| Author | Message | ||
     Tlrich |
After reading the many threads, and posts about the "product enhancement"-- I'm not sure whether to upgrade the wiring harness, or leave it stock...I'm still confused. Can you tip it one way or the other? | ||
| Timebandit |
Just my opinion, but to me the decision to get the harness upgrade is a no-brainer. When it works, it helps you. It only hurts you if/when you fail to maintain it by not keeping an eye on the status of the relays. I prefer the higher output charging system, so here's what I would do. I'm sure other people would have different recommendations. A. 2009 STREET + TRACK APPLICATION: If you are riding a 2009 on the street, then you need to do the following right now; These steps will do the most that is possible to protect your stator: 1. Replace the shunt regulator with a series regulator. 2. Get the harness upgrade. 3. Keep an eye on the relay in the harness to make sure the harness upgrade is properly functioning. 4. Only place reasonable loads on your charging system. Bear in mind that relays are wear items. Check them regularly and replace them as needed. Consider it normal PM. Failed relays will cause charging system failures. If you choose not to get the updated charging harness, then you are rejecting H-D's attempt to prolong stator life. Plan on buying more stators. The fact that relays fail/wear out does not mean that the harness update doesn't work; it only means that the harness update doesn't work if you fail to maintain it properly by replacing relays when they wear out. I would also implement each of the following upgrades as soon as they become available: 1. Replace the series regulator with a switching regulator. (Definitive solution!) 2. Get the 2009 rotor upgrade that does the oil squirt. another valid option for people who wouldn't mind a lower output charging system for street applications is listed below: B. 2009 TRACK-ONLY: 1. Get a series regulator. 2. Get the EBR low output charging system with the oil cooling mod. | ||
| Tlrich |
Timebandit,Great reply, thanks. And Happy New Year! What is a shunt regulator, and where do I get one? | ||
| Timebandit |
You don't want to buy a SHUNT regulator. You've already got one and you want to get rid of it, because they force your charging system to operate at full output at all times, which burns up stators. What you should be looking for is a SERIES regulator. glad the post was helpful. | ||
| Yugi |
Why would you need a harness together with a series regulator? | ||
| Shags |
Timebandit were are these relays located and what do they look like.Sorry electronics are not my thing. Thanks | ||
| Timebandit |
> "Why would you need a harness together with a series regulator?" Yugi, that is a REALLY good question: is the harness update/relay needed with a series regulator, and why? the answer isn't exactly simple. I've spent a fair amount of time looking at sample data from tests of the charging system, I've calculated and plotted it's insertion losses, and I've crunched lots of numbers while modeling series and switching regulator designs. i don't have all of the data yet, so some of my answer will based on opinion and not backed by numbers. the first thing to consider is why was the harness update designed in the first place, and to ask what are the operating conditions that the harness update is designed to avoid. the harness update is designed to switch off legs of the stator when system loads are high and RPMs are low. presumably, the reason for shutting down stator legs at low RPM is because the engineer who designed the control logic considers low RPM conditions to be functionally equivalent to low MPH conditions, where the bike doesn't get adequate air flow for cooling. in the low-RPM states (which I'll define for this answer as being equivalent to low MPH states), forced air cooling is insufficient to remove heat from the charging system. our model then, says that low RPM and high load (shunt regulation) is BAD. that's what we're trying to avoid -- low RPM (low airflow, low cooling) and high load (high heat generation). that burns up stators, so the legs get switched off in an effort to save the stator. now let's look at series regulators and how they're different from shunt regulators. the difference is that while shunt regulators place a heavy load on the charging system that represents a 100% duty cycle, a series regulator places a load on the charging system that is defined by the actual loads that the user has hooked up to the system. in other words, while a shunt regulator places a full load on the charging system regardless of how much load the user places on the bike, a series regulator places the same load on the stator that the user places on the bike. there is a widely held misconception on this forum that series regulators are always superior to shunt regulators. that's not always true. series regulators are thermally superior to shunt regulators under low load conditions but not under high load conditions. under similarly high load conditions, they offer no relative benefit whatsoever. for example: if someone loads down a series regulator with so much heated gear that he reaches the maximum output rating of the charging system, then he is operating at maximal load and he is as bad off as if he was using a shunt regulator. maximal load (heat) at low RPM (low speed, low cooling airflow) is bad for the stator. it doesn't matter if you have low RPM and high load with a shunt regulator, or low RPM and high load with a series regulator. maximal load is maximal load. the result is the same. in that circumstance, you'd still want to have the harness update on-line to be able to shut down accessories that would overheat the stator under those conditions in which you can't supply adequate cooling. with high loads this represents a serious problem. with low loads, this wouldn't be an issue. ideally, you'd want to upgrade the charging system to use switching regulation rather than series or shunt regulation, because at high load levels a switching regulator is so much more thermally efficient that cooking the stator at low RPM shouldn't be a problem. with a switching regulator you'd want to remove the harness update. well that's the theory, anyway. we'll see how it turns out when mathematical models become prototypes. | ||
| Timebandit |
shags, somewhere on this forum is a TSB that documents the wiring harness update and shows all the parts involved. i don't have a copy handy, so i'd recommend doing a search for the document. | ||
| Reepicheep |
Nice summary as usual TimeBandit. The one point i might quibble with is the assumption that airflow is the critical issue. I suspect its more to do with oil flow (which is also directly proportional to RPM). If the oil is rapidly flowing, the stator probably sheds heat fast enough to stay alive. | ||
| Timebandit |
thanks Reep -- that's a really good point. it's not nitpicking to point out that oil circulation can be the limiting factor in the movement of heat from the stator to the oil cooler. RPM and oil flow play a direct role in heat removal. of course we should all recognize that this idea is familiar -- it's the basis for the EBR oil-squirting rotor mod. When I wrote that post I was primarily thinking about low RPM resulting in low airflow across the oil cooler. you're right -- RPM directly controls oil flow and oil flow is every bit as important. i guess i should stop posting at 02:30 when i should be in bed. thanks for the helpful idea! |
