mhardy said:
...what can the D16Y7 engine hold as far as boost pressure on stock internals?
Well, off-hand I'd say 6-9 PSI should be okay. I wouldn't go over that. More volume gives less density, so there's a trade-off at some point; probably around 9 PSI in your situation. More than 9 PSI will probably lower your air density to the point that you won't get any additional gain in power anyway. It may even lower power in your particular application.
The problem is: increasing air volume through the use of additional boost will also decrease air density because of added air temperature. Volume times density equals mass, and mass is what you are seeking, not simply boost.
Nothing is ever simple! The unknown variable is your chiller. Although it increases air density by decreasing air temperature, it also decreases boost, theoretically allowing you to go above 6-9 PSI, but I don't think it's going to make THAT much difference. I certainly wouldn't pump it up to 12 PSI...
madtownhonda made an excellent comment which needs to be noted. No matter how much additional air you huff, no additional power is going to be made unless additional fuel is added. Fuel is what makes HP, not air. Additional air allows you to burn additional fuel which gives you additional power, so without bigger injectors you're only doing half the job.
If it was me, I would leave my boost at 7 PSI for now and buy some bigger squirters. After installing them [and a FPR if you done so already] then I'd go about playing around with the boost.
Sorry I can't be of more help. There's no pat answer
to this question...