Now that I have the GMS1 installed, looking into a downpipe. What are the hp numbers difference from catted to offroad. Not sure I want to have to swap back to stock every year for inspection. Is it even worth the catted for hp numbers?

 

I'm doing the same research. Based on my own research gains for a catless are around 15whp. I stand to be corrected. That's what Synapseturbo claimed.
Hahn claims that the catted is only 5% less power. At 15whp for the catless that would make the catted about 14whp.
If that's true, I might just go catted.

Then there's the ceramic guts and metal guts of the cat.
At the moment I'm leaning towards CIA's catted dp (metal internally) or Synapseturbo if I go catless. Hahn has a metal cat too I think, Synapse doesn't offer a catted that I found, and ZZP uses ceramic although I think they may offer metal if you request.

In my research the metal one's can better stand the heat and such.

 

FYI Even without a tune a catless DP is worth 10-15 over stock I have seen before and after dynoes to prove it.

 

get ZZP catless, they angles the o2 bung so you wont throw a code and will pass inspection. Same angle bung as hahn and CIA but ZZP is the cheapest

 

Talk to Dan at CIA, he hooked it up for me. i got my Catted CIA pipe for 315 shipped to my place...

Ill buy from them again if i need anything else... He was super helpful..

 

wow 315 shipped, dont know how u did that but congrats, the group buy was $300 plus shipping.

 

I picked up a dejon used with 3000 miles on it and no cat for 190. But i think dejon powerhouse has the best price so far.

 

I still don't understand why people keep making new downpipe threads...just find an old one and bump it with your question...there's like 1234214 downpipe threads already.

 

^^^ seriously. I got mine for $200 shipped though from CIA

 

it was 215 or 230 shipped for catless and 315 shipped for catted...

i live in cali, so shipping from washington isnt bad.