Series Regulators for Improved Stator Reliability
In the case of those bikes which suffer high prevalence of stator fails, then a better choice (than MOSFET Shunt) in the R/R department is to go with a Series Regulator.
Yes the choice of R/R design can really make a difference in the longevity of your stator!*
I was one of the first early adopters & promoters of the MOSFET R/R - however important to note that this is primarily to address high failure SCR Shunt Regulators.
The MOSFET Shunt R/R is a HUGE improvement in reliability of the R/R itself - however will do nothing to offer any insurance for the stator.
It works identically to the SCR in that it shunts peak current from & directly across the stator winding.
So the best solution for preserving stator is to use a Series Regulator rather than the predominantly common Shunt designs.
There are not too many choices out there - one that is extremely well proven is the Compufire 55402
A true Series Regulator, it is rated at 40A and is well established & has documented success with good reliability.
A Champion of this module is a gentleman who goes by 'posplayr' - you can find a lot of data & endorsements of this module on the GS Forum
Here is one piece of his data that summarizes why it is kinder to the stator than a shunt R/R:
It's simple - this type of device only conducts for part of the cycle of the generated wave, dictated by the controller
So instead of shorting the source - and making the stator supply its maximum-capable current - it actually 'opens' or blocks the source.
And hence because there is no shunt current, the stator is supplying much less (only what is demanded by the load i.e. the bike) and so runs cooler.
Cooler means it will no longer be susceptible to frying its insulation and failing.
Why not universally endorse this over MOSFET R/R? Again simple answer - cheapest price of the Compufire is about $155 shipped (at this time of writing)
If the model in question has a generally good history of stator reliability, then the MOSFET represents possibly better value.
However if failed stators are a concern, then that extra cost pays back real quickly vs having to replace a stator also!
Note from pic above however that it comes with the cables, connectors and fuse for installation (so unlike the Shindengen in that respect where the special Furukawa connectors are required)
There is another Series R/R that has just been identified as a good candidate for the after-market - this one is also made by Shindengen (the primary MOSFET manufacturer) and indeed is actually the exact same form factor as the FH012/020 MOSFET model. This one is designated the SH755. With the same form factor it would utilize the exact same connectors as for the MOSFET
(indeed if you have an FH012/020 installed already, it will plug n play as replacement for that)
This particular unit is a Shindengen SH775 regulator and is used on Polaris models.
It is VERY inexpensive - brand new -
e.g. $73 shipped!!!! ($60 & change plus shipping)
http://polarisparts123.com/partnumber-search/ (enter 4012941)
Polaris REGULATOR-3PH,35A,SERIES,105C for 2011 Polaris R11HR76AG/AR RANGER 6X6 800 EFI 4012941
(or wherever else you can source Polaris parts)
Here's the first shocker - it's SCR based!!!
But major difference in that this is a SERIES config,
NOT SHUNT!
Unlike a diode bridge with reverse biased shunt SCRs, the SCRs themselves form the bridge rectifier - again, they only conduct for part of the generated cycle and this is how the output voltage is controlled
Here is a nice simulation that shows how the firing angle of the SCRs determines the output voltage.
http://www.youtube.com/watch?v=s24U0GaBx-o#
The big advantage this unit has is - can be found for as low as $70 shipped!!!
The spec is actually 35A - it is rated as 14A completely uncooled but virtually doubles to 27A with only 1m/s of cooling (that equates to moving through air at only 2mph!) and 35A with higher cooling.
The important factor again is that the Series R/R will only draw as much current from the stator as is demanded by the load.
So if you turn the lights off, the stator current will actually go DOWN.
(With a SHUNT system, reducing the bike load merely makes the R/R shunt more current - so the R/R actually generates more heat with less load, but makes no difference to the stator current either way)
And same as you increase rpm - up till saturation, with a shunt R/R the stator current will increase with rpm - so if you are running all day at higher speeds, the stator is going to run much hotter than it will at lower rpms with the same load
But with the Series module, higher rpm does not mean higher stator current.
The SH755 actually comes from Polaris ATV/Utility Vehicle applications - so is used as OEM equipment.
As after-market is less prevalent as yet, fairly recent 'discovery'
So there is less lifetime data of it running at higher current levels (that run in the 15-20A continuous range)
The early adopters are probably less than that, so there is not real data available at this time of writing on reliability long term with sustained high current use.
I would caution AGAINST using this unit on high-rpm motors - testing on bike that runs over 10K redline showed the R/R went out of control beyond this level - it presumably cannot switch at that frequency. But up to 10K rpm appears to do just fine.
The fabulous news is that Shindengen shows TWO MORE Series Regulators at 50A rating currently in development!
Something exciting to look forward to (scroll on down to the bottom of this post for more information)
You can find more on my thread at T'Rat .....
http://www.triumphrat.net/speed-triple-forum/104504-charging-system-diagnostics-rectifier-regulator-upgrade.html.
I have always been a huge advocate/proponent of the MOSFETs - in a lot of bikes they are the answer to low reliability SCR SHUNT Regulators (Which themselves fail predominantly for lack of cooling to remove the incredible heat they generate - they simply self-destruct)
But when stators are failing, the Series type is virtually a no-brainer - the stator will operate with half (or better) of the current that it will with a Shunt regulator - that means the stator runs cooler inherently increasing its reliability and further the rotor epoxy will be less inclined to let go.
The SH755 is less field proven at higher system loads in after-market applications, however the Compufire is.
The Compufire is costly vs a MSOFET - but still cheap insurance vs having to replace a stator - and especially if you have to add rotor into the mix!.
Some have successfully installed Compufire on stators that already show quite a lot of heat 'damage' (discoloured epoxy) *- as long as the stator insulation has not actually broken down, it will most likely continue to operate without further damage (of course there is no reversal of the heat indications on the epoxy, but that in itself is of no consequence). And similarly for the rotor - if it has not yet suffered breaking magnets, it should be fine going forward.
Tests have proven *that the temperature on the Stator cover is significantly lower on a Series Regulated Stator.
Here is a very basic test done by one of my Triumph Friends on his 2007 Triumph Sprint (955cc EFI Triple with Twin Headlights)
Recognize that is the temperature on the COVER! The actual temps of the stator and rotor will be differentiated considerably higher.
And from another forum/thread:
Here's some excellent Thermal Images from a
post by oberon on the Aprilia forum with some pics comparing temps with his original Aprilia R/R (SCR Shunt) vs. Compu-Fire (scroll to post #460). *
Here are the pics which are directly sourced from the contributor in the linked thread:
(the first two pics show that the actual Series R/R also runs 'cooler' than the Shunt R/R, installed in the same physical location)
This is a picture of the original aprilia (SCR Shunt) R/R:
and this is a picture of the Compu-Fire 55402 Series Regulator:
....also pictures of the stator cover.
Stator Temp with original R/R:
Stator Temp with Compu-Fire 55402:
Photos courtesy of oberon
linked from Aprilia forum
The Compufire comes with a GM WeatherPack type connector already crimped onto the stator input wires and a mating connector is included with it.
For some bizarre reason however, they include the connector shell for the stator end but
NOT the terminals!!! *:wall:
Picture courtesy of Andrew Vanis of GS Forum:
Available in the US at NAPA Autoparts -
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Wire-Terminal-GM-Weather-Pack-OEM-Series/_/R-NW_725170_0282444263
You actually want the seals also if you want a true sealed connector -
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Wiring-Grommet-Rubber/_/R-NW_725152_0293960868
You can find on EBay out of US or Australia - did not see any listed directly in EBay Europe
You can either swap the OEM Stator Harness Connector to the WeatherPack type or swap the Compufire R/R stator input connector to OEM type (this would be the case for ANY bike)
- Or use
any other 3-way connector set of your choosing and swap the stator connector on both R/R & the OEM stator harness as matched set.
I like MetriPacks myself, the WeatherPack is also a good Sealed Connector.
The output wires are already equipped to connect directly to the battery - there is a Fused link for the Positive side. These wires are approx 1m long so will be good to accommodate most locations on the bike for mounting of the module. The wires can of course be trimmed to length as required.
In the picture of the Compufire in the first post you can actually see the stator connector and the FuseHolder Link Wire.
For the SH775, follow same installation instructions as for the MOSFET Shindengen
Now there is also a brand new Series R/R out from Shindengen, on the 2014 Suzuki VStrom 1000
This one may be the best yet!
The Shindengen model # is SH847AA
(It is possibly one of these per the Shindengen spec sheet)
Suzuki Part # 32800-31J00
Not at all the Suzuki on-line parts sources yet, but definitely found several, including BikeBandit even (at $165)
This is cheapest I have seen so far at $142 -
http://www.shspowersports.com/fiche_select.asp?mfg=Suzuki&partnumber=32800-31J00
At least it is
LISTED as available - would need to check with actual supplier to see what availabilty / lead-time is.
Here is a low-cost way to install the Shindengen SH775 or the new SH847 (or even the MOSFET FH012/020 Shunt units):
Triumph has created an adapter lead for their MOSFET retrofits on the Daytona 675 (Triumph calls it Link Lead) -
T2500676 - that is only about $10 USD - ridiculously inexpensive for what it is!
This cable will connect to many different models as-is, or simply change the input & output connectors if you have to (I like to use MetriPack connectors on the stator input regardless).
The summary - Series R/R will result in your stator having to supply significantly less current than with a Shunt Regulator - this means the stator will run much cooler and consequently improve reliability dramatically.