The idea is good but result is terrible.................There are many types of turbo extension (dump)pipe.....The purpose to change to this pipe is... let exhaust gas and pressure out more efficiently, Yes Most of Japanese parts are working good. However there are many copies.....
Like this twin pipe extension .............We tested without boost controller and run......the boost start from 0.5 bar(which is actuator preload) and end up....1.3 bar...........exhaust pressure build up at end...........worster than factory pipe.........minimum boost 1.3?
They are cheap...but you need to replace to another one.....wasted....
Be careful with these type.......From our test, Big single type (such as HPI or TOMEI) made more torque and better response than twin...... even better than HKS twin type......(same result for RB engine as well)..................
