Wasted Spark System
#16
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Very good explanation! I would add that the WS enables you to use of a wider plug gap.
As a side benefit; if you are using a adjustable cam sprocket, you can free up the front to gain access to the cam sprocket with ease. It makes life easier on the dyno when adjusting the cam gear.
As a side benefit; if you are using a adjustable cam sprocket, you can free up the front to gain access to the cam sprocket with ease. It makes life easier on the dyno when adjusting the cam gear.
#17
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The WS fires on both the compression and the exhaust strokes. The fire on the exhaust stroke is wasted (which is why it's called Wasted Spark).
#19
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At Hi boost is were we typically can see improvement in a better and more constant spark were simpler designs like the"our" conventional rotor setup can fail to ignite the fuel We can gain HP/TQ with a WS kit and multiple coils. As i also forgot to mention but later quoted by John is that you can run bigger gaps in the plugs. The second Spark reduces exhaust gas emissions because the spark plug that is fired during the exhaust stroke burns remaining fuel left over from the previous combustion stroke before it has a chance to exit the engine through the exhaust .
#20
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Forget about reducing exhaust emissions. I'm a little worried about TOO much fuel left over during the exhaust stroke (ie. throttle lift MAF richness) being ignited, and wondering what could happen.
I'm leary about backflash through the intake with any kind of valve overlap.
Also, if one can use a wider gap, is that sort of like advancing the timing a bit (idea of starting with a larger spark kernel creating a flame front that will be ahead in time a bit)?
But, I like the idea of a stronger, reliable spark and definitely tempted to get one of these setups.
#21
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Thomas, How much overlap does your cam have? Lots of overlap is not turbo friendly wasted spark or not.
Backflash through the intake? With many wasted sparks in use, many on race cars, I'm yet to hear about anyone having this issue.
Backflash through the intake? With many wasted sparks in use, many on race cars, I'm yet to hear about anyone having this issue.
#22
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Awesome news that comes at the crappiest time for me. I just sell my turbo and piggyback...then bam. This happens. I hate you John! Lol
I'll be back very soon though. I promise. Heck...I'm actually starting work on the 951 later this week!
I'll be back very soon though. I promise. Heck...I'm actually starting work on the 951 later this week!
#23
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Does this mean that I won't have big flames out of my exhaust anymore with a WS system. lol
So if it ignites the extra fuel in the combustion chamber but it's on the exhaust stroke what is the main benefit from WS?
So if it ignites the extra fuel in the combustion chamber but it's on the exhaust stroke what is the main benefit from WS?
#24
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The original wasted spark system absolutley woke up my motor. I was able to open the gaps back to something normal (.26-.28) and run 20+ psi with no issue. Previously, I was closing down my gaps and changing plugs every month trying to keep the flame alive for higher boost. No way I could have made it to 500rwhp without this system. And, the laptop control over ignition timing is darn helpful as well.
#26
I have the one I got from Jeremy with his VR stage 3,just haven't got around to installing it all.My buddy's wife couldn't wait till the due date and he's home taking care of her after C section.Need the heated garage and his help
#27
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The second spark does not actually do anything – there is not much left in the cylinder by that point (approx. 20 degrees before TDC on exhaust stroke). Any unburnt fuel has left the cylinder – the exhaust valve is almost closed (fully closed by 3 degrees BTDC) and the intake valve has not opened yet (1 degree ATDC).
If you are running rich (we all are when on boost) the reason there is unburnt fuel is there is not enough oxygen to fully combust all the fuel. The rest of the unburnt fuel will combust when it gets enough oxygen.
If there were enough unburnt gasses in the cylinder to ignite with the wasted spark there would be reversion issues in to the intake manifold – and that would cause dilution of the intake gasses.
If you are running rich (we all are when on boost) the reason there is unburnt fuel is there is not enough oxygen to fully combust all the fuel. The rest of the unburnt fuel will combust when it gets enough oxygen.
If there were enough unburnt gasses in the cylinder to ignite with the wasted spark there would be reversion issues in to the intake manifold – and that would cause dilution of the intake gasses.
#28
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So Chris, you seem to refute the advantages of WS? ...or am I misreading what you're writing?
That's why I asked the question. If the 2nd spark is igniting during the 'off' cycle then what is the advantage?
I'm sure I'm missing something fundamental.
That's why I asked the question. If the 2nd spark is igniting during the 'off' cycle then what is the advantage?
I'm sure I'm missing something fundamental.
#29
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The point that I was working on is that there is no advantage to the actual ‘wasted spark’ spark – the second spark does nothing. Its there because one coil pack is firing two cylinders. With the electromotive set up you could go to individual coil packs – if you add a cam sensor.
The fundamental reason for the ‘wasted spark’ arrangement is that your engine management system does not know if the engine is on the intake or exhaust stroke – you need a cam sensor to know that. So John’s wasted spark (and the basic Electromotive system) has to fire the injectors and spark plugs on both the intake and exhaust strokes.
The name is the best description – wasted spark. The second spark is wasted (no advantage)….
The advantages –
No distributor or rotor
Twice as long dwell time (charge time) for each coil
Runs without adding a cam sensor
Disadvantage –
Not full sequential (this would add a bunch more cost!)
#30
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wasted - serving no useful purpose; having no excuse for being;
The system gets its name "wasted spark" because the fire on the exhaust stroke serves no purpose or wasted.
I cannot believe the "wasted" portion is needing so much wording!!!!!
Chris, don't tempt me! The idea of getting the ignition switched to full sequential crossed my mind. Of course, the cost may become a issue.
The system gets its name "wasted spark" because the fire on the exhaust stroke serves no purpose or wasted.
I cannot believe the "wasted" portion is needing so much wording!!!!!
Chris, don't tempt me! The idea of getting the ignition switched to full sequential crossed my mind. Of course, the cost may become a issue.