I'll second that - prepare to be humbled by an 8v

Right, Inters this Year we need a 8 valve Vs. 16 valve and see who comes out on top

But i will concede, if they were that similar why did VW bother to build the 2 side by side

BUT a later 8 valve in good condition, that's nice amd loose with a sneaky chip and exhaust / filter will more than give you a run for your money!
The 16v really does lose out in by book by having mechanical fuel injection ... so bin it and get some DCOE's !! That's half the reason you seem to get such a mixed back - dodgy tuning and making it worse !!