Hey guys, as long as you have that new plenum in your hand, take a peek inside. Most of them have casting goobers and minor defects in the surface that impede flow. If you have a dremel or handheld die grinder remove the bumps. I was easily able to access all of mine with a hand-held die grinder. After you do that, spend $10. on a 3M scotch brite/emory wheel (they are about 2.5" diameter and easily fit in a 75mm plenum. Polish the S**T out of the inside! This setup yields a smooth surface and enhances flow, better flow equals HP, every little bit helps on a NA 2V 4.6. Also, if you dislike the "whistle" on part throttle, (mine sounds like a belt chirp) carefully break the edges on the IAC ports (Idle air Contoller) and EGR port* (especially here, because the incoming air has most velocity at this point) I used a ball grinding end of about 3/4" on my die grinder. When finished, wash thouroghly in a pail of warm suds (clean completely with a rag and toothbrush through all ports. I noticed alot of you are installing TB/Plenum setups, I figured I'd through out this tip to y'all.
John

 

thanks john, i'll check it out when i get mine in a few weeks.

 

which plenum did you buy?

 

I bought the professional products satin 75mm plenum, and I'm using the pro products 70 MM throttle body. I have no complaints with either, the TB is smooth, no hang ups, and the fit and finish of the intake is great for the money. I paid $215 fo the combo. I don't know if anyone offers the inside polished, plenty offer the outside. To me, the inside is what I care about. I remember years ago that FORd "found" 8 hp in the Probe Gt's intake by extrude honing it. This process basically polishes the runners of the intake. That is the one thing I do like about the factory plastic intake, the runners are smooth, unlike cast aluminum.
John

 

But, with this plastic intake, you cannont port it.. You are just stuck with how it is.

 

Thats why you whack it with a hammer, contact ford about the recall on your cracked intake. Then spend the money you get on a performance metal intake

 

So you are happy with the PP plenum+t-body? I might go with that one as a low cost alternative to the 300 dollar combo I was considering before. Where did you order yours from for $215?

 

i just recived mine in the mail today $215 from ebay

 

i dont know if its just me, but what is the point of spending 250+ on a plenum and whatever of a intake and only get like 5WHP... seems like a waste of money for little HP... if i am wrong please correct me.

 

consider yourself corrected