Attention: TDR Forum Junkies 
About this time last year I installed the Jannetty 4 inch exhaust system. It is a full four inches to the rear and flows through a stubby Walker muffler. Its a straight thru design, but it has a chamber inside as well.
I have always had a terrible drone on the highway that will drive you crazy. I have 4:10 gears as well and this moves my RPM up a tad over most guys on here.
I tried everything to kill the drone. I welded on a piece of angle to the long straight pipe from the turbo to muffler. I tried clamps and welding. Clamps alone. Wleding alone. Nothing worked. After about two months of this I gave up and cut the whole mess out and started over. I removed the muffler and straight piped it.
It killed the drone but it was just a bit too loud on the highway.
Out it all came again. This time I went with two 4" mufflers that were called Twisters. They are straight through but they have a twisted piece of steel inside to spin the exhaust gas as it travels throught the muffler to develope a low pressure area to help scavenge the pipe faster. Well, either they are junk or having two of them was too much restriction. I lost about 50 or more HP it seemed. So off they come and back to the drawing board.
It was super quiet with the Twisters though.
I called around and got the last Walker 21471 muffler from the local NAPA here in Big D. I ripped out all the pipe and started from scratch. Used some existing pipe and bought some new stuff too.
After I welded all the joints up and used the Walker 21471 muffler I can tell you the drone is history and I got my power back I lost from the Twisters. That was a very long and expensive learning experience. BTW, the Walker is what DD uses and I got the idea from Donnelly on what the heck I could do to fix it right.
Don~
I have always had a terrible drone on the highway that will drive you crazy. I have 4:10 gears as well and this moves my RPM up a tad over most guys on here.
I tried everything to kill the drone. I welded on a piece of angle to the long straight pipe from the turbo to muffler. I tried clamps and welding. Clamps alone. Wleding alone. Nothing worked. After about two months of this I gave up and cut the whole mess out and started over. I removed the muffler and straight piped it.
It killed the drone but it was just a bit too loud on the highway.
Out it all came again. This time I went with two 4" mufflers that were called Twisters. They are straight through but they have a twisted piece of steel inside to spin the exhaust gas as it travels throught the muffler to develope a low pressure area to help scavenge the pipe faster. Well, either they are junk or having two of them was too much restriction. I lost about 50 or more HP it seemed. So off they come and back to the drawing board.
It was super quiet with the Twisters though.
I called around and got the last Walker 21471 muffler from the local NAPA here in Big D. I ripped out all the pipe and started from scratch. Used some existing pipe and bought some new stuff too.
After I welded all the joints up and used the Walker 21471 muffler I can tell you the drone is history and I got my power back I lost from the Twisters. That was a very long and expensive learning experience. BTW, the Walker is what DD uses and I got the idea from Donnelly on what the heck I could do to fix it right.
Don~
