What is the diameter of the stock throttle body?

[p3u]

Also, anyone know the distance between the four mounting holes?

Thanks!

[Works2shoot]

Be right back, let me go check google.

[p3u]

Be right back, let me go check google.

Lol, I've Google'd and searched the forums. Let me know your findings.

[Works2shoot]

Lol, I've Google'd and searched the forums. Let me know your findings.

It appears that the outer diameter between 2.75 and 3" from this thread (http://www.audizine.com/forum/showth...-throttle-body) - a further search shows that the APR the Ultracharger is 80mm which is 28% larger than stock which equals an inner diameter of 57.6mm or 2.268"

[p3u]

It appears that the outer diameter between 2.75 and 3" from this thread (http://www.audizine.com/forum/showth...-throttle-body) - a further search shows that the APR the Ultracharger is 80mm which is 28% larger than stock which equals an inner diameter of 57.6mm or 2.268"

Your search yielded the same results as mine. No mention of the throttle body diameter. The stock is somewhere around 70mm, not 57.6mm btw.

[Works2shoot]

Your search yielded the same results as mine. No mention of the throttle body diameter. The stock is somewhere around 70mm, not 57.6mm btw.

Apr says that the ultracharger is 80mm which they said is 28% larger than stock. Lots of different info out there.

[MSq5]

APR may still be right. "Larger" may mean area rather than merely diameter. As diameter increases, the area increases at a greater rate. The amount of air or fluid a pipe can flow over the same distance (volume) goes up far greater than the increase in diameter.

Here is an example. A 3/4" diameter pipe is only 1/4" larger in diameter than a 1/2" pipe, a 50% increase. Yet it flows more than twice the volume of air or fluid. Seeing a cross section helps one understand how much the volume increases. Look at the shaded area.

[GandalfTheIbis]

If they're getting their 28% increase from surface area (seems likely) that would make the stock diameter 68mm... math came out to 67.82mm in case it's that exact

[Works2shoot]

If they're getting their 28% increase from surface area (seems likely) that would make the stock diameter 68mm... math came out to 67.82mm in case it's that exact

I did 80x.72.

[GandalfTheIbis]

I did 80x.72.

I know. That would have been correct for a 28% reduction in diameter. I was using Area = π(R²) starting with the known specs of APR's throttle body.

[Works2shoot]

I know. That would have been correct for a 28% reduction in diameter. I was using Area = π(R²) starting with the known specs of APR's throttle body.

Ahhh. Ok. Yea that makes sense.