# how big for the exhaust



## suprfast (Apr 6, 2009)

Im going to run my a local exhaust shop today and get a piece of piping but im unsure of how long or how wide.  

Im thinking minimum of 3" in diameter(do i need bigger, or would smaller be better to help maintain heat consitently?

Does it need to be 13' in the air like most smokers, or is this done for the sole purpose of keeping the smoke out of your face?  Im thinking of coming out the side of the box about 12" then have it going straight up(90° angle) about 36".  

Kris


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## m1tanker78 (Apr 6, 2009)

Hi Kris, in my opinion (and own experience), it's almost impossible to build an exhaust that's too big. On the other hand, too small of an exhaust can have devastating consequences (creosote flavor).  Another thing is that it depends on what type of smoker it is, how big the cooking chamber is, and more importantly, how big of a fire you're going to build.  If it's an electric then you can go slightly smaller. 

Personally, I'd go with 3" on a small horizontal type smoker. If you're going to spend the money then spend it on some pipe that the tractor-trailer trucks use (not sure about the diameter but I estimate 5". 

Just my humble 2 cents,

Tom


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## suprfast (Apr 6, 2009)

sorry, i guess that would help if i said it was the SnP.  

I  might go with 4" to be on the safe side then.  What about the length of the pipe?  Does it need to be X amount of feet high above the smoker, or is the height just to keep the smoke out of the face of the cook.
kris


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## bigbaldbbq (Apr 6, 2009)

The height is just to keep it out of your face. I have seen some that have very short pipes with no problems. The concern is how much movement you get through said pipe. I would think that on a smoker that size a 3" would be fine.


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## suprfast (Apr 6, 2009)

The exhaust shop has up to 5" piping, so i might just get a 4" to be on the safe side, unless the prefabbed piping on the SnP is smaller.  

Is anyone at home right now(before 4pm PST) that can measure the opening for the SnP exhuast?  

Ill post pics when i get it done.
kris


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## tasunkawitko (Apr 6, 2009)

according to the BBQFAQ, 4-inch is optimal for the SnP Pro, i am guessing it would also be good for the SnP.


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## suprfast (Apr 6, 2009)

thanks Tasunka.  

Im off to the exhaust shop, i will post pics later
kris


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## suprfast (Apr 6, 2009)

The exhaust shop failed to tell me they were back logged an hour before i drove over there. I didnt have an hour to kill so ill have to get the exhaust made another day. A side note is the diameter. The largest they can do(for a reasonable price) is 3". The 3" piping will be approximately 25.00 where the 4" will jump to 50.00+ and labor(cant be bent, has to be cut and welded). The 3"' was just going to be bent.

Does anyone think the 3" is more than enough. We run that on our all motor race cars all the time and make great power, why wouldnt it be enough for my ALL CHARCOAL race smoker?

Lastly, will 16 gauge(approx 0.0598in or 1/16 in) weldable sheet metal be thick enough for the heat shield / diverter plate / horizon knock off?? I can find 16 gauge for a reasonable price, and i cannot find much thicker than that without quadrupling the price.
kris


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## tasunkawitko (Apr 6, 2009)

kris - regarding 3" versus 4" - i can't say for sure. the BBQFAQ does cover this in their "smoker mods" section but i dind't read it too closely because i had an ECB at the time. you might take a look in there - simply google BBQFAQ - up near the top of the search results is a link with EAGLEQUEST in it. from there, you can download the FAQ and take a look at it in word format. lots of good info.


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## tasunkawitko (Apr 6, 2009)

kris - here's the link:

http://www.eaglequest.com/~bbq/faq2-w97.zip


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## azrocker (Apr 6, 2009)

I bought a 4" exhaust elbow on e-bay with the idea of putting a chrome stack on. Decided it was overkill on my el cheapo craiger. Still have elbow in the event I do a build.


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## pinkmeat (Apr 6, 2009)

I built a 55gal drum into a horizontal smoker. I used 3" crush bent car exhaust from a muffler shop. I had them bend it to a 90deg angle. Plenty of draw with this setup for the size smoker (55gal drum).


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## suprfast (Apr 6, 2009)

Awesome, ill go with the 3" crush bent route.  
kris


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