my stock bnr34 has about 350hp on wheel but only 38 torque, running at 1.0 bar max. Is the torque figure too low? How can I increase the torque figure without have to modify the engine and turbo, perhaps the exhaust? Any sifu please enlighten me... Tq
The only way to really get torque gain is via camshafts and adjustable cam gears. Unfortunately, that means modifying the engine. You get a power gain by changing the exhaust, due to better flow, but no gains in torque.
Below is a dyno graph featuring a Nissan RB26, complete with aftermarket exhaust, ECU tune, and 1 bar (14.7 PSI) of boost pressure. The red line represents mods. The blue line represents those mods plus the adjustable cam gears.
The owner of this engine is a member on Skylines Australia, and he claimed that the cams required five adjustments to obtain the power increase that you see here. Impressive large gain in power, but what really jumps at you is the mid range torque improvement.