Member Contributer kaldek Posted May 13, 2011 Member Contributer Share Posted May 13, 2011 So.......I bought a Compufire and when I went to install it, I realized that if you mount it like the above pic's the fins are running the wrong way for cooling air flow, yes.....no? I bet they don't even get hot enough to matter. Link to comment Share on other sites More sharing options...
Member Contributer swas Posted May 13, 2011 Member Contributer Share Posted May 13, 2011 ......................................... I realized that if you mount it like the above pic's the fins are running the wrong way for cooling air flow, yes.....no? Keeping the RR at the temperature of the frame it is mounted on is more important than the effect of the airflow over the fins. Not enough heat energy could be radiated solely from the fins of these devices to keep the electronics from frying. Even though it seems the frame is hot, it will sink more of the heat from the RR than is ever cast off via the fins. Hence the importance of using a heat transfer grease between RR and frame. Once it was used to eliminate air pockets which are a heat insulator now there are some fancy products available which actually conduct heat (computer CPU goo under whatever name you find it). As well as having the linked surfaces as flat and as clean as one can get them Unfortunately at nearly 200 bucks an RR it is a bit exxy to experiment and mount one on a sheet of plastic or sheet metal out in the airstream and check it's longevity Looking forward to reports in the long term on these Series regulators. Link to comment Share on other sites More sharing options...
Member Contributer DaveB Posted May 13, 2011 Author Member Contributer Share Posted May 13, 2011 When I stop at traffic lights and put my hand on the compufire unit it is not hot at all. Link to comment Share on other sites More sharing options...
Member Contributer coderighter Posted May 13, 2011 Member Contributer Share Posted May 13, 2011 Keeping the RR at the temperature of the frame it is mounted on is more important than the effect of the airflow over the fins. Not enough heat energy could be radiated solely from the fins of these devices to keep the electronics from frying. Even though it seems the frame is hot, it will sink more of the heat from the RR than is ever cast off via the fins. Hence the importance of using a heat transfer grease between RR and frame. Once it was used to eliminate air pockets which are a heat insulator now there are some fancy products available which actually conduct heat (computer CPU goo under whatever name you find it). As well as having the linked surfaces as flat and as clean as one can get them Unfortunately at nearly 200 bucks an RR it is a bit exxy to experiment and mount one on a sheet of plastic or sheet metal out in the airstream and check it's longevity Looking forward to reports in the long term on these Series regulators. It seems the factory R/R install is not in direct, full, contact with the frame. When measured the temp of the frame and R/R after an ride, the frame is hotter. I know there's been people that have moved the R/R off the frame to below the fairing, it would be interesting to see how they do sitting still. Link to comment Share on other sites More sharing options...
Member Contributer Solomoto Posted May 15, 2011 Member Contributer Share Posted May 15, 2011 A by product of the series regulator is that the overall mpg will improve slightly (with the caveat described below). Since the engine is no longer supplying wasted power to the shunt regulator, that translates directly to less energy drawn from the gasoline under otherwise identical conditions. I'm an electrical engineer also like the OP so I can say this benefit will be realized only if the series regulator is efficient at converting the high 3 phase stator input voltage to 14V at the output. A well designed DC-DC switching regulator can achieve as much as 90 to 95% efficiency. For example: for a 100W output load, a 90% efficient regulator would take 100W/0.9 at the input, and the regulator itself would consume 100W*(1/0.9 - 1), or in other words for 100W delivered to the load, 111W is needed from the source (stator), and 11W would be dissipated as heat in the regulator itself. If the series regulator is NOT a DC-DC converter but rather a resistive pass transistor, then the overall power efficiency would be pretty much a wash compared to that of the shunt regulator, i.e. it would be dumping large amounts of power as heat. The primary difference would be the voltage vs. current tradeoff. Whereas the shunt regulator would operate as low source voltage but high current, the series resistive regulator would operate as high voltage but low current. Since power is the product of voltage and current, the net result would be close to a wash, meaning both the shunt and series resistive regulator would dump large amounts of power as heat. That said, if I were to choose between a shunt or series resistive regulator, I would choose the series resistive regulator. Why you ask? It's because high voltage/low current results in less IR losses in the wiring harness compared to low voltage/high current. This is precisely the same principle as used in high voltage power transmission over a power grid. The extremely high voltage of several hundred kV in a power grid reduces the resistive power loss in the transmission lines by reducing the current. In a bike's wiring harness, reducing the current by increasing the voltage will if nothing else reduce the likelihood of melted wires and/or connectors. A series DC-DC switching regulator is the best of both worlds by not only reducing IR losses in the transmission wiring harness, but also by greatly reducing the power loss in the regulator itself, and thereby reducing the power required from the source, which ultimately comes from the gasoline. I think one can reasonably assume that whomever designed the Compufire series regulator was well aware of the shortcomings of the shunt regulator which is used by almost every bike on the market due to it's relative low cost, and with that in mind designed it to be an efficient switching regulator. For the more mathematically inclined, you can calculate the expected mpg benefit by making certain assumptions about how much power the series switching regulator saves at a steady speed, say 65mph. Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted May 15, 2011 Member Contributer Share Posted May 15, 2011 If the series regulator is NOT a DC-DC converter but rather a resistive pass transistor, then the overall power efficiency would be pretty much a wash compared to that of the shunt regulator, i.e. it would be dumping large amounts of power as heat. The primary difference would be the voltage vs. current tradeoff. Whereas the shunt regulator would operate as low source voltage but high current, the series resistive regulator would operate as high voltage but low current. Since power is the product of voltage and current, the net result would be close to a wash, meaning both the shunt and series resistive regulator would dump large amounts of power as heat. Based on the document below, it looks like it's a switch-mode regulator. http://www.posplayr.100megsfree3.com/FH012AA_Charging/RR_Tutorial.pdf Having said that, it's marketed as a *series* regulator, which kinda infers it uses linear regulators! Link to comment Share on other sites More sharing options...
Auspanglish Posted May 15, 2011 Share Posted May 15, 2011 I just installed a Compu-fire 55402 series regulator; I bought it from Chrome-Addiction.com for $173. The unit is a little smaller than the standard Honda R&R but the mounting holes line up nicely so installation was easy. I just cut off the stator connector and lengthen the wires then connected them to the new regulator using a connector block. The unit came with 2 long and very beefy power output wires which I connected directly to the battery via the 40 amp fuse that it came with. This avoids using the old cables and connectors that everyone here on this site seems to replace with a VFRness. The regulator gave 14.25 volts at the battery and was supplying 15 amps to run the bike and charge the battery i.e. much less that the 40 amps that is continuously supplied by original shunt unit most of which is dumped to ground. The major benefit of the series regulator is that the power supplied is typically half that of the standard unit as it doesn’t regulate by dumping excess power to ground. So I don’t expect to burn up regulators and stators on regular basis as many people here seem to. The regulator is rated at 40 amps which gives it has plenty of reserve power for more accessories. How is it for keeping cool itself? I mean when my OEM R&R failed on my 2001, you could fry and egg on the fins (I burned my hand through a leather palmed work glove). So when I installed the Rick's unit I mounted it on a heat sink plate and now it gets warm, but not hot. What I'm most concerned with right now is the fact that the Honda wiring harness is causing a nearly .7V drop between voltage at the regulator connector and the battery terminals. Getting a VFRness should solve that issue. It is interesting that the compu-fire unit only needs one positive and one negative output wire. Still I'm going to be watching this thread to see how the compu-fire unit holds up. Do this mod!! Link to comment Share on other sites More sharing options...
Misspent Youth Posted May 15, 2011 Share Posted May 15, 2011 Thanks for that added info. My motive to change would be based on prevention of failure(s), but it's nice to know there's another benefit. Link to comment Share on other sites More sharing options...
Member Contributer Infidel Posted May 15, 2011 Member Contributer Share Posted May 15, 2011 It appears that everyone doing this change has a 6th gen. Is their a cutoff on Year when Honda might have fixed this issue or is it recommended ALL 6th Gen Owners perform this? Link to comment Share on other sites More sharing options...
Auspanglish Posted May 15, 2011 Share Posted May 15, 2011 It appears that everyone doing this change has a 6th gen. Is their a cutoff on Year when Honda might have fixed this issue or is it recommended ALL 6th Gen Owners perform this? 2002-2005 are sitting ducks. 2006-on should in theory be bug free Link to comment Share on other sites More sharing options...
Member Contributer Solomoto Posted May 15, 2011 Member Contributer Share Posted May 15, 2011 If the series regulator is NOT a DC-DC converter but rather a resistive pass transistor, then the overall power efficiency would be pretty much a wash compared to that of the shunt regulator, i.e. it would be dumping large amounts of power as heat. The primary difference would be the voltage vs. current tradeoff. Whereas the shunt regulator would operate as low source voltage but high current, the series resistive regulator would operate as high voltage but low current. Since power is the product of voltage and current, the net result would be close to a wash, meaning both the shunt and series resistive regulator would dump large amounts of power as heat. Based on the document below, it looks like it's a switch-mode regulator. http://www.posplayr.100megsfree3.com/FH012AA_Charging/RR_Tutorial.pdf Having said that, it's marketed as a *series* regulator, which kinda infers it uses linear regulators! Hey nice little white paper! Kinda warms the cockles of my heart as an engineer, lol! Link to comment Share on other sites More sharing options...
Member Contributer Infidel Posted May 15, 2011 Member Contributer Share Posted May 15, 2011 It appears that everyone doing this change has a 6th gen. Is their a cutoff on Year when Honda might have fixed this issue or is it recommended ALL 6th Gen Owners perform this? 2002-2005 are sitting ducks. 2006-on should in theory be bug free TY sir!!! Link to comment Share on other sites More sharing options...
Member Contributer coderighter Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Well, got a couple thousand miles on the Compu-Fire. Works perfect, runs very cool, couldn't be happier. Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Well, got a couple thousand miles on the Compu-Fire. Works perfect, runs very cool, couldn't be happier. Nothing like empirical evidence! Looks like these should be the recommended solution for folks from now on! Link to comment Share on other sites More sharing options...
Member Contributer mello dude Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Well, got a couple thousand miles on the Compu-Fire. Works perfect, runs very cool, couldn't be happier. Nothing like empirical evidence! Looks like these should be the recommended solution for folks from now on! I'm there, plus the heavy duty stator rewind by Jim at Custom rewind, (at least for a 5th gen), the hobby king connectors (thxz kaldek) up gaged wires and fused. - It's looking like a winter time job....- Electrics with cajones. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 ...I hope this makes sense. Very nearly, yes. Thanks! I think I may need to invest in one of these Compufire untis for the RC51. I just replaced the stator with a used one, and added a voltmeter to keep an eye on things along with the monitor wire mod. Still not 100% satisfied with the results. Voltage jumps around a fair bit while riding, and reads a volt lower than the battery on the meter. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Just a quick note: The tails of these bikes get very hot. I think it's just the "V" engined sportbikes. My Fifth Gen and SP1 are the same, and I think it's the rear facing cylinder(s) heating up the tails. I've had water bottles in my VFR tail that were hot, not ambient, not warm, but hot after several hour rides. The big bolt heads that hold the SP1 tail have brushed against skin while backing the bike into the garage ant not burned me, but did get my attention. How any electronics survive in there is beyond me... At least newer VFRs have the R/R out if there. Link to comment Share on other sites More sharing options...
Member Contributer coderighter Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Well, got a couple thousand miles on the Compu-Fire. Works perfect, runs very cool, couldn't be happier. Nothing like empirical evidence! Looks like these should be the recommended solution for folks from now on! After the install, I made some quick measurements. Thanks to the 35 watt HID's and all my bulbs now LED, my stator is running about half the current it used too. I foresee a long stator life at these current levels. Link to comment Share on other sites More sharing options...
spud786 Posted September 7, 2011 Share Posted September 7, 2011 When it gets into the winter time, running electrics and gadgets, how does the compu fire hold up on voltage? I run an RD even 100 degree heat the RR runs cool to the nakid hand, I dont see a problem with stock unit, plus it provides more power at a lower current that the compu fire by what everyone has posted. Just sayin use some electricity, maybe that will extend your stator too. I do have 90,000 mile on original RR and all wiring is in perfect new stock condition, obviously it works pretty damn good. Let me know when a comufire gets more than 50,000 miles, till then its just gimmick to me Link to comment Share on other sites More sharing options...
Member Contributer mello dude Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 Just a quick note: The tails of these bikes get very hot. I think it's just the "V" engined sportbikes. My Fifth Gen and SP1 are the same, and I think it's the rear facing cylinder(s) heating up the tails. I've had water bottles in my VFR tail that were hot, not ambient, not warm, but hot after several hour rides. The big bolt heads that hold the SP1 tail have brushed against skin while backing the bike into the garage ant not burned me, but did get my attention. How any electronics survive in there is beyond me... At least newer VFRs have the R/R out if there. Agreed on that one! That is really my only real bitch on the viffer, the thing cooks my ass. I have been looking at kevlar sheets and the like to figure out some shielding to help. Link to comment Share on other sites More sharing options...
Member Contributer DaveB Posted September 7, 2011 Author Member Contributer Share Posted September 7, 2011 If the series regulator is NOT a DC-DC converter but rather a resistive pass transistor, then the overall power efficiency would be pretty much a wash compared to that of the shunt regulator, i.e. it would be dumping large amounts of power as heat. The primary difference would be the voltage vs. current tradeoff. Whereas the shunt regulator would operate as low source voltage but high current, the series resistive regulator would operate as high voltage but low current. Since power is the product of voltage and current, the net result would be close to a wash, meaning both the shunt and series resistive regulator would dump large amounts of power as heat. Based on the document below, it looks like it's a switch-mode regulator. http://www.posplayr.100megsfree3.com/FH012AA_Charging/RR_Tutorial.pdf Having said that, it's marketed as a *series* regulator, which kinda infers it uses linear regulators! I have 10,000 miles on the Compufire now. It does not get hot at all. I'm very happy with it. I believe it must be a switch mode design series regulator as it generates so little heat. If it were series resistive as suggested earlier then it would run much hotter. The power taken from the stator is calculated as current squared times internal resistance of the stator so it will be much less for the series regulator as it draws less than half the current of the shunt type. Link to comment Share on other sites More sharing options...
Member Contributer Ranger77 Posted September 7, 2011 Member Contributer Share Posted September 7, 2011 I'm a tad worried about the 40 amp fuse. On my vehicle (yea, I know two different worlds), I just have a 30 amp fuse and have been told not to use anything bigger. Harleys use a 30 amp battery and ours (stock) are just 15amp batteries. Do I just need to shut up? Link to comment Share on other sites More sharing options...
Member Contributer TomG33 Posted September 8, 2011 Member Contributer Share Posted September 8, 2011 I have 10,000 miles on the Compufire now. It does not get hot at all. I'm very happy with it. That's good to hear, Dave, 10K miles in 3 or 4 months, is a good bit of riding. It's good that you can get out that much. Just a couple of questions, thou, if you do not mind. What year is your Viffer? Does it have the R/R up on the front right hand side of the frame, or is (was) it down the back. ? I know they changed it at some stage as mine is on the front, (2010 model). Tom Link to comment Share on other sites More sharing options...
Member Contributer mello dude Posted September 8, 2011 Member Contributer Share Posted September 8, 2011 I'm a tad worried about the 40 amp fuse. On my vehicle (yea, I know two different worlds), I just have a 30 amp fuse and have been told not to use anything bigger. Harleys use a 30 amp battery and ours (stock) are just 15amp batteries. Do I just need to shut up? Aint the stocker fuse 30amp? That's probly what I would use... Link to comment Share on other sites More sharing options...
Member Contributer DaveB Posted September 8, 2011 Author Member Contributer Share Posted September 8, 2011 I have 10,000 miles on the Compufire now. It does not get hot at all. I'm very happy with it. That's good to hear, Dave, 10K miles in 3 or 4 months, is a good bit of riding. It's good that you can get out that much. Just a couple of questions, thou, if you do not mind. What year is your Viffer? Does it have the R/R up on the front right hand side of the frame, or is (was) it down the back. ? I know they changed it at some stage as mine is on the front, (2010 model). Tom My commute is 120 mile a day but I only use the bike if the weather is fine, then 150 on the weekend and 1000 mile going to TMAC . My VFR is a 2004 with the R&R on the front right hand side you can see from the pics of the install Dave Link to comment Share on other sites More sharing options...
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