Also finally got the downpipe made up for this! Now running a full 2.5” straight pipe system.
I wanted to give my personal
review of each of the different exhaust stages I’ve went through and how they’ve changed the performance of the vehicle...
*All stages were during when the car was remapped*
Stock exhaust w/ dpf and cat: Not much to write in this section, fairly average
Stock exhaust, DPF + EGR deleted, cat still present: Apart from getting rid of the annoying regens, and issues that the dpf and egr give, torque was felt to be improved in the lower rev range, noticeable straight away when first pulling out of a junction. The car seemed much happier and not held back as much.
2.5” Cat-back, DPF Delete, Cat present, Stock Downpipe:
Made a difference through the whole rev range, less throttle was needed to achieve the same speeds. So on my normal drive home where I know the road and speeds needed to drive comfortably, where I’d usually travel at 40mph, I automatically ended up driving the same parts at 50mph with no difference to driving style. Noise was good, slight owl noise during gear changes like the old pd engines do, quiet on idle, throaty on boost.
Full 2.5” system, No Cat, No DPF:
So I only have minimal experience so far (45mins worth actually) but I’ll add to it in a few weeks. First thing I instantly noticed was the jet turbine whistle coming from it as soon as I started it up. On boost it rips very loud, almost sounds like it’s rattling like most straight piped diesels do. I also felt that the car didn’t bog as much during the 1st > 2nd shift change. Unfortunately it sounds like the owl noise has disappeared due to the new dp which is up to personal preference if that’s a good thing or not haha. Happy overall with it, I’ll keep tabs on fuel economy and other subtle things I pick up on.
(Photos for rear view of exhaust)