ZR-1 Net Registry Forums - View Single Post - Removing Secondary Vacuum System questions.

DScott600 · 08-11-2009

When I read about and look at the LT5 it is a marvelous engine. The only thing that really bothered me was the secondary system. It looks like a last minute cobbled together idea and it is way over complicated. In the late nineties I had a 1996 mustang cobra. They had secondary throttle blades too that opened up at 3250 RPM. They were used for low end torque. The system was much simplier, they had plates between the intake and heads that were operated from a control box under the intake. It was a compact design and if you wished to eliminate it you pulled the intake to do so. In 99 Ford changed the design of the heads so that the system was no longer needed and they haven't used it since. My point is the system could have been similar to fords and we would have little to know issues with it. And everyone who has done it says that you notice no torque loss and even Marc says that it was for emissions. The Ford design was for low end torque but even they went away from it when they redesigned the heads to promote better low end torque.

08-11-2009	#16
DScott600 Join Date: Aug 2008 Location: LaFayette, GA Posts: 31	Re: Removing Secondary Vacuum System questions. When I read about and look at the LT5 it is a marvelous engine. The only thing that really bothered me was the secondary system. It looks like a last minute cobbled together idea and it is way over complicated. In the late nineties I had a 1996 mustang cobra. They had secondary throttle blades too that opened up at 3250 RPM. They were used for low end torque. The system was much simplier, they had plates between the intake and heads that were operated from a control box under the intake. It was a compact design and if you wished to eliminate it you pulled the intake to do so. In 99 Ford changed the design of the heads so that the system was no longer needed and they haven't used it since. My point is the system could have been similar to fords and we would have little to know issues with it. And everyone who has done it says that you notice no torque loss and even Marc says that it was for emissions. The Ford design was for low end torque but even they went away from it when they redesigned the heads to promote better low end torque.