Well then I wish ya nothing but the best of luck with it
What's your friends build consist of? All the time I've wasted on the interwebz I've just never seen anybody making that kind of power with these engines without a power adder. Everybody who knows their sh!t and has the credit card bills and busted knuckles to prove it would generally say that although 400rw+ n/a is possible, it's likely to be unstreetable and definitely not cost efficient. Being that you have a 4V that helps, but with your stated goal of 600rw you've definitely got an uphill battle through mud and snow ahead of you.