As some have said forget what power it makes on Dyno that's just for pub bragging and nothing else.
I've said it many times before and will say again that Bhp means very little, it's how it delivers the power that you have that really matters and besides that it's actually the torque figure you should be more interested in rather than Bhp.
The way the torque curve looks "amongst other relative things" gives you a good indication of how the car will drive in everyday real conditions.
I've beaten far higher Bhp cars that have been poorly set up and mapped, I.e a so called 520bhp pulsar with one running less than 340bhp simply because it was set up better with minimal lag and maximum response from turbo and ancillary items fitted ( it's all very relative in the real world) of course the big power car would have beat me on a long straight bit of road but that means jack shit as its about low down grunt and pulling power and how the thing handles and stops, without those things the cars pretty much just a one trick pony on a drag circuit.
Anyway il play the game as it would be rude not to
I have no idea what the car will make and that's the truth so my prediction could be way out with this one although I'm generally not too far away with most cars running from 250-450 Bhp
But would hazard a guess at around 526bhp @ fly.
wheel hp is the accurate figure but as said it's the torque which means much more.
You've seen how this car pulls at 400bhp Pete the thing is awesome with the way it puts the power down (remember the huge grin on our faces lol) so if it makes nigh on 80 bhp more but with good drivability throughout then it will be a very serious bit of kit indeed