I've now got two 6BT-powered rigs (the tugboat '93, and the '78 Ramcharger trail rig), and I just got a muffler from the local Kenworth dealer for the tugboat. It is 45" long, and appears to be just right.
Look inside -
This muffler is from a company called ACRAFIT, and it has a wall dead center within it that forces the exhaust (and sound) to go through the perforations verse just straight through. I cannot help but believe this will be great for noise cancellation. Has anyone else seen such a muffler, and if so do you like the noise level, and did you notice a performance difference?
I figure the longer the muffler is the better it will perform, right?...more surface area = more perforations for cross-flow = less restriction in flow...and an increase in performance potential, ja?
I have heard of the Donaldson line but I cannot get any info on what it looks like on the inside and/or how it 'sounds'.
Now, I'm wanting to install a similar muffler on the Ramcharger, which has a lot less wheelbase to work with, so I'm looking for a similar muffler...but is about 2-3 feet long. I may be able to get this 45" monster to fit in the RC's chassis, and if so, bonus. This muffler was $75 bucks at my local KW shop - not a bad price, and I'll be happy to get another one just like it for the RC unless I can find one a bit shorter.