Your driving style impacts the noise produced.
If you are about mid aggressive on the throttle - and lift off just on change up, you can regularly produce loud blarping noises from yoru stock exhaust.
A small amount of practice and you can do it on commmand on the 1-2 and 2-3 upchanges.
The kids at my local school love it, and I am a small enough child inside my mind to keep doing it as well.
More practice and you can extend how long you produce the blarp noise - I have managed to make it last about 10 seconds with fine throttle control.
And apologies if this blarp has a well established technical name.
