m http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... eName=WDVW (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=32094&item=7903232052&rd=1&ssPageName=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
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:
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.
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?
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!
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:
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.
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.
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?
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...
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.
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.
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
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)
Didn't Darth try and experiment with something wrapped around the inlet pipe, any update on that??
http://www.mr2roc.org/forum/viewtopic.php?t=3884&highlight=remember
Missed that! Oh well glad it worked! Right back to my particle accelerator... s:lol: :lol: s:lol:
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!
Have you seen the price? s:lol: :lol: s:lol:
yes, and if i'd have won tonights mammoth lottery, id have one! s:lol: :lol: s:lol:
To match the gold-plated visor on my helmet?
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...
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.
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)
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:
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
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...
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.
just read this m http://forums.s2ki.com/forums/showthrea ... did=204172 (http://forums.s2ki.com/forums/showthread.php?s=&threadid=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
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
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:
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
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.
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
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
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
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.
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 (http://www.stephengrant.com/celica7/aeminstall.htm) m
or this
m http://www.mgf.ultimatemg.com/importan.htm (http://www.mgf.ultimatemg.com/importan.htm) m
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.
true
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...
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.
(http://www.spydermagazine.com/files/rubberYintake.jpg)
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.
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) 8) s8)