Bonneville car. LOTS Of data.

[dieselgeek]

Just wanted to share this stuff with the DIY EFI crowd.

I'm wrapping up the #97 landracing car's EFI system. It's more appropriate to call it a "Powertrain Management System" as it does a heluva lot more than run the injectors and coils. Figured I'd share all the inputs and outputs I am running. This is 100% DIY, I assembled all three of the computers in the car myself. I am using as much Open Source tools as I can find, the goal is to make this a competitive and informative system that's reliable and gives us useful data.

To that end, we've come a long way with Megasquirt in a few years.

Here's what I am monitoring (inputs) on the megasquirt 3x, some of these are routed to the MS3x via CAN Bus using a JB Performance "IO Extender" which is a DIY electronics kit add on to Megasquirt devices:

Crank position (every 10 degrees)
Cam position (one signal per engine cycle)
Throttle Position
Manifold pressure (vacuum, boost)
Pre-intercooler air temp
Post-intercooler air temp
Fuel Pressure
Fuel Temperature
Oil Pressure
Oil Temperature
Coolant Temp
Coolant Pressure (monitor this to avoid headgasket failure!)
Intercooler Coolant Temp
Exhaust Gas Temp on all 8 cylinders
Front wheel speed
Rear wheel speed
Suspension Travel at all four corners (using linear potentiometers from RacePak)
Turbine Speed on both turbos (uses a cool Borg Warner sensor!)
Left and Right bank O2 sensors, wideband
GPS Speed

That all works out to nearly 200 separate circuits. +5v, +12v, low current grounds, high current grounds, etc. Most sensors require power, ground, and signal wiring.

So far I have everything working except the EGTs (waiting on custom cable lengths to be made).

I have the system set up to run a single red warning light (MSD light) to notify the driver of any critical problems. So far I have the following that will light up the shutdown light:

high coolant temp
high coolant pressure (head's lifting!)
low oil pressure
low fuel pressure
high oil temperature

I do NOT let the computer control the actual shutdown of the car - that's up to the driver. I'm simply letting him know that the computer is seeing something we all decided beforehand, we don't like. If the driver is on a record run in the last mile, red light be damned!

AS for computers in the car, I am running:

(1) a Megasquirt-3x in full sequential EFI and spark mode. This is the only CRITICAL computer in the car. It's gotta stay running. I carry spare parts, and a complete Engine Simulator for testing this box thoroughly.

(2) a JB Performance "IOX" box, this thing is awesome. It takes 20+ inputs of all types, and routes all their data over the CAN Bus (same thing as RacePak VNET) into the megasquirt-3x, making all those extra inputs usable inside the megasquirt-3, and writing them to the datalogs with the rest of the megasquirt data. Basically the IOX adds a ton if Inputs and Outputs to the whole system. This box CAN die if it has to, as all of its inputs are noncritical to engine operation.

(3) an Intel "CarPC" that I assembled myself using a VoomPC2 case, an Intel Atom processor at 1.8ghz, it's just like a laptop without the monitor and keyboard. THe reason I added this box (cost $550), was because the fastest way to record megasquirt data - maximizing samples per second - is through a good old 115200bps COM port. So I bolted this computer in the car to not only capture all the megasquirt log data, but to act as a communications server with its WiFi antenna so I can connect remotely from the push truck and monitor critical data as the car is on course... and I can also manually toggle the shutdown light in the car, remotely. Finally, if the car is in range of a wifi hotspot or has its Verizon AirCard installed, I can connect to the car from ANY internet connection and make adjustments, view run data, and even tune it remotely if I need to.

When all was said and done, for all these inputs and outputs including the sensors we've spent less than $5000. The bulk of that money is in sensors that couldn't be built by hand.

I welcome any comments or questions. I've been preparing this for 3 years, testing, testing and testing nonstop to work out as many bugs as possible before our runs which happen in one month.

-Scott

[CDMBill]

Scott, that is just way cool. An amazing accomplishment at any price but especially for so little money compared to the McLaren or similar stuff. Does this engine run closed loop or just run on the VE/spark tables down course?

It seems you could spoof some the baro or other correction factors via the IOX box and manipulate pressure ratios on the turbos electronically or with some form of chemical intercoolant? Or is that illegal? Are you supplying cooling air to the EMS, does it require it to stay in spec? Between solar heat gain and turbo plumbing could there be heat issues any where near the critical components or sensors?

Will the individual EGT's join the Red Light trigger group? That way the driver would get warning of an individual cylinder going lean before the bank AFR would see it out of aggregate range. At the target speed how long is the long course course pull expected to take?

Does this engine run a crankcase vacuum pump? If so it would be interesting to log crankcase pressure via an additional MAP sensor. It would also tell you if there is a crankcase sealing or ring seal issue once you have your baseline. I bought a standard GM MAP sensor for this purpose and it'll mount near one of the valve covers with a short vacuum line to a fitting as I'm not sure how heat tolerant they are.

[dieselgeek]

Scott, that is just way cool. An amazing accomplishment at any price but especially for so little money compared to the McLaren or similar stuff. Does this engine run closed loop or just run on the VE/spark tables down course?

I am running a loose closed loop program with the O2 sensors in case he gets into a part of the VE map that I have not tuned yet, which is entirely possible. So yes.

It seems you could spoof some the baro or other correction factors via the IOX box and manipulate pressure ratios on the turbos electronically or with some form of chemical intercoolant? Or is that illegal? Are you supplying cooling air to the EMS, does it require it to stay in spec? Between solar heat gain and turbo plumbing could there be heat issues any where near the critical components or sensors?

I am using the Boost Control feature of the MS3x to set target boost based on MPH, or TPS (my choice). MPH based boost keeps the power down for the first 3 gears, then lets me increase with more MPH. However TPS-based lets the driver modulate boost (and power output) with the throttle making the car more drivable. We'll see which one works best on the salt. Our drive pressure ratios in the turbos are mapping out to be almost 1:1, something I've never seen, but it's working good. Chemical intercoolant is OK but I can't spray anything as fuel except event gasoline as we're in the Gas class. I have the EMS mounted in the cabin, should be good to 200* F, same with the IOX, both are passively cooled (but have heavy heatsinks, heaver than what you find in any commercial EMS as the 5v regulators are sharing a big load here). We spent many thousands of dollars on heat protection as you'll see when the car is finished. Coatings, Wrap, and physical heat shrouds over the hot parts protect from infra red heat as well as hot underhood temps. We'll see how it works! I warned the guys I always melt SOMETHING at Bonneville under the hood of turbo cars, so I am bringing spare harnesses in case.
[/quote]

Will the individual EGT's join the Red Light trigger group? That way the driver would get warning of an individual cylinder going lean before the bank AFR would see it out of aggregate range. At the target speed how long is the long course course pull expected to take?

I can add the EGTs to the warning system, as well as the O2s. Haven't set it up yet, still thinking how I want to approach that. I know the tune is on the rich side, the EGO feedback will be pulling fuel... I might just let that go, but may watch EGTs not for lean/rich but for cold/hot. Cold cylinders mean we broke valvetrain parts, killed a coil or injector, and are a good reason to abort a run.

The run will take just around 80-90 seconds once top gear is reached. Which is a heluva long time at 1800+hp. The good news is, this engine flows so well that we can make 1800hp with only 10-12psi. My hope is I can get by on simple wastegate spring pressure without having to resort to fancy boost control options, but it's there if I need it.

Does this engine run a crankcase vacuum pump? If so it would be interesting to log crankcase pressure via an additional MAP sensor. It would also tell you if there is a crankcase sealing or ring seal issue once you have your baseline. I bought a standard GM MAP sensor for this purpose and it'll mount near one of the valve covers with a short vacuum line to a fitting as I'm not sure how heat tolerant they are.

Skip the GM MAP - I forgot to mention that we do monitor crankcase pressure. I found where to get real pressure transducers as small as 0-15psi that can tolerate heat, fluids, etc. They're about $30 bucks on ebay, same thing as what comes with a pressure gauge from autometer (except cheaper), has the 3-pin GM connector and everything. We can use one of those on your car.

[squirrel]

Thanks for sharing. This is good stuff.

How many of those sensors are providing data that is used by the computer to control things? It looks like many are just being logged.

[Bob Holmes]

I think I read in the Langlo's posts on Landracing that you can run water in an injection system. But it has to be observed and sealed, just like with the event gas.

Wow Scott, no wonder you've been so busy!!

[TheSilverBuick]

Way cool! To follow up with what Scott is doing, if the driver wasn't needing 100% focus on the track and controls, it would be easy enough to hook up a small monitor (like what I'm doing with my digital dash stuff) to illuminate a light/indicator saying what is giving the problem. Or have gauges that shift colors when something goes out of range. All depends how busy or not you want the screen. In this car's case, a big red light is all you need if your thresholds are set right.

BTW, how big are those datalog files by the time it's shut down? And is the datalogging still going after the engine is shut off? Might be useful to see if a turbo bearing is going if one spools down way faster than the other or something.

[dieselgeek]

Thanks for sharing. This is good stuff.

How many of those sensors are providing data that is used by the computer to control things? It looks like many are just being logged.

Great question as usual,

I started off with a KISS principle, I only run the minimum sensors to run the engine and give me, the tuner, feedback on the tuneup. Stuff I normally do all the time, no sweat.

But then the chassis tuner starts asking me "can it log suspension travel so we can tell if there's too much downforce, or lift, during the run?" and then the Turbo guy wanted to know "can you log turbine speed so we can monitor turbo health" and it spiraled from there.

I put together a couple different options for standalone datalogging, and we were looking at something like $20,000+ to capture this data. Meanwhile, the Megasquirt guys have been working hard at logging numerous extra channels, integrating CAN bus technology, and testing it hardcore to make sure it works. I had used the IOX on our Engine Masters project, just for 8 O2 sensors, so I went ahead and spent the $60 on another and started testing these things at home on my kitchen table with the Stimulator (engine simulator). It all worked nice and smooth, so i told the guys I could do it for less money - the tradeoff is, it's goiing to end up very customized and only a small handful of other guys in the world will be able to follow what I am doing...

So I documented the CRAP out of the entire system. All wires, colors, locations. All wires are labelled in the car at both ends. The system is easy to follow. The goal here was, god forbid I get hit by a bus, then guys like Jerry Hoffman, Mike Higginson, or Randal Burns can take over the tuning and support.

This was good enough for the rest of the guys on the team. Fact is, this car would not have made it this year if we'd have had to spend any more money on systems. We have a fixed monthly budget we've been working with for 3 years now, and every single month we meet to decide who gets to spend how much on what.

Hopefully this plan works out. It's DIY but as professional and documented as I can make it.

[dieselgeek]

Way cool! To follow up with what Scott is doing, if the driver wasn't needing 100% focus on the track and controls, it would be easy enough to hook up a small monitor (like what I'm doing with my digital dash stuff) to illuminate a light/indicator saying what is giving the problem. Or have gauges that shift colors when something goes out of range. All depends how busy or not you want the screen. In this car's case, a big red light is all you need if your thresholds are set right.

BTW, how big are those datalog files by the time it's shut down? And is the datalogging still going after the engine is shut off? Might be useful to see if a turbo bearing is going if one spools down way faster than the other or something.

Log files are big but not too bad, average one may be .5 megabytes. You are correct, I offered up a number of display options but the pilot (he's got 30 years flying 727s and 777s for American, plus another 20 years flying for the Air Force) wanted to keep his eyes on the course and minimal inputs to monitor. He wants to know if there's a critical problem and shut down, that's it.

And yes, the system is set up so that the ECUs all have power even when the car shuts down. Only the "oh shit" cutoff or the external battery switch will shut them down in an emergency. This way I can log temps as the car cools down, on turbo cars at bonneville (in my experience anyways) it's nice to know what's happening under the hood during shutdown, when all that heat needs dissipated ASAP.

[dieselgeek]

I should add, the car is equipped with two independent Accusump systems. Anyone out there every used these little babies?

When I shut the car down, the turbochargers have full oil pressure for SIX MINUTES !! it's awesome. The engine has oil pressure for about 3 minutes after shutdown.

Accusumps take up space and add weight but man do they seem to work awesome! I had an emergency shutdown on the dyno, no problem at all - turbos spin down and continue cooling without the engine turning.

[Barry Donovan]

impressive compilation.

is future looking simple, instead of com, use like a usb hub or other throw it all at one spot?

I run away from extras, all because of cables. you are very patient.

[TheSilverBuick]

Accusumps take up space and add weight but man do they seem to work awesome! I had an emergency shutdown on the dyno, no problem at all - turbos spin down and continue cooling without the engine turning.

As cool as that sounds, is there any consideration if an oil fire starts from a leak in a turbo line, etc? In our haul trucks, shovel's etc. the fire suppression system has no chance of working if the engines are still running and spraying oil/hydraulic fluid everywhere. When ever a report from another mine comes in from a piece of equipment burning up it's 99% of the time because the operator didn't hit the "oh shit" kill switch before hitting the fire suppression.



**Oh and thanks for the info!

[Bob Holmes]

We run an accusump.

I've been telling our guys that we have to come up with a data logging system. I'm tired of using the least reliable component for datalogging, the driver.

Let me suggest one other potential input. Add a button on the steering wheel. If the driver wants something checked on a run, he pushes the button and it marks the general location in the data log. It could save you from having to look through the entire trace for the "event."

[CDMBill]

That's a great idea, we do that when do the driving tuning on the EMS with the space bar. Scott likes the passenger seat WOT tuning.

[OldMachinist]

Man this is really interesting! I appreciate anyone as knowledgable as Scott sharing info with us. I am totally ignorant about this kind of thing but reading these type posts helps to somewhat understand the possibilities out there.
The accusump has a valve to turn it off if I remember correctly. Would it be possible to devise a way to turn them off if the fire suppression system was activated thus removing that fuel for a fire? Maybe turn off the fuel also with supression system activation.

[Caveman Tony]

Very VERY cool stuff, DG.

Just outta curiosity, what type of intercooler is utilized? Ice water? Dry ice Air-to-air?