If the S4 was

Sorry to chime in so late

I think that you could make 2-2.5hp per cubic inch easily in a built motor that was n/a and if you really push it you can make 3 + or - .35

I think that you could take a 2.7L FULLY built with 15.1 compression and 116 octane and make 3-400 wheel hp with the correct heads cams intake and open headers.
I also think that you could make 225-275 wheel with out much problem… all it takes is money

Now I think that without going into the engine you would be shy of 200 wheel i agree there…

my 2Cents