I am putting a hood stack on my trail truck and wanted to get an idea on what size I should use and about how tall it should be. My take on it is the samller diameter the exhaust the shorter it can be as it will funnel the smoke higher in the air. Does the diameter of the pipe on hood stacks make a difference in the sound? On how tall it needs to be I dont want it so tall it hangs on trees or limbs while trail riding and I fear if I do it to short you wont be able to see when it starts smoking up. Any options and opinion are greatly appreciated.

 

is it going on the yoda or the dodge? 5" diameter 18" long flat top, chrome for the dodge, and for the yoda, id say 4" 12" long and crome, or shorter.

 

Going on the yoda! 12'' from the top of the hood or from the turnup at the turbo?

 

when i had a hood stack on my mine, i bought a 5in flange from a truck store, and used about 12" long 5in pipe and welded it to the flange. the flange had a lip on it so i drilled self tapping screws into the hood to hold it steady. for the inner pipe i used 3in to fit inside of the of the 5in. if you get the measurements right for when you close the hood, you could go with 4in on the inner and make it fit snug. the 5in sounded pretty good. im sure if you went with 4in on the inner it would make it a deeper tone than a 3in inner pipe. i could see just fine and had no problems with smoke covering the windshield. infact i never had any soot stains on the roof or windshield

 

actually i take that back, it was probably about 18in long for the 5in

 

I am going to make the stack easily detachable so that I can pull it off before opening the hood. I am planning to do it this way so the hole in the hood is minimal as possible to prevent alot of water and mud from coming in and ontop the motor. I plan to afix the stack to the down pipe (which has been flipped to now point up) where it sits over the factory pipe approximately 2-3 inches. I will weld flat plate on the bottm of the stack with a hole the size of the down pipe cut in it. The down pipe will also have pegs on it where the stack will require 1/4-1/2 a turn to remove it.

 

on my hood stack i took 4" pipe and welded a 4" v band flange on it so it would clamp on my A3K. thenused a 90 bend to teh side then gradually bent it up so it was liek a 90 turning into 180 going up then straight up. i hate how 1st gens exit so far back on the hood i wanted it further up on the hood so thats why i did the crazy bend. i measured where my up pipe was located on my hood and drew that 4" circle on there. i was going to use my 7' mitre stack i had cut. 7 is bigger than 4 so you have room to put the stack really any where that the 4 is in. so i put it up front adn the the center as possible and cut the hole. i welded 90 degree tabs all teh way around the stack underneith and used self tapers to screw the stack on so i could use a difffernt stack if i ever decide to. my 7" comes through the hood about 6" and i took the back side of the stack and trimmed it so it would clear the up pipe upon opening the hood. so i never have to touch the stack at all to open the hood. the 4" actually comes 2" above the hood inside the 7". sounds mean and has a nice glow at night. i will have to post some pics up

 

 

hood stacks are awesome man! On mine, i just have a 4" elbow welded to my turbo flange. I have 3 different tips i can choose from. I have a 18" long 5" angle cut exhaust tip that just bolts on for my stack, and then i have a 24" tall 5" stack with a flapper on it, and then i have a 24" tall 5" turnout stack. I think the 5" sounds good, but the bigger you go, the deeper the sound. It will shoot about a 6" flame out of the stack when the turbo lights, you can only see it at night though. I have never had a problem with smoke gettin on my windshield, even with the short stack. It just blows the smoke right up over the cab, and when goin down the road, the draft just carries it over the windshield and over the cab. I just cut a 5 1/2" hole in my hood and cut it far enough that i can open my hood and it will clear the stack just fine. Here is some pics:






good luck man. Let us know how it goes and post some pics.

 

Other than the louder, more appealing sound that a hood stack provides, do they offer any types of performance gains or spooling benifits? How is daily driving with one on a 12v?

 

hey 92smokin blacky lets see some under the the hood pics.

 

boy i thought bed stacks were bad.......but ooooofffffffffff

 

Its really not that loud, It surprised me. The way i had my exhaust before was louder. (3" coming out right behind the front right tire right underneath the door) With the windows up it isn't very loud, but with the windows down its pretty loud and sounds good. And there is definately no restrictions!!! which is how a flame comes out of it! and it definately turns heads! ha ha

here is some under hood pics:

and an older pic:

 

when i had mine on, i could definitely tell a difference in spooling. since the exhaust is so short, it exits faster, also keeping EGTs cooler