Bigmouth & Lost Wax. Weight Reduction & Free Flowing Performance Gains.
When aiming for optimum exhaust efficiency, the catalytic converter becomes a major obstacle. The stock front pipe has the catalytic converter included; this also adds to the weight of the pipe and lacks strength. The TOMEI down pipe solves this problem with the result in a drastic performance gain.
The lost wax casting method provides added strength and precision from the lack of welds.
Exhaust gas flows are optimized with the larger mouth diameter. This was also made by the lost wax casting method.
EXTERNAL SIDE OF THE FLANGE
The stock flange design is weak, it can’t secure a proper contact pressure and can easily distort over time. So we’ve made our flange thicker and more suited to a wide range of aftermarket muffler options. (NOTE: Not compatible with the stock muffler.)
The larger diameter reduced the exhaust gas resistance by eliminating the catalytic converter. This also contributes to the vehicles performance with the added weight reduction.
PART NUMBER: 431101
APPLICATION: USDM GDF EJ25 ’04-’07 STI
DESIGNED FOR COMPETITION USE