Most restrictive part of exhaust? Looking for power/quite

[Not7fifteen]

What are the biggest restrictions on the factory 2011 exhaust?

I'm running a Paxton kit with stock manifolds O/R X-pipe and a MAC axle back.

Really want it quiet as possible without restricting too much power by toning the sound down.

Insights on what free's up most power? Recommendations?

 

[fuelforfire87]

The biggest restriction in the exhaust is the Cats. Looks like you already have that taken care of with the offroad x-pipe. From there if you want more power you would need to get headers. That should free up another 30-40hp on a boosted car. Headers will make your exhaust louder but with the right choice of axleback it can still be pretty quiet while driving normally. The over-axle pipes can be a bit restrictive as well because they have resonators and aren't mandrel bent, but replacing those would be the last piece of the puzzle and would only free up a bit more HP. Plenty of cars on here making over 600 rwhp while still running the stock over-axle pipes.

 

[98 svt]

What are the biggest restrictions on the factory 2011 exhaust?

I'm running a Paxton kit with stock manifolds O/R X-pipe and a MAC axle back.

Really want it quiet as possible without restricting too much power by toning the sound down.

Insights on what free's up most power? Recommendations?

Well, you already have an off-road midpipe and aftermarket exhaust.
I'd say headers are the obvious next step.
More power + quiet exhaust is a conundrum, though.

 

[Recon]

Put a factory cat back on it. The stock mufflers and resonators should quieten it down quite a bit.
As for more power longtubes are the next step for you but it'll be louder.
You've picked two antonyms for exhaust. Unless you want to go with a very mild Magnaflow muffler.

 

[Not7fifteen]

My next step was long tubes and switching to an O/R X-pipe. I have the over axles section as well.

Mainly worried if I go with a quiet axle back am I choking gains made from long tubes or are the manifolds more of the restriction and the axle backs just sound for most part.

My inclination is long tubes, OR X, 3" over axles and then gt500 axle backs.

 

[fuelforfire87]

My next step was long tubes and switching to an O/R X-pipe. I have the over axles section as well.

Mainly worried if I go with a quiet axle back am I choking gains made from long tubes or are the manifolds more of the restriction and the axle backs just sound for most part.

My inclination is long tubes, OR X, 3" over axles and then gt500 axle backs.

Axlebacks (mufflers) mainly just alter the sound of the exhaust. A straight through type muffler will flow better than a chambered one, but will not affect power that much. The gt500 axleback would be a good choice. The magnaflow street axleback is another good choice. I used to have that axle back and with headers and O/R X and it was only loud when going WOT. I currently have the corsa sport axleback as it offers the best of both worlds with their RSC technology.

 

[Brutal Metal]

Put a factory cat back on it. The stock mufflers and resonators should quieten it down quite a bit.
As for more power longtubes are the next step for you but it'll be louder.
You've picked two antonyms for exhaust. Unless you want to go with a very mild Magnaflow muffler.

How can he put the oem catted midpipe back on THEN get long tube headers?

 

[Recon]

The resonated over axle pipe and stock mufflers is what I meant. It wouldn't be hard to modify an OEM mid pipe to accept longtubes.

 

[Stang_456]

Weld on a bunch of sound resonators ?

 

[Gruca]

I think the GT500s are your best bet, from my personal experience. I currently have lethal off-road X with stock manifolds (soon to be Kooks Super Street) and stock OTA pipes (just ordered the lethal ones since they are $50 off). My car is currently pretty quiet with the exception of my Tial BOV....

 

[Not7fifteen]

Turbos really help quiet things down too. My T67 single 2v was like a damn ghost though no cats and magnaflow