Ignition BTDC
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Re: Ignition BTDC (Corvettewolf)
A good starting point for most engines is 36º total with the vacuum advance disconnected. To really know what is best requires a dyno or a drag strip. Seat of the pants testing can be deceiving because a 10 hp increase at lower rpms might be much more noticeable than a 20 hp loss at higher rpm that resulted from having too much total.
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: Ignition BTDC (Corvettewolf)
The question you pose is vauge. There are recomended settings for idle and recomended settings for full throttle higher rpm's. Theres the length of the advance curve and at what rpm it comes in. Then you got vacuum advance....all of these things can be individually taylored to perfection.
one things for sure, you can get yur answers here. The rule of thumb for SBC is 12 to 14 degrees at idle with 36 total in by 2500rpm. This covers the mechanical curve and advance. These adjustments and setting are done with vacuum advance unhooked. Vacuum advance is added to these settings to improve throttle response and fuel mileage. Vacuum advance can also be taylored as to how much and how soon it activates.
one things for sure, you can get yur answers here. The rule of thumb for SBC is 12 to 14 degrees at idle with 36 total in by 2500rpm. This covers the mechanical curve and advance. These adjustments and setting are done with vacuum advance unhooked. Vacuum advance is added to these settings to improve throttle response and fuel mileage. Vacuum advance can also be taylored as to how much and how soon it activates.
