I have to say... I hate my HKS SSQV. I can say in it's favor that it stays closed past 35 PSI, but it's the chatteryestest son of a fothermucker I've ever had to deal with. The repeated chu-chu-chu- ch-ch-ch-chchchchchchchatataterring that occurs at part-throttle when you're cruising around town isn't just annoying... It's hell on your engine mounts, axles, drivetrain parts and just about every other damn thing bolted to it; not to mention the people riding with you may lose fillings and develop spine injuries. Sure it sounds wicked, but so-what if it annoys the driver. It's the worst when you're passing at highway speeds trying not to look like a jackass. You don't have to blow everyone's doors off to pass, but if you can easily spool your turbo anywhere below 4000 RPMs, then even in 5th gear your turbo spools, and it starts chattering you to bits and peices unless you floor it. It sux royally. I have a highly-tweaked tiny little 50-trim turbo, some burly cams, and 3" turbo-back that love to spool it to 21 PSI before 3000 RPMs. This BOV is a problem for me.

What's paid the price for me 4x now in a year is my intercooler end tanks. Probably wouldn't be as bad of a problem for me if I had cast end-tanks instead of TIG welded 3/16" 6061 plate aluminum. Cast end tanks don't polish up as well, and yes we used the right filler rods. The pneumatic vibration inside the intake caused by that BOV has broken the welds on my end tanks yet AGAIN. It really sucks to have to pull the front bumper off of a freshly-painted car over and over again. There's no way that I can adjust the SSQV even though mine has an adjustment screw. HKS eventually proved it does nothing by design, and the new units don't even have an adjustment point anymore.

I wish I bought a TIAL BOV instead of the HKS and had my custom pipes flanged differently. When those things vent, they mean it. At part throttle, they leak without chattering. It has a working adjustment on it that lets you set it the way your car or the driver likes it.

What you're building sounds seriously nasty. I think you've developed a sickness. What I see listed should handle 320-330 whp at 18 PSI on pump gas... but that's a modest guess. I saw no mention of wheels and slicks. I hope you have those covered becuse radials are not going to work once you're done.