Author Topic: Diesel Pulse Adapter Info Thread  (Read 77383 times)

Reply #15February 10, 2014, 03:12:10 am

Toby

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Re: Diesel Pulse Adapter Info Thread
« Reply #15 on: February 10, 2014, 03:12:10 am »
Its all relative anyway. If you are just playing with one pump on one motor, you do not need anything other than the dial indicator. If you even need that.

Set it IP timing at whatever you think is a good starting point. Stock specs are a good place to begin.

Make some Norwegian dyno runs. (Find a stretch of road that you can run flat out on through 3rd gear. Preferable uphill. Run that same stretch of road from a set speed, say 30 mph. Note your speed from some fixed point to another. Make the speed  runs and note your "trap speed".

Adjust the timing to the advanced side a small increment, and make some more Norwegian dyno runs. If things are getting better add some more initial advance. If you are getting slower take some out and do it again.

Eventually you will find the sweet spot. It will be worth your time.

Reply #16February 10, 2014, 09:39:18 am

TylerDurden

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Re: Diesel Pulse Adapter Info Thread
« Reply #16 on: February 10, 2014, 09:39:18 am »
Its all relative anyway. ...
Adjust the timing to the advanced side a small increment, and make some more Norwegian dyno runs. If things are getting better add some more initial advance. If you are getting slower take some out and do it again.

Watch out. That's close to HILLBILLY talk... and that word starts with the same letter as HERESY.

It also raises pesky questions like when does the piezo trigger?... start of delivery, start of injection, somewhere in between... how do you know?... (There can be 25 degrees of crank between the two ends.) Or, since the the piezo cannot detect needle lift, can it really detect the difference between break pressures? Not to mention the issues of combustion lag which changes with compression, engine temperature, spray pattern, fuel, etc. . Plus, piezo pickup only measures one line, so one must assume the injectors and delivery valves are matched, so timing is not based on a sole outlier, unless the flywheel is marked every 90o and each line is tested. But I digress...


Followers of Satan tune their engines based on performance.

Reply #17February 10, 2014, 10:49:01 am

libbydiesel

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Re: Diesel Pulse Adapter Info Thread
« Reply #17 on: February 10, 2014, 10:49:01 am »
The piezo adapter fires at the start of injection.  The micro-expansion of the metal line is what charges the crystal pickup and it fires it's pulse when the line starts to relax which is at the actual start of injection which precisely coincides with needle lift.  Yes, the piezo pickup DOES detect needle lift very accurately.

With an engine at normal operating temperature (which is always what you time for), the start of injection and start of combustion is very closely related.  The variations in engine operating parameters that you describe are factors with any timing method, including hillbilly.  There is also not any timing method which times for the individual injectors and trying to time the injectors individually on a VE pump would be anti-productive.  Having injectors in decent tune and as close to each other as possible in break pressure is necessary regardless of timing procedure.  The piezo pickup method DOES allow you to check the timing of individual injectors easier than any other method.  The crank only needs one additional mark at 180 on a 4-cyl 4-stroke.  It is faster, easier and less subjective than any other timing method.  Doing controlled dyno runs could certainly result in a better end result but the time and effort involved would be HUGE in comparison.  500 times the effort might result in a 1% gain?

Reply #18February 10, 2014, 10:54:53 am

rodpaslow

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Re: Diesel Pulse Adapter Info Thread
« Reply #18 on: February 10, 2014, 10:54:53 am »
I would agree to point of 'satan' as these are not usually stock engines, Not speaking for the majority, but I look for peak performance.  Since some are MTDI and usually larger nozzles than stock, stock setting are not going to be at 'peak performance'.  I think a bit of both which is what I see in this post is what needed to get extremely to correct timing.  I'm sure the diesel pulse adapter would help to confirm this.
99' 1.9 1Z Tdi, hybrid pump -1.9 housing & rover internals, 2052 wastegate turbo,.25 hflox nozzles, SDI intake, CTN tranny
96' 1.6 TD Golf, Giles pump, VNT 17, Gas changed to Diesel, Air to Water Int.

Reply #19February 10, 2014, 11:08:46 am

libbydiesel

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Re: Diesel Pulse Adapter Info Thread
« Reply #19 on: February 10, 2014, 11:08:46 am »
I have used the pulse adapter on a significant variety of pumps/injectors/engines and it will do a better job than 99.9% of the diesel  tuners out there can do with hillbilly tuning and at in an extremely small fraction of the time required.  A smart phone dyno app or G-Tech with multiple accurately controlled runs and slight timing adjustments between sets would probably return a marginally better timing spec but take vastly more time and effort.  I certainly don't feel that 'Hillbilly tuning' is wrong or bad.  It is just vastly more time consuming and labor intensive.  The subjective aspect is also a real turn-off for me and in order to eliminate the subjective aspect one would need to either use something like gTech or Dyno app as mentioned above or some other piece of equipment more expensive or more complicated than the pulse adapter or take the long-term approach of multiple tanks of fuel which has even more margin for error due to varying fuel blends, driving conditions, etc...

Reply #20February 10, 2014, 02:37:36 pm

92EcoDiesel Jetta

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Re: Diesel Pulse Adapter Info Thread
« Reply #20 on: February 10, 2014, 02:37:36 pm »
The piezo adapter fires at the start of injection.  The micro-expansion of the metal line is what charges the crystal pickup and it fires it's pulse when the line starts to relax which is at the actual start of injection which precisely coincides with needle lift.  Yes, the piezo pickup DOES detect needle lift very accurately.

......................

Is this info from the SnapOn pulse adapter manual? It would be interesting to verify  with an oscilloscope if the injection line pulse coincides with needle lift. Wouldn't be too difficult to set up on an engine with a needle lift injector. I think all TDI's have one. IIRC needle lift is on #3 cyl? Why did VW do that instead of on #1?

Reply #21February 10, 2014, 02:39:58 pm

92EcoDiesel Jetta

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Re: Diesel Pulse Adapter Info Thread
« Reply #21 on: February 10, 2014, 02:39:58 pm »
All the ones I've counted so far have 125 teeth.

IIRC, Mark in UK might have a different count on the Quantum.

Thanks for the info. I knew someone counted already. I have a spare Eco engine. When I can get to it, I will verify the count.

Reply #22February 10, 2014, 03:36:11 pm

libbydiesel

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Re: Diesel Pulse Adapter Info Thread
« Reply #22 on: February 10, 2014, 03:36:11 pm »
The piezo adapter fires at the start of injection.  The micro-expansion of the metal line is what charges the crystal pickup and it fires it's pulse when the line starts to relax which is at the actual start of injection which precisely coincides with needle lift.  Yes, the piezo pickup DOES detect needle lift very accurately.

......................

Is this info from the SnapOn pulse adapter manual? It would be interesting to verify  with an oscilloscope if the injection line pulse coincides with needle lift. Wouldn't be too difficult to set up on an engine with a needle lift injector. I think all TDI's have one. IIRC needle lift is on #3 cyl? Why did VW do that instead of on #1?

That would be great.  Please get back with the test results ASAP.  Which injector has the needle lift sensor is irrelevant to the engine management.  It just changes the one variable in the code.  I imagine they used #3 in order to most easily maintain the same metal line length.   

Reply #23February 10, 2014, 07:03:13 pm

monkey magic

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Re: Diesel Pulse Adapter Info Thread
« Reply #23 on: February 10, 2014, 07:03:13 pm »
It occurred to me some time ago that we could make a timing device that plugged into the crank position sensor and the needle lift sensor, would that be right? And what sort of 'signal' do you find if you measure those sensors? What would the device be detecting? Probably not a difficult thing to set up with an arduino i'd guess, I may have a play with this.
mTDi syncro

Reply #24February 10, 2014, 07:27:10 pm

92EcoDiesel Jetta

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Re: Diesel Pulse Adapter Info Thread
« Reply #24 on: February 10, 2014, 07:27:10 pm »
The piezo adapter fires at the start of injection.  The micro-expansion of the metal line is what charges the crystal pickup and it fires it's pulse when the line starts to relax which is at the actual start of injection which precisely coincides with needle lift.  Yes, the piezo pickup DOES detect needle lift very accurately.

......................

Is this info from the SnapOn pulse adapter manual? It would be interesting to verify  with an oscilloscope if the injection line pulse coincides with needle lift. Wouldn't be too difficult to set up on an engine with a needle lift injector. I think all TDI's have one. IIRC needle lift is on #3 cyl? Why did VW do that instead of on #1?

That would be great.  Please get back with the test results ASAP.  Which injector has the needle lift sensor is irrelevant to the engine management.  It just changes the one variable in the code.  I imagine they used #3 in order to most easily maintain the same metal line length.   

I would if I have a TDI and a pulse adapter. I have a scope though.

Reply #25February 10, 2014, 09:07:17 pm

TylerDurden

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Re: Diesel Pulse Adapter Info Thread
« Reply #25 on: February 10, 2014, 09:07:17 pm »
... the start of injection and start of combustion is very closely related. 

Hrrrrmmm.... not sure I buy that. Start of combustion is more dependent on fuel and compression. Start of combustion is regularly a few degrees after SI and that's with good compression. Low compression can delay combustion much further. Air in the cylinder needs to reach autoignition temp (~500F depending on fuel), which happens later in low compression engines.

Not sure I buy the relaxing lines bit either, but I'm open to seeing any mfr documents to 'splain that up.

As for timing individual injectors... nah. But checking each line and setting for the average... ja, I'd sure do that if I had the spendy toy.





Reply #26February 10, 2014, 10:29:50 pm

libbydiesel

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Re: Diesel Pulse Adapter Info Thread
« Reply #26 on: February 10, 2014, 10:29:50 pm »
Don't quote only half of the sentence I wrote.  "When up to normal operating temperature..."  Yes, Start of injection happens before start of combustion but once an engine has reached normal operating temp, the combustion chamber is always very well above ignition temp when the fuel is injected.  Go ahead and read up on piezo pickups and how they work.  When a crystal is compressed it stores a charge.  When the pressure decreases, the charge is released.  I'll let you spend your time to educate yourself on it if you want to.  I couldn't care less.

Reply #27February 10, 2014, 10:40:58 pm

TylerDurden

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Re: Diesel Pulse Adapter Info Thread
« Reply #27 on: February 10, 2014, 10:40:58 pm »
I'll let you spend your time to educate yourself on it if you want to.  I couldn't care less.

Blah blah.

I did just get off the phone with a pal versed in piezo and dipoles and he did clue me on the charge reversal. We've been working with triboelectrics more than piezos.

As for the combustion lag, the fact that there is a term and graphs for it indicate that it occurs even when engines are up to temp. Consider that a cylinder with 200psi will have half the temperature or less since it is leaky, and while it may reach ~650F, it will do it quite a bit later than a 490psi air charge.

But you don't have to take my word for it... lots of papers on combustion lag online.

Reply #28February 10, 2014, 11:09:34 pm

theman53

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Re: Diesel Pulse Adapter Info Thread
« Reply #28 on: February 10, 2014, 11:09:34 pm »
I would think that timing an engine with 200 psi with any method isn't going to yield the best performance. If you are trying to ride a dead horse, don't expect to win the derby. I think the spec for rebuild is around 375psi and probably most engines with those types of numbers or above will have a temp more what you are looking for to light the fuel. If you publish the paper on here we could make a chart, if there isn't one already, on what the delay vs temp is. Also, the more retarded the timing approaching 0 degrees, I would think the closer the interval between injection and combustion is. As the piston would be further up the bore and compressing the air to ignition temps. I would think that even a whipped engine with 200 psi or 1/2 of what it should have will still light the fuel when it reaches the proper temp/compression. I am just thinking in my head and have no clue about this specifically, but to me it would seem logical like this: if normal optimum injection was at 12 degrees BTDC and if it is linear, then a 1/2 compression engine would light similar at 6 or when the air is compressed equal to where a healthy engine was timed at 12? Too many factors, but it interests me, I would love to learn more, and I think it isn't something that we all couldn't grasp if explained correctly.

Reply #29February 10, 2014, 11:31:53 pm

745 turbogreasel

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Re: Diesel Pulse Adapter Info Thread
« Reply #29 on: February 10, 2014, 11:31:53 pm »
The fuel is already hot from being compressed, hot from being in the injector, and sprayed directly across the hot glow plug regardless of compression.


 

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