J
Jack Klarich
Guest
Good Post Hoop, Thanks:s and no Im not yelling Boss
Some Theory on Ion Knock Sub-System
- Thread starter Hoople
- Start date
J
Jack Klarich
Guest
There is only the resistance of the gas/air between the plug gap, that's why it take 20,000 volts to cross the gap. My guess is that the ions produced from a detonation allow a very small current to leak across the gap hitching a ride on the excess ions. How they would measure that current, I have no idea. It sounds pretty cool though.
ion sense works just fine with engine hot ups, the amount of ions from healthy combustion is the same on any engine. i have reviewed knock on many sest recordings and they are all much the same, the odd 4-6 degree retard, and it is still the same if you take a stage 1 map and modify it for stage 2 etc. it isnt like a harmonic knock retard that basically listens for knock so change in bore etc change the frequency of knock being listened for, it is testing the combustion to estimate the likelyhood of knock before it even happens.
Hoople
Account Removed
Everything I have read seems to indicate that is not what happens. The presence of Ion's in abundance is what triggers knock retard.
On my bike, using a VCI data recording I have actually detected by EAR engine knock. After downloading the data, I did see where the sound of knock took place along with the Ion sensor afterward performing as it should.
Hoople
Account Removed
When I look at the spark advance timing tables for some of the Stage 1 maps (which I can not believe are too far from a factory map) what I see is a way over abundance of spark advance in order to achieve good fuel mileage and low emissions. In my opinion, the factory and stage 1 spark advance curves RELY on the constant use of the knock system to protect the engine. I would bet if you took a factory fresh bike and filled it with 91 grade octane fuel (by book) and disabled the Ion sensor software, the engine would rattle itself to death from detonation. I have never seen an air cooled engine that can eat 45 degrees of spark advance. That's how much advance there is in Several cells across the map.
45's, 44's 40's 42's lots of them and all under engine load... Not during de-acceleration but under part throttle engine load with no regard to cylinder temp. The real funny thing I noticed was if you go into those cell locations to see what the allowable range is, the maximum number you can set it to is 45 degrees. Several cells are at or near 45 already. When have you ever seen a factory setting be "Pegged".?
A Knock retard system (both piezoelectric or Ion) should be incorporated in the engine management system to protect during those unusual events or circumstances and not be used all the time like the spark curve itself.
45's, 44's 40's 42's lots of them and all under engine load... Not during de-acceleration but under part throttle engine load with no regard to cylinder temp. The real funny thing I noticed was if you go into those cell locations to see what the allowable range is, the maximum number you can set it to is 45 degrees. Several cells are at or near 45 already. When have you ever seen a factory setting be "Pegged".?
A Knock retard system (both piezoelectric or Ion) should be incorporated in the engine management system to protect during those unusual events or circumstances and not be used all the time like the spark curve itself.
RibEye
Senior Member
My point exactly. I recently saw what the timing tables contain and about fell out. Looks like a single-point failure catastrophe waiting to happen. Nothing like blowing the top off a piston, or such like, to just about ruin your day.
Enjoy,
Rich P