So I just got my cobb accessport for my evo x and before I instal it I want to make sure my info is right. The stage 1 is a bone stock evo tune correct? Stage 2 is for evo's with a turbo-back exhaust system (test pipe, down pipe, cat-back exhaust) and then stage 3 is for evos with stage 2 upgrades PLUS boost control solenoid, and intake (SF intake, turbo inlet hose, and hard pipe kit). I Just want to make sure Stage 1 is for stock evos. But knowing about stage 2 and 3 isn't a bad thing either hehe.

 

You are correct.

The cars are highly sensitive to changes in airflow and that's why they have the calibration guide for various intakes. However, when it comes to the exhaust modifications, you'll most likely be able to run a majority of the other brands out there as long as they're 3" in diameter. If you're running a widemouth downpipe like AMS, Tomei or MXP, slight adjustments may need to be made as Cobb's downpipe retains the stock O2 housing but you can always send logs to Cobb and they'll look it over.

I was running just the Cobb HFC with the stock downpipe and stock catback on their stage 2 OTS map for a month with zero issues and was validated by Cobb So-Cal. I then added the Perrin catback exhaust and again, had the logs validated by the So-Cal guys. I've now replaced the stock downpipe and Cobb HFC with the Perrin downpipe/HFC single piece, added a Cosworth drop-in filter and flashed to their Stage 2 + CHFF map (they have maps for their own high-flow drop-in filter but the filter hasn't been released yet). Everything is looking good and running smoothly.

I think the key is to using similar-spec exhaust parts and using the proper MAF scaling with any non-Cobb intake you use. The only thing I don't know is if using another brand 3-port would create problems on the stage 3 maps. Other than that, the the turbo inlet hose and hard pipes are recommended but not necessary and can be added later.