Why does the same thing have two names? Is there a difference?

 

unless I am wrong.....

a manifold is cast

a header is bent tubing

 

Manifolds are cast iron where as headers are tubular steel.

 

what are the performance differences in them??

 

A header usually has tuned exhaust runners, all the same length, helps keep gas velocities conistant and helsp scavenging. (Adds power) On a NA engine headers are the thing to add for more power. Shorties for more low end (and to keep clearance in some lowered cars) , full leingth for peak. (Generally) Now as fora turbo engine, when you hang somthign like a turbo from the header you add stress adn can cause cracks to form over time. This is somthing to consider if you race a lot or drive on rough roads. If you do a cast manifold might be worth the extra reliability over the extra HP you'd gain with a tuned header.

BUt cince I'm assuming you mean a cobalt, by all means man, get a header. It's worth it, and most smaller cars nowdays get big increases with pre cat exhaust mods, much more than with a catback. Since your biggers restriciont honestly is that cat. So andy restrictiosn you can negate before it will get you some impressive gains. A scoin TC I have seen has gotten 10 HP and 12 Tq from just a header, meanwhile a catback is good for 3 and 1 respectively.

 

From what I hear, both the aftermarket heders and GMPP manifold yield about the same 5-6hp increase. Looking for the dynos….

I’m about to get the GMPP Extrude Honed Manifold and put it to the test

 

Normally. Headers can be made of titanuim or aluminum also. Though the -vast- majority are steel. IF you do get steel, buy a ceramic coated one. They dont rust, and they lower underhood temps.