As the subject suggests, been R-tech stage 1 for around 500 miles and seem to have developed a boost leak. The car at full chat now feels as it did before the remap, though perhaps a bit more sluggish to react to the throttle than ever before. Logged the car with VCDS and a friend this evening and the expected vs actual boost levels seem to confirm a boosting issue. A general code scan threw no related errors, only an engine over-speed and ECU comms error noted, but these existed as a result of the remap and before this issue occurred.
At full load the requested boost sits at 21.5psi and tails down to 17.5psi across the rev range of 2000-6000rpm on WOT in 3rd gear. The actual achieved boost lags significantly behind the requested, only achieving 15psi at around 3600rpm, tailing of parallel to the requested boost trace with only 10psi being achieved by 6000 rpm. This was performed in map 5 (full beans).
I repeated the exercise after switching back to map 1 (stock) and interestingly the requested boost remains at the same levels but achieved boost is reduced to a peak of only 6.5psi, tailing off to 3.5psi. The N75 activity between maps 1 and 5 seems to account for this with increased N75 duty cycle in map 5. I guess this is how the variable mapping is achieved, by leaving requested boost alone and manipulating the N75 valve to control impeller speed?
In any case, I'm going to crawl under the car at the next opportunity. My suspected culprits and plan of action are:
1)Remove/inspect DV - even though this is only 3-4k miles old, it could have torn already? Currently a rev G but the rev C which it replaced was actually okay when taken out so this can be put back in temporarily if it is the DV at fault.
2)Inspect piping - focus on couplings at the intercooler, I hear this is a common area for leaks.
3)PCV - look up and try method for testing. Blowing into it or something of the like?
4)General inspection of other charge air system hoses etc.
5)If nothing found at this point, CRY!
If anyone else has had similar symptoms and experience with tracing this kind of issue in the past, I'd be glad to hear any advice you might have. My suspicions are formed only from an hour or two researching on various forums etc. If any more data might be useful, I'm happy to provide Dropbox links to the excel sheets containing the data. Car is an '06 GTI with 34k, noted to be in superb condition by the guys at R-Tech and was fully serviced and prepared for the mapping with pre-emptive replacement of the usual failing points (DV, PVC, timing chain).
This on top of a niggling sluggish cold start (fuel system priming/battery perhaps??) give me a couple of things to get sorted out
p.s. if i have any terminology muddled here please feel free to point this out. I'm relatively new to trying to understand my car more fully and so may be ignorant to any wrong statements I have made.
