CAI Intakes..Cold Air or Ram Air?

Anonymous · May 30, 2004, 23:17

Tem, do you have a PPE header (no heat shield) by any chance?

Interesting thread on CAIs, Physics of: http://forums.s2ki.com/forums/showthread.php?s=&threadid=204172

Tem · May 31, 2004, 06:17

Quote from: "Beanie"Tem, do you have a PPE header (no heat shield) by any chance?

Nope, I have the:

Quote from: "Tem"Apexi intake kit

s;)

s;)

...with a heat shield that came with it...

Anonymous · May 31, 2004, 14:50

Well, I thought Finland was too cold for your car to have such a high temp in the engine bay unless maybe you had a PPE header, which would mean no heat shield. Nevermind.

Anonymous · May 31, 2004, 17:11

just read this m http://forums.s2ki.com/forums/showthrea ... did=204172 m

shame i am not still at uni i could ask the human calculator he was an absolute genius at fluid mechanics and combustion engines, what a combination

is it just me but i always thought that laminar flow is much much worse for an engine as the air does not 'mix' (probably not the best word to use) with the fuel as well. thus you get a lesser explosion

therefore we want turbulent flow. preferably very cold air for the o2.

it would be ideal for the flowing air due to the car moving at speed to be forced down a tube or duct straight into the engine at speed causing turbulent flow thus the sealed box type filters. this air would be both cool and under some pressure

but on the other hand this is no use when you are pulling away from stand still as the car has to try and suck the air down the pipe so the shorter the pipe the better ie less resistance

i had one idea of having two filters (dont laugh) one which had a cone style filter which dragged the air from wherever it could with the least resistance possible the other would be piped in with polished pipes to reduce the friction factors involved thus keeping the speed of the air as high as possible.

the problem would be trying to fit some sort of none return valve to the open cone filter so that when the flow of air down the boxed filter is greater than the suction of the engine then the air would be pumped into the engine and not out the open cone filter

this would all probably be a waste of time due to the amount of weight i would add to the car

i can see me having to dig out my copy of Ansys for some further tests

any suggestions

Anonymous · May 31, 2004, 17:23

another thing.

i cant remember where i saw it but some one on here tried a dyno test without the filter at all with no increase in bhp

as i have never even seen a test carried out please bare with me.

is the test carried out with air pushed into the inlets at the same speed as the road test would produce.

as i think this is were you would see a difference

MRMike · May 31, 2004, 17:56

I'm pretty sure Steve, or Tem tried it. I've tried it as i didn't believe them s:lol: :lol: s:lol: no out of curiousity and it made no difference on the GTECH. Same with venturi tubes going into the bottom of the airbox. It might make a difference, just to small to see taking into account sampling error.

I will find something..haha s:lol: :lol: s:lol:

Anonymous · May 31, 2004, 18:15

those tubes they are talking about on that site, where they use a pipe which reduces in diameter and then grows again. only work with a contsant flow rate of air. and they only work if the air reaches super sonic speed just at the point where the pipe then increases in size. i doubt you will get this speed from the air ducts. it might work well with a super or turbo charger

if you figure something out let me know as i am thinking about some sort of custom intake mod

even possibly piping cold air over a sealed cone filter with some sort of variable speed fan in the ducting to increase the airflow

are the side scoops/vents for collecting air for the engine or are they purely for the engine cooling

all this and i think i will need to chip the car and map accordingly

why oh why did i not pay more attention in my fluid dynamics lectures s:roll: :roll: s:roll: s:roll: :roll: s:roll:

another idea was to try and connect some sort of cooling system to the air intakes using th ac unit but having this on will negate the little power increase achevied

ah another idea peltier coolers surronding the air pipe these use twelve volts as well

Anonymous · May 31, 2004, 21:02

I made an intake that had a short ram and a longer tube (they met in a Y) with a filter on the end of each tube. I started out with the idea of having a solenoind close a butterfly valve (bought a 82mm throttle body and put it in there and everything!) to open up the short tube at a crossover RPM, but found that this direction was not the way to go.

With both tubes open, it performs OK, but not as well as with most of the long tube blocked off, leaving a resonant cavity (that way it performed well enough to (temporarily) claim the 1/4 mile record for N/A according to Monkeywrench. My new design is a little better.

Anonymous · May 31, 2004, 21:14

i idea what the max flow rate that the engine requires? i know this will vary for rpm temp humidity and all sorts of things but i am after a worst case senario

just heard about a guy who had a collapsable bag with a pump and an in built filter this was plumbed in with a cooling element which he wouldnt diviluge. the idea behind this was to produce a pocket of cooled air for those 1/4miles when the car was up to speed it would automatically push more air than the engine needed thus inflating the bag

did that make sense
does it sound like it would work

MRMike · May 31, 2004, 21:42

Quote from: "Beanie"With both tubes open, it performs OK, but not as well as with most of the long tube blocked off, leaving a resonant cavity (that way it performed well enough to (temporarily) claim the 1/4 mile record for N/A according to Monkeywrench. My new design is a little better.

Yeah sorry about that Old Boy! s:lol: :lol: s:lol: So have you got enough people to trial your new intake? Hows it progressing? I see your time is being taken up with the fan idea.. Any more news on the Street configuration?

Cheers,

Mike

MRMike · May 31, 2004, 21:47

Quote from: "adz648"those tubes they are talking about on that site, where they use a pipe which reduces in diameter and then grows again. only work with a contsant flow rate of air. and they only work if the air reaches super sonic speed just at the point where the pipe then increases in size. i doubt you will get this speed from the air ducts. it might work well with a super or turbo charger

if you figure something out let me know as i am thinking about some sort of custom intake mod

even possibly piping cold air over a sealed cone filter with some sort of variable speed fan in the ducting to increase the airflow

are the side scoops/vents for collecting air for the engine or are they purely for the engine cooling

all this and i think i will need to chip the car and map accordingly

why oh why did i not pay more attention in my fluid dynamics lectures s:roll: :roll: s:roll: s:roll: :roll: s:roll:

another idea was to try and connect some sort of cooling system to the air intakes using th ac unit but having this on will negate the little power increase achevied

ah another idea peltier coolers surronding the air pipe these use twelve volts as well

Well my ideas are completely trial and error as I have no idea about volumetrics, or fluid dynamics etc apart from what I learn as I go along! Which tubes are you referring to in your post Adz?

Mike

Anonymous · May 31, 2004, 22:13

i think they are called converging-diverging nozzle

what happens is that when the air or whatever is passed down the nozzle when the diameter decreases it increases the speed of the airflow till it reaches a supersonic speed then (if setup properly) then you can increase the speed even further by increasing the diameter of the nozzle. this will only work if you reach the supersonic state at the very point that the nozzle expands.

this all comes at a cost though you drematicaly increase the resistance in the tube

i had to complete a 5000 word sa on this thing explaning why this happens and i still to this day have no idea why. it just does alright!now what did i right for the other 4996 words?

i think this is the one they are going on about.

Anonymous · May 31, 2004, 22:59

after reading that site once more they all said that cooling was the way forward

perhaps we can come up with some sort of scoop to force cold air into the filter i will get under my car and see what we have got

i wouldnt mind the peltier coolers but i dont think they will have enough umph

it would be worth lagging all pipes and trying to make the tubing as smooth as possible

i will get on to my mate he is a design engineer for cooling of nuclear power stations so hopefully he will have some tricks

not sure if this is any use
m http://www.stephengrant.com/celica7/aeminstall.htm m
or this
m http://www.mgf.ultimatemg.com/importan.htm m

Bongo · May 31, 2004, 23:03

I'm guessing most cooling solutions will be too heavy to actually show any benefit - otherwise they'd surely be fitted to (at least some) cars as stock.

Anonymous · May 31, 2004, 23:07

true

MRMike · May 31, 2004, 23:19

I've tried to find ways of fitting venturi pipes to the base of the filter, and flow forward. It's quite a job to find any clear space to fit them. And ultimately the only place I could, ended up with the pipe near enough making a loop, which evidently did nothing for performance. I could really do with a pocket logger...

Anonymous · June 1, 2004, 00:55

MRMike,

Corky (CeeDapp) has mailed me the new tubes, but they have not arrived yet. There is no reason to believe they will not work well is all I can say at this point. He wants to try the short tube w/out internal vanes because it will be harder/more expensive to get the vanes inside the tube. I think we will need the vanes to cause smooth (I guess you could say "laminar") airflow going past the MAF. He's fabricating the exact size (inside diameter) tube for the short section and that is critical for accurate MAF reading and the right velocity. I'm really looking forward to having a finished product.

My short tube narrows down from 3 inches ID to 2 9/16ths, but does not do it gradually. I forget if I have posted a picture here, so here it is. This is without insulation and still using a stock part. It is just the "racing" configuration.

As installed right now, there is a lot of insulation around the resonator and the rest will be covered, too. The filter is HP Racing and very much the same as an Apex'i... inverted cone at end. A hose routes air from side vent to filter and I'll add another one. I had a heat shield around it (not completely), but performance suffered. There is more info SpyderChat.

Tem · June 1, 2004, 06:25

Quote from: "Beanie"Well, I thought Finland was too cold

It's not that cold over here s;)

s;) Actually it's not uncommon to have +100F in the summer...

Quote from: "MRMike"I'm pretty sure Steve, or Tem tried it. I've tried it as i didn't believe them s:lol: :lol: s:lol: no out of curiousity and it made no difference on the GTECH. Same with venturi tubes going into the bottom of the airbox.

I tried removing the stock filter, but keeping everything else in place and that made no difference. Didn't touch the tubes or anything s8)

s8)