i used to own Ibiza with Jabba stage 3 IHI kit and never had any problems really. Only probs i had were usuall ibiza problems i.e. coilpacks, mafs etc etc. Great conversion and highly recommended if you love going VERY fast :lol:

Traction was a bit of a problem and that was with pelequin diff etc

As long as you servicec it regularly should and warm up and cool down and have decent FMIS or charge cooler its great fun
 
you might want to do a searchy...
madmile, custard cupra, bens1 & myself to name a few are all running or have run IHI on the ibiza in various stages of tune.

lots of info on here m8