First of all, please don't consider boost on a stock engine...especially a B18C5.

It's true you can run 8 PSI boost with the stock ITR engine and you can expect about 12 months before it blows without rebuild. But in the end, why spend $4,000 on only 8 PSI when you can put $4k to your engine? You would get more HP/$ if you spend it strait on your engine vs. 8 PSI turbo.

On the other hand, if you spend money on your engine getting it ready and then 15 PSI, well then...

Again, it's all in your decision on where you want to go with your ITR...

Jake