Which Junkyard Throttle Body to choose

[gregs78cam]

Way to cool!
Don't just put a K&N airfilter on it as it messes with intake air from fan etc...

Never. That will be routed to fresh cool dense air. OR compressed cooled air, eventually.

[gregs78cam]

Well, it took way too many hours, but this is just about the final model. I still have to decide how to do the back of the plenum, and then the valley, and then the water jacket/neck.....it just doesn't end.

[1project2many]

Whatever you choose, try to ensure it uses a decreasing radius throttle arm. The largest percent changes in airflow through a TB occur at the lowest throttle angles. With a constant radius, especially if it's a fairly small one, this means the engine wants to snap to life when you try to leave a light, or an intersection, or when you're trying to cruise at low speed. Sounds like fun but it can get tiring when you have to constantly work to prevent the tires from breaking free and pay attention to not pushing the throttle too hard.

my $.02.

[RobertISaar]

Whatever you choose, try to ensure it uses a decreasing radius throttle arm.

i take it this is the EFI equivalent of a carb with progressive linkage?

[1project2many]

i take it this is the EFI equivalent of a carb with progressive linkage?

Yes, and even more equivalent to progressive with small primaries.

BTW,Greg, any idea how plenum volume compares to engine displacement on this manifold?

[RobertISaar]

http://mysite.verizon.net/vzezeqah/id1.html

that intake article is about the extent of my knowledge for intake design.

"V8's with one large plenum feeding all 8
cylinders does not work all that well as far as the
Helmholtz resonator goes, but if this is the case, plenum
volume should be about 40-50% of total cylinder
displacement. "

"If a boost is desired in a higher rpm range, closer
7000-7500 rpm, the plenum will need to be 10-15%
smaller. To get a boost in the 2500-3500 rpm range, it
will need to need about 30% larger. "

[EagleMark]

Wow that is a great article! It's in pdf as well!
http://mysite.verizon.net/vzezeqah/s...ionsystems.pdf

Greg came by and grabbed my 75MM single barrel Vortec/LS type TB. He's going to do some measurements and drawings for future but not sure if he is going to use it. Just about the same thing as jeepandguns ended up using.