have i been cheated ?

[jethro]

I have been reading about the (good) sounds of straight piped 12 valves......
I just finished making my stainless down-pipe with a stainless woven anti-strain gizmo where it goes horizontal-
then a bout 3 feet of pipe- then a 8 inch dia. - 30 inch long straight-through muffler (with the cheese grater center)
and then about 6 more feet of ss pipe to the rear bumper. Got the pipes and muffler test fit hanging from safety wire.
started her up - drove it around the yard gently. First time with other than a 12 inch stub off the turbo-----
OK- I cant believe how quiet it is all of a sudden..... back at the tail pipe it is as quiet as my gas Tahoe----
The muffler and pipes seemed to have quieted the turbo too- no more whine.....
Now the loudest part of the motor is the IP ( I think-) and the piston fuel pump.....
I let it idle about 15 min and warm up and it got even smoother.... just a little minor vibrations
transmitting up through the body but otherwise amazingly smooth and quiet.
Is the lack of "roar" out the tailpipe an artifact of not having the fuel turned up much and stock injectors ?

I have not tried it on the road yet--- should be getting a tag and new tires this coming week-

Did I somehow mess up and get it too quiet ?
tim

[justin.loehlein]

Not sure you can consider your system straight-piped since you have a muffler? Did you weld the muffler in or just clamp it? If you want it louder and the muffler is just clamped in, replace it with a section of pipe.

Also - what diameter pipe did you use? Seems like that could make a difference.

[spencerdiesel]

Believe it or not (most) straight through mufflers do quite a bit of muffling.

And it will be much louder with the passenger window down, more fuel and WOT. Not much load at partial throttle

[thrashingcows]

I have a stock 3" system on my crewcab...old and crusty, but still sound. I was running straight pipe for a coupe years, but got tired of the noise and drone...fun for a while. I ended up being given a 4" flow through muffler and I couldn't believe how much it quieted it down. But it still has a nice deep sound to the exhaust...I really like it.

[jethro]

It is 3 inch piping all the way back. It goes straight back to the bumper. I have it welded solid from the turbo connection
-down and back to the woven flexible thingamabob- then just slipped together for now till I get all the clamps\anchored into the frame.
I guess since the engine is governored- the resistance (load) controls the fuel flow- so with it lightly loaded
(like it will be 95% of the time) -- that would tend to keep fuel flow (and exhaust noise) down----- is that kind of how it works ? (my tractor seems to work like that- doesn't make much racket till I try to pull an immovable object-)

Tim

[jethro]

It is 3 inch piping all the way back. It goes straight back to the bumper. I have it welded solid from the turbo connection
-down and back to the woven flexible thingamabob- then just slipped together for now till I get all the clamps\anchored into the frame.
I guess since the engine is governored- the resistance (load) controls the fuel flow- so with it lightly loaded
(like it will be 95% of the time) -- that would tend to keep fuel flow (and exhaust noise) down----- is that kind of how it works ? (my tractor seems to work like that- doesn't make much racket till I try to pull an immovable object-)

Tim

[spencerdiesel]

Basically. If you can ever apply 100% load you'll hear her

[jdiesel_us]

Yes having run both a flow through muffler and no muffler you would be surprised how much the muffler changes the sound. I actually turned my muffler around so the openings faced the back of the truck and liked that the best. It helped with the resonance these engines produce.