I have an 06 that i put a 4.5 liter whipple on last year. Since then when i get after a WOT pull the car will go into a vacuum lock and the engine will run away because vacuum lock holds throttle body wide open. So i have modified the air box and it only does this once ever 5 or 6 pulls. I want to know where i can but the carbon fiber inlet tube and has anyone had a new airbox made that will move more air with a filter.
4.5 litre whipple questions.
- Thread starter B Street
- Start date
PeteK
GT Owner
This is curious. The throttle is cable-actuated. I don’t see how vacuum could hold it open. Did you put the throttle return spring back on correctly? Please describe what is happening in more detail.
twobjshelbys
GT Owner
I suspect he's getting vacuum because the air intake collapses because the air box can't supply enough. Two things:
Several places have stiffener inserts. My power kit from Rich had one. Check with him.
My setup came with K&N filters that were the same size as the factory ones that (in my opinion at least) allowed more air flow than the factory units.
Rich(?) also has a CAI setup that replaces the standard filters.
PeteK
GT Owner
Even if the rubber intake duct collapses, the throttle should still close under spring pressure. This doesn’t make sense as stated. If indeed the throttle sticks open, I’d be looking for another cause.