I talked to a local exhaust guy who told me it was impossible to do true dual exhaust on my truck due to gas tank placement. Is this true? Is there a way around it to run two Flowmaster 40 Series Mufflers through from the stock cats back using 2.5" piping to the corners?

Matt

 

Theres a couple guys on here that have true duals from catback. i wanna say smoke20 is 1, but dont quote me on it, but it can be done. I have a custom catback system from a local muffler shop but mine is 1 in, 2 out, with the Flowmaster 50 series, and it sounds awesome. I didn't want anything obnoxiously loud, just with a mellow tone, and a lil bit of bark when accelerating. $400.00 straight out the back, installed............... Jim

 

allthrottle member has 99 sierra 4wd with true duals with super 40s they just stood them sideways down drivers side with no problem

 

Yes you can do true duals, I have it with flowmaster 40s and an x-pipe. They are both on the right side about where the bed and cab meet. There is plenty of room. The guy you talked to just doesn't have enough experience. I do not recommend true duals though as you lose too much back pressure, and low end and gas milage will suffer.

 

Thanks guys. In georgia its illegal to do what I wanted to do with the HighFlowing Cats (at least according to this exhaust guy. Can anyone verify?). He recommended I do Single in Dual Out Flowmaster 40 Series with 2.25" piping to the corners. I'd like to do 2.5" piping, which is an easy thing to change. But I would really love to run true dual. I'll go look around for another exhaust man to ask about the true duals, and let you know how it goes.

Thanks,

Matt

 

single in dual out with 2.5" will be best. True dual sounds good (as it did to me) till you floor it the first time. Like I said, soo much lowend loss, then you are adding reducers to te end of the pipes to get lowend back. I gained 1 full second after adding the reducers. As far as the cats, there is no real gain in removing them anymore. Plus your gas milage will drop. Just leave them in there.

 

I suggest a 3" SI/2.5" DO.
with the muffler of your choice.

Smoke, what reducers are you referring to? Im not familiar with such.

 

They are just pipe diameter reducers that drop the 2.5 down to whatever size pipe you wnt to add after. What I did is put 2.5 down to 1.75 reducers on the end of each pipe. You cannot see them as they are hidden in the tips. There has also been comment that reducing the pipes closer to the cats would give better gains, I just haven't tried it yet.