Peter Carmichael Posted July 21, 2007 Share Posted July 21, 2007 I've been playing. I've got a new wiring loom, hooking up an EFI-Tech Euro-1 ECU (refreshingly low tech and secondhand) to my K-series. I've scoured the manual and examined the pinouts to work out exactly what combination of features I can bring to bear on proceedings. The ECU has two outputs that can be set to one of a selection of output criteria. I've currently got it rigged so that... ... one of the outputs runs a radiator fan relay (obvious really) ... the other output runs as a shiftlight... only I've connected it to the programmable input that runs the power shift function This allegedly means that when the revs trigger the shift light, I will get a 60ms cut in ignition and I'll just need to be leaning on the sequential gear lever for the next gear to slot in (I've tested it at fartaround revs and it works). What I can't tell is whether this functionality is actually going to be of any use and whether it will become second nature to use, as opposed to the normal setup of a strain gauge. I can see that upchanges will require two different techniques depending on whether it is a power shift at full chat or a normal shift. My reasoning for setting this up was purely to experiment as it has cost about 5 minutes of setup time and insignificant cost to give it a try. Comments? Link to comment Share on other sites More sharing options...
metal mickey Posted July 21, 2007 Share Posted July 21, 2007 Sounds good but won't it cause extra wear on the selector forks if you have to 'ride the stick' waiting for the upshift ignition cut - that is unless you can wire in a pre shift signal light maybe to give you a heads up for the next change 🤔 60ms shift sounds very fast. Link to comment Share on other sites More sharing options...
Julian Thompson Posted July 21, 2007 Share Posted July 21, 2007 Peter I'm with Mike on this -these shifts are very quick indeed and I just don't see you being able to use that with any accuracy given that the ignition will cut automatically. I think you need an actuator that will be fired by the trigger? It's a suck it and see, of course. Link to comment Share on other sites More sharing options...
rj Posted July 23, 2007 Share Posted July 23, 2007 Peter, I think the power cut needs to be initiated by the gear change, not the gear change to be initiated by the power cut. Regardless of how fast you respond I doubt that you'll make it within the 0.06S /regin Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 23, 2007 Author Share Posted July 23, 2007 OK, those are three opinions telling me it won't work and I am listening. I'll just add these considerations... 1. My long-practised operating procedure is to lean on the lever and momentarily feather the throttle. This is obviously how most motorbike clutchless upshifts are achieved and works fine and is quick. Power shift functionality will just keep the established airflow in the engine, which should see a marginally quicker return to full power. 2. I've implemented the shift light/power shift hook up through a "jumper plug", so I can unplug it and I'm back to normal. 3. The ignition cut time is programmable, so whether it is 60ms or 130ms is moot. A bit of experimenting will be required. 4. This system only triggers at shift light rpm. In normal usage you would be paying attention to rpm/shiftlights preparing for a gearshift anyway, so is it really all that different? Link to comment Share on other sites More sharing options...
rj Posted July 23, 2007 Share Posted July 23, 2007 Peter, It would be interesting to - IE by a strain gauge - log the timing of your interaction with the engine. I do doubt, but it's not impossible, that you'll be much more accurate than within 0.05-0.15 sec. On the other hand, the human ability to respond is amazing, so I may be completely mistaken... With a little luck I have a couple of strain gauges. Soldering up something with an op-amp and to connect it to a datalogger ought to be do-able, I think I've got a pile of OP07's too. Do you want me to have a look? /regin Edited because of Spelling, spelling, spelling... Why don't you all speak Danish? Edited by - RJ on 23 Jul 2007 11:25:32 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 23, 2007 Author Share Posted July 23, 2007 I might be able to come up with something simpler. I can log the raw output of the gear potentiometer which will show me how long it takes to physically slot the gear. I can log this at 100hz and I should be able to see the delay between the trigger event and the gearshift moving... If I rigged up a strain gauge, wouldn't it be worth using that as the trigger event rather than just data logging? Link to comment Share on other sites More sharing options...
rj Posted July 23, 2007 Share Posted July 23, 2007 If I rigged up a strain gauge, wouldn't it be worth using that as the trigger event rather than just data logging? Probably, but I'd just make something temporare for logging rather than an utterly reliable for daily abuse. To be honest I don't remember the logging rate of my loggers, but ISTR I've got something faster than 100Hz - you are of course free to borrow anything I have for testing. Link to comment Share on other sites More sharing options...
rj Posted July 23, 2007 Share Posted July 23, 2007 Peter, just a thought: If you've got a gearchange pot, can't you just amplify the output of it via a capacitor which would give you a spike when the leaver is moved? Or is there too much vibration / noise? /r Link to comment Share on other sites More sharing options...
Sheds Moderator Posted July 23, 2007 Share Posted July 23, 2007 Peter, if you need a longer effective ignition cut how about using the output from the ignition cut to trigger a monostable oscillator which you can configure to your own needs? It's a long time since I played with this kind of thing though. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 24, 2007 Author Share Posted July 24, 2007 BOSS, the ignition cut is programmable... but... I've already tested this (first post) and with a change point of 5000rpm it works with 60ms cut. My concerns are mostly around usability. The consensus seems to be that it won't be usable. Link to comment Share on other sites More sharing options...
MartinWoodham Posted July 24, 2007 Share Posted July 24, 2007 Peter, a couple of observations - Haven't you just implemented a rev limiter? And given the ease of taking this out, why not suck it and see? (and report back!) I appreciate you might not normally drive to the revlimiter in everyday use, but you can give it a go can't you? Like you, I can't see any difference between what you're describing and doing a clutchless gearshift on a bike, only that the shift is initiated by hitting the shiftlight threshold rather than a lift on the throttle. Martin Aero'd supersported ex-Roadsports B...anyone got a cheap LSD? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 24, 2007 Author Share Posted July 24, 2007 Haven't you just implemented a rev limiter? Indeed. The thought process began by considering changing gear when the revs reached a traditional rev limiter. The benefit of this approach is that I can drive through the 60ms cut and the engine will pick up and carry on to the soft cut/hard cut limiter, allowing me to hold a gear to the end of the straight if necessary and also allowing some headroom in sixth. I appreciate you might not normally drive to the revlimiter in everyday use, but you can give it a go can't you? Well, I think that sums it up very nicely. I don't *need* a power shift function. It is almost completely useless on a road going Seven - there just aren't occasions when I am concerned about the shaving a further hundredth from my home to Sainsburys time. I guess I need to get the car on track and see if I get an extra 😬 😬 from a power shift gear change. Link to comment Share on other sites More sharing options...
Paul Deslandes Posted December 12, 2008 Share Posted December 12, 2008 Sorry to resurrect an old thread but did you get to try this out Peter? If so, how did you get on with it and did you find any worthwhile reduction in your upshift times? I thought it might help my hillclimb times (probably not but something else to play/experiment with) so I've been looking at doing something similar using a switch on the clutch, which is already there for launch control activation. Anyone else tried it with 'H' pattern box/light flywheel/race clutch etc? Paul Link to comment Share on other sites More sharing options...
caterhamnut Posted December 12, 2008 Share Posted December 12, 2008 Peter is enjoying the snow somewhere until the weekend Paul, in case you think he is ignoring you.... www.mycaterham.com here Videos here 102,000 miles car Link to comment Share on other sites More sharing options...
Paul Deslandes Posted December 12, 2008 Share Posted December 12, 2008 Thanks Angus Lucky chap, although personally I prefer warm to cold Paul Link to comment Share on other sites More sharing options...
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