I am thinking of porting my TB and my question is about filling in the large cutout space. If I fill that space in with epoxy, what are the best sizes to drill the holes? Another question is whether or not this mod will affect CA emissions. Thanks for helping out.

 

I originally drilled mine to the specs writen in this how-to:
http://www.ls1info.com/article.php?sid=250

I wound up going bigger because I think the IAC was having trouble with the smaller hole. Here is a BIG closeup of my homemade ghetto ported TB:
http://www.tatommy.com/images/homeporttb.JPG

Tommy

PS I used aluminum epoxy. It worked aswome!

 

I did mine also with no instructions or tubes. Just filled it in then drilled the holes. The holes came out better than I thought. I didnt think the crankase hole would be as perfectly placed. I drilled and I went right through to the back opening(i thought I would have to go in from both sides and make the holes meet.

As for the size of the Holes: I was suprised, I tested the TB on my buddys TA with a mild cam. I figured the IAC hole was more restrictive on my new TB which would cause the IAC to work harder thus raising the readings on the scanmaster. the readings were at 80 before and 50 with the new TB. Im thinking that scince the "hump" before the blade was grinded off that air can penatrate the TB through the edge of the blade.

Ill post the link to some pics a little later, as webshots require 30min before they are available.

 

 

Thanks for the help guys. I'll probably get around to doing the mod sometime this week.