Guys with Ls2 throttle bodies.....
Originally Posted by Sigforty
No hole drilled in the stock ported TB that came off my vette. The hole will increase idle air, but you would need to adjust the throttle blade to account for this air to keep from idling at 2k.
When I drlled the hole in my TB Blade, the goal was to lower my KpA at idle, I didn't need to move anything to keep the idle revs at the same level.
-It was 900rpm and 8% of TP before the hole
-It was 900rpm and 4% of TP after the hole
KpA moved down a little bit
No need to move anything related to the TB position with a FbW in my case.
Christian
11 Second Club
Joined: Jun 2005
Posts: 1,537
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From: Was New Orleans, but swam to Baton Rouge
Originally Posted by miami993c297
Hi Sigforty,
When I drlled the hole in my TB Blade, the goal was to lower my KpA at idle, I didn't need to move anything to keep the idle revs at the same level.
-It was 900rpm and 8% of TP before the hole
-It was 900rpm and 4% of TP after the hole
KpA moved down a little bit
No need to move anything related to the TB position with a FbW in my case.
Christian
When I drlled the hole in my TB Blade, the goal was to lower my KpA at idle, I didn't need to move anything to keep the idle revs at the same level.
-It was 900rpm and 8% of TP before the hole
-It was 900rpm and 4% of TP after the hole
KpA moved down a little bit
No need to move anything related to the TB position with a FbW in my case.
Christian
Ported the TB, RTV'ed the MAP sensor, and rerouted the valve cover vent tube back into the airbridge. The car still have the same problem, but I did notice I got a bit better throttle response probably from the porting on the TB. But the rpm is still dipping to 500rpm to bouncing back and forth when I clutch in, it usually takes about 3 to 4 tries before it finds the 900rpm idle. Even put the hole on the TB as well, still no help. 
You need to have your tuner lower the rate the engine decels (decay rate) as the clutch is put in. On FBW the computer will open the throttle plate a little on decel when the clutch is pushed in and slowly close the throttle until the car reaches the idle speed that is set up. On cars that have big cams and free-flowing intakes the rate at which the computer closes the throttle is too quick and cause the car to lose RPM too rapidly and almost stall (this can also happen with cars with lightweight flywheels). So, you just need to have your tuner slow down the rate at which the throttle closes after the clutch is pushed in. I think if you post the issue over in the tuning section you could probably have someone tell you what area in the PCM needs the update.
