If exhaust isn't leaving quick enough, then fresh air and fuel isn't coming into the cylinder fast enough
Originally Posted by exterminater
So more fuel to the engine would help reduce some of the popping ? Not a wrench just a bolt on specialist. Like adding a type of fueler like a Rev-Tech DFO ? Or did I miss the whole point?
, or without the correct intake volume of air and fuel, it creats a lean condition. The mixture needs to be richened.
This is why you see cam specs including "Duration". This is the time, marked in degrees, that a cam lobe holds a valve open. The more lean (EPA compliant) a bike runs, the less duration you'll see for the intake and exhaust valves. That duration is a direct reflection of the narrowness of the cam lobe, at its highest point of lift. The cam LIFT, is also another factor for air in, exhaust out, as is the diameter of the valve/seat, and flow characteristics of the cylinder head.
Richen mixture= more exhaust=more exhaust velocity=more intake air brought in for combustion = more torque and HP.
You're correct. Adding fuel to the mixture, creates a richer, more powerful mixture and explosion, replacing exhaust velocity, increasing the intake air and fuel intake, that was lost with decreased backpressure.
Extreme example: Dragsters. Straight pipes, but short and one bend.
That BEND, creates resistence (backpressure) to speed up exhaust velocity. The mixture is soooo rich, to produce sooo much HPs with such advanced timing and tremendous amounts of scavenging, that the fuel is STILL BURNING in the exhaust, as it exits the end of the exhaust pipe.
The EPA doesn't like this, because unburned fuel from the exhaust with a rich, powerful mixture is called "Hydrocarbons". Unburned fuel. That's barely noticable in an EPA complicant 14.7:1 (Stoich) mixture.
Of course, like with anything, your total tuning and HPs are directly related to the timing, cams, head flow, fuel delivery and ignition.
It all works together, but one change to one thing can cause a drop in Hps, Torque and total performance.