'07 Throttlebody massage

[HD99FXR3]

Took my Tb assembly apart and under the tutiledge of  u4HD2  did a little blending and cleaning up and ended up with 160.95 CFMs a gain of almost 7 CFMs, without a backing plate and 163.5 with K&Ns backing plate. Put an SE plate on for the heck of it and didn't gain or lose anything.

[Admiral Akbar]

I be interested in what you did to the TB, from a little cleanup point of view. I get only about 150 cfm with a stock TB and SE backing plate. It would be interesting to see if it can pick 7..  WT 57 mm went from 166 to 172 by boring the port spigot out to 1.7 inches.. Which seem to be  the main restriction as 57mm is pretty big so the main restriction there is the port.

I'm assuming flow was done at or corrected to 10 in H2O..

Max

[Don D]

The 07 single piece TB has some other issues. They machine the openings into the castings at the port outlets and the cast portion where it meets the machining is usually a restriction that responds to smoothing. Not much to do to them to make a real difference as you are saddled with the casting and no way to weld practically. Personally I like the looks of the SE58 cable drive two piece TB. No experience with it yet.

[Admiral Akbar]

Thanks Don,

Makes sense.. I was thinking of an early Delphi which seemed to be layed out pretty well.. Not sure I'd see that much increase. 99 difference in TB flow compared to mine is partly the bench I'm sure.. %increase is interesting tho.. Bruce

[HD99FXR3]

Max, all I did was clean and blend the seams and any abrupt transitions. Nothing fancy really just tried to make the transitions as linear as possible. Flow was at 10 in H2O.