Camshaft Timing - Advance/Retard Optimization
Thread Starter
Burning Brakes
Joined: Sep 2001
Posts: 1,013
Likes: 9
Camshaft Timing - Advance/Retard Optimization
It seams that nearly every off the shelf cam comes with a ground-in 4 degrees of advance. Every single engine combintation that I have simulated on Desk-top-Dyno shows best power with 0 degrees of advance (about 20-40 hp better than with 4 degrees of advance). The dyno curves also show very very little low end loss at 0 degrees of advance, and better hp from 4000 on up.
So what gives? If Desk top dyno has any accuracy, why are all the cam manufactures recommending installing them 4 degrees advanced? Am I missing something here? Is it not done because of a reduction in idle quality?
So what gives? If Desk top dyno has any accuracy, why are all the cam manufactures recommending installing them 4 degrees advanced? Am I missing something here? Is it not done because of a reduction in idle quality?
Melting Slicks
Joined: Sep 2000
Posts: 3,099
Likes: 0
From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Camshaft Timing - Advance/Retard Optimization (Mr6spd)
dont hold your breath with those desktop dynos they can be off upto and beyond 100hp :cheers:
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 34
From: The Top of Utah
Re: Camshaft Timing - Advance/Retard Optimization (Mr6spd)
It seams that nearly every off the shelf cam comes with a ground-in 4 degrees of advance.
...why are all the cam manufactures recommending installing them 4 degrees advanced? Am I missing something here? Is it not done because of a reduction in idle quality?
...why are all the cam manufactures recommending installing them 4 degrees advanced? Am I missing something here? Is it not done because of a reduction in idle quality?
Generally, advancing the cam gives a stronger bottom end. Advancing the cam would improve idle characteristics, at the expense of upper end horsepower. Good luck, and...
RACE ON!!!
Thread Starter
Burning Brakes
Joined: Sep 2001
Posts: 1,013
Likes: 9
Re: Camshaft Timing - Advance/Retard Optimization (CFI-EFI)
I entered the cam grinder's numbers, and then put in a -4 advance to bring the net back to zero degrees advance. CFI-EFI: What happens to your Desk-Top Dyno curves if you enter a -4 advance?
Melting Slicks
Joined: Sep 2000
Posts: 3,099
Likes: 0
From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Camshaft Timing - Advance/Retard Optimization (Mr6spd)
i put in all my cams 2-4 degrees advanced for example if it says 112 and has a 4 degree built in at straght up it will show 108 i then install at 104-106 for more power down low and dont care what the program says for a street and or street strip car you need power down low :cheers:
Melting Slicks
Joined: Sep 2000
Posts: 3,099
Likes: 0
From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Camshaft Timing - Advance/Retard Optimization (CORKVETTE1)
now case in hand a 1.44 60 ft and a 125+ mph is a preety good compromise considering i am only running a 307 gear :cheers:
