Discussion
GTRCLIVE said:
Do a search for PDM there are more and more coming on the market now. ISIS Power seems to be the most flexible but still has fuses, I'm leaning towards the Smartwire by RacePak...
The RacPak system looks simple enough, though there is a caveat on the install pages of the manual that states "When connecting to devices, if the manufacturer of the device recommends the main power beconnected to the main direct battery power, follow the manufacturer’s requirement and DO NOT
connect items through the SmartWire."
That sort of rules out most aftermaket goodies. I know a starter motor might be better wired direct through a relay.
but guages and the like??
F.C. said:
The RacPak system looks simple enough, though there is a caveat on the install pages of the manual that states "When connecting to devices, if the manufacturer of the device recommends the main power be
connected to the main direct battery power, follow the manufacturer’s requirement and DO NOT
connect items through the SmartWire."
That sort of rules out most aftermaket goodies. I know a starter motor might be better wired direct through a relay.
but guages and the like??
If you think about it those kind of recommendations are normally for unfused direct power lines, not for lines you normally put any form of switches or relays on. But well spotted anyway, are you a Lawyer or just a lover of fine print ... connected to the main direct battery power, follow the manufacturer’s requirement and DO NOT
connect items through the SmartWire."
That sort of rules out most aftermaket goodies. I know a starter motor might be better wired direct through a relay.
but guages and the like??
I normally get bored with that fine print stuff and give up before finding the Juicy bits..
OUCHGTRCLIVE said:
If you think about it those kind of recommendations are normally for unfused direct power lines, not for lines you normally put any form of switches or relays on. But well spotted anyway, are you a Lawyer or just a lover of fine print ... I normally get bored with that fine print stuff and give up before finding the Juicy bits..
LOL, its in large red letters at the bottom of the instructions. I normally get bored with that fine print stuff and give up before finding the Juicy bits..Just covering their arse like most!
king mint. Good gear though!The problem with the aftermarket CAN based power distribution modules (PDM et al) is that they seem to just move to switching power locally, usually soon after the battery. This means you still need all the normal thick power distribution wires, just the same as with fuses or relays. Truely "smart" power distribution would switch the power at its destination, allowing one to run just one thick cable say to the front of the car plus CANH & CANL. Only locally would you then branch that out to the consumers. This way your loom can be sized to deal with the average current etc. The ideal would be to have a simple, say maybe 4 channel, high current distribution module near the battery, with current sensing to detect shorts etc, and a number of small external modules based out at the consumers. The remote module report their individual current consumption to the distribution module, and if it detects more current output than is being pulled than the remote modules account for it can take remedial action.
if you think about say just headlamps, with an conventional system there is a wire for dip beam, that has to be sized to carry say 10A, and another for main beam, sized to say 15A. However, you never run mains and dips at the same time, so a single wire sized for 15A could support the headlamp operation if it were remotely switched close to those headlamps etc. This way, i could imagine a "high" power distribution loom containing say 4 channels (front, back, cabin, engine for example) that splits out from a PDM near the battery. Then there could be say 5 or 6 remote switchers at the end of those power routes to actually control the consumers. The main loom in that fashion would simply be 3 wires for the vast majority of its distance!
if you think about say just headlamps, with an conventional system there is a wire for dip beam, that has to be sized to carry say 10A, and another for main beam, sized to say 15A. However, you never run mains and dips at the same time, so a single wire sized for 15A could support the headlamp operation if it were remotely switched close to those headlamps etc. This way, i could imagine a "high" power distribution loom containing say 4 channels (front, back, cabin, engine for example) that splits out from a PDM near the battery. Then there could be say 5 or 6 remote switchers at the end of those power routes to actually control the consumers. The main loom in that fashion would simply be 3 wires for the vast majority of its distance!
first a disclaimer: I am not an electrician! but I have gone trough the web site demos and conversations with folks that have workrd with these systems and I thought the premise was that you provide one main power cable fore and aft in the car to a junction box and then feed it out to the different lights, pumps, ect and then the ground and signal wire are fed in series to the turn signals pumps ect and controled by the logic in the main box usually mounted in the middle of the car. you then have a lighter more controlable system. Am I missing something? Lee
ROWDYRENAULT said:
first a disclaimer: I am not an electrician! but I have gone trough the web site demos and conversations with folks that have workrd with these systems and I thought the premise was that you provide one main power cable fore and aft in the car to a junction box and then feed it out to the different lights, pumps, ect and then the ground and signal wire are fed in series to the turn signals pumps ect and controled by the logic in the main box usually mounted in the middle of the car. you then have a lighter more controlable system. Am I missing something? Lee
The ISIS system is closer to what your saying yes,(multiple boxes localized around the car) but the PDM units are only one box still, so you still have the same issues with power cables going from one place to all the loads where ever they are. More control and more flexibility, Can based single cable input with a Local module behind the dash for all you normal Low Voltage switches yes but thats the only weight saving...Either type system will be lighter I'm sure but, its the More ECU /PLC control of the outputs that I'm attracted too, with the ability to have some active aerodynamic parts maybe with positioning sensors that can given some basic Intelligence to the outputs....
Like almost anything else its the thought thats gone into the Layout of the Loom and placement of the various Loads and devices
that will save some weight and complexity.
I am in awe of the skills of some on here. I get the gist of what you are talking about but that's about it, as I wouldn't know where to start.
But bu**er you do like to make life much more difficult than it needs to be.
For those building their first Ultima - just get it built and enjoy it. As time goes on you will identify things you would change and what you wouldn't (there will be less changes than you think). Make the changes in your second build.
BTW. Think about the second owner who will have no factory backup on your bespoke wiring.
Paul
But bu**er you do like to make life much more difficult than it needs to be.
For those building their first Ultima - just get it built and enjoy it. As time goes on you will identify things you would change and what you wouldn't (there will be less changes than you think). Make the changes in your second build.
BTW. Think about the second owner who will have no factory backup on your bespoke wiring.
Paul
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