I will let you guys know what kind of difference I see because some local guy is going to port and polish my throttle body on my 2000 4.8 singlecab with K&N intake,electric fans, mangnaflow muffler,and hp tuning

 

Anything that is going to un-restrict incoming air, will pick up power. It might not be much, but it will help out. And its free.

 

I had the TB on my WS6 ported and I could feel a difference, but never had it dynoed. I plan on having the TB on my truck ported too.

 

One thing that I've read repeatedly is that most guys who get their tb ported and polished report better throttle response, which right there makes it worth it IMO, especially when it can cost little to nothing to do

 

ported tb pick up to 5-10rwhp on ls1's without any loss of lowend or other issues. Its a cheap mod and easy to install but it doesnt make that much hp.

I wonder how much of the hp comes from making the blade open up all the way.

 

Exactly, and what most everyone (on the negative side of the debate) has seemed to overlook here is the fact that the so-called "ported" throttle body is not actually opened up any larger than stock. The butterfly is still 78mm or whatever it is, but the inlet side of the throttle body is "smoothed" & "blended" from it's largest part (at it's opening), to the butterfly, creating kind of a "smooth cone" or funnel shape which can do nothing but INCREASE velocity, not decrease it....there's where the throttle response gains come from.

Anyone can look into the inlet side of a stock throttle body and see no less than two rather large steps that air has to stumble over to get to the throttle blade. One is about 5/8" inch in from the outermost edge, and one is about 1/2" from the throttle blade itself. "Porting" removes these restrictions and allows a smoother, straighter shot directly to the throttle blade, which allows higher velocity of the incoming air.

The very slight hp improvement is pretty much a byproduct of the throttle blade stop being modified to allow full opening, and not 80% or so opening like they all are when un-touched, un-modified.

 

According to that Shaner website, it's not so much the peak gains, which is in the 5-12hp range I think it said, but rather the gains under the entire curve.

Sounds like a legit mod to me, but I have yet to do it..