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I thought folks might like to see what the data from a race TPMS system gives you. It gives you lots of data on how fast and when a tire builds pressure, internal air temp (to allow you to actually calculate pressure build/volume), and to determine what the optimal tire pressure is for maximum grip and driver feel. In April I'll be able to couple this with full IR tire temp data that I can share to show just how a tire builds pressure as the tire surface and internal temp build. Very cool stuff!
This system is a little different than many in that it goes on the valve stem rather than replacing it. Very quick to install, service (when needed) and it doesn't risk damage when changing tires.
As always - cool stuff Matt! Please keep us posted.
I run an internal TPMS system that displays pressures live in the cockpit. I am using the external ones on my trailer. The external ones should be really only used with metal valve stems because with the rubber ones, they move around quite a bit. My recent experience is that these internal TPMS sensors were not made for the heat that you are encounter on the front wheels of a race car. I have been melting my valve O rings and the vales started leaking air. We are currently working on a fix for that.
As always - cool stuff Matt! Please keep us posted.
I run an internal TPMS system that displays pressures live in the cockpit. I am using the external ones on my trailer. The external ones should be really only used with metal valve stems because with the rubber ones, they move around quite a bit. My recent experience is that these internal TPMS sensors were not made for the heat that you are encounter on the front wheels of a race car. I have been melting my valve O rings and the vales started leaking air. We are currently working on a fix for that.
There are 3 or 4 companies that make the systems with internal sensors. Some have temperature problems. These are good good far north of 400F.
Not had an issue with the Beru, bf1 or Stack systems.
__________________ -Peter Krause www.peterkrause.net www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
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SO I ran the externals all last year and loved it. So much so all my wheels were balanced with the valve caps on to compensate for them. The problem with the externals was two-fold. 1. They just got so damn hot it made it really tough to do any type of quick pressure checks/adjustments and 2. That little rubber grommet used to create a tight seal inside the TPMS end cap just melts and you get the slow leak syndrome similar to what Frank was describing with the internal unit.
On the internal unit however, there is a reason Peter has probably had success with the units he has. The difference is in Snap in vs Clamp in style valve stems. The problem is evident in this picture.
So what we learned through Frank because we are both moving to internals at the same time is that you need a Snap in style sensor. That is unless anyone knows of a high temp grommet to use...
So you have two options, use a stock valve stem or something of the likes on the sensor body or get a specific set like this where you can specify snap in vs clamp in style. Fortunately they are 433 Mhz so any TPMS system with a learn capability in North America should work with them.
These have made it through well over 400 degrees without trouble. They have seen use at Martinsville and lives to tell. That's the place where they have set tires on fire from the brake heat.
Which system is that you are using Matt? Thiss is so above my knowledge level but I'll ask anyway LOL.
Are you using some sort of receiver like the Brightwater to get the data via CAN? I've always wondered why this data couldn't be read from a Porsche OE TPMS system... This will all get so much easier once SDV becomes mainstream
Which system is that you are using Matt? Thiss is so above my knowledge level but I'll ask anyway LOL.
Are you using some sort of receiver like the Brightwater to get the data via CAN? I've always wondered why this data couldn't be read from a Porsche OE TPMS system... This will all get so much easier once SDV becomes mainstream
This one is custom made. Some components, like the sensor housing, is from a cheap kit to keep the cost of manufacture down, but then the sensors and electronics in it are replaced. The CAN protocol and electronics in the receiver are custom.
It is a little frustrating that the stock systems don't communicate the TPMS info well. For the right people, it's not hard to do the electronics (I'm not one of them!). This system is a terrific value and works really well for people. As you know since you have a system, they give some great data and insight into how the tire works. Add in a little math (PV=nRT) and you'll be way better at setting tire pressures.
This one is custom made. Some components, like the sensor housing, is from a cheap kit to keep the cost of manufacture down, but then the sensors and electronics in it are replaced. The CAN protocol and electronics in the receiver are custom.
It is a little frustrating that the stock systems don't communicate the TPMS info well. For the right people, it's not hard to do the electronics (I'm not one of them!). This system is a terrific value and works really well for people. As you know since you have a system, they give some great data and insight into how the tire works. Add in a little math (PV=nRT) and you'll be way better at setting tire pressures.
I don’t have the ability to log tire pressures but it is invaluable information to see the actual pressures live. I would love to have both live and logging capability at a reasonable cost.
These are $1,800, so much more reasonable than other systems. Full CAN communication, Bluetooth phone app, and replaceable batteries in the sensors. You can also have more sensors for multiple sets of wheels.
I've always wondered why this data couldn't be read from a Porsche OE TPMS system...
In the GT4 street car I can tell you that the OE TPMS system does provide pressure and temperature values -- those are in messages on the CAN DISPLAY/MMI bus. I have logged those on the C125 I have in the car. It's not as satisfying as what Matt's example shows though -- the sample rate is apparently very slow so the values move in pretty large step functions. The temperature values are interesting but they represent the temp of the air in the tire rather than temperature of the tire carcass which would have been more useful -- perhaps that's why the MFD only shows the pressures even though the car has the temperature values too.
In the GT4 street car I can tell you that the OE TPMS system does provide pressure and temperature values -- those are in messages on the CAN DISPLAY/MMI bus. I have logged those on the C125 I have in the car. It's not as satisfying as what Matt's example shows though -- the sample rate is apparently very slow so the values move in pretty large step functions. The temperature values are interesting but they represent the temp of the air in the tire rather than temperature of the tire carcass which would have been more useful -- perhaps that's why the MFD only shows the pressures even though the car has the temperature values too.
Very cool. The internal temps are also really important. That is what lets you predict pressure gain. PV=nRT Ideal gas law, just like Deflate Gate. If you know the hot temp, cold temp, and desired hot pressure, you can calculate your starting temp.For anyone that uses heating blankets, this is critical.
03-05-2018, 04:14 PM
Race TPMS Data
They all have weak points that don't always show up in all applications.
