# CAI



## callen (Jul 31, 2005)

I see Hotshot ect CAI going for mad money $300usd for some bent tubing? Why? Makes no sense at all when you can get some PVC piping heat it up with a hotair gun and have the same thing or better as it won’t get heat soak like an aluminum tube CAI would. Am I wrong or on to something? :fluffy: (maybe I've inhaled too much PVC glue) :fluffy:


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## psuLemon (Apr 23, 2003)

callen said:


> I see Hotshot ect CAI going for mad money $300usd for some bent tubing? Why? Makes no sense at all when you can get some PVC piping heat it up with a hotair gun and have the same thing or better as it won’t get heat soak like an aluminum tube CAI would. Am I wrong or on to something? :fluffy: (maybe I've inhaled too much PVC glue) :fluffy:


you honestly have absolutely no clue about how metals vs pvc pipe work.. you wont gain shit from a pvc cai. the hotshot cai has been dyno proven and has the non ricer appeal to you. think before you speak please... ss intakes actually product gains and flows better and isn't bad for you car.


and the intake direct from hs is 225.. not even close to 300


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## xbrandonx (Mar 27, 2004)

and whlie it may just look like bent tubing, alot of time and money goes into "bending the tubing". The bends are set up to produce max hp not just because it fits.


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## psuLemon (Apr 23, 2003)

that doen't even include the fact the pvc will do wonders when particles go into your engine and make it go buh byes..


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## callen (Jul 31, 2005)

psuLemon said:


> that doen't even include the fact the pvc will do wonders when particles go into your engine and make it go buh byes..


WoW take a pill dude. First: of all what makes the power is the tuned intake length and width. These determine torque and hp increase and decrease so if you copied the diameter and length you'd get the same effect. Bending wouldn’t really matter unless it’s a curl as it’s a smooth bend. Second: partials from where? It’s not like its going to see the 250*f it needs to melt (or anything else plastic in the metal bay would) and if you cleaned up the cuts and used silicone flex tubes for the joins (just like hotshot does) at the filter, throttle body and intake manifold your not going to get any plastic to metal contact. And in the unlikely event a piece of plastic does come off and its not a huge piece it would just melt in the combustion and do nothing. Remember the stock intake box and other parts are made of pvc!


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## pete? (Jul 6, 2004)

callen said:


> Remember the stock intake box and other parts are made of pvc!


nope. those are made of ABS plastic.


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## callen (Jul 31, 2005)

pete? said:


> nope. those are made of ABS plastic.


Ops yeah thanks for the correction. PVC has a higher psi and heat tolerance then abs does anyways not that the heat and psi involved would get anywhere near ether plastic


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## psuLemon (Apr 23, 2003)

you can build your pvc intake if you like. But there is reasons (besides looks) why companies use a stainless steel to make intakes. First it has better flow. Yes lenght and diameter(not width) is what determines the gains from the intake. With the engine its a velocity stacker kit, 2.5" tb to maf then 3" from maf to fenderwell. A stainless steel system is more conducive to air flow. You made believe that intakes dont get hot, but take it to a track for a day and then grab the intake, it does get hot. Those partials, as miniscule as they are can get into your combusion chamble, hell if you have a shitty filter, dirty can start to clog both, thats why we say dont get weapon R intakes, filters are hella shitty. I am not tryin to be a dick, but there are reason why companies use certain martials.


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## callen (Jul 31, 2005)

psuLemon said:


> you can build your pvc intake if you like. But there is reasons (besides looks) why companies use a stainless steel to make intakes. First it has better flow. Yes lenght and diameter(not width) is what determines the gains from the intake. With the engine its a velocity stacker kit, 2.5" tb to maf then 3" from maf to fenderwell. A stainless steel system is more conducive to air flow. You made believe that intakes dont get hot, but take it to a track for a day and then grab the intake, it does get hot. Those partials, as miniscule as they are can get into your combusion chamble, hell if you have a shitty filter, dirty can start to clog both, thats why we say dont get weapon R intakes, filters are hella shitty. I am not tryin to be a dick, but there are reason why companies use certain martials.


If you look at my first post you'll notice I say PVC won’t get heat soak like the metal ones will and if they get hot they won’t get hot enough to break down or melt (PVC gets starts to get soft at 120*c or 250*f). I fail to see where or how PVC would make extra partials as well as how PVC would cause any more partials then say the stock flex tube. I understand the flow would be a little better due to a smooth polished stainless but not very much as the PVC would be nearly as smooth. We're not talking about a mechanical part with any wear going to happen from movement. As well for looks just sand it and paint it; then I'd be willing to bet it wouldn't look any different then the painted metal ones. 

I’m not trying to be silly or pushy but I want some real reasons as why I shouldn’t other then its just going to suck because I think its going to suck. If you have any temp readings on a normally aspirated metal CAI could you post them so I could see the temps that it would have to endure that would be great thanks.


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## mille-16i (Jun 16, 2004)

lets all calm down and go glue some pvc in an inclosed room in a few minutes we will be all happy again. SS has a horible heat transfer rate that is why it is used cause it will give less of its heat to the air and just hold it also you can make the interior smoother than a babys ass but thats really it you could copy a HS intake with Schedule 80 PVC and get similar results as long as you copy it to a T and remember that it is inside diameter that maters not outside diameter. If you cared not about looks you cold wrap it in insulation and that would help keep heat out and as for particles of PVC dude clean your cuts and prime it and you will have no probs I have seen PVC exposed to direct 100+ degree sunlight in the desert and it faded and weakened to preasure but did not deteriate


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## callen (Jul 31, 2005)

Thank you for an informed post you pretty much covered what I was trying to say. Unless someone can give me a clear negative I really can't see why I shouldn't just copy a Hotshot intake. If I had the money I wouldn't think twice about buying a true Hotshot as I think they make excellent products but right now $330cnd is just too much and my wife would kill me. For now I’ll just do what I can and spend maybe $15 on parts.


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## Zac (Mar 10, 2004)

As said, stainles steel does have a bad transfer rate. HotShot uses SX304 which is essentially the basic grade of high quality austenitic steel. It has excellent anti corrosive properties, good heat resistance, excellent weldability and lower cost. It may also be L304 which is a welding stabalized grade. Why is this used over plastic? Besides looking at dyno gains or flow charts, one reason of strength has to come in play. The CAI will infact heat up enough to be very hot to the touch. 304 will not corrode from the heat and will not weaken from the amount of heat it will be exposed to in an engine bay. I do not know the properties of the PVC type plastic but I imagine it has a better heat transfer rate which is worst and obviously it does not have the durability and heat resistance of 304. Unless one is willing to pay 500 dollar for an intake (which actually would yield a higher dyno gain), 304 made intakes are probably ideal. AEM uses IIRC aluminum which is also a good choice.


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## xbrandonx (Mar 27, 2004)

Zac said:


> AEM uses IIRC aluminum which is also a good choice.


Radiators are aluminum and you know they're being exposed to massive heat so there is proof to back it up.


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## callen (Jul 31, 2005)

xbrandonx said:


> Radiators are aluminum and you know they're being exposed to massive heat so there is proof to back it up.


This just made no sense. No offence. Plastic would have a much much much lower heat transfer rate then nearly any metal period. That being said its metal for two reasons it will last longer under extreme heat and it just gives you that warm and fuzzy feeling knowing its stainless. Making it out of aluminum is just silly as aluminum is really good at transferring heat. Here's a good example getting stand offs for the aluminum air intake manifold from the head will gain around 3-8hp just from reduced heat to the intake. So the less heat transfer it’s exposed to the better common sense yes? 

P.S this isn’t a race car and I live in an area that never tops 35*c. During the summer its usually 25*c and max cold -10*c.


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## psuLemon (Apr 23, 2003)

do you really think they make things stainless for that warm fuzzy feeling, cuz if you do you are dense. i did a search and couldn't find flow capabilites for pvc for air products, but stainless is known for its ability to flow and its longevity. There is a reason why car parts aren't made out of pvc. If you read the first issue of revenge of the nerds on nissanperformancemag, you will see why companies use certain materials.


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## callen (Jul 31, 2005)

callen said:


> That being said its metal for two reasons it will last longer under extreme heat and it just gives you that warm and fuzzy feeling knowing its stainless.





callen said:


> I understand the flow would be a little better due to a smooth polished stainless but not very much as the PVC would be nearly as smooth.


Read the whole thing then comment. The flow would be determined by the smoothness of the given material unless stainless is highly polished its no better. There’s also the Monster wire factor to most car stuff (standard lamp wire has been shown to out do monster wire).


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## asleepz (Feb 24, 2004)

Look...

Your not going to convince anyone but a noob here to use PVC for an intake.. So go ahead and make your intake show us pics and get back with us in a couple years when your engine dies and we'll hook ya up and tell you "I told you so"


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## callen (Jul 31, 2005)

asleepz said:


> Look...
> 
> Your not going to convince anyone but a noob here to use PVC for an intake.. So go ahead and make your intake show us pics and get back with us in a couple years when your engine dies and we'll hook ya up and tell you "I told you so"


All I want is some real answers as why not to do it. There’s nothing I've read so far that makes any sense why not to. Stainless is better it will last longer and look better this is a given but other then a slightly smaller airflow nothing is wrong with PVC. I think putting this on the forum and expecting decent intelligent answers was a mistake.


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## psuLemon (Apr 23, 2003)

dyno a before and after of the pcv, you wont get the gains like a good ss intake, i did read your post, you aren't bein logical.


if you dont believe me, please read

http://www.nissanforums.com/showthread.php?t=69827&highlight=pvc+intake


if that isn't the information that you wanted then i dont know.. But anything from Ishadoff is usually very intellegent and accurate.


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## callen (Jul 31, 2005)

psuLemon said:


> dyno a before and after of the pcv, you wont get the gains like a good ss intake, i did read your post, you aren't bein logical.
> 
> 
> if you dont believe me, please read
> ...


Thanks that’s more of what I was looking for, looks like there is real reasons not to use PVC as hydrochloric acid isn't a good thing. It would seem polypropylene or ABS makes more sense. All I wanted was some concret answers as to why I shouldn't use it not its just stupid.


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## xbrandonx (Mar 27, 2004)

just go turbo and use PVC for your turbo piping so no one complains about you using it for your intake


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## mille-16i (Jun 16, 2004)

I will be straight I scanned that thread till lew said that pvc is not used in water piping accually ABS is the most common plastic waste pipe and PVC is abundant in water distribution systems most citys use it as a repair when the old lines break and as new when laying new pipe also most modular homes use PVC since you do not have to heat it like coper and you have no leaky threads like galvanized. Please get a smarter spokesman. PVC hates UV but I have installed it as hot water lines and Domestic hot water runs around 120-140f and it holds up to that. Use Schedule 80 not the thin white schedule 40 crap.


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## xbrandonx (Mar 27, 2004)

mille-16i said:


> I will be straight I scanned that thread till lew said that pvc is not used in water piping accually ABS is the most common plastic waste pipe and PVC is abundant in water distribution systems most citys use it as a repair when the old lines break and as new when laying new pipe also most modular homes use PVC since you do not have to heat it like coper and you have no leaky threads like galvanized. Please get a smarter spokesman. PVC hates UV but I have installed it as hot water lines and Domestic hot water runs around 120-140f and it holds up to that. Use Schedule 80 not the thin white schedule 40 crap.



off topic but as of a few years ago I know that louisville KY still had some wood piping that was still in use.

I'm not sure how much pressure PVC can take but I know at the water plant i work at we push out 130PSI durring the summer on a regular basis.

All the upgrades we did were steel piping, however that was around the plant not out in the town. Granted they were 18" lines, but I do not work on the digging crew and I do not install water mains or meters so I'm not sure what all they use.

HOWEVER, I do read the meters and I cannot recall seeing any plastic pipes at all in the water lines. This is just of course being able to see aboutg a foot going to the meter and a foot going out of the meter. The jar to hold the dirt back from the newer meters is plastic though.


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