Can't decide what to do.

current setup stock exhaust with flowmaster 44 dumped

99 4.6 2wd

(2 magnaflow 94106 hi flows)
should I remove all four or leave the front 2.
Then I'm not sure

1....True duel with and x pipe and 2 si/so 14" magnaflow to 2 1/2 in rear exit.

2....si/do magnaflow 2 1/2 in rear exit.

3....si/so 3 in magnaflow dumped at axle.

Thanks Matt.

 

I was wondering the same question but I didn't really want the duals, so.....thanks to some advice from Darren, I'm going to run 3" all the way back...from the cats to a SI/SO Magnaflow and back behind the tire.

But, lately, I have been thinking about dumping it....i.e. your #3 choice.

 

I would suggest to you the full 3" system like ShadowSTX is going with for best performance, but if you want that true dual sound the duals will sound good, go with an X pipe if you do. And if you do want it quite loud go with the 11" body mufflers. My truck is running pre-cats only and 11" body true duals X'ed and its as loud as a Chevy with a Flowmaster.

If your inspection station will allow you to remove all cats to be replaced with two Magnaflow converters go for it. Otherwise you may be best off with the pre-cats left alone then the hi-flows. The rears are what really kill the volume and flow.

 

DO THE X PIPE! Do not ever ever ever not have an X pipe

 

What does the X pipe do?

 

Eliminates scavenging, which helps give back low end torque and power. And a better tone for that matter.

 

Eliminates? Sorry man but that is very false. An X pipe helps balance the scavenging to be 50/50 for both banks. The passenger bank is usually stronger due to its shorter length and bends ( left bank true dual is usually 3.5' longer than the passenger! ) so the left bank will make the engine dog out a little when unbalanced forcing it to work harder, which will cause it to run a little lean, not to mention drink down the gas more. The X pipe 50/50 balances by jointing the banks together in a 4" center section and them flows out through the exhaust. Another plus to the X pipe is it balances the sound out much better because un-balanced the left bank will usually be much quieter than the right bank.

 

Yea I know for sure run an x pipe for true duel.
I also found this from summit racing.
PSM-82-1153
3 in y pipe goes form cats to muffler.
so pre cats stay in, then hi flows.
should I go
pre cat, 2.5 in hi flows, adapter then the 3 in Y.
or pre cat, 2.5 adapter to 3 in hi flows to 3 in Y.
with that then 3in si/so dumped.
or maybe 3in si/do 2.5 dumped then i could always put tailpipes on to quite it down if needed. Man decisions decisions.

 

Bad choice of words.

 

Sounds like a great setup. I would suggest running the hi-flows then putting the Y pipe adapter in for inspection/emission reasons but if you can get away without running rear cats then go for it at your own risk.

 

Im just concerned if I switch from 2.5" from the y pipe to 3" I might ******* up something, especially without a tune.
What I was thinking is that keep the 2.5" and have a dual exhaust... same pipe used for the cats... and then out back.
I heard an H pipe is good for us 4.6L engines..?

 

You wont. 3" is a much healthier set up to run. Dual 2.5" to a single 2.5" is restrictive and not only kills down sound, but it slugs the performance down a bit too. Exhaust does not neccessarilly need tuned unless you have modified your cats. H pipes aren't as great as X pipes are. The X pipe will retain low end power whwere the H wont do so as good. It joints both banks together to level the pressure and gases 50/50 out the exhausts. H pipe straight flows but has a pressure joint that doesn't opperate as good as a crossflow does.