oook. I would recommend tuning with OEM Cat, then installing the cut OEM cat and retuning. Otherwise you'll never know the net effect.

Good luck and let us know how that goes!

 

Simplify the discussion, from the header with a OD of 58mm going into the OEM Cat with 60mm. It hits the core and due to CPSI gets reduced to 50mm for the length of 24". You intend to cut it in half, so instead of travel through 24" of CAT @50mm, it will only travel 12" of CAT @ 50mm.

It's still traveling through 50mm pipe. If you can pick up any "significant" improvement (5hp/tq is not signification), please post back and let us know.

 

That's true. I'll try to do 2 dyno runs before and after the mod soon but without tune.

 

Can you weld the heat shield over a test pipe if it's just a visual check? Does the car get an emission inspection in Greece?

Personally, I would save up the extra $$ and get the high flow cat. If you have the $$ for standalone and tune, you can spare a few $$ for the right parts. Also, I've run a high flow cat on my old DSM for well over 100k miles with absolutely no problem. Why do you think it will be dead in 20k miles?

Olympiacos or Panathinaikos?

 

Yes I beleive its easy to weld the heatshield over but our car get emission inspected every 2 years and also the cops aren't stupid they can smell the decat and occasionaly in road blocks have vans with the emission checking tools. It is very rare but it happens and it's not worth it in my point of view. About the berk HFC cat for 250$ I've seen 2 or 3 members mention it in this forum that they fall apart after 20k, but idk i don't have any personal experience! I guess I can try both the cat mod and the HFC but it would only be reasonable to try the mod first haha! Olympiacos! You?

 

LOL, Berk HFC's do not fall apart after 20k.

Goodluck with what you end up doing.

 

If your boosted they do.

 

My family is split. My dad is Olympiacos, my cousins in Maroussi are PAO. Naturally, I must align with Olympiacos, otherwise I'm out of the will Your English is pretty good, are you from the US originally? There is a Greek sub-forum also, in case you weren't aware. There may be some alternate solutions to be found with that group.