So I got my stacks on...

[ghunt]

...and, ***?

OK, let me start from the beginning.

I've been playing around with the exhaust on this truck since I finished the ATS upgrade. Started with straight pipe, didn't like that...then, I put on a huge, 4" stainless Magnaflow and it seemed too quiet (through the tailpipe at least).

So, then I tried a ****** maximum flow and it sounded great, seemed like it had just enough volume. In fact, it sounded so good, I thought man, I bet that would sound cool through stacks. I bought everything I needed to do stacks, and in fact even picked up another 4" "bullet" muffler to run in front of the ****** maximum flow to just muffle it a tiny bit more. I ran it with those two mufflers and a side exit exhaust for a little while and it sounded awesome, so I figured I was good to go.

I got my stacks installed last night, didn't change anything except physically putting them on. Drove into work today and cracked my back window so I could hear it part of the way.

Wow, these things are a lot louder than I expected, and not really in a good way. I realize the stacks act as resonators, but why am I getting way more engine noise and seemingly less sound from the turbo through the stacks than I did through the side exit exhaust? Guess I'm gonna have to start playing with the mufflers again.

BTW I don't have pics yet, will take some today since I finished at 11 PM last night...I was unsure before doing this as to how I would like them, but now that they're done...man, they look good! If I can just get them to sound as good, I'll be happy!

 

[partagas]

Would love to see how you put the stacks in. I am thinking of doing that to my 87 F350. But not sure how.

 

[ghunt]

Well, mine's a bit different from most others. I bought the stacks, and built everything else myself. So my splitter pipe is 4" rather than 5" like most other people have. Overall I think it looks good and came out very well. Of course, the stacks aren't 100% plumb but that's hard to get right anyway.

 

[Cat_Rebel]

You all must have better hearing then I do. I drove mine for almost a year with dual & later a single stack N/A. Now with the turbo & 3.5" pipe feeding into the 5" single stack I can't even hear the engine or exhaust when I'm cruising. I also have a single cab too.

 

[ghunt]

You probably ruined your hearing with the stacks on it when it was n/a

 

[MeanGreen]

...and, ***?

OK, let me start from the beginning.

I've been playing around with the exhaust on this truck since I finished the ATS upgrade. Started with straight pipe, didn't like that...then, I put on a huge, 4" stainless Magnaflow and it seemed too quiet (through the tailpipe at least).

So, then I tried a ****** maximum flow and it sounded great, seemed like it had just enough volume. In fact, it sounded so good, I thought man, I bet that would sound cool through stacks. I bought everything I needed to do stacks, and in fact even picked up another 4" "bullet" muffler to run in front of the ****** maximum flow to just muffle it a tiny bit more. I ran it with those two mufflers and a side exit exhaust for a little while and it sounded awesome, so I figured I was good to go.

I got my stacks installed last night, didn't change anything except physically putting them on. Drove into work today and cracked my back window so I could hear it part of the way.

Wow, these things are a lot louder than I expected, and not really in a good way. I realize the stacks act as resonators, but why am I getting way more engine noise and seemingly less sound from the turbo through the stacks than I did through the side exit exhaust? Guess I'm gonna have to start playing with the mufflers again.

BTW I don't have pics yet, will take some today since I finished at 11 PM last night...I was unsure before doing this as to how I would like them, but now that they're done...man, they look good! If I can just get them to sound as good, I'll be happy!

Having had stacks on a '88 F-250 IDI ATS turboed truck, and also on my 97 Powerstroke, I can tell you where the turbo sound went. The splitter pipe eats up some of the whistle. As for the extra noise, not only are the stacks magnifying the sound but depending on how you mounted them to the bed can also cause the bed to resonate. My stacks are connected to the exhaust with tractor-trailer grade flex pipe (about 1 foot long) and then the stacks have brackets I built that use polyurethane end-link bushings to completely isolate the stacks from the metal. I'm not a big fan of the "kits" either, doing it yourself is much better. Not to offend anyone, but those kits that use the T bracket that is bolted to the bed and then sandwiched into the stack clamp looks cheap and transmits a lot of heat/vibration into the bed.
Jerry

 

[Agnem]

I'd agree that how you do your stacks will affect your whistle. You would need to get into the math of the frequencies involved and the acoustical properties of the piping to maximize the sound. When it turns out good, it's cause you got lucky in most cases. Think about the way a Microwave oven door is made, and you get the idea. Plumbing can be done in such a way as to cause certain frequencies to cancel each other out. The splitter is a key piece, since the sound wave will have to bounce just so to make it through cleanly.

 

[ghunt]

Well that sucks. I figured the splitter pipe wouldn't make that much difference in the sound.

Especially since I hear all these Powerstrokes and Cummins that have stacks and whistle like nobody's business.

Sigh...well, maybe that's why everyone goes with a 5" splitter pipe.

 

[4x4TruckinGirl]

Hey..... I have a 4" Splitter pipe in the bed.... my exhaust goes from a 2.5" downpipe into 3" for about a foot and then into 4" and only the stacks themselves are 5", the pipe in the bed is all 4"....... I suppose my truck is loud... I don't think it's too bad at all, but then again thats how I like it! The sound is good also..... I have no mufflers/cats etc....

 

[forcefed]

When I put my stacks on , my turbo whistle got louder. Also I have no mufflers and my exhaust is not that loud at all. Seems kinda strange that yours is so loud with a turbo on it. I have the ats upgrade on with the 3" downpipe into the 5" y pipe. and 5" stacks. I will say under a load it is quite noisy but just when cruising its not loud at all. Thats my perception though.

 

[6.9poweredscout]

man i can't wait to see how my scout is gonna sound... twin turbo, 3" straight to 4" stacks, one turbo feeding each stack.......

-Jon

 

[ghunt]

Well, cruising around town, yeah mine is fine...but under load and/or once the RPM's get high enough, it's pretty loud. I suppose it's not as bad if you only have the side windows open, or all the windows shut, with the sliding rear window open it's pretty loud.

Anyway, I listened to it a bit on the way home from work yesterday, and I guess I didn't really lose my turbo sound...seems like the exhaust noise just got louder, I guess since it resonates up through the stacks.

I ordered some silicone rubber to hopefully help isolate the stacks from the rest of the bed, because it also resonates through the bed, which is rather annoying.

Anyway, here's some pics!

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

These were 36" tall stacks...I didn't want them sticking up too particularly high, and when I first test fit them I didn't really like how they were, so I cut 3" off the bottom of both. I think they're just right now.

I tried to get a pic of how they mount up, but I couldn't get a super good one since my toolbox was in the way.

You must be registered for see images attach

Pretty much just used a bunch of muffler clamps to mount everything up. In retrospect, I probably should have just bought two of those "strap" stack mounts I've seen on ebay, but these work.

 

[redneckaggie]

the height is the main issue with noise inside the cab my bro put stacks on both of his dodges both single cabs and both gen 1 cummins one he ran the stacks to like two inches above the cab because he was having to go in and out of parking garages all the time. the next one we ran them up a good foot or so above the truck and they sound really no different from the outside but inside the cab you wouldn't believe how much less annoying running them higher makes them also insulating them from the bed as far as like rubber grommets helps to

 

[ghunt]

Well I don't want them any taller than they are. I'd like to be able to get it in and out of my garage, it has about 6'-10" clearance and I think these will clear it by 2 inches or so. Plus I don't really like the looks of really tall stacks.

The volume is not bad at all with the windows shut, there's a slight drone between 50-60 mph in fifth gear, but otherwise hardly noticeable.

 

[tractorman86]

sound clips or video with sound...