Real world CAN stub lengths

[Fwdmn]

Quick one, now CAN is much more common than in previous threads here, does anyone have any experience with out of spec CAN spur lengths?

 

I usually daisy chain ECU to Dash to the next component, CAN Lambda or whatever it may be.

 

This time I have 5 x CAN components to connect on 1 BUS and daisy chaining this seems wire/bulk-heavy but components are relatively spread out, a few certainly over 300mm away as most literature says is "required".

 

Thank you for any input!

[Adamw]

I have seen many significant deviations from the commonly quoted CAN “rules” and haven’t seen any obvious consequences personally.  One F3 car loom I had to copy had a 1.8M stub and that was on a highly loaded, critical bus.  There are also several devices on the market like the Haltech or AEM CAN hubs that completely ignore the recommended architecture and effectively make every device a stub and I haven’t heard of too many people having issues with them.  

My suspicion is in the typical aftermarket installation the bus is so lightly loaded that you aren’t going to notice the odd CAN error or rejected message, each device will just resend until the message is acknowledged without errors. 

[Fwdmn]

I had seen the Haltech CAN box and that was partly where the question came from, not that I'll stray from Link (in no small part due to the support on this forum, and of course from yourself Adam).

 

That is good to hear as it will make things simpler than excessive daisy chaining, though I don't usually have trouble that way, just have to draw a line somewhere.

 

Thanks again!

[Monsterbishi]

I've been playing with can cabling a fait bit lately, like Adam, I made one that had stubs well over 2m long so I didn't have to keep getting in and out of the car, no issues whatsoever.

I suspect if you looked at some OEM harnesses you'd find some seriously wacky stuff.