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Discussion Starter · #1 ·
hi guys. i put a straight through 3 inch muffler on the effer. it seriously restricted the show. it is just a bit of perforated pipe in the guts of it. no double pass or anything. is there anything particularly special about diesel mufflers ? is 3" too small ?
 

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I use stock 1989-1993 Dodge CTD mufflers on all my trucks. The NAPA number for what they call 'soundmaster' is 18371. List is 152.50, I pay 84.00. Its 3 inch in and out. I am pleased with the performance and sound .

Paul
 

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Discussion Starter · #3 ·
thanks paul. not sure i can buy it here. i have been looking in a walker catalogue. found some 4 inch truck mufflers that look promising. guess i'll find out what it's all worth tomorrow.
 

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hi guys. i put a straight through 3 inch muffler on the effer. it seriously restricted the show. it is just a bit of perforated pipe in the guts of it.

Going from an open down-pipe to any muffler will always result in a loss.....but it shouldn't be a serious loss, especially with a straight through 3" perforated pipe. I have seen a LOT worse restriction mufflers still work OK on turbo diesel engines. Go look at a large semi truck muffler for the 12+ liter engines.......NOTHING straight through about them!
 

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Discussion Starter · #5 ·
it was too much. it went from sitting on 3-4 psi cruising at 55 in top, to nothing. full boost was slightly down as well. the extra heat in the exhaust was really noticeable.
 

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it went from sitting on 3-4 psi cruising at 55 in top, to nothing. full boost was slightly down as well.
That is a significant change. How is the sound level with a straight 3" pipe all the way to the rear?
 

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hopefully i don't have the same experience...we will see in a week or so hopefully.

I am currently running a 3" downpipe to a 4" back with a donaldson truck muffler. Soon to be going full 3" with a borla cat back. The 4" really doesn't fit and has fallen off a couple of times...oops.
 

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Discussion Starter · #9 ·
souns level was ok with a straight piece of 3" pipe. the only problem with it was i need to get the conversion approved by an engineer. so a muffler is necessary. i managed to get onto a 4 inch walker truck muffler, and some reducers. it is rated to 225 hp in the catalogue. it is 8 and 1/2" around and 40 long. it should fit in between the chassis and the tail shaft.
 

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Just do whatever you need to in order to get the engineer's approval, then change to whatever afterwards!
 
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