Flat spot/bogging down on high rev gear changes

[ryushi]

There is a strange flat spot or bogging down of the eninge when I change gear at high revs (around the 6,000rpm mark)
The engine does not do it at any other time, only when changing gear at high revs, and before anyone asks no it's definately not hitting the rev limiter.
If I pull away in first, change at 6,000rpm into second gear, for a second or two the engine bogs down, kind of feeling like there is no boost, then the power will suddenly come back, it does this in every gear.
If I change gear at a lower rpm or just normal in gear accelleration it does not happen.

Any ideas?

If it was the MAF I would have though it would be doing it all the time?

I changed my diverter valve last night as the car has fluttered since I got and though maybe it was to do with high boost pressures at high rpm not being released properly or something but it made no difference (apart from losing the flutter sound)

[topher]

Possibly just turbo lag, you wont notice it when driving like a granny but becomes more obvious when you redline it.

[ryushi]

I don't think it's lag, my old passat 1.8t never did it, if it was lag it would still do it at a lower rpm gear change,

If I change at 5,000 rpm there is no bogging down it just hits the next gear on full song with no lag/bogging down - at the moment I make quicker progress changing gear lower down the rev range as it don't bog

[Say bye bye]

I had exactly the same thing with mine... if i take off in 1st gear upto 6000rpm and change to 2cnd drive slooooooow for a second then the boost would kick in again?! at the time i put it down to turbo lag.... Ive since changed the diverter valve to a forge one, most the guys on here reccomend it, and it makes the WORLD of difference... problem gone.
My orig Diverter valve had gone, it was making a chattering/flutter noise when you let go of the accelerator, these cars arent supposed to. The Diverter valve was suking in the air from the air box and when you let go of the accelerator you could hear the air being dumped back up the air box...not sure if yours is the same.. thats what was happening to mine.

[ryushi]

I thought it was the diverter valve too which is why I changed it (it was fluttering) no flutter now but still the lag, maybe i'll try the forge diverter, where did you get yours from and how much?

The car has been chipped so maybe the OEM diverter cant handle the higher boost properly?

[Ivor Mk4 Turbo]

I've got a Forge diverter on mine, & I have the same prob as you.  (May just be a feature of the 1.8T's??? )  I've also noticed that many other cars of mine, have not 'liked' it when 'red-lined'.  I found that changing around 5.8-5.9k revs, works best for me in the Golf.

[Say bye bye]

Heres the one i bought....
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=72205&item=8046152126

One other thing i thought about, i dont know if this has any affect on yours, Topher was giving me bit of advice on changing the Diverter vavle and he said to disconnect the battery for 30 mins to reset the ecu once your fitted it? like i said i done it and even at 6000rpm you cant notice the lag on mine.

[Stu-1.8T]

Mine has the 'lag' effect aswell.....also does a quiet Tsssh when I change gear. Still drives pretty much like a new car though even at just over 80k miles.