[upnorth]

Has anyone who went TGVless noticed an increase in fuel consumption upon startup? I know the TGV's are there to increase turbulence at low flow speeds and light of the cat's faster ... i was just wondering if anyone has datalogged a difference? I would think that without them air/fuel mixing would be worse and more fuel would be required on a cold engine... anyone care to comment?

[bluedemon_II]

I think that it has to do more with the tune than with the tgv's not being there. They are there for emissions purposes and giving back pains to the ppl removing them. But really it would be interesting to know since I think of removing them for my Dominator 3.0 install.

[upnorth]

just curious if someone has checked it before and after without changing the tune. I think it would be noticed as a difference in A/F learning (short term).

PS what they are good for is getting a more turbulent mixture in low airflow situations (like cold startup and idle). On a cold engine, super rich mixtures are needed to burn the fuel since it likes to condense on the cold cylinder walls and oxidizes (burn) less easily. TGV's create more turbulence in the air which is most beneficial at low flow speeds when the flow is of a more ordered nature (less turbulent). Having more turbulence on startup allows for less fuel to be needed and for combustion temperatures to rise more quickly. This lights off the cats sooner and allows the catalysts to reduce emissions sooner. Its too bad they couldn't have made them less of a flow restriction when not in use through with a better system!