Street Demon tuning experience
I'll give it a shot.
First thing I found really useful was an adjustment in my thinking about engine Air:Fuel ratios.
https://www.tapatalk.com/groups/racingfuelsystems/viewtopic.php?p=16323#p16323
Idle is relatively rich. More power matches leaner AFR until about 60% of maximum, then AFR must get richer.
That illustration from Larew shows an engine that needs a power valve (rod lift) well before maximum power, like a 10.5 Power Valve would provide.
An engine with better part throttle efficiency would need enrichment closer to maximum power, like a 6.5 Power valve would provide.
Same graphic marked up showing Air:Fuel ratio equivalents to F:A ratio
The important thing to start with is the idle. The jets and rods have minimum impact on idle and low speed driving, that's the function of the idle restrictions and air bleeds. Adjust idle mostly with throttle position, and the idle mix screws.
Unfortunately, all of these things need to be tested under load.
Proof?
I posted an example here. overlaying a data log of increasing the throttle in neutral with a log increasing the throttle while driving.
I'll give it a shot.
First thing I found really useful was an adjustment in my thinking about engine Air:Fuel ratios.
https://www.tapatalk.com/groups/racingfuelsystems/viewtopic.php?p=16323#p16323
Idle is relatively rich. More power matches leaner AFR until about 60% of maximum, then AFR must get richer.
That illustration from Larew shows an engine that needs a power valve (rod lift) well before maximum power, like a 10.5 Power Valve would provide.
An engine with better part throttle efficiency would need enrichment closer to maximum power, like a 6.5 Power valve would provide.
Same graphic marked up showing Air:Fuel ratio equivalents to F:A ratio
The important thing to start with is the idle. The jets and rods have minimum impact on idle and low speed driving, that's the function of the idle restrictions and air bleeds. Adjust idle mostly with throttle position, and the idle mix screws.
Unfortunately, all of these things need to be tested under load.
Proof?
I posted an example here. overlaying a data log of increasing the throttle in neutral with a log increasing the throttle while driving.