FD Seeker

I want a small scoop on my hood directly above an air box that seals to the hood from the inside such that I get COLD RAM AIR. I know most would generically not like the looks of this, but my concern is more functional. That said, I'd like it to look as good as possible.

Would such a direct flow of air be hazardous to the filter (water or debris)?

Anyone seen a setup like this? Pics? Testimonials?

Where can I get a scoop that might fit the FD look?

Could an existing cold air box be modified for this purpose?

No need to debate the effectiveness of cold air on IAT. Been there done that in other threads.

FDreaming

The sealed airbox your suggesting, while functional in design becomes more of a hinderance at speed. When you fill up a air box with velocity pressurized air like that it eventually fills, then a hig pressure area forms right infront of the scoop itself. Once the enigine suckes in enough air to reduce the pressure the cycle starts all over again(it actually can get to near vacuum at times depending on speed and a ton of other variables). It creates a pulsing effect that can have an ill effect on performance as well as aerodynamics. The F1 guys have spent alot of time developing airboxes with sort of trap doors that will keep the pressure constant and optimized at all the speed their cars travel at.

Your idea would be great if you didn't seal the box. I'd suggest just an open air fillament with a heat shield that makes them only suck air from around the radiator.

rynberg

The stock, Racing Beat, and PFS intakes all get air rammed into them from the front of the car. The turbos get plenty of cold air (well, with the Racing Beat and PFS setups anyway). Why destroy your hood with a nasty looking off-center scoop .in the hopes of gaining a few more hp at high speeds?

Kevin T. Wyum

Easy, do what I did. Put the filter under a non popup headlight and remove the combo light. You'll have to cut a little sheet metal to make the opening large enough for a 3" tube or whatever size you use. Your opening is then at the leading edge of the front of the car, a far better option than up on the front of the hood which is actually a lower pressure area. No real visual impact either.

Kevin T. Wyum

scarhart94FD

The Feed fresh air headlight cover here http://www.jt-imports.com/FEED_FD_Parts_List.htm or the Border NASA air ducts set here http://www.jt-imports.com/Border_FD_Aero_Kits.htm may compliment a heat shielded intake kit like one FDreaming suggested.

FD Seeker

I guess I could see that happening. While it kicks my idea in the ***, I appreciate the scientific feedback.

FD Seeker

My theory was that the hood scoop would provide more direct ram air at higher volume than the traditional boxes. I wouldn't do this unless it could be shown to have a measurable impact on performance at moderate speeds. And, not to spend too much time on subjective opinions, I don't think an offset scoop would necessarily look nasty. If Photoshop proved that, I'd back off.

FD Seeker

I'm intrigued with your solution, but I'm not quite sure I get it. Can you post some pics?

FD Seeker

As a compromise, I could consider the headlight cover option, but the opening looks pretty small. While the NASA option is more in line with my idea, it looked pretty bad.

jimlab

Does anyone want to comment on the fact that you can't "ram" air into a forced induction engine, or shall I?

widebody2

Anyone ever seen Vinny Ten's hood on his Supra. He has a hole in his hood so that you can actually see his turbo from the outside. He doesn't even have a filter on there since he's just dragging. The air is guided right into his compressor by the hood

jimlab

His turbo still can't take in any more air than the rpm of the compressor wheel will allow. You're not going to shove more air past the blades.

The only benefit of this arrangement is that it's drawing directly from ambient air and not underhood air.

Riccardo

iTrader: (1)

Jimlab is right
There are factors that limit the amount of air that comes in - Some can be improved, i.e. by improving the way the air comes in removing possible hinderances (ps. pipes with corners - the manufacturer might have put these in for noise restriction etc etc.) - but there is a limit to this, and the only other improvement factor is guetting cooler air in (ambient vs. underhood)

FD Seeker

It seems logical to me that higher pressure on the intake side of the turbo will allow for quicker spooling and more efficient operation.

Right?

DaveW

Higher inlet side pressure means the turbos have to do less work to obtain the limit boost level, and below that value higher inlet pressure should provide higher boost pressure.
So, I agree with you.

MilesBFree

iTrader: (2)

I think Jim LaBreck summed it up nicely.
In addition: The headlight scoops offered by some vendors are more for looks, as the opening is too small to do any real good.

The "remove the foam next to the radiator" trick offers an opening that is larger than the turbo inlets (i.e.- the pipes going from the airbox...), therefore works in terms of not offering a restriction. So a sealed airbox will work just fine.

Cheers,

jimlab

So you're saying that because the turbo can spool more quickly, that you'll reach higher boost levels more quickly? True, but you won't increase boost levels beyond the preset limit without other changes.

While removing all restriction in front of the turbo (i.e. no intake piping, no filter) will allow it to spool as quickly as it possibly can (assuming the exhaust system is not a restriction either), it will not allow any additional air past the compressor wheel than it can ingest at a given rpm. You may hit your boost level sooner because of the lack of restriction, but unless you change boost level physically with a controller or wastegate spring, you're not going to see an increase in boost level. In other words, you can starve a turbo with restrictions in the intake path, but you can't feed it more than it can eat at a given rpm, even with no restriction whatsoever. You can only make it reach that rpm sooner.

"Ram air" works on naturally aspirated engines because they have to rely on cylinder/chamber vacuum to fill themselves. If you can pressurize the intake path even slightly by using the vehicle's movement to "ram" air in to the intake, you may see an increase in power because you're filling each cylinder more completely on each cycle. However, if you place a mechanical restriction (turbocharger, supercharger) in the intake path between the outside air and the engine, there is no "ram air" effect possible from the intake arrangement. Obviously a turbocharger or supercharger also forces air into the engine, but the vehicle's movement is not a requirement, so it is not, by definition, "ram air".

Bottom line, you can have a "cold air" intake on any type of car, but you can only have a "cold ram air" intake on a naturally aspirated car. If the car is turbocharged or supercharged, all you've got is a "cold air" intake with very little restriction. The term "ram air" no longer applies.

suganuma

Actually Jim, some friends and I have found that (at least on a larger frame turbo) placing a length of tubing (essentially a venturi, but of constant diameter) before the compressor housing allows for quicker/better spool. We tested this statically (sitting still, using anti-lag) also and found that we would create on the order of 7-8 psi with no tubing and ~15 psi with the tubing. This screamed to me that the length/diameters used could essentially be optimized with some surely lengthy calculations and real world testing, but is interesting/useful none the less. After we found this out, I did some research and found a few examples of people running what I can best describe as a monster "air horn". They were ~4 inch O.D. peices of different lengths belled out at the end much like you'd see on a set of webber carbs or something of that nature. I had enough trouble at school making these out of ~2" O.D. 16 gauge aluminum for an FSAE car and never tried making one for my turbo. I also liked the idea of having a filter on a street car to help keep out the dirt

Anyways, just FYI

I plan to do a setup similar to what Kevin described, but am still attempting to save up enough money to buy the needed sleek lights. I'll definitely post pictures when I get around to it.

FD seeker, I would also advise not placing the intake source on your hood.

Fatman0203

Damian also made a pretty nice ram air intake using dryer ducting and some piece its connected inside his heat shiel. Pretty dam nice if you ask me. Search for it.

pugg57

intakes aside, would it be beneficial at speed to create some kind of ducting from a nacel inlet in the front of the hood (similar to the Scoot design) to push more air through the venting on the IC? i'm assuming yes, but has it been done to any success yet?

bigmack000

here go read all of this fd seeker will help you out alot. http://www.autospeed.com/cms/A_0629/article.html
read 1 rigth to the end of 5. it inforative.
joel

FD Seeker

Thanks all for the input.

Jim: I appreciate your technical definition of ram air. I can live with omitting that specific designation from the description of my idea, but I think that concept needs to remain as it provides benefits that you mentioned yourself.

Because of the buffeting problem mentioned, I will probably not purse this anyway.

ReodDai

Just cuz I own a firebird I get to make this comment. There is no such thing as "Ram air" even trans am owners know this. The Ram air system on a trans am only added horsepower because it accomplished the same things as a cold air intake with improved piping. If you want I'll dig up a scientific article on why "ram air" is impossible.

jimlab

But apparently didn't understand it...

"Ram air" only works on naturally aspirated engines, and only when the vehicle is in motion. Using that term to refer to an intake on a forced induction car is not only technically incorrect, it makes you look like you picked up all your car knowledge from watching The Fast and the Furious. Are you with me now?

maxpesce

You did not say so BUT if you were planing on using the stock air box another problem is that in the stock airbox the TOP of the filter is the CLEAN side, So you need to ram the air in from the bottom.