Connorhvb Posted December 7, 2020 Share Posted December 7, 2020 Hello everyone, Im new to this forum, and i had a question regarding the ignition system. I would really like to know how the ignition system works because i want to instal a custom iggnition/efi system(for now i want the ignition only) with vw coil on plugs. Now for this to work I was told that these system needs a cam trigger input in order to use it on a odd firing engine. Now is my question how does original ICM know when to fire in the correct sequence when the triggerwheel rotates twice when both cams rotate once, if i know how they managed to do this I might be able to imply this on the custom ICM greeting Connor Link to comment Share on other sites More sharing options...
Jeffo Posted December 8, 2020 Share Posted December 8, 2020 They have pulse generators at the RH end of the crank outside the starter clutch. The plugs fire every revolution of the engine. Lost spark system Link to comment Share on other sites More sharing options...
Connorhvb Posted December 8, 2020 Author Share Posted December 8, 2020 @Jeffowould you perhaps know wich coils fire at the same time due to the 2 pulse sensors Link to comment Share on other sites More sharing options...
Connorhvb Posted December 8, 2020 Author Share Posted December 8, 2020 @Jeffo i think i have to come back to you aboit that one because i'm almost certain that i figuered it out, There are 2 cylinders 180 degrees opposite each other, right? Then 2 others that are also 180 degrees opposite each other, but have an angle of 90 degrees to the previous pair. So you send a signal from sensor 1 to channel A. Then 180 degrees later to channel B. Sensor 2 does the same. But this one is at an angle of 90 degrees and does channel C and D. Because the ignition is an digital system it can count the tooth on the pulse generator, therefore cylinder 1 and 3 wil controlled by sensor 1 and wil fire once every 180° cycle and the same for cylinder 2 and 4 with sensor 2 none the less wil this way of ignition fire during a exhaust stroke much like with a wasted spark ignition but they will fire individually. I made a drawing to explain what in mean. Let me know what you think Greetings Link to comment Share on other sites More sharing options...
Member Contributer jefferson Posted December 8, 2020 Member Contributer Share Posted December 8, 2020 I may be wrong, but don't these bikes have a coil for each cylinder? I was thinking they did even though it is a wasted spark system. Link to comment Share on other sites More sharing options...
Connorhvb Posted December 8, 2020 Author Share Posted December 8, 2020 Yes that is correct, it has every cylinder has its own coil. But i also made a similar drawing of a wasted spark ignition but it does not seem possible with this enigne cycle. Link to comment Share on other sites More sharing options...
Connorhvb Posted December 8, 2020 Author Share Posted December 8, 2020 Im going to instal the new ecu later this week. this system wil only work with one pickup so i will learn the ecu to fire once every 90° turn of the crank with the information from the pulse generator, so now i can run the VW coil on plugs and will be able to fully adjust the timing and curve of my ignition. Link to comment Share on other sites More sharing options...
Smack Posted December 9, 2020 Share Posted December 9, 2020 I am interested to see if you can get this to work. Adjustable ignition timing could be useful. Link to comment Share on other sites More sharing options...
squirrelman Posted December 9, 2020 Share Posted December 9, 2020 1 hour ago, Smack said: I am interested to see if you can get this to work. Adjustable ignition timing could be useful. and it could damage the engine if timing wasn't accurate. seems like alot of complication for very little possible advantage. isn't the optimum advance curve built into the black box ? Link to comment Share on other sites More sharing options...
Smack Posted December 12, 2020 Share Posted December 12, 2020 Not if one is changing fuel types. C'mon man, think outside your box. Link to comment Share on other sites More sharing options...
Member Contributer DannoXYZ Posted December 16, 2020 Member Contributer Share Posted December 16, 2020 Yeah, factory ignition-curves are typically tuned for lowest-octane you can get at pumps. By advancing ignition couple degrees, you can get more power using higher-octane fuels. I did this on my '86 VF500 by using the trigger-wheel off '84-85 engine. The actual TDC trigger-tooth is advanced by about 5-degrees on earlier bike. Another way to do it is to slot the mounting-hole for pickup-sensors. Then you're able to slide sensors couple degrees towards advanced side. Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted December 23, 2020 Member Contributer Share Posted December 23, 2020 FWIW, Factory Pro Racing once sold ignition advancers (different trigger wheels) for RC36 VFRs, but they stopped selling them at some point because they really didn't make much of a difference on this engine. If someone with as much dyno experience as Marc Salvisberg said that, I'm inclined to believe it is true. Ciao, JZH Link to comment Share on other sites More sharing options...
CharlieFoxtrot Posted December 28, 2020 Share Posted December 28, 2020 Here's a conversation I had with Marc Salvisberg earlier this year, FWIW: Me: Hi! Do y'all still do ignition advance modifications for VFRs? I have a 1990 VFR750. Marc: Not anymore. Try Ignitec Me: Thanks, I just emailed them. Is the modification complicated for a machine shop to do? Would you be willing to tell me the procedure? Marc: The way I did it involves a lathe, an oxy/acetylene torch, high nickel content brazing rod, a specially shaped punch, some math and a hammer. The Ignitec is nicer. Me: Super, thanks! Marc: Keep in touch! The VFR liked about 4 degrees more advance. Link to comment Share on other sites More sharing options...
Member Contributer DannoXYZ Posted December 29, 2020 Member Contributer Share Posted December 29, 2020 Hahahhahahh!!! Modern hot-rodding is done with electronics and software!!! 🙂 Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted December 29, 2020 Member Contributer Share Posted December 29, 2020 All I can tell you is what he told me, nigh on 20 years ago... Here's Ignitech: https://www.ignitech.cz/en/ Looks interesting, and (if I'm reading the price list correctly) under $200. Ciao, JZH Link to comment Share on other sites More sharing options...
Member Contributer DannoXYZ Posted December 30, 2020 Member Contributer Share Posted December 30, 2020 That's pricey for maybe 3-5hp gain. For another $100, you can get Megasquirt ECU and have finer control with 3D mapping of both fuel & ignition. And you get wideband auto-tune, datalogging, knock-sensor, map-switching and bunch of other features too. Much more power to be had with ECU replacement. While peak-HP won't increase significantly, you can improve mid-range and partial-throttle response to where bike feels much lighter and more nimble. On older tech, there's more to be had. Several decades ago, I had Porsche tuning shoppe. I was able to get +40% more HP out of '80s 2-valve Porsches using just chip-mapping alone! On more modern 4-valve engines, biggest gains start on inside with big-bore high-compression pistons, fully-radiused valve jobs with bigger valves, porting, aggressive cams, and ECU mappings to tie it all together. This too will give you +40% bump in power. Link to comment Share on other sites More sharing options...
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