sbelles

Since installing a brake pressure sensor, I'm seeing some apparent brake pressure after I'm off the brakes, usually at apex. My guess is that it's back pressure from pad knock back but I don't feel any in the pedal. The video below is from sprint 1 at Summit. I do think I had a wheel bearing going out at the end of the enduro but I noticed this at VIR as well.

ProCoach

For sure you want to look at the actual measure. In your MXm, select Live Measures and look at the mV (millivolts). Verify the with 0 pressure it’s reading 500 mv. Ok for the pressure and voltage to fluctuate a little. Then, look at your data and take a look to see pressure on that. Could be that the camera is still set for inline acceleration for the brake measure and just needs to be switched to brake pressure with the maximum in the camera config marching what you see in your data. PM me and I’ll be glad to help.

Matt Romanowski

That is a bit odd. I would first check the SCHD setup like Peter said. Make sure you have the braking graph set to brake pressure and that the values are appropriate (0 or 10 for min, 1200ish max). Also make sure you're logger has the brake pressure (not position) set to transmit.

You can also make sure your sensor is good. When sitting still, using live measures, make sure it reads around 0. You will see some variation, maybe +/- 10 psi. If that bothers you, look at the resting mV range like Peter said and then you can make a custom sensor with the min. that you see in live view (around 500 mv) and 4500 mv for the max.

It is possible that you are seeing knock back. Look in the data and see what it shows. If you see the spike in the data, then something is going on.

Report back what you see.

ProCoach

I think the only phantom pressure you might see is if the wheel bearing were going out and allowing the rotor to move axially, it might register, but then you’d have to pump the pedal to get a pedal, if that were the case.

Matt Romanowski

Knock back can take pumping too. I've seen it be spindle stiffness, caliper issues, wheel bearings, pad issues, brake line issues, lots of things. I've found knock back to be one of the things that you have to go through the system and make sure every component is right.

sbelles

It may remain a mystery until next year. When I look at the channels on the MXM, the brake pressure is there but not in my files?! Weird.




I had a shop install both sensors and they obviously configured the channel (channel01) but why doesn't it show in the data? Now I wonder what the SCHD is using but I'm not going to be able to check it out until next week. If it's using the accelerometer though then you would think that the phantom pressure would be there turning both right and left. It only seems to be there on rights.

Matt Romanowski

I think the brake pressure is probably not set to log, so it's in live view and not the data file. To be honest, you're system wasn't completely set. You need the channel names set, units set correctly, and to make sure everything else is configured. I'm happy to help if you want - you'll need the config on your laptop, RS3, and the car. If the shop won't finish it, feel free to call me and I'll help you 603-674-3250 We will get it so it's much more useful for you.

ProCoach

I haven’t seen a channel show in live view (required to set it up to see it) that doesn’t log. Other systems can turn logging on and off, but not AiM.

To be honest, the throttle and brake were added well after the original installation by the shop, so it’s just a simple matter to correct this situation following AIM’s method, as Matt describes. We can do a TeamViewer session anytime.

It’s not going to be possible to retroactively see brake pressure and throttle on your data until this is fixed. I am now curious for you to download the camera config and see what that brake bar is set on!

sbelles

Me too. At first I thought maybe they forgot to transfer the config after setting the channels up but then they wouldn't show in live view and the throttle position wouldn't have been there when we re-calibrated. It wasn't my laptop they used either. Seems very odd. I'll try to figure it out when I get back home again next week.

Matt Romanowski

Are you a left foot braker?

sbelles

Only certain corners like turn 3 at NJMP. I sometimes do at Summit turn 5 but I wasn't at all that weekend. The car actually felt more stable in the chute then it ever has. Maybe a little rear brake drag at apex isn't all bad?

Matt Romanowski

Just an idea I had the other day. We'll have to see what the config says.

ProCoach

Camera config listed brake bar as inline accel to a limit of 1.2g Now changed to brake pressure in psi. MXm config has correct brake pressure sensor listed for Channel 01 but the config in the MXm is older than the one in RS3. We don't have access to the shop's config but this is now matching between the MXm and the camera. yay!

powdrhound

I'm having a similar issue with the brake pressure display overlay using the Smartycam myself. You can see this in the video below. The brakes pressure seems very spiky on the display yet that is not the case when looking at the Motec I2 data. Not sure what the issue is or what the solution is. I am using a Motec C125 Dash, a Motec brake pressure sensor, and an Aim ECU bridge to work with the SmartyCam2.

ProCoach

Looks like a crappy connection or scaling's off. Probably not a connection issue with the MoTeC data reading ok. I would check the input for the brake bar in the SCHD config.

Three choices: brake position, inline acceleration and brake pressure. Should be brake pressure and scaled to the maximum psi you see on the MoTeC data.

Odd that you get temps on the SmartyCam, as that is not usually transmitted through the VCS_CompoundFull_Transmit template from the dash to the Bridge.

That car is a BEAST! Love that vMax!