Maybe it's just less muffled exhausts and tunes that are optimized for spooling the turbo, but it seems like lately I see lots of brodozers that are running some tune that makes them whistle and roar like they're trying to get a loaded semi trailer moving while just pulling away unladen and not quickly...
Any idea what's up?
Probably deleting the catalyst/reductant system and then 15" diameter exhausts.
Lol, and very apt. I roll up my window every time I’m near anything diesel powered. I know this won’t be popular opinion, but wish those things were outlawed.
The stank is so bad it makes my eyes water and my nose cringe. The coal dust has GOT to be cancerous. Why are these things allowed to run uninhibited? This is one time I’m actually for the Dept. of air quality stepping in.
I don't think I explained it very well, but the thing that strikes me beyond the pure loudness that's been going on for years, is that it really appears to mimic being under a serious load.
My audio impression of throttle position is way beyond what's apparent from watching them pull away at a modest pace. You'd think they had an invisible weight sled behind them...
We did the DPF delete and a tune on our shop F450 and in my opinion it absolutely ruined the truck. It is so much noisier and smellier than before. You used to be able to leave it idling while you hooked up a trailer but now it will make you retch and stink for the rest of the day if you try it. They did it for the 3mpg increase because the truck is primarily used for hauling a 2 car trailer a minimum of 300 miles per trip.
The other day at the stop light next to work there was a mid oughts era semi with a 30" trailer full of lumber, next to that was a Dodge Ram made within the last 5 years or so. The Ram had a 6" lift and of course had the towing mirrors fully extended. When the light turned green there was simply no way you could hear the Freightliner over the colossal racket made by the Dodge. It was easily twice as loud.
Some people want to hear a bunch of spool going down the road. I've seen people mod subies and Evos to make a bunch of turbo noise too. Gotta let'em hear those spooly bois yo!
The diesel guys are almost certainly running nothing downstream from the turbo (federal crime to remove emissions hardware), they probably have some aftermarket intake kit that doesn't muffle any of the intake whistle, and its possible that their tune may even alter or lock VGT position to make more noise (at the expense of bottom end power). Aftermarket turbos or compressor wheels are fairly common too
That whistle always sounds like a damaged turbo to me. I know mine doesn't whistle with a Banks intake other than a slight whine under load.
BTW, don't mock newer Dodges for having their mirrors in the tow position. Visiblility around the truck is much better that way, and when your vehicle is 8000 lbs and 20' long that's good for everyone.
I have a 6.7 Ford. Just a SCT x4 tune on it at the moment. The truck is fantastic to drive.
I do intend on doing an intake and downpipe, but the DPF and EGR will remain intact.
The DPF delete is just too tempting for most. 60 extra hp, 100 ft lbs, and better gas mileage sounds like a no brainers. However, I hate the diesel small and my family rides in the truck all the time. Not worth it.
We chipped the ICBM(Idle Clatter Bus Mobile) and gained throttle response and 2mpg at 85mph. It changed that 22 passenger bus without blowing any excessive smoke.
A lot of it has to do with the big tip and large diameter exhaust. My two 2002 7.3s, both with stock turbo, one had a 4" straight exhaust, one had a 5" straight exhaust with a 6" tip. The larger exhaust was significantly louder. Now add some VGT tuning and you have that jet airplane sound.
I for one think it sounds awesome. I miss the sound and presence of my F250 almost every day, but I love love love my Land Cruiser for daily driving, road trips, and commuting. But tailgating, trips to Home Derpot, and driving around with the windows down is not nearly as enjoyable.
To answer the actual question, VGT stuff. Gives you turbo spool sounds under very light load if nothing in the exhaust system is killing that sound.
_ said:Lol, and very apt. I roll up my window every time I’m near anything diesel powered. I know this won’t be popular opinion, but wish those things were outlawed.
The stank is so bad it makes my eyes water and my nose cringe. The coal dust has GOT to be cancerous. Why are these things allowed to run uninhibited? This is one time I’m actually for the Dept. of air quality stepping in.
No. I’m with you. And I even own one.
Coal rolling for no reason just plain infuriates me. I’ll admit though that I have done it when nobody was watching. And I’ve done it a couple times when I’ve had to pass. I’ve got an older Super Duty with a good tune. 4” turbo back WITH a muffler. It won’t smoke unless you’re really getting after it.
Ransom said:I don't think I explained it very well, but the thing that strikes me beyond the pure loudness that's been going on for years, is that it really appears to mimic being under a serious load.
My audio impression of throttle position is way beyond what's apparent from watching them pull away at a modest pace. You'd think they had an invisible weight sled behind them...
Extremely heavy truck, combined with how Diesels cannot accelerate, and yes, even moderate vehicle acceleration has them working their ass off. When you eliminate the muffling, you can easily tell that the thing is struggling to keep up with traffic.
^ you’re either trolling or know nothing about diesels built since 1990.
In reply to A 401 CJ :
Have driven a bunch, yes. From all three of the Big Three (including all flavors of Powerstroke) as well as a smattering of VW, Mercedes, and BMW Diesels. (Yes, modern ones - got to drive wae's ML350's twin last month, albeit with 100% less rod knock)
Diesels cannot accelerate. That is not their forte. They are oxen to be loaded down, not horses that can run.
A 401 CJ said:
So what? That has no bearing on what I am talking about.
If you plant the throttle and it takes noticable effort for the engine to accelerate itself without any load at all, it means that much more effort is needed when trying to move an actual vehicle. Combine that with Diesel's inherently low specific torque output, requiring turbos in order to even reach gasoline-engine levels, and you end up with something that is bog slow until the turbo spools up.
The 2.0 TDI isn't terrible. Not great, but livable. Not coincidentally, it also has a fairly lightweight rotating assembly.
What's more annoying, the noise, the smell, or the fact that the majority of these trucks are driven around by utter jackwads as daily drivers for no apparent reason other than they're big and scream LOOK AT ME?
So people complain about the “work in my garage” thread, not understanding that someone did something stupid that results in new laws.
Same thing here. The more people disable the emissions hardware, the more likely that we will all suffer for draconian laws against race cars.
I'm the last one across the intersection every time in my 6.7. The combination of 4 tons of weight and a stick means I accumulate velocity rather than accelerate. Like Knurled said, it's working hard. When you've got a bit of mechanical empathy and the manual transmission lays bare just how how the thing is working, choosing to limit your rate of acceleration is an easy choice.
I will admit that I've altered the emissions gear on my truck. I deleted the EGR because of concerns about long-term durability of the engine. I left the cat in place and the rest of the powerplant is stock. The truck doesn't stink when idling. Under a heavy, heavy load - usually when shifting gears while towing a two-car trailer up a pass - I sometime see a small puff of smoke out the back for about a half second as the engine takes up the load again, although I have to be watching the mirror that shows the tailpipe to see it. That's my "coal rolling". It's less obnoxious and less sustained than what you can smell when following a brand new stock WRX that's under boost.
Diesels breathe for E36 M3 and can barely move without boost. Drive a modern diesel with no boost and you'll realize how completely worthless they are without boost. I recently drove a 6.4 powerstroke with no boost and i think i had to floor it for one mile to hit 40mph. If you floor a 6.4L Ram with no boost (hemi) for 1 mile it'll probably be bouncing off its speed limiter for the last half mile of it. Psi for Psi (of boost) they are trash compared to a gas engine until you get to the point where you're fighting detonation in the gas engine, and you're not in the diesel because the diesel literally cannot detonate the way a gas engine does. But i get the point of diesels themselves being totally worthless without a bunch of boost. The one major advantage a diesel has over a gas engine is just that 100% of the fuel is never present in the cylinder at any one moment which is the major liability that limits how hard you can run a gas engine. Other than that, any typical gas engine of similar displacement will make more power at any boost level from 0 to whatever.
it's not the tune per say, it's the fact that most of these are running unrestricted exhausts, so you hear all of the turbo spool unmuffled.
Vigo said:To answer the actual question, VGT stuff. Gives you turbo spool sounds under very light load if nothing in the exhaust system is killing that sound.
Bingo. You beat me to it.
Prior to VNT, the poser way to do it was engineer a wee bit of backpressure into the system to keep the turbine spinning. It was the ultimate stupid choice - kill power and raise EGT just to hear a whistle.
I'm not in the brodozer camp, but I am a huge diesel fan. I must say there is a lot of misinformation and "ew, icky black stuff" misconceptions. Just because you can see and smell diesel exhaust more than gasoline exhaust doesn't make it horrible stuff. It is actually not that bad. As of 2008, light and medium duty diesel trucks had to conform to the same emissions standards as a gas vehicle, hence the Urea and DPF. EPA has cracked down hard on shops that do DPF delete mods, so much of the aftermarket has found ways of tuning and modifying that keeps the DPF and still makes power.
There are some wildly huge benefits to diesel; both before and after burning it.
Wow, much hatred for diesels in here based on some previous posts?
Of course an engine designed to work with boost is going to be underpowered and poor performing with no boost. I’d be surprised if it performed well with no boost.
It no different than if you design an engine for E85 and run it on 87 octane that will result is performance issues.
Or if you add big tires and a lift without re-gearing and it’s not surprising that the engine has to work harder getting everything moving and up to speed from a stop.
Come to Bend, OR. Spend a week here. I’m not saying EVERY diesel is horrible, but I am saying I can “smell” a brodozer from a mile back in traffic. I’ve watched them dust poor pedestrians on sidewalks. I’ve seen them nearly kill people because they can’t see over the gigantic lifted hood. I’ve watched them gently pull away from a stop light, only to gun it when the car in the next lane starts to pass, JUST SO they can “fog” them out and blind them while driving.
Whatever they are doing, tune wise, out here it’s intentional. Kudos to the folks that are not. You deserve to own that vehicle.
I drive a Miata, and I swear to god, if one of them dusts me with my top down, I WILL pursue them, call them in to the police, get their info, and sue them for taking years off my life.
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