what kinda hp gain can you expect to get by adding a test pipe on a stock exhaust vs adding a test pipe with a cat back exhsust is it really worth the extra noise for daily driving?

 

If i were you man I put a 60mm test pipe and took off my mufflers and welded on some nice and cheap ebay mufflers that look SICK.(burnt tip ones) i get compliments all the time and its not to loud at all with very little drone and I got the added power from the test pipe as well.

 

Consensus is that a 70mm single exit exhaust produces the most gains. Although the gains are minimal the added bonus of saving weight is there too. The stock exhaust is pretty damn heavy.

 

I'll never understand how people forget to search first

 

More than anything, you want the sizing to flow in the correct order. Go from small to large and not the other way.