As the truck sits now I have the eforce blower @9psi and alky control meth that flows into stock manafolds, offroad Y pipe with a vibrant resonator and race magnaflow muffler feeding into a borla s type cat back. After almost a year I still cant get used to the ticking(may be exhaust leak, I need to hook up a shop vac to the tips to presurize it and check for leaks with windex) and the nasty drone. I didn't go with headers like my last truck to avoid this, and it looks like that was all for nothing haha.

I went offroad y pipe when I went meth with the advice of many people that meth will melt the stock or any other cats. The way I see it now is I either put cats back on and remove the meth or deal with the noises. With two mufflers and a resonator I don't have much exhaust room left to add anything expect before the two sides join.

I just wanted to pulse the forum for other ideas I haven't thought of. Dont know if any sort of sound deadenting foam under the cab would help or it would just get water logged/caked with winter salt and rust out the cab.

 

Who told you meth will melt cats? Id love to see the logic on that one. The volume of meth ingested is so miniscule that you wont have any problem. The way you described your setup sounded like you have the meth spraying into the exhaust, its going into the throttle body, right?

What valve springs do you have? The stock cats do quiet it down a lot. Drone has a lot to do with exhaust length and muffler.

 

Stock valve springs. I have a single nozzle spraying right behind the throttle body, pre blower. New Era Performance in Rochester NY where I had it tuned mentioned the cats and meth.

 

Removing the cats is 90% of the added noise you get when you add headers.

Meth burning as slwo as it does I can see being a little tougher on the cats... Hmm. have you thought about adding another muffler in line?

 

With the second magnaflow muffler and vibrant resoinator under the cab before the borla catback muffler, I don't have much exhaust length left lol. About all I can do is see if I can add a couple small ones in the location of the off road y pipe where the factory cats used to be right after the manifold flange. That would give me 4 mufflers haha, might want to add more support brackets if I go that route to help take the weight of the exhaust.

 

Oh sorry I missed that in your first post



I think the only thing left to do is add high flow cats. Where did you get he high flow off road pipe?

 

New Era made it. Honestly I'm regretting not sticking to just a cat back on stock exhaust, but I have that fear of a melted cat in my head from all the internet horror stories

 

I have never heard of that one honestly. Most cats are destroyed by ingesting broken parts or from general wear and tear. Performance builds are harder on cats because of increased airflow and increased heat, but that happens with or without meth. Meth as a total fuel consumed is very very tiny.

 

I am going to side with Richard on this one. I don't think meth specifically causes the issue.

 

I'm not sure I fully understand what the ticking is about. How are all of these exhaust parts joined? Slip joints and clamps? Welded? V-bands? 3 bolt flanges? Ticking could come from a leaky slip joint. A fix would be either welding that spot or v-banding it. What about exhaust gasket at the manifold flanges?

I also hear that the brass rocker trunions quiet the valve noise slightly. LS engines are going to be noisy regardless, though.