How much variation in factory cam timing adjustment? - ZR-1 Net Registry Forums

mike100 · 12-22-2014

I have driven or ridden in about half a dozen ZR-1's and everyone of them had a different personality and seemed to have different torque characteristics. Some were real soft down low and fairly "top-endy". My car has a great grunt at 4000 rpm but is a little flat on the top, and the car I drove last Saturday had normal to good mid range and super great top end and it was still on factory 91 manifolds (Erik-YZPilot's 91). Erik's car has the same timing curve as mine seeing as how I made the chip for it so pretty much all things being pretty equal with a similar home grown plenum and inj housing port job, same chip, same weight, same car, etc...

I'm seriously considering degreeing the cams on my car to make it run better. This is of course assuming that there are gains to be realized there. I'm very much thinking that this is the silver bullet to Permagrin and the intangible difference and the mysterious reason some cars have the extended torque peak/cylinder pressure and others are just 'ok'.

I'm remember reading this is easiest with the engine removed?

btw, I think I'm going to keep this car assuming I can keep it smogged in this state. If I can get it to run like Erick's I would drive it a lot more often.

12-22-2014	#1
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	How much variation in factory cam timing adjustment? I have driven or ridden in about half a dozen ZR-1's and everyone of them had a different personality and seemed to have different torque characteristics. Some were real soft down low and fairly "top-endy". My car has a great grunt at 4000 rpm but is a little flat on the top, and the car I drove last Saturday had normal to good mid range and super great top end and it was still on factory 91 manifolds (Erik-YZPilot's 91). Erik's car has the same timing curve as mine seeing as how I made the chip for it so pretty much all things being pretty equal with a similar home grown plenum and inj housing port job, same chip, same weight, same car, etc... I'm seriously considering degreeing the cams on my car to make it run better. This is of course assuming that there are gains to be realized there. I'm very much thinking that this is the silver bullet to Permagrin and the intangible difference and the mysterious reason some cars have the extended torque peak/cylinder pressure and others are just 'ok'. I'm remember reading this is easiest with the engine removed? btw, I think I'm going to keep this car assuming I can keep it smogged in this state. If I can get it to run like Erick's I would drive it a lot more often.