If it can, how much horsepower is it good for on a 99+ na 4.6? I've read that some owners do it themselves with a dremel tool. But, who does this kind of work professionally?
just about any speed shop could, you should expect somewhere in the 5 rwhp range, possibly less, possibly more (but kinda doubtful) depending on the quality of the work. for the money they would charge you, it would almost be as cost effective in the long run to go ahead & get a upper intake plenum, like c&l or accufab
There was a Dyno Test done by someone on MD and they got 2-3 RWHP out of it.. more with other intake mods.. but not much.. you'll get more if you get an upper intake plenum like accufab or dragon. Accufab has seen the most gains of power, but is also the most expensive.
um, guys, hes already got the accufab upper intake plenum. i believe hes talkin about the intake manifold. my thoughts would be that a shop would charge pretty close to the price of buying a new one. i heard a bullit intake would only net ~8 rwhp on a stock 99+ engine, so this would lead me to believe that porting and polishing the stocker would gain a little less, maybe 5 rwhp but this is all heresay (sp?) i would reccomend doing a search on stangnet for "bullit intake" and "porting intake manifold" then do some additional research for these topics. hope you find what youre lookin for.
The elbow can be ported, the plastic can not. Ported elbow can show gains as much as 8-10 hp. There was an article in MM&FF about this a little while back.
It would be interesting if someone who owned a vacuum
guage would hook it up to the I.manifold, during a dyno test. That reading, probably a few tenths of one psi,
would be indicative of how much potential gain there is to be had with throttle body-plenem-etc changes.
Rio
My advice would be to take it to you local speed shop and ask if they can port and polish your plastic intake...and then report to us the reaction you get.