5 Type R

Yesterday had a little bit off a panic and was looking for some experienced netters to offer some thoughts.

Was enjoying a sedate drive around yesterday when a MY03 Golf GTI came for a play over about 3-4 miles of dual carriageway and roundabouts.
As you would imagine with a 310/310 Type R, I completely demolished it , however I did notice that in either 2nd/3rd as I was coming off the roundabouts I was getting a big puff of blue smoke. Only for an instant but enough to see in the rear mirror???
Also out of the blue I came of one of the last roundabouts and the car just intermidantly shut down...........nothing then 2-3 secs later all back up and running?????

I run a Type R (5) with Unichip, Mapped Water and exhaust

Any ideas on the cause of the sporadic puffs ..Blower? Engine??
Also any clues on the shut down??

The car performed fine after that and is hitting the boost it should.

Can confirm that the car hant smoked at all resently as I filmed it at the pod and there were no signs.

Ideas please netters