just for the record, changing a TB geometry is definately a call for a tune. You're engine is calibrated based on assumed hydro-diameters and whatnot. You just changed a lot.

 

okay just did the porting as per your instructions on a second TB I bought. It had a strange Idle at first but then it seemed great. I took it for a drive and the Throttle response was very very veryyyy noticable. It seemed to slow down slower meaning when you took your foot off the peddle the truck just seemed to keep going and then slowly slow down with the gears. I have a Chevy SS AWD so I expect it to slow itself but it just coasted. My fuel economy went up from 16.4 to 17.0! I did find it a little unsettling to have to stomp on the brakes to slow down pulling out of the driveway at low speed/not touching the throttle. Seemed to like to roll/coast at 20mph now!
Thanks for the help.

 

if you have hpt tuners try to lower your base running airflow. this will let the pcm know that you need less air to idle (less open tb) since you ported th tb its getting more air at the same % throttle position. lower those tables in the warmer ranges and it should stop the cruise control effect. do a small amount at a time to keep from over shooting.

 

Barney,

That was one of the exact problems I had with my shaner ported TB on my old crew cab. I had it tuned several times and was never able to get rid of that problem.

 

did he ever try to change this table?

 

Honestly I couldn't tell ya. I know that it was Allen Nelson that was doing my tunes for me, so I would have imagined that he would know to look there.

 

Okay I changed the tune and all I can say is WOW. This should have come from the factory with a polished TB. I went so far as to use up to 600 grit paper then polished with a buffing wheel and rouge. Its pretty smooth I originally wanted to chrome the houseing but dont think that will ever happen now.

 

what did you change?

 

Yeah, what did you change? I would likely give this mod another chance if I knew that it could be done and not have the cruise control effect.

 

is it ok to cut the tb blade shaft when boosted? its not going to break and blow off is it?