JB4 Review

George Smooth said:

Thats not compressor surge.
On our cars it sounds like a bird chirping and goes away at around 3800rpm when valve lift occurs.
On all our maps on JB4 the torque ramp up is low to avoid this.

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George, is the noise being generated by the DV bleeding boost off? The "bird chirping" is the best explanation I've heard for it

Now with my DP and CTS Turbo Inlet tube (JB4 /w map2) the bird chirp is much more audible and happens sometimes at low cruising speed with steady throttle.

vw671 said:

George, is the noise being generated by the DV bleeding boost off? The "bird chirping" is the best explanation I've heard for it

Now with my DP and CTS Turbo Inlet tube (JB4 /w map2) the bird chirp is much more audible and happens sometimes at low cruising speed with steady throttle.

Click to expand...

On full throttle at low rpm the noise heard is the compressor wheel stalling.
The dump noise similar to the video is the DV recirculating.

There should be much noise heard under cruising and that is most likely the
DV you hearing.

Just installed the JB4 rev1 upgrade kit yesterday. Went on pretty smoothly except for a little struggling with the grommet for the OBD cable run. After comparing to my buddy's DSG doing this on the 6MT is a tad more difficult with the clutch in the way, especially for my wide-framed ass.

Initial butt-dyno impressions were quite good. Low gears seemed to pull harder, smoother and more consistently. Further experimentation planned very soon...