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Radar71

How does the FZ07 not need a camshaft sensor?

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Radar71

Hello all! Me and my race team are planning to re-purpose an fz-07 engine for a Formula SAE car. We are going to run an aftermarket ECU and as we were analyzing the motor and the wiring diagram we realized there is no camshaft position sensor, only a sensor from the crankshaft that is part of the AC magneto. Given that the FZ-07 crankshaft is crossplane a wasted spark system would not work here so we were wondering what Yamaha did to figure out which cylinder is on its intake cycle and thus which coil needs to be fired. Any ideas or discussion on how this bike and similar bikes operate without a camshaft position sensor and a crossplane crank would be great!

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r1limited
10 hours ago, Radar71 said:

we were wondering what Yamaha did to figure out which cylinder is on its intake cycle and thus which coil needs to be fired

They engineered it.

  • Haha 1

“Laws that forbid the carrying of arms disarm only those who are neither inclined nor determined to commit crimes.” --Thomas Jefferson quoting Cesare Beccaria

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cyow5

Misfire detection works by looking for changes in crankspeed, so you could use the same idea to see when cyl #1 is under compression (the crank will spin slower than when it is on the exhaust stroke). This is just an educated guess though. 

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twf

Intake air pressure sensor tells computer which cylinder needs to fire. 

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cyow5
55 minutes ago, twf said:

Intake air pressure sensor tells computer which cylinder needs to fire. 

Are you positive? My experience has been that MAP is not useful at such a low rpm because the manifold is not yet pulling a vacuum. 

 

Edit: The more I think about it, my experience with MAP and ITBs has usually had a pressure port at each ITB and then the MAP sensor was reading the average, so it was very unsensitive to pulses on purpose. For our bikes, I could see how that would probably work though. 

Edited by cyow5

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r1limited
19 minutes ago, cyow5 said:

Are you positive?

I question that too.  because if the degree of pressure equals or is greater than the degree of vacum then the firing order is in flux.  This is due to the amplitude of the ingiitions inability to rate a higher coefficient side draft from the balance resonator in the flux capaciter.  Another words not enough jiggawats


“Laws that forbid the carrying of arms disarm only those who are neither inclined nor determined to commit crimes.” --Thomas Jefferson quoting Cesare Beccaria

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shinyribs

 There's no variable valve timing on these motors, so the cam is always in the same relationship to the crank. You could still use a cam sensor if wanted, but it's not necessary to have a cam and crank sensor together in this situation. 

 

I'm very interested in the air inlet pressure sensor discussion. I'm not arguing that idea, I just can't wrap my head around it and would like to learn more. 

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twf

When you cranking bike it is wasted spark. Once it fires IPS detects it and computer switches to spark only when needed. 

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cyow5
35 minutes ago, shinyribs said:

 You could still use a cam sensor if wanted, but it's not necessary to have a cam and crank sensor together in this situation. 

The issue is that, on a four stroke, the crank sensor cannot tell the difference between TDC compression and TDC exhaust, so cam sensors are used to tell the difference. After that, they are dead weight. 

 

@twf not saying you are wrong but just curious - do you know for a fact or are you taking a guess? Again, this probably sounds more offensive than I intend, so don't take it that way. 

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shinyribs

@cyow5 I haven't had my bike apart to know what's inside, but I understand what your talking about. Yes, the crank sensor can't determine TDC from BDC, which is why we have wasted sparks on typical distributor-less ignitions. I know you already know this.

 

But being crossplane doesn't mean wasted spark can't work. Instead of one trigger being fired every 180° you can have two seperate pickups being triggered every 270° , or 90° depending on how you want to look at it. 

 

I don't know if these bikes use a magnetic pulse trigger, or even an optical trigger. I really don't have a clue and don't want to suggest I know how these bikes fire, but I do know that a cam sensor isn't required in conjunction with a crank trigger unless VVT is being used. 

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twf

Go to svrider.com and do search for it. When I told them it is ips somebody did some tests to find out. 

 

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cyow5
22 minutes ago, twf said:

Go to svrider.com and do search for it. When I told them it is ips somebody did some tests to find out. 

 

It should be made clear then that you are guessing the FZ07 and SV both use the same logic. Probably a good guess, but not definitive. 

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cyow5

I just checked - my '17 just cranked up twice without the IPS connected, so that is not how it determines phase unless it has a backup algorithm looking at crank speed. If that's the case, it doesn't make sense for there to be two algorithms, so I'm going to cast some doubt on the theory that it uses the same logic as the SV. 

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twf

It will run without it connected. Probably in safe mode firing every revolution.

Try connecting ips to other cylinder. 

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Powernut

Sorry to add . I've a issuise with getting my bike running mt07 2016 

Spent months. Still carnt work out why or what issuise is 

Good compression

Good spark

Good feul prime

And fuel injectors injecting fuel

Yet wont attempt to fire or backfire .

If I pop fuel into the rear of throttle bodies it will start run then die . Which possibly points to fuelling. 

Yet I removed throttle bodies  .(away from bike and extended  the coil and plug  went to crank and it set fuel alight..

So why the hell dosent it fire when injecting fuel... it will crank and crank and nothing .  Sure if timing was out it wouldn't start by putting fuel in carbs??

It's like possibly injecting fuel at wrong time.only thing I've not connected is the abs pump rest is connected. Ie sensors earths lives wireing conectors immo system..

Anyone ever come across this or possibly help advise issuise also tryed another fuel pump and ECU kit 

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