Engine/Transmission (1998.5 - 2002) Straight-piping downfalls?

[snowracer69]

Am having an argument with a guy that straight-piping a diesel engine (specifically this is on a new Furd 6. 0, but now it's onto diesels in general).



He is claiming that by running a straight-piped exhaust, you will end up burning the valves and won't have enough back-pressure for it to run correctly. I'm pretty sure this is all untrue, otherwise why would we go to 4" and 5" systems and why would people be able to run them trouble-free while straight-piped for so many miles? I do realize there is a certain amount of back-pressure needed, but didn't think it was anything like that of a gas engine.



Josh

 

[01smokinram]

pipes

First off that butthead is trying to confuse diesel engines with gas engines. Gas engines are designed to have back pressure. Diesel engines are better when you straight pipe them. less back pressure means lower temps on turbo and cool down is easier.

 

[bmoeller]

Diesels need some back-pressure too. The reason that straight-piping a turbo-charged diesel isn't a problem, is that the turbo creates enough back-pressure. From the turbine housing to the tailpipe is where you want the least amount of back-pressure.

 

[Jim Ross]

bmoeller-----What you said! Right on.

 

[Turbo Horseman]

Gasser buttheads... think they know everything... why we oughta... geesh!

 

[WestTN]

Back pressure

Actually, gas engines don't need back pressure any more than diesels. In the carburator days, removing the muffler would cause the mixture to become lean. In some cases this could drive an engine which was already too lean into detonation or excessive combustion temperatures. In computer controlled engines the oxygen sensor enables the computer to sense and correct the condition. In earlier times the owner had to rejet the carb to compensate. Diesels have absolutely no need for back pressure.

 

[Deezul1]

Do you mean to tell me that after 50,000 straight piped miles now something bad will happen? With 174,000 miles on it I thought it finally was getting broke in.

 

[LSMITH]

NOISE, it SUCKS it is LOUD. I am straight piped and I wish I was not. I put anywhere from 500-1200 miles a week on my truck, that is a lot of seat time to have it noisier than it needs to be.



I would not straight pipe again... ... ... ...

 

[Ray Torresdal]

noise?

I rode in a friend's truck with what I assume was Geno's muffler eliminator, and it wasn't any louder in the cab than mine. I had to crawl under the truck before I would believe that there wasn't a muffler under there! The resonator was still in place. When he left, you could tell the difference, but I swear there was no difference in the cab with the windows up. I was surprised!



ray

 

[n7gxz]

Straight Piped Diesels

My D2 Cat is straight piped with a 2 1/2"x24" pipe right off of the manifold and it has been running for 50 years.



Kevin

 

[Sticks]

Originally posted by LSMITH

NOISE, it SUCKS it is LOUD. I am straight piped and I wish I was not. I put anywhere from 500-1200 miles a week on my truck, that is a lot of seat time to have it noisier than it needs to be.



I would not straight pipe again... ... ... ...

If you took out your resonator, put it back. I plucked my muff and was a little disappointed that I could not hear a difference in the cab, with all the windows open. Even with all of them closed, no extra noise/drone than normal. Even standing forward of the rear passenger tire, I can't hear the difference. I have to be next to or behind the truck to hear it.

 

[kaptn]

Hey Remember some people don t like Mozart. I liked my straight pipe and the music it made. You ought to hear my HX-50 spinning with with the two 5 inch organ pipes sticking up behind the window. Now thats loud! I jump out of the cab just to hear the turbo finish its concerto after shutdown. lol

 

[TomGolden]

Ahhhhh, there is truly nothing quite as invigorating to me as a rousing rendition of Cummins Symphony #2 in 4" Straight Piped Major



Well... except for maybe a chorus of Harley-Davidson or top fuel dragster music :-laf :-laf :-laf

 

[MD500E]

[I jump out of the cab just to hear the turbo finish its concerto after shutdown. lol]



I am right with you on this one!!!!!!!!!!



AS for back pressure, In a turbo diesel you want as little back pressure after the turbo as possible. The more back pressure you have in the exhaust system, the less pressure differential between the exhaust input and the exhaust output of the turbo, and therefore less power is generated to spin the compressor side.

 

[Ray Torresdal]

Decided

You pushed me over the edge Sticks - I'm going to dump my muffler ASAP. I didn't know if it was an anomoly that I couldn't hear the difference in my friend's truck, or if I was already partially deaf.



Ray

 

[Old Iron]

WestTN is 100% on

 

[Turbo Horseman]

100% straight pipe, stock size for well over 100k KM.



Those who complain about noise... what's that all about... my stealth bomber... why you can't hear it from a mile or two away... that's much better than the US airforce bomber. So I'm stealth all the wayOo.

 

[LSMITH]

Originally posted by sticks

If you took out your resonator, put it back. I plucked my muff and was a little disappointed that I could not hear a difference in the cab, with all the windows open. Even with all of them closed, no extra noise/drone than normal. Even standing forward of the rear passenger tire, I can't hear the difference. I have to be next to or behind the truck to hear it.

Resonator is still there. Must be a shortbed thing... ... . Maybe it is a power thing, mine runs really strong... ... . Maybe it is my hearing, I have lost a significant portion of my hearing, with background noise while on the phone or something like that is nearly impossible to hear... ... ...



It is a LOT louder in my truck. I have no drone or anything like that, just noisy. It is louder with the windows up, and with them down it is a LOT louder. If I get on it at all it just BELLERS. I gained zero power, zero lag reduction, zero fuel economy gain, I got NOTHING positive from the muffler removal. If I had it to do over again I would not straight pipe MY truck.



Try to keep the muffler useable in case you don't like it straightpiped.

 

[csevers]

Straight piped 4 & 5 inch pipe empty at 70 mph 2200 rpm is annoying, under even an emtpy trailer if is simply deffening. I had a hearing problems before I baught my first diesel so I can stand it most of the time but I put the muffler back on in the winter do to the fact I can't drive with the right window down to hear the music. The sound quality is good sound quantity is not. I have a major drone problem I will figure out some time.



LSmith I have a muffler off of my 98 or 99 you could have if you want to put back on.



Craig

 

[Fireman Dave]

Originally posted by LSMITH

Maybe it is my hearing, I have lost a significant portion of my hearing, with background noise while on the phone or something like that is nearly impossible to hear... ... ...

eh? What did you say?



Howard, didn't your momma tell you if you didn't stop doing that you'd go deaf? :-laf