Discussion and questions related to the course Motorsport Wiring Fundamentals
I have a Holley Dominator ECU, as well as one of their dashes. Getting things gathered up for the wiring of my car. Strongly considering a Racepak Smartwire to wire the car. I've looked at the Motec units as well, but price on the smartwire is much better for the number of outputs I need. While the software doesn't seem to be the best in the world, it is not terrible.
Here is my question however, If I connect the Smartwire to my Holley unit VIA the CAN connection. I know I am able to send outputs from the holley instead of hardwiring switches. However, am I able to send an output from the Smartwire VIA CAN?
Example: Turn signal switch hardwired into the smartwire, Output wired to bulb, as well as a can output sent to use as a turn indicator in the dash
Is this sort of thing possible with the smartwire? Or any other PDM? Or would I still need to run a wire back for the turn indicator (or split the output from the switch to the PDM and ECU?
My issue with Racepak gear is specifically its proprietary V-Net shenannigans (which is just another serial network, and it is a CAN, its just not J1979 and has some other BS on top so it works only with their gear) so you'll need a V-Net adapter for it to talk to your ECU.
I am aware of the need for the v-net adapter. However, the Holley ECU is now able to read holley's as well as Racepak's CAN data over the same channel so it's not a big deal.
The main thing I'd like to figure out before purchasing is whether this communication is one-way to the smartwire, or if the smartwire can "talk" to the ECU as well.
The smart wire cant transmit anything to the ECU, only receive. I have only played with one about 5 years ago and It really was a pile of crap, maybe ok for a basic hotrod or something but it is very limited, the more you look the more you find missing.
Do the Holley ECU's even have any CAN receive? What do you want to send to/from the ECU over CAN?
Take a look at the ECUmaster PMU, only 16 outputs but it is pretty good value, works well and has a whole lot more functionality than the smart wire. They have a CAN receive template for Holley.
10-4 thanks for the information. I'm not sure if the Holley ECU is able to receive CAN data or not, I will look into it. I'm in rural Wisconsin area, there's few local guys using EFI, let alone anything other than the Holley systems, which are most popular around here in the states.
Honestly, I really don't have any planned items to have the ECU receive from the PDM, just seeing what options are all out there.
I will definitely look into the ECUmaster setup. I would need 2 however, due to the amount of outputs. This is a street legal car, wiring from scratch, Id really like to run everything through the PDM and eliminate all relays/fuses if possible.
If you don't mind me asking, is it mainly the software limitations that make the Smartwire a sub-par unit? I have heard this from several people. I can control virtually everything from the ECU. Flashers, pwm fans, etc, so I don't need to dive too deep into the software of whichever PDM I decide to go with.
"If you don't mind me asking, is it mainly the software limitations that make the Smartwire a sub-par unit? I have heard this from several people. I can control virtually everything from the ECU. Flashers, pwm fans, etc, so I don't need to dive too deep into the software of whichever PDM I decide to go with."
It sounds like you have fairly basic requirements so the smartwire may well do you fine. I cant remember all the limitations as it was quite a while ago when I last touched one but I remember being frustrated at almost everything I went to set up compared to the motec I had used earlier. A couple I remember: There was there was no functionality for two speed & intermittent wipers - I had to do some weird hack they suggested with a change over relay to give me the two wiper speeds, but then park was very hit or miss. Back when I used it they didnt even have a keypad option, only the switch panel, but even since they have added a keypad option, it is very limited - you cant do stuff like you can with most other brands such as short press/long press, count up/down etc. No control over the keypad LED's etc. Also as previously mentioned, no configurable CAN which mean every input/output needs to be hardwired.
I suggest you download the software and have a play around with setting up what you think you will need as that is often a good way to find the limitations or find the questions that need to be answered...
Thanks very much for the input on this.
I am going to look into the Motec units some more. I downloaded the software for both that, and the Smartwire to try out. I did find out that Holley and Racepak CANbus now communicate directly with each other. So I know I can use CAN for inputs from the ECU.
The ECUmaster is not an option for me, there is one dealer in the states, and they are halfway across the country. That's a deal breaker for me.
"I did find out that Holley and Racepak CANbus now communicate directly with each other. So I know I can use CAN for inputs from the ECU."
Make sure you asses that claim closely before committing - As far as I remember they still only allow you to communicate one way with the fixed Vnet data. So for instance - you cant send fuel pump or fan status from the ecu to the PDM - you still need to wire an actual fuel pump output from the ecu to the PDM. For some things like fans you will have coolant temp on the Vnet so you can do some logic to control fans but it is still not as nice as having the ECU control it with hysteresis etc. You also cant send info from the PDM to the ECU - for instance if you want one of the buttons on the keypad to turn on launch control or activate NOS.