I did some searching on the forums but didn't see a compare/contrast on this issue.
I currently have an open wastegate on my new set up but I kind of miss the quietness of my old closed system. I could really just hear the turbo spool and blow off previously. Now its just a pretty load wastegate @ wide open throttle.

What are your thoughts/opinions?

My goals are 400whp on pump gas and 500whp on e85. But more importantly I'm looking for quick spool and great low end. I enjoy weekend street driving, an occasional autocross, and a quick/snappy response. I'm not looking for huge power numbers. I want it to be more on the conservative side for reliability. I live in Colorado so elevation is a contributing factor at 8000 feet.
My current set up is:

Injector dynamics 1000cc
Walbro 255 pump
Inline pro fuel rail
Aeromotive fuel pressure regulator

Science of speed big bore throttle body
Greddy dual spectrum elite
test pipe

Okada project coil packs
NGk Iridium bkr8eix

GTX3071r with .82 A/R housing turbo
custom forward facing manifold
Tial 44mm wastegate
HKS blow off
Mase intercooler and piping

 

I have my dump recirculating because I hate the open dump pipe sound, you can't hear anything going on. The sound of the turbo spooling is much better than the sound of a big exhaust leak. I hear you lose a bit of power vs open dump but I can live with that.

 

Open dump will make more power. How much is the question. As long as you have a real full 3 inch turbo back exhaust with no cat and straight through muffler and resonators a closed dump tube should not rob that much power if any espically at the 500whp level.

 

The way the dumptube is routed back into the exhaust plays a big role. Make sure the guy making your dump tube knows his stuff.

 

Open dump on all of my setups. Wastegates are closed under normal driving conditions anyway, so not loud at all.

 

^ x2

 

Same here. Never hear my dump unless I floor it.

 

All my cars has always been open dump. It makes more post and it's cheaper to build. And it's only loud when you hit full boost.

 

Yeah, I totally understand open dump for high HP goals. But if I can reach my goal of 500hp with a closed dump I'd be very happy.
I like being wide open throttle. I prefer hearing the sound of the turbo and a relatively quite car.
Times change I guess, I sold my J's Single years back because of the drone. I'm very happy with my spectrum elite!

Thanks for the info guys!

 

Open