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I'm looking to go with an AEM Infinity Series 5 ECU for a project I'm building right now and really want to add traction control. The Series 5 states that it has 2 wheel traction control option in its specs and I will be running VR wheel speed sensors that are integrally mounted in the Corvette ZR1 hubs I'm using.
This seems straight forward, but I want to confirm my approach will work before I dump $$$ into this setup. The way I understand this, I can connect the rear (drive wheel) speed sensors to the ECU via the two channels set up for traction control and calibrate for VR sensors. I will then connect the front (non drive) sensors to two open VR inputs on the ECU, calibrate and be good to go. Then tell the ECU which channels to pull data from in order to setup traction control.
Does this sound like the right approach?
Your thinking seems sound however at this point we haven't used the traction control in the Infinity so it's a little hard to give you much more info. One thing you do need to consider is the trigger you're using for the wheel speed sensor. An obvious choice would be to use an ABS speed sensor however I've struck a few ECUs where the high tooth count is problematic at high speed. I'm not sure on what the Infinity will allow here in terms of maximum frequency. We have one of AEM's techs in here so hopefully he can add to the conversation.
I greatly appreciate you chiming in and providing some feedback. I'm really looking forward to digging into this system and learning everything I have picked up in your videos on tuning. You guys have really put together a quality product here and I'm so glad I decided to jump in.
Hopefully the AEM Tech can chime in here as well.
The Infinity-506 and Infinity-508 ECU have two VR inputs that can be used for wheel speed, and two digital inputs that can be used for wheel speed. So your options with those ECU platforms is to either run just one sensor front and one sensor in the rear, or VR sensors at one end of the vehicle and digital sensors at the other end if you need a speed signal from all 4 corners. The Infinity-708 ECU has more inputs, it can do four VR speed inputs.
I'm not aware of problems from high tooth counts, and a couple of our engineers have run their Infinity-equipped racecars in land speed racing where it's not uncommon to see speeds above 200 MPH. From here, I'm going to copy/paste some generic TC info that I've posted in response to other questions. Apologies if the formatting gets weird, copy/paste can be funny and I'm not very familiar with how to adjust text formatting on this forum.
Once you have the speed sensors connected and configured, the channel GroundSpeed [MPH] will use the maximum speed from the GroundSpeed(Left) and GroundSpeed(Right) inputs, and the channel DriveWheelSpeed [MPH] will use the maximum speed from the DriveWheelSpeed(Left) and DriveWheelSpeed(Right) inputs. Comparing the maximum speeds for front and rear allows the traction control to continue functioning if one of the four sensors becomes disconnected, or if the vehicle only has one front and one rear speed sensor installed.
From there you configure the Traction Control settings to tell the ECU how much slip is allowed (many people use a multi-position knob in the cabin to change the amount of slip allowed) and what reactions the ECU should take when too much slip is measured. It can retard timing, decrease DBW throttle position, cut spark on some or all cylinders depending on how much slip is detected. For example, you can configure to retard a little timing if there is a little slip, then more timing retard plus a partial spark cut if there is a lot of slip.
We've heard from customers using Infinity traction control on road-race and time-attack vehicles with good results. Having the knob for live adjustment lets the driver find what works for them without losing tons of track time fiddling with a laptop. If you have a very fast drag car that lifts the front tires, the front wheel signal is not going to work well for traditional front vs rear speed traction control. We have other strategies that can be useful for that sort of thing, but I don't want to make this post even longer unless that's something people are specifically interested to hear about. Even if all the tires are staying on the ground I don't think traction control is the best way to improve times on a drag car. In my opinion, the key seems to be using other strategies like gear-based, time-based, or speed-based power management to prevent the engine from overpowering the tires and losing traction in the first place.
Hope that helps,
That is the exact feedback I was looking for to answer my concern. Sounds like I have this all all figured out and am ready to pull the trigger on this entire setup. I greatly appreciate the time you guys put into providing quality feedback here in these forums. Time to go spend some money :)!!!
What Happens when the tyres hit a kerb and becomer airbone for a moment ? is there a way to prevent TC kicking in when this happens ?
In that case, you tune the dampers, not the ECU's traction control.