Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">If I find any articles referencing diffuser angle I'll post some references.</TD></TR></TABLE>

i have some of the simon mcbeath aerobytes articles and one of them deal with the exact thing you just mentioned, would you like me to shoot you a copy?

Niles

I've got every copy of RE going back like at least 4 years, I'm just too lazy to search
Thanks for the offer though. Glad to know that someone else on this board reads something more advanced than the usual import mag junk.

driveahonda

Hook me up. IconTuning@***.net

thehatchninja

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.E.G. &raquo;</TD></TR><TR><TD CLASS="quote">




this is a mugen undertray for the honda fit. they have vents like i just described. again, this is a compromise and the car will perform better with this smooth underbody and all of its integrated downforce producing devices, however it would be more efficient if the air that blows acorss the radiator never saw the undebody of the car.
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That's pimp...I didn't plan on making it span the whole length of the car, but i'd love to have a piece like that.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">I've got every copy of RE going back like at least 4 years, I'm just too lazy to search
Thanks for the offer though. Glad to know that someone else on this board reads something more advanced than the usual import mag junk.</TD></TR></TABLE>



i need to get a subscription. i usually just go to barnes and nobels and read the whole thing and then put it back on the shelf. lol.

yeah after the first time i read RE i couldnt stomach super street or any of those. the only thing you get out of the regular import mags is, well... not much.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thehatchninja &raquo;</TD></TR><TR><TD CLASS="quote">That's pimp...I didn't plan on making it span the whole length of the car, but i'd love to have a piece like that.</TD></TR></TABLE>

yeah thats a bit excessive, but you see what i mean.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by driveahonda &raquo;</TD></TR><TR><TD CLASS="quote">Hook me up. IconTuning@***.net</TD></TR></TABLE>

PM sent

Kevin

I understand what you guys are saying. As i stated i am no expert and am still learning, most of my knowledge is of offshore racing catamarans. I should have been more detailed with my explanation as i had considered doing a reverse scoop or two on the hood to have the hot air pulled out by the air flowing over the hood. To keep the car looking stock i thought about just spacing the rear of the hood as ive seen this done on racecars but now you guys are saying this wont work? I run into high pressure issues with our cockpits which are force fed air via naca ducts / blower fans to cool off the driver/throttleman and the pressure is relieved with a reverse naca duct on the back of the boat.


I was just worried about closing in the engine bay and then not venting to allow the hot air somewhere to go. I figured with the addition of a front mount intercooler it would be good to have some small scoops to allow more cool air into the engine bay (it has to go through the front mount, ac condensor and then radiator) and take away some of the air that flows under the car.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gLok &raquo;</TD></TR><TR><TD CLASS="quote"> To keep the car looking stock i thought about just spacing the rear of the hood as ive seen this done on racecars but now you guys are saying this wont work? </TD></TR></TABLE>

the short answer is "i dont know". it depends on the angle of the windshield and a number of other factors. it may work for you car or it may not. i guess first off we should ask, what car is this for? but i can say that no matter how you slice it that is not the best place to vent the air at. if you just cut a vent in the hood a few inches you have a better chance of not hitting some high pressure area.

since you car seems to be turbo charged i imagine that you get a good deal of heat soak under the hood. i wouldnt want to block it off either, but your idea with the holes on the bottom sucking in air really wont work and produce downforce. the air will only flwo form high to low pressure and if the pressure is high enough under the car to force air through the holes in your design, then you wont be making downforce. see what i mean.

how about this. can you take some pics of your car for us? if you can, try to get a good shot of the front of the car, a good shot showing the entire area under the hood, a shot taken from above showing the clearence between the block/ turbo manifold and radiator support, and a shot that shows how low you exhaust and down pipe hang, and any alse that you can think of.

we CAN help you make a decent system, but we are just kind of shooting in the dark at this point.

thehatchninja

1. http://www.gassavers.org/showt...age=2

2. http://www.gassavers.org/showthread.php?t=660

3. http://www.gassavers.org/showthread.php?t=671
just scroll down for some ghettfabulousness

JDMCRX

iTrader: (2)

I remeber 3 years ago when i was working at a shop speedstyle. We had this full Integra race car. the whole bottom was air defusor prob them had was **** got hot under there. The exhaust started a fire once.

But i love the idea super smoth bottom would be less drag and so forth

Niles

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thehatchninja &raquo;</TD></TR><TR><TD CLASS="quote">
just scroll down for some ghettfabulousness</TD></TR></TABLE>

Wow, I think I give those guys a D for safety, a B- for effort, and I almost vomited. I really hope the "screws, caulk, and duct tape" method is more secure than it looks, if any of that flew off and hit my car on the highway I would be upset.

JDMCRX brings up a good point, manifolds and cats get pretty hot, the only source of cooling they have is airflow. Another thing to consider

thehatchninja

yeah, those guys definitely didn't take heat into consideration.

Of course they are shifting at 3k max and coasting as much as possible.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thehatchninja &raquo;</TD></TR><TR><TD CLASS="quote">1. http://www.gassavers.org/showt...age=2

2. http://www.gassavers.org/showthread.php?t=660

3. http://www.gassavers.org/showthread.php?t=671
just scroll down for some ghettfabulousness</TD></TR></TABLE>

holy ****. what are these ******** thinking?

and theres a whole forum of idiots cheering them on.

i could understand getting that ghetto if you were in some kind of contest, but doing that just to possible save (maybe) a thousand dollars in gas over the course of a year. unbelievable

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">

JDMCRX brings up a good point, manifolds and cats get pretty hot, the only source of cooling they have is airflow. Another thing to consider </TD></TR></TABLE>

if i was going all out on a car i would have an electric fan to blow air across the engine etc that would exit through a vented hood. i would keep it isolated from the air that blows across the readiator. ideally i would want a duct that vents through the center of the hood and then smaller vents on either side. just think JGTC. in the front engine jgtc cars thier engine gets little tono contact with air from outside the car (except through thier take manifold, obviously)

Niles

There are alot of novel solutions to heat issues on jgtc cars because engine placement is (somewhat) free. Some of the front engine cars run thier motor close to touching the firewall. They also make good use of lateral real estate because the cars have to be factory spec in profile only. Here's one place fender vents could be of good use, moving air across the sides of a manifold and out, for example. For a race car this makes good sense as you would be using the airflow off the back and sides of the wheels to help pull air across the engines when you need it (at speed) but I feel like you would need the fan assist on a street car, as you say. Whenever I get my car rolling I am for sure going to bust out some pitot tubes, that's for sure.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">Whenever I get my car rolling I am for sure going to bust out some pitot tubes, that's for sure. </TD></TR></TABLE>

damn straight

L-CON1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.E.G. &raquo;</TD></TR><TR><TD CLASS="quote">

i agree. the top of the hood venting method is releasing the air into a lower pressure area. the windshield area will have a good deal of pressure built up on it.

i realize that my drawing was a bit extreme and not ideal for street cars, but i was just showing a best case scenario and you can take away the elements individually and use what will work best for your application.

thats exactly my point. stock cars have **** *** underbody aerodynamics. they choose to let radiator air blow out of the bottom for packaging reasons and this is no bueno for aerodynamics. i am not trying to be a smartass or anything and im not trying to tell you you're wrong but your vents arnt really doing anything. there are plenty of cars (think mid engined) that have no airflow blowing across the engine itself. your main focus should be getting air through the radiator and out of the engine bay and then more or less closing off the engine bay. in your drawing you show the air entering from the underbody but i cant see why you would want that to happen.

i think a closed engine bay is the bast way to go... now to contradict myself a little, its all about compromises and ther are someinstnaces where you will need to let the air tat blows across the radiator vent though the bottom of the engine bay since it has to go somewhere. you can meet in the middle and block off the majority of the engine bay and then make vents sort of like the ones you had in your picture only they would be working in the opposite direction. obviously they would effect the underbody airflow, but the only thing worse than having poor underbody airflow is having your engine overheat




this is a mugen undertray for the honda fit. they have vents like i just described. again, this is a compromise and the car will perform better with this smooth underbody and all of its integrated downforce producing devices, however it would be more efficient if the air that blows acorss the radiator never saw the undebody of the car.

again, i am not trying to sound like a dick or anything, but i happen to know a quite a bit about aerodynamics, and i can say that this is a subject with a lot of misconceptions</TD></TR></TABLE> those vents are facing so that the air would be pulled out of the bay.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by L-CON1 &raquo;</TD></TR><TR><TD CLASS="quote"> those vents are facing so that the air would be pulled out of the bay.</TD></TR></TABLE>

i know, thats what i said.

RMF

I know it made a huge difference on this car. It has a belly pan from the front to the back bumper.It picked up .400 just from the belly pan.

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RMF &raquo;</TD></TR><TR><TD CLASS="quote">I know it made a huge difference on this car. It has a belly pan from the front to the back bumper.It picked up .400 just from the belly pan.

</TD></TR></TABLE>

cool beans. any underbody pics?

nice work

Oilpan Assasin

I've been looking into something like this but not for aerodynamics. My car is so low, just want to protect everything under there

thehatchninja

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Oilpan Assasin &raquo;</TD></TR><TR><TD CLASS="quote">I've been looking into something like this but not for aerodynamics. My car is so low, just want to protect everything under there</TD></TR></TABLE>

you probably should get a honda

Mr.E.G.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Oilpan Assasin &raquo;</TD></TR><TR><TD CLASS="quote">I've been looking into something like this but not for aerodynamics. My car is so low, just want to protect everything under there</TD></TR></TABLE>

damn dude, raise that car up a tad and you wont need and underbody tray. your car is waaaaaaaaay too low.

gldndrgn14

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">

JDMCRX brings up a good point, manifolds and cats get pretty hot, the only source of cooling they have is airflow. Another thing to consider </TD></TR></TABLE>

i couldnt understand his engrish until i read your post. haha but on that topic, dont you wnat the exhaust to stay hot? the heat in the exhaust gases would keep the velocity up and exit out the back sooner. wouldnt that be the reason for heat wrapping them and coating them? and if i am wrong on my thought, then you could just add inverted vents for the air underneath to draw the hot air out from the exhaust and engine bay. but not too much, because then that would void out the flat bottom that has been made right?