Myles Posted July 8, 2006 Share Posted July 8, 2006 here They've replaced* the £200+ ACES unit in my car - so far, I'm very happy with them. Not sure that there is a UK distributor yet (Aussie product), but mine cost me *Yep, the ACES will be for sale if the Shift-i continues to perform. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
shn7 Posted July 9, 2006 Share Posted July 9, 2006 Looks excellent and at a decent price. Keep us informed Myles. Steve. Not forgetting Percy the Polar Bear Link to comment Share on other sites More sharing options...
mav Posted July 9, 2006 Share Posted July 9, 2006 I've done a little investigation with the guys in Oz, and they all say this is an excellent product with 1st class support. Link to comment Share on other sites More sharing options...
Chris W Posted July 9, 2006 Share Posted July 9, 2006 Having read the installation manual, two thoughts occur to me. These thoughts are based on the fact I have designed and built my own set of shiftlights so I understand the different options available to measure the rpm circuit-wise. 1. It appears that the unit is calibrated against the tacho, viz: according to the installation manual, one has to adjust the shift-lights to match the tacho readout. The problem on a lot of (most) 7's is that the tacho is notoriously inaccurate and so the shift-lights will be wrong too. The manufacturers have this issue because they are NOT using pulse counting to measure the rpm (as they state themselves in their marketing material). But the only way to get a truly accurate rpm measurement is to count the pulses over a predetermined period (a fraction of a second). I would guess they are using an "integration" method to determine revs, viz: the higher the number of input pulses, the higher the average voltage input and the higher the average voltage the higher the number of LEDs that are lit. This is why, I presume, they are having to incorporate an "anti-flicker" adjustment for when the average voltage is hovering around the next trigger-point. 2. No mention is made of how one uses them with normal and/or wasted-spark ignition. Wasted-spark ignition will give twice as many pulses for any particular revs and therefore provision needs to be made to allow for this. I am assuming that most bikes (which seem to be their target market) are probably wasted-spark so the unit may be OK with say K-series 7's, which have wasted-spark ignition, but will read at half rate for normal ignition engines. As I say, I can find no mention of this in their documentation. Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
mav Posted July 9, 2006 Share Posted July 9, 2006 Unfortunately we are not all wizard electronics experts like yourself, so rely on others to help out. I'm quite happy with the info I have from Owners in Oz that this sytem will work perfectly well with my car, and at 60 ish quid probably chaper than anything available over here ❗ Link to comment Share on other sites More sharing options...
Chris W Posted July 9, 2006 Share Posted July 9, 2006 Mav I wasn't trying to be a smart-arse, as your veiled sarcasm implied, but in fact I was indeed trying to help you by asking what I thought were 2 very relevant and important questions. £60 is a good price so long as it functions to your expectations. Most people want shift-lights to replace the (inaccurate) tacho read-out not just to get an LED copy of it. And the normal/wasted-spark issue is a real one. It won't work with both automatically. It doesn't know it should ignore half the pulses unless there's some way of telling it and there's nothing in the documentation about spark systems. Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
Myles Posted July 9, 2006 Author Share Posted July 9, 2006 Chris - agree with the first point - but if you are changing gear at the moment based on the rev-counter, what is the loss....? I have two alternative methods of calibration - the output from the Emerald and the ACES (I'd bloody-well hope that the ACES LCD readout is accurate given the price...) Second-point - this unit does have a calibration thingy that can be used to halve/double/whatever the output. It isn't as 'clean' a setup as the ACES (i.e. you tell the ACES how many cylinders/coils/whatever you have) - but it will work. So-far, so-good. Horses-for-courses. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
mav Posted July 9, 2006 Share Posted July 9, 2006 I wasn't trying to be a smart-arse, as your veiled sarcasm implied Wasn't implying anything, sorry if it came across like that. I'm no electrical expert, and whilst I understand that I need to be careful with the way the thing is set up, I am just after a more visable shift light other than the one in the tacho. Have you developed your system further, or can you make it available to us, at a simliar / reasonable price. I'd be tempted by your offering if it was similarly priced... Edited by - mav on 9 Jul 2006 23:09:22 Link to comment Share on other sites More sharing options...
Chris W Posted July 9, 2006 Share Posted July 9, 2006 Mine works by pulse counting so is totally accurate. It can be set up for any rev range and each LED can be set to any rpm setting. They don't have to be equally spaced in rpm value, although most people want it that way. There is a jumper to select normal or wasted spark and a second jumper to select all LEDs flashing at max revs or not. The LEDs can be manually dimmed too (the auto-dim on the Aussie one is a neat idea and not difficult to implement so I may do that). However, I build these just out of interest as I really enjoy circuit design, and not for profit, so I can't match the £60 price because I only make a couple of dozen total. There is a tremendous amount of work and time involved in individually printing, etching and drilling the circuit-boards and then soldering in the components and then testing each unit in-situ. So no chance of coming close on price - I would need 100's to do it commercially. I spent a lot of time designing the unit and indeed, at first, I used a similar method to the one that I believe the Aussies are using. It worked really well but eventually I scrapped it and redesigned it using a microprocessor to pulse-count, because I wanted accuracy and stability just from a pedantic circuit-design point of view. It was a very interesting intellectual exercise to figure out how to do it. Since it worked, I offered it to club members but had no visions of selling more than a handful. Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
mav Posted July 9, 2006 Share Posted July 9, 2006 Ok. Thanks for the update Chris . What's the damage to the back pocket for one of your systems then? Link to comment Share on other sites More sharing options...
Chris W Posted July 9, 2006 Share Posted July 9, 2006 The "CatShift" is £100. Even at that price I'm barely above minimum wage once you deduct the price of materials and components. It takes me a day to produce the circuit board, then build and test one from scratch. But you do get first class customer-service for that price!! One member, who has just bought one, had a really neat idea. I will be supplying the (9) LEDs on a separate circuit board connected to the main unit box by a flying lead, rather than incorporated into the box, so that he can mount them directly into the dashboard with the box itself hidden underneath. Chris Edited to say: I forgot to mention that the LEDs are 3 green, 3 yellow and 3 red 2003 1.8K SV 140hp see it here Edited by - Chris W on 9 Jul 2006 23:49:45 Link to comment Share on other sites More sharing options...
Jason Plato Posted July 10, 2006 Share Posted July 10, 2006 over what rpm range do the leds on the Shift i illuminate ? and is this range adjustable ? and isa it water proof ? looks good Myles . here is C7 TOP South Wales AO Link to comment Share on other sites More sharing options...
MartinWoodham Posted July 10, 2006 Share Posted July 10, 2006 Chris, having read the manuals as well, the unit isn't referenced to the rev counter (II read it C), it's initially set to 1000 rpm and button presses can change this in 250rpm increments. (Increment steps can be changed as well) So it probably is pulse counting, and whether the ingition is wasted spark or not is immaterial, the thing is just counting pulses and lighting the appropriate number of lights. I'd be very surprised if the tacho drive signal were any different between wasted spark and conventional systems. Why would an ecu give a double-rpm signal as a tacho drive just because the engine's running wasted spark? Looks like a good system and seems to work on Myles car - Myles, did you just buy it off the website? Martin Roadsports B with upgradeitis Link to comment Share on other sites More sharing options...
mav Posted July 10, 2006 Share Posted July 10, 2006 Dave, over what rpm range do the leds on the Shift i illuminate ? User programmeable and is this range adjustable ? Yes and isa it water proof ? seeing as it is designed originally for Motorbikes, then I'd assume so... Link to comment Share on other sites More sharing options...
Jason Plato Posted July 10, 2006 Share Posted July 10, 2006 ahhhhhhhh here is C7 TOP South Wales AO Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 Martin The unit is not pulse counting because the manufacturers state it is not. The set-up manual instructs you to match the reading on the tacho and so it does appear to use the tacho as the "reference". I'd be very surprised if the tacho drive signal were any different between wasted spark and conventional systems. Why would an ecu give a double-rpm signal as a tacho drive just because the engine's running wasted spark? Trust me - the wasted-spark systems give twice as many pulses per cycle because they're producing a spark on the power stroke AND the exhaust stroke - hence "wasted" spark. That's why, on my design of shiftlights, there is a jumper option for normal or wasted-spark. If you set this option incorrectly the shiftlights would read either twice as high or half as high in revs depending which way round is incorrect. This option is also present on the standard Caterham tacho too, for the same reason. The reason why wasted-spark systems works like this is that it makes the coil electronics and spark distribution much simpler if you produce a spark on every other stroke per cylinder rather than on every 4th stroke (the power stroke) per cylinder as in "normal" ignition. Thus you get a spark on the power stroke AND the exhaust stroke (although the latter contributes no power) but the tacho doesn't know the difference and just integrates pulses. Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 Myles and is it water proof ? seeing as it is designed originally for Motorbikes, then I'd assume so... They state it's "splashproof" rather than "waterproof" which they say means it must be operated behind a windscreen. I suspect this is the same as all shiftlight units. Chris 2003 1.8K SV 140hp see it here Edited by - Chris W on 10 Jul 2006 09:53:37 Link to comment Share on other sites More sharing options...
MartinWoodham Posted July 10, 2006 Share Posted July 10, 2006 Chris, I'm familiar with how wasted spark works. Whilst it gives double the number of pulses *to the coils* there's no reason for it to double the tacho signal as well. Although if it does, changing rpm setting on the shifti unit can obviously adjust this out. I didn't spot a reference to the unit not being pulse counting. Ref referenced to tacho, read it again. They recommend an initial check to see whether the first led lights at 'around' 1000 or 2000 rpm (the difference down to wasted spark or not?), then all adjustments are made without reference to tacho - it's all increments via push button, with (default) 250 rpm steps from a base of 1000 or 2000 rpm. Martin Roadsports B with upgradeitis Link to comment Share on other sites More sharing options...
MartinWoodham Posted July 10, 2006 Share Posted July 10, 2006 *arrowup*"you don't have to rev the engine to set these points, in fact you can change them with the engine off" Martin Roadsports B with upgradeitis Edited by - mwoodham on 10 Jul 2006 10:16:33 Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 Martin I'm familiar with how wasted spark works. Whilst it gives double the number of pulses *to the coils* there's no reason for it to double the tacho signal as well. The K series is wasted-spark and the ECU does give double the number of pulses to the tacho. eg: at say 3000rpm one would expect to measure a pulse rate of 50Hz. If you connect a scope (or a multimeter that measures frequency) to the tacho input you will read 100Hz on the meter for a K-series and 50Hz for a normal ignition 7 variant. I didn't spot a reference to the unit not being pulse counting.it's on their website under FAQ's and states: "The RPM measurement algorithm does not use the basic pulse counting technique, or frequency to voltage converters. The RPM is digitally calculated per pulse!" I assume what they mean by "digitally calculated" is that they gate a timer to start on the leading edge of each pulse and end the timing on the leading edge of the next pulse. The electronics calculates the reciprocal of the time between pulses which is of course the frequency of the pulse input . (Due to wasted-spark considerations, this is not necessarily the same as engine revs so it's still not clear to me how they are overcoming this). This pulse timing technique would also explain the "sensitivity" adjustment they have. Since an engine can never exactly hold a set frequency (rpm figure) a measurement based on every single pulse would hunt up and down very rapidly, so I assume that by tweaking the sensitivity control, what one is actually doing is telling the electronics how many pulses to ignore before it makes a new measurement to average out the reading. Just a guess but I would bet that's what's happening. Please don't get me wrong Martin, I'm not trying to rubbish this piece of kit. It looks a really good buy at £60. I'm just exploring the in-and-outs in more detail as I do have some electronics knowledge in this area. I'm not trying to sell you one of mine instead - I can only make a handful anyway as I am not set up to do a production run and I don't make any real money on them anyway even at a much higher price. It's just that something that seems too good to be true, often is and I'm just trying to help everyone with some pertinent questions. Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 I have emailed the Shift-i people in Australia to ask about how they cope with wasted vs normal spark ignition as I am only surmising so it's better to get it from the horse's mouth. I have asked them: "Enquiry: ------------------------------------------------------------ How does the unit cope with "wasted-spark" ignition which will produce twice as many pulses-per-second at the tacho input as compared to "normal-spark" ignition? How does one correct the reading when setting up a wasted or normal spark installation? Thanks Chris" ------------------------------------------------------------- Chris 2003 1.8K SV 140hp see it here Edited by - Chris W on 10 Jul 2006 11:05:00 Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 Wow.......... I have had a response back from Shift-i almost immediately - the guy must have a laptop in bed! It appears they do indeed have an adjustment to correct for pulses-per-sec (although I can't spot it in the installation instructions). Their response to my question above is: --------------------------------------------------------- Hi Chris, It has no problem with operating on a wasted spark ignition setup. You can easily set it for 0.5, 1, 1.5, 2, 2.5, 3, 5, 6 & 8 pulses per revolution. Cheers, Tony ----------------------------------------------------------- Being able to set the pulses-per-revolution means that it can also cope with a wide range of cylinder numbers as well. There you go - solved Chris 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
mav Posted July 10, 2006 Share Posted July 10, 2006 It is in the user guide. I'll dig out the relevant section tonight when home if you like... Link to comment Share on other sites More sharing options...
Chris W Posted July 10, 2006 Share Posted July 10, 2006 Yes, thanks, I have found it now. It's in the User Manual and I had been looking in the Installation Manual. 2003 1.8K SV 140hp see it here Link to comment Share on other sites More sharing options...
mav Posted July 10, 2006 Share Posted July 10, 2006 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now