Hi Guys. I've had an extra stock throttle body on my bench here for nearly a year, and just for giggles, since it will cost me nothing but my spare time, I'd like to try my hand at porting this sucker. I've read countless threads that date back two decades about porting the stocker, lots of debate on if it makes any extra power at all or if it's just placebo. Not interested in carrying on that debate. My build is going to be a very mild HCI build, certainly within range where the stock throttle body likely isn't holding me back very much at all. However my question concerns sanding down the ridge inside the throttle body. All the old tutorials and write-ups I've seen in the archives just say to grind that down and flatten it out. My question is, do I remove that ridge all the way around the entire mouth of the throttle body before the throttle blade? Is my goal to make the intake side as wide as the exit side? I feel like if I sand down the bottom ridge it will allow way too much air at idle. The lower part of the throttle blade actually rides along that ridge until the throttle is open past 20% or so, which is what is confusing me. The top of that ridge (where you would epoxy the giant hole) can easily get grinded away as the throttle blade never comes anywhere near that ridge. I've seen plenty of pics of beautifully ported and polished throttle bodies, but can't tell from the pic if the bottom ridge is sanded down not.


Pics from LS1Howto.com

 

Too bad you couldn’t test it on a flow bench…

 

Not currently in my tool set, no.

If it wasn't clear in my first post, those pics are not of my porting but ones I found on LS1Howto.com.