Hey Everyone!
New to tuning and just have a quick question for you all, when looking at the data logs for knock through the tuning software, how much knock is acceptable under WOT?
Also, is it more important to monitor and treat knock when the engine is under a higher load? Thanks!
When I realized that my project saws' flywheel keys were not part of the flywheel, but these lil ~$5 metal wedges that protrude from the shaft, I immediately ordered a flywheel-puller and some woodruff-keys so I could 'mess around'
Problem is, I'm not positive what to be looking-for in my testing, I usually "benchmark" by seeing if something cuts faster but it seems there's more from timing-advances (for instance, throttle-response is frequently cited as a benefit)
I happen to know that for my particular saw, 20 thousandths off the key is "a norm", and I actually am working a pair of these saws right now so I figure I'll shave about 15 thou from one key, 25 from another, and begin experimenting -- but am eager to learn anything I can on this, including:
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fuel efficiency, any significant changes?
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is this a "snappy/RPM" trade-off against torque (kinda like raising exhaust-roofs)? I ask because, insofar as I understand power generation in a cylinder, optimizing power would mean that the highest moment of compression is when the piston is starting its downward travel -- advancing the timing "too much" would automatically pull your combustion event earlier into the rotation than is optimal (and advancing it too far would have pre-ignition which would have your piston basically reaching a flame-front while still trying to reach TDC!)
Thanks a ton for insight, am happy to trial&error but just want a better idea of what I'm even considering...I just know/expect that the oem-spec timing is not 100.0% optimal for my custom/ported units!
The gas turns on at the same time as the igniter, so as the igniter gets hot enough to light the gas, there is enough gas released to cause an audible bang. So, there’s a mini explosion every time the furnace turns on. At first, I cleaned the gas injectors(no idea what they’re called), but that didn’t help so I actually watched what was happening. Any solution to this problem? Much appreciated! Edit:video added Ignition Video
I have set the base timing to 8 degrees BTDC on cylinder one, and followed the firing order around the dizzy. it backfires through the carb I think on two cylinders. If I unplug cylinder 3 from the dizzy, the loud one goes away, but there's still a quieter backfire on another cylinder. The vacuum advance is pointed into the firewall on the driver side, and it's an HEI dizzy. Once this is solved, I can break in my cam and roll around in this thing.
I tried posting in r/chevy, but no one bothered to give some feedback.
i’m in the late stages of tuning my fcr41 swapped vtr1000f and she’s running really well, air fuel ratios are looking spot on but i feel like she’s missing out on a little bit of power and it might be due to me not having the tps attached. the bike is supposed to be 15 degrees btdc timing at idle and 42 degrees btds at 9500 rpm. iv heard of a lot of people disconnecting the tps on their yz450f’s before and just relying on rpm to control timing advance so i assume most carbureted engines will default to rpm only ignition advance, is that thought true enough? with no tps will the cdi unit still give me the majority of the ignition advance
the reason it’s not plugged in yet is because the fcr41 has a different tps mount and the tps on the fcr is a much higher ohm range than the stock tps, also i kinda broke the stock tps so i need to order a new one and try to get it mounted onto the fcr carb
another thought i was having was that a tps is just a potentiometer used as a voltage divider, so it shouldn’t matter too much that the ohms are different on the fcr’s tps because the voltage fed into it will still be 12v and ground so the output voltage should be the same no matter what tps is used. that might be a dumb idea but im not as well versed with electrical engineering as some so any help is appreciated
do i really need the tps to advance timing or is rpm ignition advance good enough, can i splice in a higher ohm range tps and will it work the same since the ignition controller is only reading a voltage not a resistance, and does anyone have a spare tps for a cb919, cb900f, hornet 900, or vtr1000f (they all used the same tps, and some old honda civics used it too)
I purchased this electronic ignition kit from 4into1.com, and I am having issues setting the timing. I reached out to the company but they said they don't offer technical assistance (which is reasonable for a retail store) but they said there is no manufacture contact info and its just a generic branding made in Taiwan.
My static timing is set perfectly for full advanced following the instructions, however when I use a timing light my idle is perfect but my advanced timing is off.
I have maxed out the counter clockwise rotation of the electronic board and cannot adjust it further.
Spark advancer has been cleaned and properly lubricated with no binding or stiffness. It moves smoothly.
Does anyone have experience with this electronic kit? Any suggestions on fixing? It runs ok but I'm not sure about potential damage.
Mark when idling using a timing light (Demonstration purposes)
Mark when >5000RPM using timing light (Demonstration purposes)
I want to use my Arduino to read the resistance change from a hall-effect pickup that feeds to a CDI box. I found a project for that:
https://create.arduino.cc/projecthub/iasonas-christoulakis/how-to-make-an-arduino-ohm-meter-90fda8
Seems pretty straight forward.
The next part would be to read the voltage over time on the output of the CDI/Ignition box that feeds the primary (12VDC) side of the coils.
This shows how a coil works, seems pretty straight forward, it supplies 12V to a coil, the removes it. When it's removed a spark is generated on the secondary side.
https://www.youtube.com/watch?v=lWyn_eV-DzM
So, best I can figure, it supplies 12V all the time, until it wants a spark, then it removes the current for a period of time.
I just need to verify the input and the output so that I can test the ignition box to see if it's triggering the coil and if it's getting the input.
I would have to read this at a certain speed range (sampling rate) and I have no idea what that is, but I can make it a variable that I can change interactively (I hope).
I wouldn't be reading the secondary side because the voltage is far too high and I have a light made for that.
I have no idea how fast an Arduino can poll a feed, it's the Mega 256 if that matters and I'm thinking of a pretty simple loop that would just poll and display 3 feeds, 1 input, 2 outputs and then check for up/down adjustments for scale.
This would be use to test an ignition box at first, then maybe later an engine control box. It doesn't have to be fast enough for higher RPM work, as I can move over to a faster chip setup later if I need to, this would just be a prototype.
Update the first part of this reading the resistance it's bouncing all over the place I don't know if I need to smooth it or if I hook something up wrong is there anyway to get a smooth reading?
i’m in the late stages of tuning my fcr41 swapped vtr1000f and she’s running really well, air fuel ratios are looking spot on but i feel like she’s missing out on a little bit of power and it might be due to me not having the tps attached. the bike is supposed to be 15 degrees btdc timing at idle and 42 degrees btds at 9500 rpm. iv heard of a lot of people disconnecting the tps on their yz450f’s before and just relying on rpm to control timing advance so i assume most carbureted engines will default to rpm only ignition advance, is that thought true enough? with no tps will the cdi unit still give me the majority of the ignition advance
the reason it’s not plugged in yet is because the fcr41 has a different tps mount and the tps on the fcr is a much higher ohm range than the stock tps, also i kinda broke the stock tps so i need to order a new one and try to get it mounted onto the fcr carb
another thought i was having was that a tps is just a potentiometer used as a voltage divider, so it shouldn’t matter too much that the ohms are different on the fcr’s tps because the voltage fed into it will still be 12v and ground so the output voltage should be the same no matter what tps is used. that might be a dumb idea but im not as well versed with electrical engineering as some so any help is appreciated
do i really need the tps to advance timing or is rpm ignition advance good enough, can i splice in a higher ohm range tps and will it work the same since the ignition controller is only reading a voltage not a resistance, and does anyone have a spare tps for a cb919, cb900f, hornet 900, or vtr1000f (they all used the same tps, and some old honda civics used it too)
