Quote:
Originally Posted by BlooDReigN  According to that, my throttle body is about 2x the size that I need. I saw some dyno numbers though going from a 75mm to a 90mm throttlebody on these TFS box R intakes and gaining a decent amount of power. |
There are many factors to why people get gains from throttle bodies.
They didn't match the inlet the first time and then dynoed it again after they port matched it.
They dynoed on different days with more mileage on the engine (you gain horsepower that way).
I have yet to see a back to back dyno with a bigger throttle body that gained power.
One way to tell if it is the day/dyno showing the gain is if you see a gain across the powerband. That shows that it is inaccurate, because if it is showing a gain at 2,500 or 3,500 rpm it is off. Reason being is because, as in your example, a 75mm TB would flow plenty at that rpm, why would the 90mm TB gain it more horsepower if the 75mm can easily keep up at that RPM.
I hope that made sense.
What I would like to see, in which I have yet to see, is a back to back dyno. I imagine if any gains it would have to be in the upper rpms.