Porsche dont run their turbo cars in circuit racing so you wont hear them there but check out the WRC series where all the cars are turbocharged. They will all use some kind of dump valve/BOV rather than a recirculating valve. Why? Because they all are small 4 cylinder turbos which cant make that much torque on their own so they need the turbocharger to spool as fast as possible. You're asking for data? I doubt anyone here has the equipment to measure spool times. The closest thing is to just drive the same car before and after BOVs and watch at what RPM the turbo starts to spool. I read the FAQ and believed it too until I ran across a great deal on a set of used BOVs. I decided to try them out and there is a noticable difference in spool times between shifts. Do you need a dyno sheet to see if an exhaust system you installed made power? Probably not because the power increase is THAT noticable. Same thing for the BOVs, spool times between shifts are that noticable. Its been said time and time again here: Those who have them know and those who dont wont believe.
John Yim (Houston) 91 ZTT Stage...stages are confusing. Just read the mods. :) SM2, Houston Region SCCA "...Just as they're about to catch me... Twin... Turbos... Kick... In..."
