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Somehow I've missed the start of this thread. I am an LS fan. Have FIed and tuned a few LS3s. All AA setups on stock bottom ends; getting the tune correct (HPT) was my biggest enjoyment; mechanical build was pretty simple/easy.

I am interested in ALL that you are willing to share on CANBUS mods.

Here is a pic of my first LS3 build/tune:

 

CAN hacking done (or at least mostly done).

I can now control, at will:

Dash Wakeup/Keepalive
RPM
Coolant Temp
Vehicle Speed
ABS Light
Traction Control Light
(Fuel level doesn't have anything to do with the ECU, so I'm not worried about that as it'll "just work")

Vehicle Speed, ABS Light and Traction Control Light are all controlled by the ABS module, and don't appear to need the engine computer at all. I'm told that the other one of these that was built always had a TRAC light on, though, so I'm guessing losing the engine computer makes the ABS computer angry. If that's the case, I can send a message every 100ms to keep that light off (or maybe just send a message to make the ABS computer happy to begin with).

The other controls all simply command status, and I've mapped transmit times from the stock ECU, so I'll replicate that on the new controls. The dash still has a few warning lights for electrical system, etc, that I think happen because it's not receiving some data from the ECU. I need the "keep-alive" to... keep it alive... long enough to validate I can shut those off. I'm going to program an Arduino talk on the bus as my current test program can only send one message at a time. Once I have the Arduino setup, I can mimic a constant stream of data, which should let me send "everything is happy" messages to the dash constantly, which should squelch any warning messages.

I need to sort out the math for converting the RPM signal to display correctly, but that's easy enough. Coolant temp just has a sweep of decimal values from 95 - 185 to go from "C" to "H" on the dash, so I can just map those temps however I like from the stock computer.

I feel like this is really the hardest part of the swap, as I don't have documents to work on. Making it fit is just cutting/welding, no big deal. Wiring work is complex, but I have diagrams from both cars, so it's just a matter of clean integration. CAN data control is completely undocumented, so I had to forge my own way on this bit.

I'll have a video put together shortly. I want to get the Arduino in and programmed/controlling things to finalize everything, then I'll edit it (poorly) and share it out. I'll publish out the CAN data as well at that point, as I want to fully validate which bits are qualifiers and which are the data payload a little bit more to make sure it's as cleanly executed as possible.

 

Thanks for doing this and sharing. This is the future of automotive repair - might be time for me to get smart on CANBUS!

 

Hi @Digitalsolo

Thanks for the update on the CANBUS work you're doing. Hope you keep reporting.

A comment about one section I highlighted - For most systems that I've worked, there is a needed connection with the ECM and any active handling features such as skid/yaw controls, ABS, etc., as these systems rely on throttle control as a component of the feature. This is evident when any one or combination of powertrain faults, a couple of examples of which are - misfires, loss of drive by wire, fueling faults, etc., will, along with a CEL, set messages such as:
SERVICE REAR AXLE,
AH DISABLED
etc.,

These messages, that come on communicate to the operator there is a powertrain fault that AH, ABS rely on and to not count on them as safety features until the powertrain fault(s) are corrected. They are often misdiagnosed as additional failures and not just features the system suspends because the powertrain control feature is unreliable.

 

Valid point on the faults; I really only care about ABS continuing to function, as any traction control (if it works at all without the ECU) would not be well positioned to manage 2x the factory HP and an entirely different torque curve.

That does make me think I should sort out the DBW pedal information. I'm pretty sure I have that already, but I'll double check. If I can send RPM and APP (throttle pedal) position, I should be able to keep ABS happy, but we'll see. Worst case I'll put an MK60 universal racing controller in it and do it that way. That's all assuming that it doesn't "fault" to functional, of course.

 

Some more info on throttle position (but you likely know this already)

There are 4 different throttle measurements used in most systems (this DL is a GM E38 ECU)

Commanded Throttle
Relative
Actual
SAE

Commanded throttle is obviously an input signal. Relative I "think" is neutral, then Actual/SAE throttle positions are output signals and these are what I believe the chassis functions will be looking for. Hope this helps if not redundant.

 

Beginning disassembly. First though, starting weight/balance to see where I end up by comparison.

Specs for reference on the weight:

2007 V8 Vantage, 6 Speed
VAP Valvetronic Muffler
Tubular Headers
EGR deleted
X Pipe (modified stock H pipe)
Stock brakes
DBS Swaybars (front/rear)
Stock shocks, H&R Springs
BC Forged RXZ39, 19x9 Front, 19x10 Rear
Falken Azenis 255/35/19 Front, 295/30/19 Rear
ECPS Carbon door pulls, center console/waterfall
Aston Installations HD Nav upgrade

Balance is amazingly consistent stock. I'm very interested in seeing the weight difference. I expect it'll add a little, but my guess is less than 100 lbs all-in. We shall see.

 

Started disassembly of the car. Exhaust and cooling system out here, I've since pulled the oil system as well. Intention is to get the drivetrain dropped this weekend.





Engine prep is underway also. Headers, new accessory drive and adapters for the dry sump oil tank are in place. I'll have an AC compressor, power steering pump and upgraded balancer shortly. Motor mounts are en route also. I'm going to use C6 poly mounts then build custom adapters from the block to those mounts. That will allow for the easiest replacement in the future as needed.

 

That was easier than expected.

 

Sweet project!

Hope you can keep pics coming.

All the Best,

 

Subframe holes drilled out slightly to fit C6 Corvette mounts. I'm using polyurethane mounts from Hinson Motorsports.





Mocking up the engine on the subframe. I cut out the rear cross brace on the subframe. This will get plated on the ends, and new reinforcements to tie it all back together properly.







Mocked up in the engine bay. Engine is tilted slightly forward in the photo, but has since been sorted out while I mock up mounts. I have a driver side mount cut in cardboard now, I'll do the passenger next, then import them into Fusion 360, then get them laser cut, and bend/weld them.

 

wow great progress

 

So, the alternator wouldn't fit in the OEM location, which led me down the rabbit hole of needing to relocate it, which then required me to relocated the AC compressor. I can get off the shelf bits to relocate the alternator an add power steering, but none of these put the AC where it needs to be to fit. So I bought the kit, cut off the intended AC location (high passenger side on a US car) and moved the AC to low driver side. This needs a custom mounting bracket and idler pulley to clear the belt around the power steering assembly and improve belt wrap on the crank pulley.

Step in 3d scanner and Fusion 360. I scanned all the parts, mocked it up and 3D printed a few revisions to sort out the final fitment. I'm having the flat areas of the final part laser cut in and will CNC machine the other piece, than either bolt or weld it all together (probably some of both) to install on the car. Little more effort than I intended, but you have to do the work to get the result.

 

Wow - you are making a serious exersize here, impressive.

Its always takes an amazing high effort, when you try to modify things in such a cramped arrangement as a modern engine bay.

You may want to avoid sharp corners, they are stressraisers and cracks may start there.

 

Noted on the corners. I'm pretty sure I could lift the car by this AC bracket, so it should be well enough overkill to minimize risk of stress risers.