I have 17" rims on my 98 prelude. The turbo setup for around 500hp, still have to tune it. Which Tyre size/brand shall I buy?

 

Size will depend on how wide your wheel is. Brand/model will depend on what you're trying to do with it.

 

You need 17" tires for 17" rims

 

Am running 215/45/17 in the front and 225 rear at the moment. Can I run 225/50 or it will rub? I don't know the width of the wheel. How can I measure it with the tyres installed?

 

with that kind of wheel gap hardly nothing rubs

50 profile tires just looks stupid. 215/225 is the width of your tire. Width of the rim markings should be on the innerside of rim

there is calculators in internet which show you how much diameter changes

 

On my Accord which is a very similar chassis to yours, I'm on 235/45/17 tires on 17x8.25 wheels and I dead hook ~350whp in second and nearly 400whp in 3/4/5 with some Kumho 4X II tires in the summer. They are an ultra high performance all season tire designed for "sport coupes" like BMWs, etc. I am using boost by RPM to slowly ramp in boost to keep from shocking the tires. Torque delivery is a very important thing that most people overlook when it comes to traction. Suspension, gearing, etc will also determine what kind of traction you get. For 500whp you will definitely need something a little stickier than what I have. Look at ultra high performance summer tires or a competition tire that is street legal like R888Rs or similar if you plan to run that kind of power on the street.