with my dual output 4 inch kit, there is NO popping on accel. you can ask the rally guys how mine sounds. I love it.
5" Exhaust Anyone?
- Thread starter bookite03
- Start date
PwrSmoke
Full Access Member
Geez, going from 3 to 4 made my truck a LOT noisier and gave it a nasty drone. Can't imagine what 5 would be like. I'm going back to 3 next chance I get. 4 was tight on my 4x4 but cleared everything OK... it was the Dynomax kit with some adaptations.
'94IDITurbo7.3
HAMMER DOWN!
3" dp and then 4' straight factory exit here and ZERO drone.......i was "bracing" for drone when i took my muffler out, b/c i was warned it would be horrible but i have yet to experience any drone at any speed.
jaluhn83
Full Access Member
I'm running 3" downpipe to 3.5" for about 2 ft then 4" back w/ no muffler and it sounds fine. That's with a turbo though, without I'd bet it'd be pretty obnoxious.
Personally I just hate the huge exhaust pipe look - strikes me as a idiotic mine is bigger than your's thing, but that's just me.
Personally I just hate the huge exhaust pipe look - strikes me as a idiotic mine is bigger than your's thing, but that's just me.
Dump the muffler and straight pipe it OR put in a actually muffler that's worth a poop.
Just going to throw it out there gents, he's already heard/ridden in my truck with full length uncorked 4", no need to sell him on it
PwrSmoke
Full Access Member
How is dumping the muffler going to help? There are a whole lot of factors that contribute to drone so each truck is different and we can't really write foolproof prescriptions for other people's trucks unless they pretty much match in the setup. In my experience, removing the muffler doesn't do that. Interestingly, when I changed my timing (well Mel did it but...) from 7.5 to 9.5, the drone lessened a LOT. Compression ratio changes and cam timing can also add or detract from a drone. Pipe size is one major contributor to a drone (the velocity and sound frequencies of the gasses in the pipe) and also pipe wall thickness. Cheap, thinwall pipe has more droning tendencies. Often, turbos help with drone too because they "chop up" the exhaust pulses. I spent a few days a Borla in the mid-'90s and watched how they prototype a system. They have to do a LOT of sound tuning and matching of characteristics (pipe size with muffler type, etc) to make a system that won't be objectionable. People are a lot more forgiving of noise when they corncob a cheap system for themselves versus when they pay $600 for a system.
What I know... with the original Banks 3-inch system... no drone on my truck. Even with the corncob 3-inch system I had to have installed during a road trip after the Banks system finally rotted off (after only 16 years, can you believe it!) ... no drone. 4-inch system... drone at 1800 rpm. I want to go back to no drone and a nice quiet truck. The difference in power between 3 and 4 (or 5)... negligible, if it exists at all. Sometimes you can go too big and move the torque band higher than you want. Some time back, I posted the flow rates of the different size pipes and the hot exhaust flow of a 6.9 & 7.3 engines. A 3-inch system is MORE than enough to make maximum power in a turbocharged IDI in most rigs. There are a few highly built IDIs that might need more but IIRC, a 3.5 inch system can flow as much as 400 hp needs and how many of us are making 400... or 300... or even 250 for that matter. Bigger beyond what's needed doesn't equate to more power so why spend more money than you need to make your max power AND then possibly suffer with a drone or noise you don't like. You can always put a 5-inch tip on it if it's that look you like.
What I know... with the original Banks 3-inch system... no drone on my truck. Even with the corncob 3-inch system I had to have installed during a road trip after the Banks system finally rotted off (after only 16 years, can you believe it!) ... no drone. 4-inch system... drone at 1800 rpm. I want to go back to no drone and a nice quiet truck. The difference in power between 3 and 4 (or 5)... negligible, if it exists at all. Sometimes you can go too big and move the torque band higher than you want. Some time back, I posted the flow rates of the different size pipes and the hot exhaust flow of a 6.9 & 7.3 engines. A 3-inch system is MORE than enough to make maximum power in a turbocharged IDI in most rigs. There are a few highly built IDIs that might need more but IIRC, a 3.5 inch system can flow as much as 400 hp needs and how many of us are making 400... or 300... or even 250 for that matter. Bigger beyond what's needed doesn't equate to more power so why spend more money than you need to make your max power AND then possibly suffer with a drone or noise you don't like. You can always put a 5-inch tip on it if it's that look you like.
Then hang a GOOD quality muffler under your truck and call it a day. Haven't ever heard any thing nice about dynomax mufflers and my experience with a set was less then stellar due to drone..........then you post up complaining about drone with a dynomax system........... Do take notice that us straight piped guys thus far in this thread report NO drone. I roll up my windows all I hear is whistle through my fire wall in a cruise condition and can carry on a conversation comfortably.
And I think you and others missed his intent for the 5" exhaust.
And I think you and others missed his intent for the 5" exhaust.
93cc7.3
needs turbo power
http://www.ftediesel.com/store/pc/viewPrd.asp?idproduct=3&idcategory=7
this is going on my truck to kill a high rpm drone their 30 inch version is supposedly the best out for noise control
this is going on my truck to kill a high rpm drone their 30 inch version is supposedly the best out for noise control
PwrSmoke
Full Access Member
I've probably tested/installed or done install stories on a good 100 performance exhaust system in my career, now over 40 year along, a few on my own stuff many more on other's rigs. I've also had the opportunity to learn a lot from people who design and build exhaust systems for a living and seen the inside of how it's all done and learned a little of the science involved. Just because you and a few others have no drone doesn't mean many times your number don't. And droning is a common thing in the performance exhaust world, gas a diesel alike, and the industry spends a lot of money to cure the problem. You're lucky not to have a drone. Many straight pipers do. Like I said, people are a lot more forgiving of it when it's something they built rather than something they bought.
There are diesels out there that need 4 and 5 inch system to carry the massive about of flow it takes to crank out 800-1000 hp. Our 6.9 & 7.3L trucks ain't it... so a monster system is merely an affectation not a performance improvement. That was my main point. You and the OP are certainly free to hang whatever you want under your trucks but I personally don't see the point when all the extra money needed really does nothing. Well that's not true... I suppose if it makes you happy, that's enough. I just jumped in so that down the road some guy who thinks he needs a sewer pipe under his truck because he heard on the internet that it made massive power, he can see a counterpoint to make him think.
There are diesels out there that need 4 and 5 inch system to carry the massive about of flow it takes to crank out 800-1000 hp. Our 6.9 & 7.3L trucks ain't it... so a monster system is merely an affectation not a performance improvement. That was my main point. You and the OP are certainly free to hang whatever you want under your trucks but I personally don't see the point when all the extra money needed really does nothing. Well that's not true... I suppose if it makes you happy, that's enough. I just jumped in so that down the road some guy who thinks he needs a sewer pipe under his truck because he heard on the internet that it made massive power, he can see a counterpoint to make him think.
fordsrawesome
Registered User
This whole discussion could have been resolved if everyone who jumped down this guys throat would have read his post he said 5 in is cheaper than 4 near him and he likes the sound jeeze just let people do what they want to do I like the deep tone that only big pipe can give you too so to bookite freaking put 5 on that sucker and let her roar! Lol
Well time for an update:
Went ahead and hung the 5" about a week ago. Very happy with the results also. Sounds a lot deeper, very little "pop", no drone and lots of whistle. Sure, it was no big power/performance upgrade...but that's not what I was after. I wanted the sound, and I definitely got it. My only real complaint is the soot buildup on the rear wheel but future plans will be to finish sending it past the axle...for now it works and I built it for under $100.
Anyways here's a pic and sound clip for those interested.
http://youtu.be/RP-uCabQbfQ
Went ahead and hung the 5" about a week ago. Very happy with the results also. Sounds a lot deeper, very little "pop", no drone and lots of whistle. Sure, it was no big power/performance upgrade...but that's not what I was after. I wanted the sound, and I definitely got it. My only real complaint is the soot buildup on the rear wheel but future plans will be to finish sending it past the axle...for now it works and I built it for under $100.
Anyways here's a pic and sound clip for those interested.
http://youtu.be/RP-uCabQbfQ
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X-NRCan_IDI
Full Access Member
Sounds real nice to me!
VERY nice
thank you for posting the video!!When you get around to getting the exhaust exit behind the rear axle, it'd be great if you could post a video of that...I wonder how different it will sound with the longer pipe and the bends, etc?
THANK YOU again
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