Does anyone know if you need a full turbo back exhaust system in order to run the cobb stage 2 access port? My friend has a 3" exhaust after the stock down pipe, would that work??
Yes! You won't get quite as much power. I ran stage 2 with just the Ap and stock exhuast. You just won't get the AP's full potential! Which is very nice!
Well, to run stg2 you really should have a high flow dp. The stock downpipe is so restrictive that the motor won't be flowing as much air. So your wastegate duty cycles and such will change in the maps (between stg1 and 2). Without a dp in the car, I would run stg1. There really isn't going to be any benifits to running stg2 withour haveing a dp installed. Russ
Because of the non-learnability of the fuel/timing maps that anyone tunes for you (off the shelf or not), it would be a problem if you were to run a stage 2 map on a car without a catless/high-flow catted downpipe. But on the brighter side, Cobb told me that their stage 2 map will work on a stock catback combined with an aftermarket downpipe.
get a bellmouth design if you're going past stage 2 (bigger turbo). I love my invidia v2. However, I've heard the ERZ dp seen on ebay are good as well.
What are you talking about?? The fuel trims are always adjusting for the current conditions, and your timing is set unless you are knocking. The stg2 map is designed around the motor flowing more air through it and without the dp you are not getting the same amount of airflow. Since the motor is not flowing enough air, the fuel/boost/timing settings are not optimal so you will not make good power. There is even a chance of knocking by not runnig the correct map for your mods. Russ
Umm... The car would run fine with a stage 2 map :ugh: There is more fuel, less timing with a stage 2 map... the load sites would be off though, but it would still definitly drive fine. Obviously more power can be had with the correct map though.
It must have been explained incorrectly to me by Cobb then. They told me over the phone that their maps are set and won't learn over a period of time. I understand that their maps are conservative, but I was told it doesn't "learn." Secondly, I pulled this off directly from Cobb's site to help answer this question: (needed some backup :biggrin: ) Q. What is needed for Stage 2? A. We actually field a lot of calls with people wanting the Stage 2 AccessECU because the dyno graph looks a lot better, but they do not have a turbo-back exhaust. Here is a diagram of the exhaust to help you visualize: The Stage 2 was tuned on a car with a full turbo-back system. If you have pieced together a less than optimal combo of parts or those that were not designed to work together you may not get the full benefits of the Stage 2 AccessECU. Boost may not come on as quickly and the peak power may be down from those that have a well designed full turbo-back system. If you have replaced the first section (second cat or downpipe section) and nothing else, then the Stage 2 map is what we would recommend. Again the results will be far less than optimal, but it will control the boost better than the Stage 1. If you have replaced sections 2-4 (third cat, mid-pipe, and muffler section then you are still Stage 1. You managed to get all except the part that makes the most difference. Again, we want to reiterate that Stage 2 will only get the intended results with a well designed complete turbo-back.
Also, there's a difference between driving fine in closed-loop and driving fine in open-loop. IIRC, the AP delivers the fuel/timing map in open-loop (when you're heavy on the gas pedal). Running the stage 2 map on a car with the OEM cats in place and racing in it is not healthy for the engine. Knowledge is power and knowing that Cobb recommends against it, I would never run a stage 2 map on my car if I want it to live long. I'm not trying to start a war, just trying to help determine what is the healthiest map to use with an AP. And yes... I'm the guy who's using an intake on an OTS Stage 2 map but with good results. I guess... I'm learning as I go so flame away. I'd rather be told what's right from wrong than to be wrong and be a **** about it.
