I don't understand why there is a need for downshift blipping either "manually" on our bikes or automatically on varies modern bikes.
Doesn't the engine automatically raise the revs when you downshift anyway to match the bikes speed?
Can someone explain it to me please.
There is no such thing as engine automatically raising the revs when you downshift which will match the bike speed.
What happens is because of the speed of your bike the back wheel forces engine to spin with higher speed which is raising the revs.
The problem here is you have a lot of braking power coming from the engine to your back wheel. This force unbalances the bike and makes suspension wobbly. Also the braking force may lock your back wheel and you may crash.
Hence clever guys invented the slipper clutch - because clutch sits in the middle between the engine and your back wheel if the clutch slips a little the force is lost and the back wheel is not forced so violently to brake. Means you will not crash and there is no need to blip.
I never blip, but I usually slip my clutch manually. Which has the same effect. By blipping you are basically making the revs of the engine to match the rotation speed of your back wheel - hence no braking force. I prefer to have the braking force coming. Not to mention the sound of the engine forced by the back wheel speed to go higher is very nice. In fact that is the most fun for me when riding. Incoming.
Which is a lot of exhaust screaming noise for bike which basically is stopping, but we must satisfy the expectations of the public that the bikers are crazy people
Summary - in order to avoid the violent braking forces on your back wheel you can:
1. Blip and equalise the engine and back wheel.
2. Use your clutch to slip a little - means you are still having braking force on the back wheel but its controlled.
3. Buy a bike with slipper clutch - there you have automatic slipping.
HTH