CAI Intakes..Cold Air or Ram Air?

Started by MRMike, May 28, 2004, 23:11

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MRMike

May 28, 2004, 23:11 Last Edit: January 1, 1970, 01:00 by MRMike
 m http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... eName=WDVW m

I know this has been discussed before..but I thought the paragraph

"expect increased accelaration at low end revs and achieve a higher top end speed. this is a resistor modification that tells the engine control unit (ECU) that all the air coming into the unit is cold, dense and therefore packed with oxygen. the ECU takes this information and tells the infectors to fuel slightly more. this makes for a more powerful detonation in the cylinders and releases the full potential of the engine."

..was interesting..

Would this cause any damage in the long run? Presumably the engine will be running rich, but what are the other side effect apart from clogging cats? O2 sensors etc?

Also generally does the ECU increase the fueling as a result of the temp of the air, or the volume of air? Or a combination of both? For instance the Pelican RAcing intake is known for its gains in performance, but is this because it receives more cold air? or that the air is rammed in and thus has more volume? I've always though that the CAI is a bit of a misdemeanour as surely the temp of the air is the same..? or is moving air always colder???

I'm bored and thinking so please forgive my innane jabbering
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Anonymous

#1
May 28, 2004, 23:18 Last Edit: January 1, 1970, 01:00 by Anonymous
The link you supplied is just one of those rip-off resistors that you fit to your ecu or something.... not sure what it has to do with CAI?

Basicly they are talking bollox   s:lol: :lol: s:lol:

markiii

#2
May 28, 2004, 23:35 Last Edit: January 1, 1970, 01:00 by markiii
absolutley no benefit at all.

so you tell teh ecu that the air is dense and cold, that doesn't make it so,

more fuel with the same air, will run rich, it won't make more power just drink more fuel and shorten your catalyst life.
Gallardo Spyder<br />Ex Midnight Blue 911 T4S<br />EX VXR220<br />Ex Custom Turbo 2001 Sahara Sun MR2 Roadster 269bp, 240lbft<br /><br />MR2ROC Committee 2002 - 2009<br /><br />

MRMike

#3
May 28, 2004, 23:40 Last Edit: January 1, 1970, 01:00 by MRMike
Quote from: "markiii"absolutley no benefit at all.

so you tell the ecu that the air is dense and cold, that doesn't make it so,

more fuel with the same air, will run rich, it won't make more power just drink more fuel and shorten your catalyst life.

When you say "same" air is that volume or temp Mark?
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

MRMike

#4
May 28, 2004, 23:41 Last Edit: January 1, 1970, 01:00 by MRMike
Quote from: "krisclarkuk"The link you supplied is just one of those rip-off resistors that you fit to your ecu or something.... not sure what it has to do with CAI?

Basicly they are talking bollox   s:lol: :lol: s:lol:

Yeah I know that the Gizmo is bollox, I was just wondering about what they said and the relevance to a CAI! ie cold air = increased performance sorry completely round about way of asking!
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Anonymous

#5
May 28, 2004, 23:58 Last Edit: January 1, 1970, 01:00 by Anonymous
i actually went and bought one of these last year for my last car, it wouldn't fit though as the MAS socket it plugs into had 4 connectors and it needs just 2. if i can find it ill happily post it to someone who's willing to try it out??   s:lol: :lol: s:lol:    s:lol: :lol: s:lol:    s:lol: :lol: s:lol:    s:lol: :lol: s:lol:

Anonymous

#6
May 29, 2004, 00:52 Last Edit: January 1, 1970, 01:00 by Anonymous
Quote from: "MRMike"http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=32094&item=7903232052&rd=1&ssPageName=WDVW

Also generally does the ECU increase the fueling as a result of the temp of the air, or the volume of air? Or a combination of both? For instance the Pelican RAcing intake is known for its gains in performance, but is this because it receives more cold air? or that the air is rammed in and thus has more volume? I've always though that the CAI is a bit of a misdemeanour as surely the temp of the air is the same..? or is moving air always colder???

I'm bored and thinking so please forgive my innane jabbering

The only reason that you get more power with cold air is that the air is denser when cold, which therefore means it contains more oxygen per unit volume and thus can support the burning of a larger amount of fuel per unit time. The ecu meters the fuel in accordance with the mass rate of flow as measured by the MAF sensor i.e for cold dense air it will increase the fuelling to compensate.

A good CAI will draw all of its air from outside of the car - which in some cases will be better than the stock airbox but TBH if you look at most CAI kits they are worse than the stock setup since they usually consist of a cone filter stuck in the middle of the engine bay with a cold air feed pipe stuck next to it. I would say that a lot of the time it's the increased noise that they make that makes the car sound faster - which isn't necessarily a bad thing.

If you can ram the air into the engine then you are increasing the pressure and thus density which is beneficial as described above but I don't know of any ram air systems for the 2 other than the obvious - turbo, which you wouldn't really describe as a ram air system.

Anonymous

#7
May 29, 2004, 01:22 Last Edit: January 1, 1970, 01:00 by Anonymous
I think that a resistor mod would make it run leaner or richer (depends on whether more of a voltage drop equates to more or less airflow) at WOT.  At partial throttle, the O2 feedback will tell the ECU whether it is running too rich or too lean and the ECU will compensate.  (You can disable feedback with a Power FC, but if you have that, you don't need the resistor.)

Ram air?  You can't get enough pressure from that to do any good.

PR intake works well because of a short, straight intake path, which has a greater effect on performance (esp. at higher RPMs) (compared to stock intake) than does intake air temperature.  You can improve upon it by routing air through a duct from the side vent right to the filter cone.  I had a heat shield on my prototype street/racing intake and the overall effect was either nothing or (I think, not measured) actually negative.  I think negative because it blocked air from moving from side vent PAST the filter and into the main area of the engine compartment.  You can improve upon PR in other ways, too.

MRMike

#8
May 29, 2004, 01:24 Last Edit: January 1, 1970, 01:00 by MRMike
Quote from: "RUSTY"
Quote from: "MRMike"http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=32094&item=7903232052&rd=1&ssPageName=WDVW

Also generally does the ECU increase the fueling as a result of the temp of the air, or the volume of air? Or a combination of both? For instance the Pelican RAcing intake is known for its gains in performance, but is this because it receives more cold air? or that the air is rammed in and thus has more volume? I've always though that the CAI is a bit of a misdemeanour as surely the temp of the air is the same..? or is moving air always colder???

I'm bored and thinking so please forgive my innane jabbering

The only reason that you get more power with cold air is that the air is denser when cold, which therefore means it contains more oxygen per unit volume and thus can support the burning of a larger amount of fuel per unit time. The ecu meters the fuel in accordance with the mass rate of flow as measured by the MAF sensor i.e for cold dense air it will increase the fuelling to compensate.



Okay Great thats what I assumed

Quote from: "RUSTY"A good CAI will draw all of its air from outside of the car - which in some cases will be better than the stock airbox but TBH if you look at most CAI kits they are worse than the stock setup since they usually consist of a cone filter stuck in the middle of the engine bay with a cold air feed pipe stuck next to it. I would say that a lot of the time it's the increased noise that they make that makes the car sound faster - which isn't necessarily a bad thing.

If you can ram the air into the engine then you are increasing the pressure and thus density which is beneficial as described above but I don't know of any ram air systems for the 2 other than the obvious - turbo, which you wouldn't really describe as a ram air system.

Yeah I know about the supposed gains of many of the CAI.  What I was asking albeit badly was, if a filter is exopsed to external airflow, why is it that its colder? Surely the ambient temp is the same, only the charge increases? Unless there is heatsoak within the Engine bay and that is why the exposure to the external air results in a slightly cooler air inlet temp?
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Anonymous

#9
May 29, 2004, 01:27 Last Edit: January 1, 1970, 01:00 by Anonymous
im planning to install a liquid nitrogen tank next to my airbox, now that would be a COLD air intake!   s:wink: :wink: s:wink:  




only jokin, its late and this topic is getting too technical for me so im off to bed...

markiii

#10
May 29, 2004, 08:35 Last Edit: January 1, 1970, 01:00 by markiii
Quote from: "MRMike"
Quote from: "markiii"absolutley no benefit at all.

so you tell the ecu that the air is dense and cold, that doesn't make it so,

more fuel with the same air, will run rich, it won't make more power just drink more fuel and shorten your catalyst life.

When you say "same" air is that volume or temp Mark?

point being yiour tricking it, you can tell it teh air is colder thanm it is, but it's still tehsametemp it's always been.

So more fuel  fine, but no more oxygen, so no benefit.
Gallardo Spyder<br />Ex Midnight Blue 911 T4S<br />EX VXR220<br />Ex Custom Turbo 2001 Sahara Sun MR2 Roadster 269bp, 240lbft<br /><br />MR2ROC Committee 2002 - 2009<br /><br />

Anonymous

#11
May 29, 2004, 08:54 Last Edit: January 1, 1970, 01:00 by Anonymous
Quote from: "MRMike"
Quote from: "RUSTY"
Quote from: "MRMike"http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=32094&item=7903232052&rd=1&ssPageName=WDVW

Yeah I know about the supposed gains of many of the CAI.  What I was asking albeit badly was, if a filter is exopsed to external airflow, why is it that its colder? Surely the ambient temp is the same, only the charge increases? Unless there is heatsoak within the Engine bay and that is why the exposure to the external air results in a slightly cooler air inlet temp?

A filter that is exposed to external airflow is colder simply because it's not drawn from within the hot engine bay. The other area in which a CAI is suposed to help is by being less restrictive and thus allowing a greater flow rate of air so basically what you've just theorised is correct.

MRMike

#12
May 29, 2004, 11:10 Last Edit: January 1, 1970, 01:00 by MRMike
Okay cheers guys think that is a bit clearer in my mind now....really musn't eat cheese before I go to bed in the future   s:D :D s:D
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

MRMike

#13
May 29, 2004, 12:32 Last Edit: January 1, 1970, 01:00 by MRMike
Never thought about this..and its a crazy ass idea..but instead of trying to get colder air/increased volume into the inlet, what if you could make the element more reactive? Say for instance on the inlet pipe, you wrapped wire around it to create an electromagnet..not sure which current you would have to use to strengthen the bonds in an O2 molecule..but say it was possible to strengthen the bond that held the oxygen molecules together... that way when it burns you'd assume it would be more reactive and thus more efficient.  If you had high enough RON you could probably ellimate knock as well....

I have no idea about Chemistry so the assumptions are probably wrong..but in my elemental thought process it seems plausible...! (probably need a rather large electromagnet to make it work though that would render it useless for car use)
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Liz

#14
May 29, 2004, 21:38 Last Edit: January 1, 1970, 01:00 by Liz
Didn't Darth try and experiment with something wrapped around the inlet pipe, any update on that??
ex-TTE Turbo, now Freelander Sport, its not a car its a Landrover!

Darth Paul

#15
May 29, 2004, 21:57 Last Edit: January 1, 1970, 01:00 by Darth Paul

MRMike

#16
May 29, 2004, 22:02 Last Edit: January 1, 1970, 01:00 by MRMike
Missed that! Oh well glad it worked! Right back to my particle accelerator...  s:lol: :lol: s:lol:
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Anonymous

#17
May 29, 2004, 22:21 Last Edit: January 1, 1970, 01:00 by Anonymous
gold is the best reflector of heat, why dont you replace the tin foil with 24k plated gold Darth   s:lol: :lol: s:lol:    s:lol: :lol: s:lol:    s:lol: :lol: s:lol:  

have you seen the engine bay of the mclaren F1? WOW!

MRMike

#18
May 29, 2004, 22:28 Last Edit: January 1, 1970, 01:00 by MRMike
Have you seen the price?   s:lol: :lol: s:lol:
[size=75]*Sold 03 UK spec, silver, Red Interior TTE Twin, Euro spoiler, TTE Chrome roll bar, Blitz Induction, VVTI Badged, Pioneer SAT Nav/DAB Tuner, Boston Acoustics Components, Boston amp, Gtech Pro C, TRD Gearknob, B&M linkage, Bama Deflector, Chrome dials, Corky Breast Plate, TTE springs,

Then.. Blue 350Z
and den....black S2000 with red leather interior  
and den.... New Imola Orange S2000
and den.....BMW Z4 3.0 - Understeer!!!![/size]
NOW M3 V8

Anonymous

#19
May 29, 2004, 22:35 Last Edit: January 1, 1970, 01:00 by Anonymous
yes, and if i'd have won tonights mammoth lottery, id have one!   s:lol: :lol: s:lol:

Darth Paul

#20
May 29, 2004, 23:08 Last Edit: January 1, 1970, 01:00 by Darth Paul
To match the gold-plated visor on my helmet?

Tem

#21
May 30, 2004, 10:48 Last Edit: January 1, 1970, 01:00 by Tem
Btw, now that I have the PFC, I've been following the intake temps with Apexi intake kit (among others)...and it has been going above 55C  s:? :? s:?  I have removed the underside diaper and the drip tray, so that should actually be cooler than with them on. So DP's idea would probably be a good idea for anyone with this intake (haven't done it myself yet).

For some reason the temps don't get that high when crawling in traffic or waiting in lights. I guess things get hotter in there when the engine is under load, even if there's airflow at that time...
Sure you can live without 500hp, but it\'s languishing.

Anonymous

#22
May 30, 2004, 17:11 Last Edit: January 1, 1970, 01:00 by Anonymous
Above 55 deg C is very surprising.  The highest I have ever seen was 50 and this was here in Florida on a hot (at least 100 deg F) day in traffic.  What I have observed, with AEM, PR, and my work-in-progress intake, is that air temp goes up by as much as 10 deg C on a hot (above 90 F) day due to little or no airflow (from forward motion).  Insulating the intake tract is a good idea to keep heat from "soaking" into it, but may not be effective enough for my taste.  My intake tract is quite short... not much to insulate.  I think a better solution is to keep air flowing through the engine compartment.

Right now I'm working on (in addition to intake) a fan that sits between the head / header area and decklid.  I plan to make it manually controlled (already have a 3-position toggle switch mounted in dash where "change jiggler" was) at first, then have a choice between OFF, ON, and AUTO.  In AUTO mode, it will work something like this:

1.  Min intake air temperature to turn on (maybe 80F).
2.  Min temp difference between intake air and outside air (maybe 10F) to turn on.
3.  Max speed (maybe 15 or 20 MPH) to turn on.
4.  Min and Max time to run once turned on.
5.  Min time between turning off and turning on.

Intake air temp can be grabbed from THA pin on ECU (or PFC).  80 deg F is about 1.0 VDC.  Outside air temp will be sensed from side vent probably.  I'm trying to talk an EE buddy into designing the whole circuit.  I'd like to publish the plans (part numbers, schematic).

The idea is to blow the hot air (this 12" SPAL pusher fan is good for 1280 CFM) out of the engine compartment when in traffic so the heat does not build up.  A 10" fan would fit better... I made a bad choice there.

Tem

#23
May 30, 2004, 17:38 Last Edit: January 1, 1970, 01:00 by Tem
Quote from: "Beanie"The highest I have ever seen was 50 and this was here in Florida on a hot (at least 100 deg F) day in traffic.

On a "hot" day in traffic I've only seen some 43C IIRC. We haven't really had any hot days this year so far though...

It went above 55C on a long drive at around 150kmh (near 100mph). So there was definitely airflow, but also load on the engine for long time. According to some roadside monitors, the air temp was around 20C, but the road temp was ~40C...and I guess it pretty much just sucks air from the road surface..


Your idea sounds interesting *thumbs up*  s8) 8) s8)
Sure you can live without 500hp, but it\'s languishing.

Anonymous

#24
May 30, 2004, 21:41 Last Edit: January 1, 1970, 01:00 by Anonymous
thats interesting that the engine air temp actually went up while doind 100mph as there would be so much air flow being directed to the engine bay.

we definately need some fans in there to shift that hot air...

or   s:idea: :idea: s:idea:  : a water cooling system, as water is 30 times more efficient at shifting heat, think that we be a very complicated thing to do tho   s:wink: :wink: s:wink:
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