,
Unfortunately, when shoehorning such an enormous turbo into an engine compartment compromises sometimes have to be made. It turns out that the actuator canister and coolant neck of the SR20 reside in the same area. No problem that a pair of Turbo Smart's Hypergate 45 wastegates won't take care of.
Although one of Turbo Smart's wastegates could have easily done the trick, we chose to go with two. So why two wastegates? Easy, using two Hyper Gates preserves the clean exhaust flow of the twin scroll configuration. Just as cylinders 1 and 4 as well 2 and 3 have their own dedicated turbine housing scrolls, they should each have their own wastegates. Full Race Motorsports has seen improvements in response of 400 -500 RPM by keeping the paired exhaust streams separate utilizing dual wastegates. Ultimately, we need all the boost response we can get since we only have 1.5L of displacement powering our enormous EFR 8374.
John Kuchta of Specialty Cars, constructed a wastegate dump tube for each of the Turbosmart Hyper Gates using 1.75″ stainless steel J-bends from Burn's Stainless. Both dump tubes, exit through an unrestricted path right behind the driver's side front wheel.
Installing fiberglass header wrap can be a real pain. To help prevent the fibers from getting embedded into the skin, 5523 Motorsports soaked the DEI header wrap in water before installing it. Once the dump tubes were wrapped and mounted, the header wrap was then safety wired in place every three to four inches.
Although the Turbosmart Hypergate 45 can independently control boost through the use of different springs, we used a Turbosmart E Boost Street 40 to finely dial in and control boost pressure. The reason we went with the E Boost Street 40 was because of its simple interface and powerful features. The E Boost Street comes with two stages of boost control, a 40 PSI map sensor, and a programmable RPM or boost level auxiliary output. The programmable auxiliary output can be used to control a methanol injection system or the VVL mechanism on our SR15VET.
