your all affected by this hp loss

[slakker]

Tonight I was testing with the thermo's and found something that sucks. First to catch you all up, I ran copper tubing from inside the car to the intake hose. I wrapped the intake hose near the throttle body with the copper tube and cut holes in it . I attached a c02 tank to the copper pipe with a valve and faced the holes towards the intake pipe. I cut a total of 15 holes in the copper tube. My attemp was by turning the co2 cannister upside down the liquid would spray on the outer side of the intake pipe cooling my intake air. We'll it worked, minimally. It did freeze the intake pipe pretty thoroughly. Only giving me about 15 degrees consistantly. But over the period of 3 minutes I went through 14 oz of co2. Thats alot.\to my point

I live in Pa and it is winter. The outside temp was 28 degrees, using 2 thermometers I placed on inside the tube next to the throttle body and the other after the cone filter (I have a modified intake. My cone sits on the passenger side). Even though there is only about a total of 2 ft of pipe, the results were bad. At the cone I was getting a temp of 34 degrees and at the throttle body the temp was 62 degrees. 28 degree difference. Thats approx. 3 hp. Not alot, but if you could deny that it sucks, then you dont belong on this forum.

The only good thing is that the longer you have it at full throttle (or close) the faster the temp dropes. Only at a rate of about 8 degrees a minute. You would have to keep it punched for awhile to get that back. Highway probably, but then your in 5th gear and it doesnt matter as much.

P.S. I changed my transmission fluid to redline mt-90 and it is freakin great. Ive never had as sweet shifts. If you dont have it, get it.

[Hijacker]

you have too much time on your hands

[themadscientist]

Does the 240SX have the intake pipe crossover the radiator? If so the pipe is soaking up heat from the radiator top tank. I countered this on my Silvia by mounting the AFM on the same side as the trottlebody by extending the AFM wiring. I then cut out the corner light turning it into an air scoop.

[slakker]

No my intake pipe is on the same side as the throttle body on the sohc. It is not near any heat radiating devices, except for the engine itself.

tenkawa_akitoTwin T51R's and NOS

You have 1133 posts, you have too much time on your hands. It is great to come here to learn, but what is the point if none of it is used. You didnt know such a thing, so you arer welcome. And Im not being rude, your post is just questionable

[C-Kwik]

Care to explain your test a little more clearly. I am quite skeptical of your numbers. They just aren't very reaonsable. It's unlikely your intake ir radiating 34 degrees of heat into the intake stream. Especially if the tests were conducted with the throttle down to any extent. And especially with only 2 feet of pipe.

Check out this article:

http://www.autospeed.com/cms/A_0527/article.html

In it, you will see where the writer discusses a rise in intake air temperature after a long boost run. It's basically because the intake air is cooling the intercooler from the inside and absorbing heat. Now keeping in mind that an intercooler can get fairly warm during a long run, and that it is designed to transfer heat quickly, it's remarkable that the guy only saw an increase in intake temperature of about 5-10 degrees. So for you to see a 34 degree increase in a 2 foot span of pipe that is not designed with heat transfer in mind is just not very reasonable. And consider an intercooler is designed to aborb a lot of heat from a relatively large amount of air.

I think something is flawed with your test(not with what you saw on your gauge, but rather that there was something else screwing up the reading). Perhaps your second temp probe is coming into contact with the intake pipe itself. I don't know. I'm speculating on that, but it seems like something like this has to be causing your unusually high reading. A hot intake pipe can easily increase the temperature of a temperature probe that is in contact with it. Considering most probes designed for mild to moderate heat are made of a soft metal like copper or aluminum. Both of which have very good heat transfer properties. The proble would also not reach the actual temp of the pipe in this case as long as air is moving across it. The air cools the portion of the probe in comes into contact with. And since these probes can transfer heat well, it pulls the heat from the area of the probe in contact with the hot pipe. Try turning off the motor with everything warmed up. If the temp probe heats up very quickly then you may need to look for contact. It should increase slowly as the air inside the pipe slowly heats up.

I'd like to know what you meant by 15 degrees when you used the CO2 as well. 15 degrees absolute? And increase of 15 degrees? A decrease of 15 degrees? And if you are in fact describing a difference, from what point?

[HaveBlue]

good work. i got a thermometer with a long wire to test this myself. most after-market intakes do still go over the radiator so the effect is even more noticeable. some people have eliminated the hose that runs coolant through the intake manifold for warm up purposes as well. try wrapping the intake with header wrap to keep the heat out, that might keep the intake cool even though it passes close to the engine. This is what i was going to try but never got around to it.

[slakker]

Holy **** man. Ok where do I start.

Well the intercooler is transfering out not in. More heat is being displaced, meaning none can be drawn in. If it is dissipitating 500 btu's a sec it cannt absorb any amount less than that in BTU's.If heat were to be applied to it then It would get hotter faster than my intake pipe. The intake does not have good heat transfer properties therefore when it is warm, it keeps it.My car is at normal operating temp and at idle showed that difference. When heavy throttle was applied and the intake air moved faster it dropped quickly. But at idle these were the results. That is a good article, but worthless in this case. I have no extreme temps and no heat dissipating abilities. Therefore qwhen I let off the throttle, heat is not reentering my inatke, as is his. It is only acheiving its normal temp after the cooling properties of a mass amount of air. At full throttle the cold air drawn through the intake doesnt even allow the intake pipe to cool down, but a few degrees if that. Therefore when the cold air is removed the intake reheats the incoming air.

I do understand how a thermo works. The temp giver itself is within the first 1/4 inch of the probe. So it would greatly affect the heat reading. This was not the case. After running the tests, and a lttle bit of time (45 min), they began to show the same temp. Not close but getting there. Showing that the intake pipe held its powerrobbing temp as long as the engine held itas temp. The throttle body, being in contact with the intake, and so close, kept its heat up. Even though the aluminum intake pipe wouldtransfer heat faster, in which case it did acting like a intercooler and soaking it up from ..1 engine bay 2 throttle body 3 Misc.

The fifteen degrees was a drop in intake air temp, from the 62 it was to 48 degrees immediately before the throttle body. . this was after 14 oz of co2 and a thoroughly frosted intake pipe. The frosted section amounted to about 6 - 8 inches of pipe

I am grateful of you questions, gave me the chance to analyzer my findings and gave me some ides for more tests. It is ashame the it isnt effecient. What about compressed air. If used in liquid form, injected into the intake pipe. If injected correctly, like right before the tb, then when it expands into the gas form, it will already be in the cylinder. Thus not being able to expand, therefore taking upm less space, therefore allowing more air, Giving a greater explosion........HP. Not to mention it temp would be ridiculiously low.

[slakker]

cool have blue. I was curious, but never expected such evil results. There is metallic heat tape at hardware stores. I am going to try that. I WILL get the best results. I am going to try everything there shouldnt be any heat loss (in magic world I know) THERE IS a hose that runs through the intake manifold. Is it always open and hot. That sucks. What would be the ill effects of removing that,. Ill have to look into that

[HaveBlue]

you don't want metallic tape. you want non-heat conductive stuff to keep heat out. unless i miss-understood.anyway, make SURE your sensors are not touching metal or excessively hot or cold parts of the intake/manifold etc.for example: your temp sensor on the filter is attached to the filter, cold air cools the outside of the filter and the whole filter itself, and thats the reading you get (too cold)or the temp sensor at the intake is touching something hot, as you rev the motor it produces more heat resulting in a skewed reading (too hot). you end up with a HUGE difference in what appears to be air temp.keep in mind also that the sensors take time to heat up and cool down to a stable reading. you would have to maintain the same level of airflow for some time to ensure the readings have stabilized (maintain speed/rpms).you are also sucking in hotter air from the engine bay the longer you maintain high rpms because the engine heats up the engine bay. so the air temp could continue rising but the sensor heats up slower than the surrounding air....damn, lots of possible little problems with the test method. a delta of 28 degrees is just too much, especially with such a short run of pipe. over the radiator i could believe it though.

[sgpnismo]

you have too much time on your hands

lol, yes he does.

[HaveBlue]

hmmm, then again i dont think energy transfer is linear. ie. if you place an object next to something very hot it will increase in temp faster than if its placed next to something just a tad warmer.the physics escapes me (http://www.taftan.com/thermodynamics/PIPE.HTM) but lets assume the engine/block is 200 degrees. if the air entering the engine is 0 degrees (for the sake of argument) it should heat up to 50 degrees. but if its 50 degrees it will heat up to 60 degrees upon entering the motor before combustion. (i made those numbers up, so if anyone can actually do the math, please do) not much difference.in the end its gona be a wash. the difference in energy you get from air thats 0 degrees and 50 degrees is insignificant when you compare it to the amount extracted from the actual combustion.the only time you start worrying and get an intercooler is when your starting temperature is much higher (coming out of a 1800 degree turbo) and thats usualy to reduce the chance of detonation. you also make more power but you are cramming about twice as much air into the motor compared to normal (and even more air the cooler it is, due to cooler air being more dense).if your not compressing the air beforehand these differences are gona be too slight to notice. think about how much performance difference you see on a REALY hot day and a REAlY cold day, not that much.

[HaveBlue]

godamnit, now you got me thinking about this.lets assume the power to be gained here is from the fact that cold air is more dense so you are burning more air with your fuel. you will be burning more fuel as well because the ecu is designed to compensate for ambient air temp to a certain degree. so just how much more oxygen molecules do we have between a 28 and 68 degree mixture of oxygen? thanks to the handy dandy internet i found (http://www-tech.mit.edu/Chemicool/idealgas.html) which makes the calculations easy. my calculations at 1 bar, 1 liter at the two different temperatures resulted in a difference of about 8%. so you would have 8% more air in your combustion assuming you could cool the air entering the engine at the intake manifold to 28 degrees. Even IF you could reduce the temp to that, thats not gona result in an 8% difference in power. all those inefficiencies working against you.

[C-Kwik]

Actually, heat always transfers from a hotter medium to a cooler one. Under boost, and assuming the intercooler remains cooler than the air temperature of the charge air, then it will absorb heat from the charge air. As soon as you let off the throttle, the car no longer boosts. This means that the temperature of the air going through the intercooler will be significantly less. If at this time, the intercooler is hotter than the air going through it, the heat will go into the air and into the motor. My point was that intercoolers have turbulators to effectively provide more turbulance and more surface area to transfer heat. So if a warm/hot intercooler only increases temps some 5 to 10 degrees. I'm gonna correct myself here and point out that the site I referred is in Celsuis. That being the case, this works out to 41-82 degrees Fahrenheit. While it works against my argument here a little, consider still. That's less than 10 degrees hotter than what you are seeing. And that's considering that air going through a hot intercooler will pick up heat much faster than air going through a hot pipe. So, if you are seeing that much heat, something is wrong. Even if it's over the radiator.

Curious....are you testing this at idle? Or Full throttle? what kind of differences are you seeing. More importantly, what is the change in temperature as soon as you go from idle to full throttle? There should be a temperature drop there, especially if you are getting some 34 degree increase in intake temperature at idle. If you are not seeing this change, something is definitely wrong. Since the change in temperature right when you go from idle to WOT would not change much, but the airflow increases and the dwell time of the air in the intake decreases, the intake temp should see a dramatic drop.

My argument is not that an intake pipe can not be hot. Of course it will absorb heat from surrounding heat sources. But it will do so at a rate that is much slower than that of something that has good heat transfer properties. As such, it will also lose heat at a slower rate as well.

Lastly, if you frosted 6-8 inches of a 2 foot pipe, I would expect much of the rest of the pipe would be pretty cool as well. That being the case, if you can transfer heat into the air as quickly with a hot intake pipe, then theoretically, you should be able to transfer heat from the intake air into the pipe just as quickly. This would result in a cooler intake air temp than what is going into the motor. I do know how cold CO2 can get. If you were able to frost the pipe, then much of the pipe was probably below the freezing temperature of water.

As far as the probe touching something, it was only speculation. I'd investigate to make sure nothing is skewing your numbers here. A 34 degree increase in heat still just seems like way too much to me. I'd even be surprised if it increased by 5 degrees.

[C-Kwik]

hmmm, then again i dont think energy transfer is linear. ie. if you place an object next to something very hot it will increase in temp faster than if its placed next to something just a tad warmer.the physics escapes me (http://www.taftan.com/thermodynamics/PIPE.HTM) but lets assume the engine/block is 200 degrees. if the air entering the engine is 0 degrees (for the sake of argument) it should heat up to 50 degrees. but if its 50 degrees it will heat up to 60 degrees upon entering the motor before combustion. (i made those numbers up, so if anyone can actually do the math, please do) not much difference.in the end its gona be a wash. the difference in energy you get from air thats 0 degrees and 50 degrees is insignificant when you compare it to the amount extracted from the actual combustion.the only time you start worrying and get an intercooler is when your starting temperature is much higher (coming out of a 1800 degree turbo) and thats usualy to reduce the chance of detonation. you also make more power but you are cramming about twice as much air into the motor compared to normal (and even more air the cooler it is, due to cooler air being more dense).if your not compressing the air beforehand these differences are gona be too slight to notice. think about how much performance difference you see on a REALY hot day and a REAlY cold day, not that much.

I'm sorry, but this made absolutely no sense.

Yes, if the difference in temperatures is higher, more heat will transfer faster. But this is really only to an extent. There's an element of weight in here as well. It's technically down to the molecular level, but we'll keep things simple. It's been a while since I learned about all that stuff anyways. But the basic priciple is that a heavier, denser object will dissapate heat slower. It just has more molecules packed tightly together. So a 1 cubic foot block of iron will dissapate heat more slowly than a 1 cubic foot block of aluminum. Even if they are the same temperature. But the iron block of the same temperature will have released more heat(energy) by the time they both cool completely. It's not highly relevant to this topic however.

As far as 1800 degrees out of a turbo, that number is quite a ways off. A typical gasoline powered car probably won't be seeing much more than 1400 degrees in the exhaust manifold. If you were seeing 1800 degrees, you're probably already detonating. Secondly, the intake will never see 1800 degrees or even close to 1400 degrees from a turbo. At least not any turbo I know of. The heat that a turbo motor sees is mostly due to the air being compressed. As air is compressed, it heats up naturally. If you've ever had a compressed air tank for a paintball gun filled, the tank will feel a little warm after the fill. In the case of a turbo, you'ld have to boosting compressing air to an extremely high psi to obtain 1800 or even 1400 degrees. An intercooler is designed to remove the 100-200 or so degrees you add into the air when you compress it.

[SunshineAcid]

1stare you testing in your driveway or on the road?because theres a BIG difference in the two. what do you do with a car when youre looking to buy it? you let it idle in the parking lot for 20 mins. this is one of the hardest things you can do on a car, for it allows the enginebay temps to soar. if youre testing on teh road, air will cool down everything in your bay, especially your intake air.2nd.if youre trying to cool down with co2, dont do it on an intake pipe. they have co2 injection kits (which personally i dont like because they introduce co2 into your intake system) that injects co2 into your ic. this cools down the temps to the same scale as nitrous. if youre running turbo, you have the setup, spray the c02 on your intercooler. this is designed for heat xfer. you hear a lot about water sray, think about something as cold as co2. if you dont and you are that serious about intake temp. buy a smic, mount it, and run your intake through it, and *then* spray co2 all over that. youll see a nice drop.3rd.the engine (unless something is really wrong) will always operate at its set operating temperatures. this means the engine bay, at the end of the test, regardless of temp outside, will be near the same temperature in winter as spring and summer. (if at standstill) you have a 2.4 liter heater sitting in a what, 3x3x2 foot area? the point is i believe the rise in temp will be much less drastic when ambient air is warmer. your engine will still operate at the same temp, thus heating the bar to the same degree (roughly).there are a few exceptions to this of course, but if youre testing at a stop, youre going to get very high readings.(try the smic idea, i think it would work wonders if youre that concerned about incoming air temp)

[HaveBlue]

I'm sorry, but this made absolutely no sense.

As far as 1800 degrees out of a turbo, that number is quite a ways off.

My point was simply that the difference in energy you get from air thats 28 degrees and 68 degrees is insignificant when you compare it to the amount extracted from the actual combustion. But since the math is overly complicated for me I cant PROVE it.

Your right, 1800 degrees for the turbo is too hot. i looked it up and the air coming out of a turbo is going to be anywhere from 200-300 degrees.My argument stands until someone proves me wrong mathematically or with a real world example/test: the lower air temperature will not make a difference that is noticeable on an NA engine.

[slakker]

I am reading this but am at work and dont have the time to respond correctly. Ill respond tonight. Thanks for all the feedback, even if it is trying to discrredit me. A good topic is worth two in the bush. HEHE