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« Last post by ZoliWorks on May 10, 2024, 09:53:34 pm »
Yeah it's definitely more punchy, that's fur sure. It has power past 6k and pulls throughout the powerband (2nd and 3rd gear). I don't regret the swap one bit. It sounds way better but that might just be because it's pushing 1.6 bar pressure almost all the time.
The throttle body was cleaned and tested, moves nicely. The MAF doesn't show any signs of being worn out just yet.
Now, regarding the loss of power and the leak. There is no leak. The map the car had demanded way too much fuel pressure and my fueling system can't keep up. We've changed the map so the car no longer stalls when coming off throttle or clutching in. It also drives a bit better but it still cuts out all the time past 5k in 4th gear or above. The map is still demanding 130 bar pressure sometimes and the stock fueling system fails to make that. I've seen it drop all the way down to 67 bar even and the idle pressure is 50!!!
Now the reason the car was stalling or idling rough when coming off throttle is because the ECU is still demanding the same fuel pressure off-throttle. Why VW did this? I don't know. What I do know is that if the fueling system can keep up, the car idles fine and doesn't stall.
Since there are no issues to speak of really, I've decided to keep it like this rather than restrict power as I rarely ever need to rev past 5k. With my daily commute being mostly city driving, I'm fine for a while. If there were no fuel cuts, the car would make between 290 and 300hp according to the tuner. It's definitely putting down power now, no questions asked, just not past 5k.
Next step, sometimes in the coming months, because I've spent way too much this past months, is upgraded fuel pump internals and a stronger fuel rail pressure valve.
TLDR: Car loses power past 5k rpm not because of vacuum leak but because of fuel cuts.
Side note
I've been switching between the DV+ and the revision D valves. Both can hold pressure equally well but the DV+ makes it sound like a supra when coming off throttle because it can't let out pressure fast enough. My mechanic/tuner said this isnt all that bad for the turbo, but the ECU doesn't like it one bit. It's constantly throwing "pressure release valve mechanical failure" errors. The rev D is fine but sounds average, as expected. I've switched back to the D for now but if I want to show off the car, I'm putting the DV+ on. It's a 2 minute job anyway since the relocation kit brings the valve to the front of the engine, right next to the throttle body.
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