i've read the arguments and participated in them... so i decided to go to the auto-x today, have some fun, and figure out what my intake temps were looking like.

the setup:

ebay cone filter on a custom bracket. the stock air duct has been left on the radiator shroud.

how i measured:

i took a thermocouple thermometer with a long lead and routed it along the fender/hood line to where my cone filter sits. the unit sat inside the car with me

results as measured by thermocouple:

outside air temp: ~100 deg F

air temp with hood open, car and fan off, car warmed up: ~120 deg F

air temp idling in grid with hood closed: 140 - 150 deg F (depending on time still and running, reached an equilibrium at ~150)

temperature during runs: ~135 deg F (IIRC: will post temp at 25 mph city)

what else?

i still haven't tested intake temps with the stock setup, which i am putting back on since i just got a K&N element. i will have the thermocouple routed into the box. i also plan to put weather stripping and new fasteners on the stock shrouds up front to get as little air from behind the radiator as possible.

will 30 deg colder air (assuming the stock box heat soaks a bit) be worth a drop in "flow effeciency"? probably.

is a cone filter that much better than a K&N drop-in in the frist place? probably not.

 

cone has better perfomance but get dirter quicker i think

 

was it cooler w/o a cold air box. Al the info ive found says that w.o the box, the high flow filters suck in hot engine air and are worse than stock,
but if you take the time and route some air into an enclosed cold air box, then the cone filter should provide performance gain(i mean omare the size rf the intake hole on the stock box to the surface area on a high low filter)
Probly not crazy power or anyhing, but i think youd br happy you spent the time and like $20-$30 at home depot for the box

 

actually it has been dyno proven that a cone filter on many cars (including the FC) will lower peak HP by about 5HP when it is used without a cold air box.

You may wish to search on this. One member actually posted his dyno sheets showing this.

 

thanks, i'll look for that. however, the reason i posted this is i haven't come across anyone actaully doing real world temperatures tests. most of the arguments on this forum about it are speculation.

i actually went out and did this at an event in the hot sun with a good instrument. i'll also be doing the stock box and a cold air box these next couple of weeks. dyno is great for tuning, but you can't race on one. i'll post any noticeable differences in response and power, though.

 

good on you for putting the effort to take measurements. I personally would place the sensor in the intake duct to read the temperature.

later

 

If your interested in cooler underhood temps, running with the headlights up (In miatas atleast) the temps have been about 20+ degrees cooler. And with no turnsignals (this is miata specific) it had an additional 20+ degrees of cooling, I think that maybe if you removed the lense in front of the headlight it may be a straight shot towards the intake, I dont spend too much time under the 7s hood so I dont remember too much but worth looking into if temps are important. Or you could always put a scoop into the headlight cover for cooling.

Just a thought

 

interesting suggestion. i've never seen anyone run a 7 with the lights up, though i have seen miatas do it. it would definitely free up some space inside the front bumper and open more passages. if i remember i'll measure bay temps with and without lights up this weekend.

as far as putting it in the intake i didn't see a point for the cone filter. i had it right next to it, but may now try it, since i will be putting it inside the stock box.

 

I have my FTP lenses out. I also have some holes drilled behind the headlight. I also have an insulated cold air box. Home made of course but it certainly works. With the headlights up I can look straight back and see my filter thru the front bumper. Even after letting the car sit, the filter doesn't really heatsoak and the inside of the box stays pretty damn cool. Mainly after a hard pull I can get out and pop the hood and the filter is almost cold to the touch. The outside of the Cold air box is almost too hot to touch because it heatsoaks.

 

How can I make a cold air box? I suppose I should search. Anyone have some links too anything though?

 

..............

 

^ LOL best way to put it 5ABaby... beat me to it

Zak

 

Santiago and James did some magnehelic testing on this issue. I think that thread is buried somewhere.

And you search ***** are starting to really irritate me..

 

im no search ****...im a jew first off but i just laughed out loud when i heard that, you dont even really have to search just scan anywhere through the pages and you can see something about cold air boxes, or clean engine bays etc.... please look at the post count... im a newb, why would i tell other newbs to search, im no high and mighty pompous *******, nor am i a person who has answered that question "a million times already" just thought the little "smilies" were amusing.


Zak

 

I should make a FAQ for NA bolt ons, since Ted has one for TII's.

 

Do it.

 

 

#1. Best bolt on for an N/A = A TURBO!!

 

J-Rat, are you confused and making a list of ways to **** over reliability.

 

And **** over 240's and Mustangs.

 

And you are speaking from experience?

 

Little tip I figured out from my engineering classes:
Every 38 degrees colder equals 1psi of boost, except without a power-robbing turbo.
Or, to put it another way, every degree increases horsepower by 0.2%. Only 3 degrees for 1 horsepower!

That means an excellent cold air box might yield 8HP on a stock N/A, and more on a more powerful car. Does this sound right?

 

I would .

 

Are you denying that a turbo rotary is less reliable than an N/A?

 

Absolutely! TIIs can be just as reliable as N/As with proper care and feeding.