it doesnt have the bellmouth, its an ecotec. but i do want to look at a spacer kit. and i hadnt actually thought about a custom tune, i had put it into the "DYNO = $$$$" pile.... ill have a look on ebay later, right now tho, iv found a thread on cam specs for the ecotec:
(QUOTE)
Standard Valve Timing for the LateVS-VT-VX-VY EcoTech V6 Engine:
Advertised Valve Lift at height - 0.006 inches
Inlet Opens - 6.7 degrees BTDC
Inlet Closes - 57.0 degrees ABDC
Exhaust Opens - 65.3 degrees BBDC
Exhaust Closes - 15.1 degrees ATDC
Inlet Valve Duration - 243.7 degrees
Exhaust Valve Duration - 260.4 degrees
Inlet Valve Lift with 1.6 to 1 ratio rockers - 0.4099 inches
Exhaust Valve Lift with 1.6 to 1 ratio rockers - 0.4112 inches
Inlet Valve Lift at TDC - 0.0208 inches
so if im reading it correctly, (if advanced 8 degrees) would make my
Inlet open @ 15.7 BTDC
meaning the valve opens earlier on the upstroke of the intake cycle. allowing the piston to push more air back into the IM?? could i possibly use that to my advantage by somewhat pressurising the plenum and helping the scavenging affect???? particularly with longer runners???
Inlet close @ 48 ABDC
meaning the valve closes earlier, preventing some of the Air/Fuel mix from blowing back into the plenum ( i see that particular as a positive)
EX open @ 74.3 BBDC
meaning the exhaust valve opens just over halfway down allowing a lot of exhaust energy out (maybe a negative, or could be positive in helping draw more air back in on the overlap)
EX close @ 6.1 ATDC
meaning that just past the top of the stroke the EX valve shuts preventing any more EX gas being sucked back into the chamber allowing any scavenging to build up speed as the piston moves back down (hemholtz??)
after re-reading my story i can start to visualise whats happening internally and i really believe that this will give me more torque in the lower rev range. and i dont care about the lost power in the top end.