Yellow Bullet Forums banner

101 - 113 of 113 Posts

·
Registered
Joined
·
3,949 Posts
ECU/PDU up front and another out back would cover pretty much everything.

Although the problem is...most PDU's are just outputs, which means that if you wanted any inputs out back, you're still screwed.

Although some offer "expanders" which have both inputs and outputs, but they tend not to have high current handling abilities.

If there was another PDU type unit that allowed say 5-10 inputs and say 10 or so outputs including a few high current PWM outputs, that would be ideal.

Engine, fans, lights, whatever all up front. Then fuel pumps, lights etc all covered out rear with another unit. For those that retain a conventional layout of course.
And likewise any inputs like suspension, wheel speeds etc can be handled locally, rather than individual wiring front to rear.
 

·
Registered
Joined
·
1,395 Posts
One needs to consider CAN messaging (definitions in CAN traffic), physical line capacity and circuit length when looking at module communication.
Then, what protocol should one use? J1939, ISOBUS, or some proprietary crap like some ECU makers use. Also, CAN messages make good status reports and error messaging and warning light signals but typically don't run anything that consumes much power, mostly just signal changes (low voltage) in my experience.
Pretty soon, you would have an extra 2-3 UCMs or ICMs and have just as much complexity as a modern vehicle all to save a few feet of wire.
The bonus is you get to learn a new software and design your own CANdb's, learn Hex, and do all kinds of neat stuff.
Or...., this is an opportunity for a NEXUS remote unit to be controlled by NEXUS Command Center...
 

·
Registered
Joined
·
3,949 Posts
CAN has no difficulty running a vehicle. Let's face it, there are few cars today that do not use CAN, although OEM's go a bit nuts with it.

A race cars requirements are very small by comparison, and simply turning a few lights off and on and a few pumps, is not an issue. CAN is simply comms, it does not carry any load.

And you would only add complexity if you choose to. As I said, it would be very simple having a unit up front, and a unit at the rear that takes care of things at either end of the vehicle. That is removing complexity.

Either way, more options is always good.
 

·
Registered
Joined
·
2,359 Posts
Obviously the Fueltech is a very good system, but it does seem a bit crazy they need different boxes for everything.

Really, a couple of well designed units could make vehicle wiring a lot easier.

One bigger unit up front for all engine/trans/dash controls, and then maybe another at the rear to take care of anything installed out back.

Then just link the two via CAN, which would really minimise any wiring needed and remove almost all long runs of multiple wiring to opposite ends of the vehicle.
not even going to comment on fueltech as its not even in the same league..

you will be happy with what new products are coming from haltech then,
 

·
Registered
Joined
·
5,660 Posts
Discussion Starter #105
CAN has no difficulty running a vehicle. Let's face it, there are few cars today that do not use CAN, although OEM's go a bit nuts with it.

A race cars requirements are very small by comparison, and simply turning a few lights off and on and a few pumps, is not an issue. CAN is simply comms, it does not carry any load.

And you would only add complexity if you choose to. As I said, it would be very simple having a unit up front, and a unit at the rear that takes care of things at either end of the vehicle. That is removing complexity.

Either way, more options is always good.

CAN Carrys control power for devices on the network. The industrial version of CAN is called DeviceNet and is an open network protocol owned by ODVA. They also own ControlNet which is also an open source network. I did industrial automation programming for 15yrs and did a lot of Distributed Control System design and programming. DeviceNet is capable of controlling large NEMA size motor starters, VFDs etc. It is generally not used to carry current for actual loads, only control power to operate larger devices that are carrying the high current loads to the actual device, motor etc being run..
 

·
Registered
Joined
·
5,660 Posts
Discussion Starter #107
Bussman also makes a similar distributed system. I tried to get them to open up the programming for end user or even dealers but as far as I know they never did. Basically wanted what a Racepak Smartwire is capable of but it was about 10+ years ago. Oh how tech changes exponentially in a decade.
 

·
Registered
Joined
·
6,963 Posts
In recent months, I have kinda shifted my thinking about having to use sub boxes. I have for a long time longed for an ecu that combined everything into one box. But as I try to tidy up wiring in a car, I see the advantage of having an engine sensor and output box near the engine, and then the can and power supply wires to connect to the main ecu. It shortens the sensor wires, and really cuts back on the number of wires that run longer distances. It's not exactly easy to find places in a dragster for sub boxes, but it's not impossible either. However, it all has to be somewhat weatherproof. Absolutely it's nice to have relays incorporated into the sub box. As clunky and techy as making your own sub box is, I see the benefits absolutely.
 

·
Registered
Joined
·
5,660 Posts
Discussion Starter #112
It depends on the data block size and baud rate. I'm pretty sure CAN is same speeds as DeviceNet which can run at 500K bits/sec. CAN 2.0 may be faster I'm not sure off the top of my head.
 
101 - 113 of 113 Posts
Top