Just Sharing - MegaSquirt Traction Control - 3G Hemi 'Cuda

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11-08-2017
GoodysGotaCuda

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Just Sharing - MegaSquirt Traction Control - 3G Hemi 'Cuda

One of the best parts about going to a MegaSquirt ECU is the amount of customization you can do. It would be a bit cumbersome if you only used it for spark and fuel.

To get the most out of it, I am using the VR output shaft sensor on my T56 Magnum transmission along with a Hall Effect undriven wheel speed sensor that I fabbed a mount up for. It reads the internal cooling vanes of the rotor, 32T/rev.
Attachment 145895

The setup only has a 100 miles or so on it but the results have been more than entertaining! The car will sense the amount of slip and react to a target difference, in this case I am using 3%, which is a bit low, but I am getting the hang of things.

The car drives completely different and it is much more managable to put power down on the street. My tires are a bit old and 1st and 2nd gear wouldn't be very useful under 35-45mph..I'd just blow the tires off of it without heavy peddling to keep it moving forward....as shown....

The car is also using the no-lift-shift/flatshift strategy [video is without traction control]
https://youtu.be/QdP39A-MyiU

With the traction control, timing is pulled to try to manage minimal tirespin and maximum acceleration. This isn't a perfect example, but you can see the rear wheel speed [VSS1] go up and down and it keeps the car going forward...and straight. It's hard to say how much quicker it makes the car around town, but it is nice to be able to get on it and let the car go as fast as it can manage.

https://static1.pt-content.com/image.../BykV8X7-1.png

Anyway, I am just sharing my results. If anyone has questions, feel free to ask. I am still working on tuning it, but I can provide some support.
11-08-2017
SSLOW6.0

I run Microsquirt on my LS swap. I might go to the Gold Box in future years. I got an Micro for free so i figured why not use it. I agree on the customization and overall ease of use for MS. I'm still a newbie to tuning and need to get my car on a dyno.
11-08-2017
btmatt

cool write up. just curious; can megasquirt utilize a strategy to control engine acceleration to mitigate wheel spin? This negates the need for wheel sensors and is similar to what the outlaw racers were using with digital MSD boxes before they were banned. thanks
11-08-2017
GoodysGotaCuda

Quote:

Originally Posted by btmatt

cool write up. just curious; can megasquirt utilize a strategy to control engine acceleration to mitigate wheel spin? This negates the need for wheel sensors and is similar to what the outlaw racers were using with digital MSD boxes before they were banned. thanks

‘I believe “perfect run” control uses a driveshaft speed sensor, but ‘I have not pursued that much. It has very little benefit on a street car.
11-08-2017
btmatt

Thanks for the response. i am very interested in this as we will be going to fuel injection shortly in a first gen Camaro my son and I are working on. I have investigated Megasquirt but have lots of ground to gain. Just to be sure my understanding of your system and application, you mounted the hall sensors on the front wheel to input front VSS to megasquirt. I read previously you are using a Tremec Magnum for transmission thus you can incorporate it's sensor to input rear VSS. MS then compares the inputs and maintains a balance (3% in you case) by adjusting timing to mitigate rear wheel spin?

If so, we are also using a magnum trans and have Corvette hubs on the front with integrated speed sensors making hardware easy. We have investigated use of an electronic throttle body and my understanding is that MS3 can drive it. Curious if it could be incorporated into the control strategy too?
11-08-2017
GoodysGotaCuda

Quote:

Originally Posted by btmatt

Thanks for the response. i am very interested in this as we will be going to fuel injection shortly in a first gen Camaro my son and I are working on. I have investigated Megasquirt but have lots of ground to gain. Just to be sure my understanding of your system and application, you mounted the hall sensors on the front wheel to input front VSS to megasquirt. I read previously you are using a Tremec Magnum for transmission thus you can incorporate it's sensor to input rear VSS. MS then compares the inputs and maintains a balance (3% in you case) by adjusting timing to mitigate rear wheel spin?

If so, we are also using a magnum trans and have Corvette hubs on the front with integrated speed sensors making hardware easy. We have investigated use of an electronic throttle body and my understanding is that MS3 can drive it. Curious if it could be incorporated into the control strategy too?

You summed up what I have setup correctly. I am not sure that an MS3 will drive a DBW setup, perhaps it can, but I have a cable throttle body. I have not seen provisions in tuner studio for DBW or traction control integration with that.
11-08-2017
krom

Last I knew the megasquirt crew didn't want anything to do with DBW because of liability issues
11-09-2017
SSLOW6.0

Quote:

Originally Posted by krom

Last I knew the megasquirt crew didn't want anything to do with DBW because of liability issues

This is correct. MS will probably never support DBW.
11-09-2017
btmatt

My mistake I was thinking of IAC. Thanks again for the info.
11-10-2017
GoodysGotaCuda

Quote:

Originally Posted by btmatt

My mistake I was thinking of IAC. Thanks again for the info.

IAC is no problem for the MS, either a stepper or a PWM
11-10-2017
HellPhish89

Quote:

Originally Posted by btmatt

Thanks for the response. i am very interested in this as we will be going to fuel injection shortly in a first gen Camaro my son and I are working on. I have investigated Megasquirt but have lots of ground to gain. Just to be sure my understanding of your system and application, you mounted the hall sensors on the front wheel to input front VSS to megasquirt. I read previously you are using a Tremec Magnum for transmission thus you can incorporate it's sensor to input rear VSS. MS then compares the inputs and maintains a balance (3% in you case) by adjusting timing to mitigate rear wheel spin?

If so, we are also using a magnum trans and have Corvette hubs on the front with integrated speed sensors making hardware easy. We have investigated use of an electronic throttle body and my understanding is that MS3 can drive it. Curious if it could be incorporated into the control strategy too?

If you want DBW the way to go would be the E40, E38, or E67 ECM's from GM.
11-11-2017
TheJDMan

I think I need to pay more attention to this. I have heard of the Megasquirt but for what ever reason did not realize it could be used for traction control. I'm in the same boat in that 1st and 2nd are a challenge to not blow off the tires.
11-12-2017
GoodysGotaCuda

Quote:

Originally Posted by TheJDMan

I think I need to pay more attention to this. I have heard of the Megasquirt but for what ever reason did not realize it could be used for traction control. I'm in the same boat in that 1st and 2nd are a challenge to not blow off the tires.

While the wheelspin can be fun, sometimes you actually want to go forward! I have found this to aid in doing that pretty substantially. Granite, my tires are quite old at the moment, new treads should help my situation out but the TC will be in place to step in as-needed.
11-13-2017
btmatt

while poking around on the MS forums, i found your post there asking about you setup. With the MS traction control, is the correction dynamic in that it can pull varying degrees of timing to control wheel spin? Once wheel spin is no longer detected, does MS revert back to normal timing tables? Is there a delay? Can you also bypass traction control if you feel the need to burn the tires? Thanks again for your help.
11-13-2017
GoodysGotaCuda

Quote:

Originally Posted by btmatt

while poking around on the MS forums, i found your post there asking about you setup. With the MS traction control, is the correction dynamic in that it can pull varying degrees of timing to control wheel spin? Once wheel spin is no longer detected, does MS revert back to normal timing tables? Is there a delay? Can you also bypass traction control if you feel the need to burn the tires? Thanks again for your help.

That’s correct, the amount of timing pulled depends on the amount of slip. There is no feeling of the delay, the ECU is running these calculations very, very fast. The reaction to slip is a blanket reduction in timing. So “spark table” - “traction retard amount” = actual timing. When there is no slip, the retard amount is 0, and it just runs off of the normal spark table.

You can setup a traction control enabling switch, a ground input into the ECU. I will get to that soon. You can also put a knob on it for the amount of wheel slip you want instead. There is also a feature of a light, which I will add as well.
11-13-2017
btmatt

thanks again for the response; it has helped clarify the control and leading me more towards MS3 control for my Camaro.
12-01-2017
jetmech442

Goodys, this is really cool man, thanks for sharing. I run EFIlive on my 442, but my buddy recently put a MS on his foxbody and tuning has been really enjoyable. I'm going to show him this link to try and help him stick with his tiny tires(245) lol.

I wonder if any "learning" can be built into this(not to say it isn't already super cool), but everytime you nail the pedal it's actively trying to pursue the correct amount of spark retard. If you had another variable such as tire temp(predicted or measured), or..i dunno something else, maybe it could use a Short term/long term spark adder based on the situation.

I'm really interested in how nerdy this can get. :revto9k: I know that a certain amount of slippage can actually increase traction...wonder if down the road you can ride that fine line just by mashing the go pedal. Anyways, I'm just geeked out at work, good luck man, love the project.
12-01-2017
GoodysGotaCuda

Quote:

Originally Posted by jetmech442

Goodys, this is really cool man, thanks for sharing. I run EFIlive on my 442, but my buddy recently put a MS on his foxbody and tuning has been really enjoyable. I'm going to show him this link to try and help him stick with his tiny tires(245) lol.

I wonder if any "learning" can be built into this(not to say it isn't already super cool), but everytime you nail the pedal it's actively trying to pursue the correct amount of spark retard. If you had another variable such as tire temp(predicted or measured), or..i dunno something else, maybe it could use a Short term/long term spark adder based on the situation.

I'm really interested in how nerdy this can get. :revto9k: I know that a certain amount of slippage can actually increase traction...wonder if down the road you can ride that fine line just by mashing the go pedal. Anyways, I'm just geeked out at work, good luck man, love the project.

The reactions respond to the amount of wheel spin. The amount of timing that is pulled is directly correlated to the amount spin you see. Once you have it dialed in to your car, I am not sure how much adaptation you would realistically need.

If you hit it with hot tires and it spins less, the system interferes less. If you hit it with cold tires and it spins more, the system interferes more. All dependent upon the amount of slip [%] you are targeting. The car essentially accelerates as fast as it can given the %slip you call out. It's not like a factory system that cuts throttle and tries to slow the car down.

If I nerded out to the next level, I would compare the average of the front wheel speeds to the rear. This would allow for a better traction control while making sharp turns [autocross].