So I went to go pull the trigger on the Cobb turbo back exhaust and much to my dismay, its going to be on back order for the near future. Has anyone else had any luck running the ots stage 2 map with an alternative exhaust system? Im just seeing if I have any other alternatives besides waiting for summer to be half over before I upgrade.

 

For Stage 2 and 3, you really just need any "short" downpipe, HFC or test pipe and catback. I ran Stage 2 OTS with a stock downpipe, MAP test pipe and CNT dual catback. I'm now on a modified Stage 3 OTS with a MAP downpipe, testpipe and MAP single catback. No issues.

Cobb will tell you that the stock downpipe retains more heat and thus, can cause knock. I did have knock issues with the older v402 map, but since the v403 came out with revised timing, all good.

 

Perfect, thanks for the help!

 

Of course, it cannot be understated that a protune is best. At the very least, set up your AP to display knock and get a quality AF meter and keep an eye on both.

 

Thanks for the info, had the same question.