# Should PVC be Used for Intake Piping?



## chimmike (Oct 17, 2002)

don't suggest to use PVC please!!!!


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## lshadoff (Nov 26, 2002)

chimmike said:


> don't suggest to use PVC please!!!!


I agree. PVC is not a good choice in this application.

Here's a quote from the PlasticUSA web site :
"_All PVC polymers are degraded by heat and light; hydrogen chloride is eliminated and oxidation occurs."_

The under-hood heat will degrade PVC and hydrochloric acid will be produced inside and outside the pipe. This will slowly corrode the intake system.

Lew


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## Zen31ZR (Mar 24, 2004)

chimmike said:


> don't suggest to use PVC please!!!!


 Do you want to give a good reason?


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## chimmike (Oct 17, 2002)

Lew just did


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## Zen31ZR (Mar 24, 2004)

lshadoff said:


> I agree. PVC is not a good choice in this application.
> 
> Here's a quote from the PlasticUSA web site :
> "_All PVC polymers are degraded by heat and light; hydrogen chloride is eliminated and oxidation occurs."_
> ...


 I don't agree. PVC has been used in many applications , and no one I know has ever had any problems with it. It's better than using a metal intake pipe which can rust. Stick to something that you know something about.


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## Zen31ZR (Mar 24, 2004)

chimmike said:


> Lew just did


 Instead of quoting a plastics website , he should try talking to people that have actually used it , myself included.


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## chimmike (Oct 17, 2002)

I personally would prefer the oxidizing of a metal over the heat deformation of a polyvinylchoride and its emission of hazardous/poisonous gases into the engine and the atmosphere.

I know you're all about low budget tuning, but somethings are just unsafe and dumb.


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## lshadoff (Nov 26, 2002)

[email protected] said:


> I don't agree. PVC has been used in many applications , and no one I know has ever had any problems with it. It's better than using a metal intake pipe which can rust. Stick to something that you know something about.


I have a Ph.D. in chemistry and have published a refereed paper in the scientific literature about corrosion.

I worked for the Dow Chemical Company (a manufacturer of PVC) for 28 years and achieved the highest rank in their scientic ladder. One of the studies I participated in for Dow was the analysis of the thermal decomposition products of PVC, specifically for chlorinated products in the gas phase.

It is my professional opinion that PVC is not a good choice for intake piping due to the high temperatures encountered. It will become brittle with time and the decomposition products will harm the intake system.

Lew


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## Zen31ZR (Mar 24, 2004)

lshadoff said:


> I have a Ph.D. in chemistry and have published a refereed paper in the scientific literature about corrosion.
> 
> I worked for the Dow Chemical Company (a manufacturer of PVC) for 28 years and achieved the highest rank in their scientic ladder. One of the studies I participated in for Dow was the analysis of the thermal decomposition products of PVC, specifically for chlorinated products in the gas phase.
> 
> ...


 And I've used the product on the street. So which of us actually _knows_ more about how it will handle certain applications?  Pre-turbo intake piping rarely encounters temperatures above 100 degrees unless it's a very warm day and the car has been sitting in traffic and heat-soaking. After-turbo is an entirely different matter , and I don't recommend PVC useage in a 250+ degree enviroment. A lot of DSM people use PVC as an intake pipe source , and their underhood space is much more confined and the pipe is in a much hotter enviroment than a Z31s intake is. And I've never heard of a single one of them having any problems. PVC piping is used in houses to carry waste water , sometimes which can exceed 100 degrees , and I've never heard of any problems there either. If PVC and plastics in general is so dangerous to use , why is most of what is under the hoods of cars plastic , and a lot of that stuff is nowhere near as durable as PVC. Let me reiterate the fact that I am talking about using it as pre-turbo intake piping and nothing else...........


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## krylonkoopaa (Sep 13, 2002)

quit being a dumbass. like they said use it if you want but dont push your dumbass credo on all of us.


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## lshadoff (Nov 26, 2002)

[email protected] said:


> And I've used the product on the street. So which of us actually _knows_ more about how it will handle certain applications?  Pre-turbo intake piping rarely encounters temperatures above 100 degrees unless it's a very warm day and the car has been sitting in traffic and heat-soaking. After-turbo is an entirely different matter , and I don't recommend PVC useage in a 250+ degree enviroment. A lot of DSM people use PVC as an intake pipe source , and their underhood space is much more confined and the pipe is in a much hotter enviroment than a Z31s intake is. And I've never heard of a single one of them having any problems. PVC piping is used in houses to carry waste water , sometimes which can exceed 100 degrees , and I've never heard of any problems there either. If PVC and plastics in general is so dangerous to use , why is most of what is under the hoods of cars plastic , and a lot of that stuff is nowhere near as durable as PVC. Let me reiterate the fact that I am talking about using it as pre-turbo intake piping and nothing else...........


I measured (bottom graph, top section) the under-hood temperature of my car using an OBD-II monitoring tool at an ambient temperature of 88*F. It was 105*F while driving on the expressway and rose to 125*F during acceleration.

Has anyone examined the inside of their intake system or the MAF to see if there is any damage after using PVC piping for a year or so?

As for the plastic materials under the hood of a car, most of them are polypropylene, a much more thermally stable plastic than PVC.

PVC is used for waste piping in homes, but not water piping. The reason is that PVC will contaminate the water with chlorinated compounds.

I guess I'd rather be safe than sorry.

Lew


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## BII (May 13, 2004)

how much can metal tubing cost? come on stop being so ghetto woth your car, its not a Honda.


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## Zen31ZR (Mar 24, 2004)

bII said:


> how much can metal tubing cost? come on stop being so ghetto woth your car, its not a Honda.


 I _have_ metal tubing on the car now. But I have used PVC in the past and was considering it here. Don't see what the problem is , if it's usable I'll use it. And learn how to spell and punctuate........


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## Zen31ZR (Mar 24, 2004)

lshadoff said:


> I measured (bottom graph, top section) the under-hood temperature of my car using an OBD-II monitoring tool at an ambient temperature of 88*F. It was 105*F while driving on the expressway and rose to 125*F during acceleration.
> 
> Has anyone examined the inside of their intake system or the MAF to see if there is any damage after using PVC piping for a year or so?
> 
> ...


 I'm kinda curious as to what temps were around the intake area itself. I know it's hard to be that specific , I'm just curious. And at what temperature does PVC start irreversible breakdown. I know it should be at least over 120 degrees or it couldn't be safe for home use.....


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## lshadoff (Nov 26, 2002)

[email protected] said:


> I'm kinda curious as to what temps were around the intake area itself. I know it's hard to be that specific , I'm just curious. And at what temperature does PVC start irreversible breakdown. I know it should be at least over 120 degrees or it couldn't be safe for home use.....


The sensor I monitored was the Intake Air Temp Sensor which was just after the air filter inside the intake.

Here it is in the air filter to MAF adaptor.









You can see where it was mounted in the pictures at the bottom of this page.

Now I have a CAI.

Lew


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## Tavel (Aug 21, 2004)

my dads a plastics engineer(for bonar plastics, know of it lshadoff?? he desighned the nifty craft foods fridges, among other things) but he said that he would not recomend using PVC in the engine compartment at all. pvc does not hold up well to temperature fluctuations and it emits all the fun gasses everyone's been talking about. 

BTW: PVC is not 'safe' for home use in the way you're thinking. it doesn't light on fire for no reason and it holds up to the conditions inside walls(very extreme im sure). the only place pvc is used in homes is for waste piping. nothing you drink or use comes from a pvc pipe, those are copper pipes...well maybe if you LIKE drinking you're own waste...


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## Dwntyme (Dec 18, 2002)

chimmike said:


> I personally would prefer the oxidizing of a metal over the heat deformation of a polyvinylchoride and its emission of hazardous/poisonous gases into the engine and the atmosphere.
> 
> I know you're all about low budget tuning, but somethings are just unsafe and dumb.


If heat is a (toxic)factor in using PVC. then why is it used in homes where the hot water flows thru it at 120deg or more...?


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## Dwntyme (Dec 18, 2002)

Tavel said:


> my dads a plastics engineer(for bonar plastics, know of it lshadoff?? he desighned the nifty craft foods fridges, among other things) but he said that he would not recomend using PVC in the engine compartment at all. pvc does not hold up well to temperature fluctuations and it emits all the fun gasses everyone's been talking about.
> 
> BTW: PVC is not 'safe' for home use in the way you're thinking. it doesn't light on fire for no reason and it holds up to the conditions inside walls(very extreme im sure). the only place pvc is used in homes is for waste piping. nothing you drink or use comes from a pvc pipe, those are copper pipes...well maybe if you LIKE drinking you're own waste...


PVC is being used to bring water from water main to the newer homes...


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## myoung (Apr 15, 2002)

lshadoff said:


> I have a Ph.D. in chemistry and have published a refereed paper in the scientific literature about corrosion.
> 
> I worked for the Dow Chemical Company (a manufacturer of PVC) for 28 years and achieved the highest rank in their scientic ladder. One of the studies I participated in for Dow was the analysis of the thermal decomposition products of PVC, specifically for chlorinated products in the gas phase.
> 
> ...


how can you argue with that?????... but I see some tried.. which doesn't really surprise me..   

hmmm street racer and his buddies says it's okay V.S. published Ph.D. for DOW Chemical

hmmm yea that's tough choice...


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## myoung (Apr 15, 2002)

Dwntyme said:


> PVC is being used to bring water from water main to the newer homes...


Since when is water coming from the water main heated?


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## lshadoff (Nov 26, 2002)

Dwntyme said:


> PVC is being used to bring water from water main to the newer homes...


CPVC (Chlorinated Polyvinyl Chloride) is used for water service. It is available in sizes from 1/4" through 2" copper pipe sizes.

http://www.ppfahome.org/cpvc/

Lew


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## myoung (Apr 15, 2002)

lshadoff said:


> CPVC (Chlorinated Polyvinyl Chloride) is used for water service. It is available in sizes from 1/4" through 2" copper pipe sizes.
> 
> http://www.ppfahome.org/cpvc/
> 
> Lew


Next? lol


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## Dwntyme (Dec 18, 2002)

K :cheers: just learn something new

man I love this place....


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## lshadoff (Nov 26, 2002)

Previously I wrote:


lshadoff said:


> CPVC (Chlorinated Polyvinyl Chloride) is used for water service. It is available in sizes from 1/4" through 2" copper pipe sizes.
> 
> http://www.ppfahome.org/cpvc/


I just checked, and PVC is also qualified for cold water service. Cold water pipe is a different product than sewer pipe since it is pressure rated.

http://www.ppfahome.org/pvc/index.html

Lew


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## pete? (Jul 6, 2004)

lshadoff said:


> I have a Ph.D. in chemistry and have published a refereed paper in the scientific literature about corrosion.
> 
> I worked for the Dow Chemical Company (a manufacturer of PVC) for 28 years and achieved the highest rank in their scientic ladder. One of the studies I participated in for Dow was the analysis of the thermal decomposition products of PVC, specifically for chlorinated products in the gas phase.
> 
> ...


oh shit u just got owned!


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## pete? (Jul 6, 2004)

Dwntyme said:


> PVC is being used to bring water from water main to the newer homes...


this is true but it is cold/cool water and it is also under the ground which provides insulation i dont think that that pipe under the ground would ever rise in temp above 70 degrees so it should be fine and if u have noticed it allways changes over to metel pipe once inside the house and like (forgot name) said pvc is only used for waste


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## Crazy-Mart (Jul 14, 2002)

that was interesting  so now i know i got to get rid of that PVC piping under my hood ... just a note even if its not good : been boosting 10lbs+/- for like 8000km without any problem wathsoever (no intercooler)... the only way it can be safe to use it under the hood might be to get the general form of the piping you need than bring that on to the exhaust/piping guy so they can match it with some nice mild steel or stainless without have mutiple welding at each bent


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## chimmike (Oct 17, 2002)

Dwntyme said:


> If heat is a (toxic)factor in using PVC. then why is it used in homes where the hot water flows thru it at 120deg or more...?



it's not......homes use copper piping for the hot water 

almost every home I've ever seen uses copper piping for the hot water.


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## myoung (Apr 15, 2002)

chimmike said:


> it's not......homes use copper piping for the hot water
> 
> almost every home I've ever seen uses copper piping for the hot water.


maybe in a few homes with wheels.. ... that never actually move.


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## Zen31ZR (Mar 24, 2004)

Crazy-Mart said:


> that was interesting  so now i know i got to get rid of that PVC piping under my hood ... just a note even if its not good : been boosting 10lbs+/- for like 8000km without any problem wathsoever (no intercooler)... the only way it can be safe to use it under the hood might be to get the general form of the piping you need than bring that on to the exhaust/piping guy so they can match it with some nice mild steel or stainless without have mutiple welding at each bent


 Yeah , I've used PVC intakes on several different cars and never had a problem. I suppose it's probably because I didn't keep the intake on very long , I never noticed any material breakdown. I think 6 months was the longest I had a PVC intake. Lot's of people use PVC that I am aware of , including a lot of DSM guys. I suppose someone should tell them.........


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## myoung (Apr 15, 2002)

[email protected] said:


> Yeah , I've used PVC intakes on several different cars and never had a problem. I suppose it's probably because I didn't keep the intake on very long , I never noticed any material breakdown. I think 6 months was the longest I had a PVC intake. Lot's of people use PVC that I am aware of , including a lot of DSM guys. I suppose someone should tell them.........


that's certainly a different way to say "I was wrong"

it's not like this is hidden knowledge or something new.. some just wish not to listen to facts.


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## Zen31ZR (Mar 24, 2004)

myoung said:


> that's certainly a different way to say "I was wrong"
> 
> it's not like this is hidden knowledge or something new.. some just wish not to listen to facts.


 The facts were never presented before , I was not aware of any problems using PVC before now. I haven't used PVC on this car yet , and now I suppose I won't , since someone has finally told me what will happen over the long term. Long term mods are something I have never dealt with in any car I've had , I'm constantly changing something. And most times I sell a car before I've had it a year or even 6 months so I've never watched the long term effects of PVC breakdown.

Aside from PVC , is there any other type of non-metal piping which can handle under hood temperatures. Stainless is a bit expensive , and regular pipe can rust , so I need to find another budget material to use.......


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## myoung (Apr 15, 2002)

[email protected] said:


> Aside from PVC , is there any other type of non-metal piping which can handle under hood temperatures. Stainless is a bit expensive , and regular pipe can rust , so I need to find another budget material to use.......


I know your key is low budget, but sometimes there's just no decent low budget alternative.

Kinda of an odd hobby to get into for a low budget...


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## Zen31ZR (Mar 24, 2004)

myoung said:


> I know your key is low budget, but sometimes there's just no decent low budget alternative.
> 
> Kinda of an odd hobby to get into for a low budget...


 Well , my wife and I both like fast cars , but when you have 2 kids it drains the wallet plenty. So I just do what I can.


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## myoung (Apr 15, 2002)

[email protected] said:


> Well , my wife and I both like fast cars , but when you have 2 kids it drains the wallet plenty. So I just do what I can.


Completely understandable..


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## lshadoff (Nov 26, 2002)

[email protected] said:


> Aside from PVC , is there any other type of non-metal piping which can handle under hood temperatures. Stainless is a bit expensive , and regular pipe can rust , so I need to find another budget material to use.......


Polypropylene piping is available in a wide range of sizes, and is much more stable (good to 190*F) than PVC.

http://www.keidel.com/mech/pvf/pipe-poly.htm

Lew


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## chimmike (Oct 17, 2002)

myoung said:


> maybe in a few homes with wheels.. ... that never actually move.



hell, even my parent's travel trailer has copper hot water pipes, lol


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## Crazy-Mart (Jul 14, 2002)

lshadoff said:


> Polypropylene piping is available in a wide range of sizes, and is much more stable (good to 190*F) than PVC.
> 
> http://www.keidel.com/mech/pvf/pipe-poly.htm
> 
> Lew



A good quality extruded HDPP pipe is the answer  (why didnt i taugh of it earlier) and its just about as easy to work with than pvc... plus its very hard to burn that thing .. ive been molding different PP up to 450f... flash point is a lot higher than PVC...


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## Joel (Jun 11, 2003)

Are we talking about a boosted car here?
With boost its not the heat you have to worry about, its the materials ability to hold integrity under a high pressure hose clamp. Metal is good because you can burr or bead the ends and stainless or mild mandrels are ultimate because of the lack of any weak points (like seams).

The intake can be made from anything though, mines a piece of consatina rubber hose at the moment.


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## Zen31ZR (Mar 24, 2004)

Joel said:


> Are we talking about a boosted car here?
> With boost its not the heat you have to worry about, its the materials ability to hold integrity under a high pressure hose clamp. Metal is good because you can burr or bead the ends and stainless or mild mandrels are ultimate because of the lack of any weak points (like seams).
> 
> The intake can be made from anything though, mines a piece of consatina rubber hose at the moment.


 Yeah , I was talking about pre-turbo only , though , not after turbo. All other things aside , that's a 200+ degree enviroment on a non-intercooled car , and there's no way I'd use PVC on that.


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## lshadoff (Nov 26, 2002)

[email protected] said:


> Yeah , I was talking about pre-turbo only , though , not after turbo. All other things aside , that's a 200+ degree enviroment on a non-intercooled car , and there's no way I'd use PVC on that.


The section of pipe from the outlet of the turbo will always carry hot air under boost whether it goes to an intercooler or the intake plenum directly.

BTW, there's a turbo outlet and intercooler outlet temperature calculator here (in the middle of the page). You input intake air temperature, boost, and intercooler efficiency. It calculates that you hit about 200*F turbo outlet temperature and 115*F intercooler outlet temperature with an intake air temp of 80*F, 15# of boost, and an intercooler efficiency of 70%.

Lew


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## Zen31ZR (Mar 24, 2004)

lshadoff said:


> The section of pipe from the outlet of the turbo will always carry hot air under boost whether it goes to an intercooler or the intake plenum directly.


Yeah , I wasn't even thinking about that , just as how it applied to Z31s....... Hot side pre-intercooler can top 300 degrees on some cars. Although I'd say that was more because of an overworked turbo than anything else.


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## Jeff Meister (Oct 13, 2004)

*Wanna go cheap?*

I personally agree that PVC is not the answer. If you want to reduce cost and maintain your engine, I would recomend a minimum of a 40 schedual electrical conduit. You can also use 80, but this is more expensive, has a smaller interior x-sectional area and not necessary. It is engineered for heat resistant applications and installers actually apply about 170 degrees of heat to shape and form the composite. The temperatures that your engine will produce in the engine compartment are not enough to cause deformation of the pipe and It will not become brittle. This is what I have used. I am not sure of the chemical composition, but I can say that if fire codes permit it as a suitable insulator for potential electrical shorts which can cause fire(obviously higher than 125 degrees) I will trust that. I am currently studying construction management and have a very good understanding about building codes. The most important thing in a building besides structural integrity is the buildings ability to withstand fire and to maintain the safty of the people inside. Therefore, I can also say that toxic emmissions of insulators of electricity are taken into account when establishing codes. Electrical conduit is code, Cheap, Easy to work with and Safe to use.


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## B11sleeper (Oct 15, 2003)

what about ABS?


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## pete? (Jul 6, 2004)

no plastic should ever be used where heat is present simple as that


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## lshadoff (Nov 26, 2002)

1.6pete said:


> no plastic should ever be used where heat is present simple as that


Hmmm. I thought that the factory intake air box was plastic. Also don't the electric radiator fans have plastic shrouds? And aren't the top and bottom sections of the radiator plastic? The coolant overflow, windshield washer reservoir and brake master cylinder reservoirs ar plastic, too, aren't they? Also all the wire insulation is plastic. 

I guess my car is doomed.  

Lew


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## pete? (Jul 6, 2004)

lshadoff said:


> Hmmm. I thought that the factory intake air box was plastic. Also don't the electric radiator fans have plastic shrouds? And aren't the top and bottom sections of the radiator plastic? The coolant overflow, windshield washer reservoir and brake master cylinder reservoirs ar plastic, too, aren't they? Also all the wire insulation is plastic.
> 
> I guess my car is doomed.
> 
> Lew


yea acually i thought about that sorry i was mostly talkin about pvc and forgot abs was what is used in cars allready. stupid comment disregard. :thumbup:


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## B11sleeper (Oct 15, 2003)

1.6pete said:


> yea acually i thought about that sorry i was mostly talkin about pvc and forgot abs was what is used in cars allready. stupid comment disregard. :thumbup:


I used abs for my intake  ABS is a better plastic anyway.


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## pete? (Jul 6, 2004)

B11sleeper said:


> I used abs for my intake  ABS is a better plastic anyway.


where would you find 3in. as tubes? thats not to bad of an idea cuz you could put threaded couplers on it so if there is deap water you could change it out by hand and it wouldnt get hot :thumbup: and it wouldnt really heat soak would it? even so you could allways just wrap it in something


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