Muffler Modification.

Everyone,


Well Ken and I modified 'Storm I forgot to take pics of where we cut off the straight pipe. No biggie, I have pics of the process after we painted the muffler. We cut the pipe about six inches from the highest point on the fender to give ourselves plenty to work with. We then fit the upper tube into place on the exhaust side of the muffler. I have the pipe about six inches over the top of my 109 box and angled about 30 degrees or so to push the exhaust from the box and not discolor it. We finished the project by adding two pieces of angle iron from Lowes Home Improvement to stabilize and secure the muffler to the truck. A good paint job and we're done! WOW what a difference in decibels! I can actually talk (that's right!, not shout or need an expensive intercom system) to my passenger with the passenger side window down and running about 50 mph or so. I can actually hear the tires humm on the pavement (a favorite tune of mine) and enjoy the wind being louder in the cab than the exhaust deafening me to the rest of the truck. I can hear the tranny gears doing their job and much more too! Ken has stated he's getting the other muffler from NAPA here in Houston to install on his truck too. It's a flow-through muffler for about $65. Money WELL spent! So here are the pics..

Desert Rat, That looks good If I wanted to do mine like that what sould I ask for at NAPA Store, (part #)

Also what size is the original exaust pipe, 3" or 3½" ?

thats pretty cool, how well does that cut down the noise, i have a muffler in mine also except its up higher on the stack doesnt really do that much but mine is nothing like that

look's good exhaust is next on my list after I add a turbo.

LD,

I'll have the number this afternoon when I'm installing my inline fuel pump (pics on that too). I had to go to a NAPA warehouse to find it in stock. Other NAPA places were going to charge to ship it closer to me. So I got in my car and $aved some money. The pipe is 3&1/2 inches and the muffler fits like a glove. You will need one clamp and re use the clamp on the stabilizing bracket to secure the muffler.

PK,
The muffler cuts the noise WAY down. I'm using the entire stack that I cut to put the end of the pipe nearly 12 feet tall (actually 11' 4") and push the exhaust away from the truck. A side benefit is it also puts the noise up and away from the truck as well.

PK, he isn't kidding. I've had a muffler for a couple of years now and his is much quieter than mine. So i'll swap to his style muffler. You can actually hear the fuel injector lines tink when the fuel goes though them.

Anything above idle and the fan noise takes over. At 50mph we were talking to each other is a normal tone of voice. You will be able to hear prevously unknown noises the truck makes. ( gear whine ETC, ETC) I can't under stand why mufflers weren't orignal equipment.

The N/A models were equipped with a muffler.
The turbo is more efficient with less restrictions down stream. How much I don't know.

LD,
The muffler is a #21470 from NAPA.

Bjorn,
This is a flow through muffler with side baffles. Actually it's three flow-through mufflers welded into one. You can actually see the different stages when looking down the inside of the can.

P.S.- I suspect Ken is a bit jealous of how quiet 'Storm is now :smilewinkgrin: [] :turn: [^]

I wonder how much the reduction in noise is because of the specific muffler, or because he has a long chunk of pipe after it. I would imagine even without a muffler, if the pipe were that tall, it would be really queit!. Any thoughts on this?

Mangus580,
It was typical of a 1D motor with a hard top cab before installing the muffler. The combination of the muffler plus added height drastically cut back the decibels. Walking around to where the pipe ends and being up on the fenders while adjusting things under and on the hood I can tell y'all it's a real quiet muffler we installed.

P.S. - Wifie looked at me working on my truck and said no pics on the fuel pump installation until after it's over. She looked at how I was coated in diesel grease and goop and nearly killed me for suggesting photos. I'll have some in the morning.

thats crazy how quite you guys got it, thats a lot of noise to damper good job!

M 580 we acually started it before we put the stack on. And it was still quieter than mine!

sound doesnt travel in a straight line, its sound WAVES. a longer pipe DOES decrease sound, but you are only taling a foot or so. very little difference. i run the same muffler, as a matter of fact i gave them the part number.

my only complaint from the muffler is after around 1500 rpm the engine makes NO additional noise and that translates into haveing to shift by feel or by looking at the tach. im serious. i notice i red-line the thing more.

I wonder what it would do to my whistle... I really like the whistle, but the rest of the noise could use to be a little less.... I have thought about retrofitting a muffler for everyday use, and being able to switch it back for parades... the spectators really like the noise!!

i dont think it will eliminate the whistle.....

I think the majority of the whistle sound is from the intake side, you might be able to hear it better without all that background noise.

I tried to find the muffler on the NAPA online site, it didn't recognize the number. I am going to run by the parts store tomorrow and see if they can order it for me. If my turbo noise is still too much, I'll swap on my D turbo and pull off the C. The turbo scream sets my teeth on edge. I know HERESY!!!! He doesn't like the "Whistle"!!!!
Sorry guys, it reminds me of a dentists' drill.

Robert,
It's a ligit number. I got it right off the box. As a matter of fact I still have the box! I forgot to leave it in Houston. Oh well.

its actually STAMPED in BIG letters into the side of the muffler!

McI,
Yep, you're right. That's how I got the numbers in the first place. I also kept the receipt just in case someone else wanted the data too.