The stock engine can hold over 300hp but its the transmission that ends up being the weak link. Oh, and being FWD.
Just fyi there arent any "bolt ons" or anything "usual" about the Capri...its about as unique and as custom as you can get! Its all in good fun though.
Basic mods are an intake & exhaust followed by a boost controller and computer upgrade. Injectors aren't needed untill you go crazy, the stock fuel system is pretty robust.
Turning the boost up to 16PSi will net you 160-190whp depending on supporting mods and the condition of your engine. Usually thats more than enough to turn your car into torquesteering monster that from a roll will rip on most cars. Remember that that power is useless without good tires and a suspension that can put it down. If you're planning on doing a lot of snow/ice driving its a good idea to keep the boost down. Having daily driven a high powered capri for the past 3 winters I can say it can get a little nutty.
You can go bigger with a larger intercooler and a hybrid turbo upgrade.
I'm going to say that you won't need a WBO2 system untill you upgrade past a VJ11/14 hybrid turbo.
So, start with the basics and work your way up! If you're interested in a Rocketchipped ECU please get in touch with me and we'll work the details out. There is a link in my signature.