PD 150/130 intake is supposed to help a bit, I just have a look at Ryans caddy van, he got that thing upto 157bhp with the nozzles and tune and standard vnt 15 turbo.
http://www.darksidedevelopments.co.uk/caddy-mk2-1-9-8v-tdi-alh/
I'll have to ask him about the air box mod.
http://www.darksidedevelopments.co.uk/caddy-mk2-1-9-8v-tdi-alh/
I'll have to ask him about the air box mod.