headlight vent!
#26
is in a boosted honda
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Evil, i dono why your pissed but I might be a "kid" but i sure as hell know more then most of the ppl who are double my age so u can just shut up with the cuz im older then you ****. I did do my research and the duct design has been PROVEN to get an okay amount of airflow so i figured, wut the hell. Also, if u didnt notice that i said twice, It took an hour. If you have a rx7, and you have a job where you cant work on it at all, then there is no point on having it. Rx7s are enthusiast cars, not something you take to a dealership to get every little thing fixed. And with that, if you have a job where you work 24/7 it isnt worth it. I dont care how much $$ your makin, if you have no time for yourself then whats the point of having $$?
And with that said please keep your comments out of my thread. Thanks.
Anyways, i did remove the weather stripping, I was tryn to get a pic of the hood closed were u could see the filter through the vent but yea.. there was no light in the hood haha. And thats why i didnt make my box depend on that air from the vent, im making it wider so it can scavenge more air from random places haha.
and i dono if i like the scoop thing. If i really wanted super air flow id just take the headlight cover off haha.
~TDR
And with that said please keep your comments out of my thread. Thanks.
Anyways, i did remove the weather stripping, I was tryn to get a pic of the hood closed were u could see the filter through the vent but yea.. there was no light in the hood haha. And thats why i didnt make my box depend on that air from the vent, im making it wider so it can scavenge more air from random places haha.
and i dono if i like the scoop thing. If i really wanted super air flow id just take the headlight cover off haha.
~TDR
#29
Lives on the Forum
Wanna bet? They sure can.
You'll MAYBE get the filter wet, but that's all. Rain is no big deal.
I agree, the ducts look better than the scoops, but mine will flow better than ANY of yours, because there will be a tendancy for the airflow to just flow right over the opening of the sunken in ducts, whereas mine's actively grabbing the air and pulling it in. When I was getting ready to make it, I figured that the opening size that I could get with a sunken in duct was much less than I achieved with this one, so I went this way.
You'll MAYBE get the filter wet, but that's all. Rain is no big deal.
I agree, the ducts look better than the scoops, but mine will flow better than ANY of yours, because there will be a tendancy for the airflow to just flow right over the opening of the sunken in ducts, whereas mine's actively grabbing the air and pulling it in. When I was getting ready to make it, I figured that the opening size that I could get with a sunken in duct was much less than I achieved with this one, so I went this way.
#30
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So, back to your logic, do I understand you to imply that it is your lack of age that makes you an aerodynamics expert? If not, then how do you justify your position?
It is great that you have the skill to do that, but most people are not capable of researching the duct, designing the pattern, removing the headlight cover, fabricating the duct, and sanding/priming the cover in only one hour.
This is a public forum. If you don't want people to comment, then either use the Private Message function to converse directly with individual forum members, or ask one of the moderators if you can author a how-to thread in the Archive.
If you do not want to see any comments from some old guy who obviously doesn't know as much as you, then you can click on my screen name and add me to your Ignore list. You will find that I am not the only person on this forum with an education, so you can add more people to your Ignore list as required.
#31
Banned. I got OWNED!!!
No, that one is only for low speed. The grating is going to murder the airflow. It also doesn't have an entrance lip. Was this home-made, or do the manufacturers of these things just neglect to have an engineer review their products prior to public sale? Maybe they don't care and just sell them as bling rather than as performance products? Hmm.
1) How would you make mine better?
2) If I wanted to (& I'm going to be vauge here intentionally) desing a vent that would be mounted under the car on a custom belly pan (16ga sheet AL) to pull air into a duct how would you do that?
-B
#32
Do Work
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I agree, the ducts look better than the scoops, but mine will flow better than ANY of yours, because there will be a tendancy for the airflow to just flow right over the opening of the sunken in ducts, whereas mine's actively grabbing the air and pulling it in. When I was getting ready to make it, I figured that the opening size that I could get with a sunken in duct was much less than I achieved with this one, so I went this way.
#33
Lives on the Forum
If you really want to grab some air, make it a scoop of some sort. NACA ducts and such CAN work well, but they have to be placed correctly so that they properly interact with the airflow over the body as a whole. With a splitter and airdam of some sort, the undertray should be a low pressure area, so you're going to have to go out and grab the air and force it to go where you want. It won't necessarily flow into a NACA duct or anything, especially seeing as the engine by is constantly being pressurized by the flow of air through the nose.
You really don't need a screen, the air filter will take care of anything. I've never found anything in there other than bugs really, and that screen's not going to stop them.
You really don't need a screen, the air filter will take care of anything. I've never found anything in there other than bugs really, and that screen's not going to stop them.
#34
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Wow, that's really nice for home-made.
The design looks OK to me, but I think you should remove the grating. If you drive the car in an environment in which filter-penetrating flying debris is a concern, you could simply offset the filter from the intake hole...
http://www.triz-journal.com/archives...02/a/index.htm
http://www.uspto.gov/web/patents/pat...-20071120.html
or incorporate a less-restrictive anti-FOD (Foreign Object Damage) system such as Ferrari-style "cheese grater" strakes.
http://www.drivingtoday.com/truckbed...ssa/index.html
If you want to get fancy, you could design a vortex generator field on the headlight cover or in the intake tract, which would act as both an air filter and as protection from FOD. I'm not sure if this would be practical though, and it wouldn't have quite the filtration of a barrier type air filter.
http://www.donaldson.com/en/aircraft...ary/052457.pdf
http://www.pall.com/pdf/Army_Aviatio..._CH47_EAPS.pdf
http://www.centrisep.com/file/C.sep%20Pdf.pdf
http://www.pneumafil.com/gasturbine/sc/inertial.html
As for improving the duct itself, see the original 1945 NACA document. Note the "entrance lip" on Figure 2, which is missing from most of the aftermarket attempts at emulating the NACA duct. Also note the raised "deflectors" in Figure 9, which may not be worth the trouble, but are still worth a look.
http://naca.central.cranfield.ac.uk/...a-acr-5i20.pdf
Given the relatively low speed of a car, and the less-critical nature of an Otto cycle engine, I think the most important thing is to have enough cross-sectional area for the engine to breathe, which it looks like you have achieved on your current inlet. If in doubt, just dyno the car with the ducted headlight cover in place, and again with the headlight cover completely removed. If the dyno shows a performance gain with the headlight cover removed, then the duct is choking the engine. If not, then don't worry about it.
Oh boy, that is just asking for FOD, lol. Anyway, a NACA type duct or just about anything would probably work just fine, but once again, you may want to offset the intake tract so that ingested objects do not hit anything vital.
If this is for a heat exchanger, you can mount the core horizontally at the bottom of the car and simply install a lip (air dam) at the trailing edge of the core. If you want to install an external duct, here is how to do it:
http://www.ch601.org/resources/cooling_systems2.htm
OK, now you know just about everything that I know.
The design looks OK to me, but I think you should remove the grating. If you drive the car in an environment in which filter-penetrating flying debris is a concern, you could simply offset the filter from the intake hole...
http://www.triz-journal.com/archives...02/a/index.htm
http://www.uspto.gov/web/patents/pat...-20071120.html
or incorporate a less-restrictive anti-FOD (Foreign Object Damage) system such as Ferrari-style "cheese grater" strakes.
http://www.drivingtoday.com/truckbed...ssa/index.html
If you want to get fancy, you could design a vortex generator field on the headlight cover or in the intake tract, which would act as both an air filter and as protection from FOD. I'm not sure if this would be practical though, and it wouldn't have quite the filtration of a barrier type air filter.
http://www.donaldson.com/en/aircraft...ary/052457.pdf
http://www.pall.com/pdf/Army_Aviatio..._CH47_EAPS.pdf
http://www.centrisep.com/file/C.sep%20Pdf.pdf
http://www.pneumafil.com/gasturbine/sc/inertial.html
As for improving the duct itself, see the original 1945 NACA document. Note the "entrance lip" on Figure 2, which is missing from most of the aftermarket attempts at emulating the NACA duct. Also note the raised "deflectors" in Figure 9, which may not be worth the trouble, but are still worth a look.
http://naca.central.cranfield.ac.uk/...a-acr-5i20.pdf
Given the relatively low speed of a car, and the less-critical nature of an Otto cycle engine, I think the most important thing is to have enough cross-sectional area for the engine to breathe, which it looks like you have achieved on your current inlet. If in doubt, just dyno the car with the ducted headlight cover in place, and again with the headlight cover completely removed. If the dyno shows a performance gain with the headlight cover removed, then the duct is choking the engine. If not, then don't worry about it.
If this is for a heat exchanger, you can mount the core horizontally at the bottom of the car and simply install a lip (air dam) at the trailing edge of the core. If you want to install an external duct, here is how to do it:
http://www.ch601.org/resources/cooling_systems2.htm
OK, now you know just about everything that I know.
Last edited by Evil Aviator; 04-25-08 at 01:24 AM.
#35
Lives on the Forum
#38
Lives on the Forum
So in short, a headlight cover duct supplies ambient air to the engine.
#39
Wiring Nightmare
iTrader: (12)
So disregarding cross sectional area, am i to understand that the shape of TT's design is good but could be improved upon by the top lip curving in a bit. In addition to it curving in a bit the underside should be relatively flat so that the air will move fasteruder the lip than over the lip causing the underside of the lip to be higher pressure causing the moving air to diffuse to the scoop rather than flowing over it. I would really like to design a proper intake scoop. I couldnt find much in my mech design book by shigley, but i think if i could get the basic design i could maximize the efficiency using some of my overly priced fluid mechanics knowledge and my book of course
#41
My job is to blow **** up
iTrader: (8)
Wanna bet? They sure can.
You'll MAYBE get the filter wet, but that's all. Rain is no big deal.
I agree, the ducts look better than the scoops, but mine will flow better than ANY of yours, because there will be a tendancy for the airflow to just flow right over the opening of the sunken in ducts, whereas mine's actively grabbing the air and pulling it in. When I was getting ready to make it, I figured that the opening size that I could get with a sunken in duct was much less than I achieved with this one, so I went this way.
You'll MAYBE get the filter wet, but that's all. Rain is no big deal.
I agree, the ducts look better than the scoops, but mine will flow better than ANY of yours, because there will be a tendancy for the airflow to just flow right over the opening of the sunken in ducts, whereas mine's actively grabbing the air and pulling it in. When I was getting ready to make it, I figured that the opening size that I could get with a sunken in duct was much less than I achieved with this one, so I went this way.
but thats if it was just submerged and then dryed ASAP..
#44
Lives on the Forum
Got some nice closeups of my homemade scoop.
I really don't think that "proper" inlet design is really possible. Sure a NACA duct is a high efficiency design, but it's not like you can make it as big as you want, because there's the headlight and all the mechanisms under there. I found that this would have severely restricted the depth of a duct, which is why I went with a scoop instead, to get more air to the filter.
I really don't think that "proper" inlet design is really possible. Sure a NACA duct is a high efficiency design, but it's not like you can make it as big as you want, because there's the headlight and all the mechanisms under there. I found that this would have severely restricted the depth of a duct, which is why I went with a scoop instead, to get more air to the filter.
#45
Wiring Nightmare
iTrader: (12)
I think you're right about the duct not really being efficient. The duct on that plane was much larger and had a much gentler slope. Also as Evil Aviator said the airplane is moving much faster allowing it to get more air. The scoop is probably the most practical design.
Do you have any pics of the whole front end of the car?
Do you have any pics of the whole front end of the car?
#46
Banned. I got OWNED!!!
Holy f*ck! I can't believe it's been a month since I've been on..... anywho........
Why thank you. I started with a stock headlight vent, some sheetmetal, cutoff wheel, welder and some knowledge on metalwork...... & some glazing putty
Damn. That's alotta reading but I really do appreciate the time you spent typing that out and linking the usefull pages. I will certainly reference that when I'm building those two vents under the car that I need. Thanks again
-B
Why thank you. I started with a stock headlight vent, some sheetmetal, cutoff wheel, welder and some knowledge on metalwork...... & some glazing putty
-B