DX Engine Modifications

Hello

I have been reading several threads and people talk about Audi throttle body, 4 branch manifold, bored out inlet manifold, panel air filter and Audi dizzy, what do these mods offer in anything please?

Thank you!
 

Any done a couple of those mods, 4 branch manifold is a good mod as it frees up the top of rev range as my car seems to pull better and revs easier higher up but no point going over 5,500 rpm.
I've a K&N panel filter, no difference in performance but it's such a pain to get into the air box with the fuel filler fitted it's less hassle than changing a paper filter every year and now after 13 years since fitting it, it's paid for it self. I do remove it every few years just to clean the leaves etc out of the air box and bang and dirt of the filter, I did clean and re oil it after 100,000 miles and 10 years.

Audi throttle body you need an updated WUR to add the extra fuel into the engine.

I can't see how an Audi dissy will make any difference to the performance?