Umm, what is this all about?

[broeser340]

So I had some time to kill and I was wandering through the local dealerships. Anyone had the chance to look at the new body style GM HD trucks with the Duramax? I mean really check them out? What is with the business end of the things. Err, tailpipe. Looks like they welded or are using a venturi effect of some kind as a tip? It seriously looks like an elongated carburetor venturi welded on the end of a tailpipe with four pieces of re-rod from concrete. To top that off, it looks like a pipe cutter partially closed off the original pipe in a cutting process. Looks necked down from about 4" to 3" maybe (didnt have a tape with me)? Its the end of the pipe IN the tip. Oh yeah, check out the restriction in that pipe from (clamping?) assembling it on the line. Ooops. Maybe someone needs to go back to exhaust flow 101. I bet the proud new owner never notices it. I have to wonder how this works in states that require smog/emissions test. It is my belief that a "tailpipe sniffer" would be thrown off with the addition of clean-air. It would not be a true representation of what actually exits the vehicles cylinders/emissions systems. I could do the same thing with my truck if I connected an oxygen tank just before the sniffer. This is not an air pump of sorts like gassers had in the past to introduce oxeygen into the exhaust BEFORE the cat to help the process along. Surely the EPA engineers would be on to this? Right? But maybe not, after all, isnt the EPA the ones that enlisted ULSD and particulate traps. Is it to maybe diffuse the soot when the particulate trap goes into its light off mode? So someone isnt smoked out and complain? Im sure the tree hugging hippies will love it when those things light off. Product of their own invention. Anyone placing bets on how long it takes for one of those things to fall off?

 

[MMeier]

Probably has to do with the self cleaning DPF thats now required on all diesels.

 

[MCummings]

On your 4th picture, the Dmaxs have been like that for a long time.



As far as the tailpipe, Ford is doing something similar with the 6. 4L TT.





Merrick

 

[Ncostello]

This is how you get a diesel to pass 07 standards. You install a venturi on the end of the tail pipe so it sucks in surrounding air and the output at the end of this contraption is 1/2 pure clean air at least. The more throttle the cleaner the emissions. It keeps getting better. The tail pipe sniffer sensor used at test facilities is hooked to the sneaky venturi end... not the tail pipe end.



PS: That is the most rediculous device I've ever seen. If I had one... hacksaw in 5 seconds.

 

[JasonCzerak]

the ford tail pipe looks cooler then the chubby.



the 6. 7 doesn't require it... interesting wonder who's more advanced here?

 

[JFlagg]

In the new DP they mention that tailpipe. Supposed to have some cooling effect, not sure why it would matter though.

 

[terrywerm]

Yeah, but just think what a neat flame thrower it would make if you added a propane nozzle and spark!

 

[HPetrat]

broeser340,

Good observation, the venturi effect is what they were after according to a friend of mine that works for a local Gm dealership.

The effect is to induce fresh air into the exiting exhaust gases to diffuse/cool them and eliminate any visible smoke, not unlike the radial holes in an ultra-light cigarette (same amount of poisons just thinned down so it seems better:-laf).



HP

 

[tkerrigan]

Maybe the exhaust gets hot enough at times to blister your hand, the introduced air could keep the tip cool enough not to blister kids hands etc?

 

[JFlagg]

Yeah, but just think what a neat flame thrower it would make if you added a propane nozzle and spark!

You beat me to it! I was just thinking the same thing:-laf

 

[BNH4221]

It is to cool the exhaust when the DPF goes into regeneration mode. Temps get pretty hot. 1200 degrees or so if I am correct.

Venturi effect introduces some cool air to keep the exhaust at a manageable temp as it exits. Hot gasses would do a number on the paint.



Steve

 

[Ncostello]

Great! Now you can't even put a chrome tip on the new diesel trucks! Just a few more things to go and they'll have removed or done away with every single thing that used to make diesel pickups cool to me.

 

[JasonCzerak]

Great! Now you can't even put a chrome tip on the new diesel trucks! Just a few more things to go and they'll have removed or done away with every single thing that used to make diesel pickups cool to me.

But think of the children!!!!!

 

[TJJEEPER]

Maybe the exhaust gets hot enough at times to blister your hand, the introduced air could keep the tip cool enough not to blister kids hands etc?

This would be my guess as well. Gotta keep the kiddies safe!

 

[BNH4221]

Great! Now you can't even put a chrome tip on the new diesel trucks!

I disagree. If the exhaust pipe works as advertised and the gasses are cool as they exit, why not a chrome tip?



If anything, the tip will need to be bigger so it will fit over that abomination.



Pretty soon you will see GM trucks with those giant chrome fart-can exhaust tips on them.

Can the chinese writing on the window be far behind?



Steve

 

[WDixon27]

cummings type R stickers :-laf

Pretty soon you will see GM trucks with those giant chrome fart-can exhaust tips on them.

Can the chinese writing on the window be far behind?



Steve

 

[raychem]

cummings type R stickers :-laf

That's classic!

 

[LLTNT]

Pollution

The solution to pollution is dilution

 

[CRuth]

A chrome tip so I can look just like the ricers? I dont' think so.

 

[WestTN]

This is likely just a way to cool the pipe tip to reduce the chance of a serious legt burn If there were a sniffer test, it would use a probe to get past the venturi.