Possible effect on tune when adding high flow CAT..

[Stifull]

Due to shut downs and lock downs etc last year, I ended up having to get my upgraded engine tuned WITHOUT a cat. The car sounds great but to loud for my liking.. I prefer the stealth mode and the fun that lets you have without attracting attention, plus the fact that I really should make some effort to keep it eco friendly so I am planning on having a High Flow 200 tube cat fitted. It will quieten it down and burn off some of the pollutants. My concern is what effect it will have on the tune.. I don't really care if it takes away a couple of kwatw but I don't want it to damage my engine..

Has anyone done this and if so was there any issues.. Cheers..

[Yowie]

Usually the original tuner charges significantly less for touch-ups compared to the original tune - you might be pleasantly surprised.

I would imagine that adding a cat will slightly worsen the turbo's performance. Whether the existing tune adapts (more-or-less) due to responding to sensor-derived information or just throws "tune Map X" at the situation is a question for tuners and their ilk.

I suspect that you would get away with driving catted before any touch-up tune is done without any harm being caused (assuming you won't try to wring the car's neck too often), but that's just the cheap opinion of someone on the internet (and it's not my car).

[bigBADbenny]

Boost is a function of restriction, so your max boost might increase without a retune!

Personally I’d be monitoring fuel correction, fuel & knock learning using Btssm android app or Romraider.

Since you have a postfl you can use wastegate boost control with the SI drive i mode, or revert to mechanical wastegate pressure.

That’s what I’m doing right now, due to a temporarily untuned for inlet pipe.

Its coping well in closed loop driving, but pulling fuel in open loop, city driving, but I can see I’m not blowing it up.

IAM hasn’t dropped, I’m probably using more fuel, but can’t wait to get the touchup tune and enjoy full, safe boost.

The intense scrutiny has revealed that it’s time to replace my fuel pump and filter, last done 150kkm ago.

[Stifull]

The part numbers for fuel pump and filter are on my vf52 build thread.