Once you put a dp or a hi-flow cat, you will push the turbo 12+ psi (unless you don't push the car at all). A dp or hi-flow cat increase the exhuast flow. And, it will not limit your boost to only 14 or 15psi!!!! There is no limit!!!!You can hit 20+ psi with that. It all depends on what octane of gas and the weather.Vitek said:Correct me if I am wrong, but I heard the boost controllers can only control boost higher than what is automatically produced by turbos. What I mean by that is say you installed downpine and your boost will automatically rise to ~14-15psi compared to a boost with CAT's it will only be 11psi max. But again I could be wrong. If any body can clarify it, that would be great.
If you install the dp /hi-flow cat without BCC or FCD, then, once you hit 14 or 15psi, the stock ecu shuts off the gas.
if you install a BCC or FCD with dp/hi-flow, you will hit 12+psi, 15+ psi and 20+psi..depends.... and, that's the boost controller controls the max. boost you allow. note that BC cannot set a level that lower than what the turbo push (for our stock TT,lower limit is ~0.8bar as MtFujiSupra said " to lower than what is normally produced").
Your case is true only if one of the following is true:
1) you have a ecu upgrade.
2) you don't push your car at all.
3) something wrong w/ your car so that you dont hit 14/15psi at all.
stock twins w/ 28psi? that's not a good sign......
This is just a basic BPU topic. Please refer to:
It said, "these upgrades are proven (by us naturally!!) to have a high degree of reproducibility from car to car if you install all of the following: " Again , *ALL* of the following... don't just put one by one.... you are going to screw up your twins like someone running 28psi here...
I am out of here.....
They NEVER say RT cat is legal because not all 100% of cats are passing. If you look at mvp's description, they claim it "should" because its close. I know someone that failed by a hairline with 1st gen RT cat. I had a 2nd gen put on last yr. i havent test yet.