Dyno Comparison -- Before And After Bypassing Throttle Body Coolant Hoses

Dyno graph of before and after bypassing throttle body coolant hoses.

Here, the dyno shows a 6.3 horsepower and 7.1 ft/lbs torque difference between having coolant run through the throttle body and bypassing it, with an average gain of 5.6 horsepower and 6.8 ft/lbs torque. I made the first test after driving the car for approximately 15 minutes. I monitored Coolant Temp and Intake Air Temp while making the run. At the beginning of the baseline run, the coolant was at 178F, intake air was at 80F, and the throttle body itself had a surface temperature of 102F. After bypassing, I again brought the car to temperature and repeated the test. This time, the coolant was at 180F, intake air was 80F and the throttle body was at 82F. To make sure the runs were accurate, I set the cruise on the dyno to 70mph in 6th and let the car run for about 6 minutes. After this time, the throttle body had reached 100F. I let the car cool to 185F coolant temp, and 88F intake air temp. Running the car again with these elevated heat readings yielded another .2 horsepower and -.2 ft/lbs torque compared to before heat soaking the engine. Check out the Dynojet Race Routine between the stock vehicle, the stock throttle body coolant routing and bypassing the throttle body coolant.


Everyone, including myself, thought this mod would be almost useless. Boy were we wrong. It is a noticeable gain, but again, due to the low percentage, I can't feel it. Oh well. Want to do this mod yourself? Click HERE for the instructions (Thanks To Brent Franker)!