Are you all running after market exhausts? It's quite common and normal I think, remember reading something about the cold water hitting the very hot b-pipe/exhaust. I remember when it first happened to me lol
If you're not too worried about the cost mate speak to TDI North. They do a turbo kit for the DC5 so it would be supplied, fitted and mapped. Would take care of all you need I reckon. DaveC has a build thread on here with info and pics etc.
I tried the Tegiwa one, it failed, haven't contacted them about a refund yet. Original second hand is a better option. It will need to be fine tuned most probably, I had romain at Eurospec do it for me.
I would say TPS maybe. If all throttle response was lost I wouldn't think it would be oil. If it was sluggish then it could be oil in my opinion, but completely no throttle response may be due to the TPS.
Speak to Romain :)
Did it completely lose throttle response? And only recovered after dipping the clutch? Another possibility could be the TPS (Throttle Position Sensor) being on its way out. A few cases of that recently for some reason.
Hopefully you won't have done anything serious, if its driving fine looks like you've had a lucky escape mate!
Just take it easy, get used to the gear positions, don't slam it into gears, you won't accidentally select first unless you really force it in.
Depends on your budget mate, RBC would be top of my list as produces good power for the money, and then exhaust manifold. Maybe even get the Buddyclub RBC and throttle body combo as mentioned above.
More extreme could be cams or forced induction :D
It is likely to be the belt slipping as lee mentioned, remember romain mentioning some sort of adhesive or spray to get the belt gripping properly, maybe worth looking into.
Romain at Eurospec is very good, heard a few horror stories about cpl, TGM recommend romain as well so peace of mind there! Mapped my JRRC Teg and would definitely recommend him!
You could probably get one made up to do the Job mate, just needs the two screws in the right place to slot into the openings either side of the vent under the bonnet. :)