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KB 80mm vs. 168mm Oval
Throttle bodies are really nothing more than potential restrictor plates-the greater the power output of the motor, the greater the potential restriction. What this means is that the power gains offered by a larger throttle body will increase with boost (in this case) and the power output of the test motor. On the supercharged 5.0L four-valve, replacing the 80mm throttle body with the (considerably) larger 168mm oval throttle body improved the power output by 17 hp (501-518 hp). This test was run at a power level of just over 500 rwhp, so the gains offered by the throttle body would be even greater at higher boost and power levels. We've seen a throttle body swap be worth as much as 50 hp or more at the 800hp level.