I have an LS swapped Solstice that needs new exhaust. Ive been running the same 2.5in dual system for a while. The car recently got some upgrades and is close to 750 crank HP and is in need of some better flow. A respected local shop is recommending 2.25in tubing for a new dual exhaust system. I'm thinking it needs 3in but they say no, 2.25in will work just fine. I'm no expert but that just doesn't make sense to me. Are they right or full of ****?

 

Sounds to me like they're just wanting to use something that is easier to work with and fit in the car. I would find another shop if I were you.

 

I vote the latter... 2.25 will choke the crap out of your engine.

 

 

This reminds me of a now-defunct muffler shop in my town. I took a '78 Chevy C10 w/454 to get duals put on. The guy actually thought he was going to put 2" pipes in the system. His reasoning was "it's only 4 cylinders going thru each pipe". I said yeah, but look at how big those cylinders are! He quietly agreed.....

 

They must also subscribe to the heavily flawed "engines need exhaust back pressure to make more power" theory.
Entertaining conversation aside I would run from those guys.

 

Imagine how much more power it would make with a single 1" system....

 

It just MIGHT break the magic 150HP barrier! lol

 

Exactly. 1"/2" = .5 750HP/.5 = 1500 HP.

Exhaust back pressure math.

 

Engine Masters:
So yeah 3"

 

Thanks for the replies fellas. Great video too.

I`ll be heading to a different shop for my exhaust work.