01-09-2020, 06:48 PM | #1 |
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OEM TPMS for track use
Fellow track junkies.... I'm ordering some wheels + r-comp tires for the track. Should I stick in TPMS sensors in there? Wondering if the pressures and tire temps are accurate...?
I also read where a TPMS warning (due to low initial pressures) will turn DSC back on and prevent sport mode. What's the consensus on this?
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01-09-2020, 08:02 PM | #2 | |
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At a Point above 7,000 RPM.
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01-09-2020, 10:50 PM | #4 |
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It's not. The air temp inside isn't necessarily close to the carcass core temp, and obviously won't tell you the temps across the tire (which is the important thing to look at).
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01-10-2020, 08:35 AM | #6 |
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I’ll throw in a diff opinion from tons of track days and trying with/without sensors.
Tire temps really don’t matter for setup unless you are properly taking temps from multiple spots across the tire in the hot pits. Good for racing, but that’s generally overkill for DE with a street car. As for pressures, I’ve found it’s more accurate to have TPMS and watch PSI on my last few hot laps to make a mental note of how they need to be adjusted. By the time you do a cool down lap and roll to the paddock and take pressure from all four tires, they are several PSI off from what is happening on track. Plus, PSI in the front goes up quickly once you park and heat from the brakes soak into the tires. Folks complain about using TPMS at the track, but you just reset it each time you go out and it works fine. And you get better on track data. |
01-10-2020, 09:00 AM | #7 | |
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Agreed. That's the issue with DEs, you barely get a good heat cycle and then it's a full cool down lap and then a lengthy drive to paddock. Im not planning on doing too many events in the M2 and yet my mods always run toward full race car, even though I have another, full race car. This is a disease. Lol |
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01-10-2020, 04:40 PM | #8 |
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I have used the TPMS for the reasons that ZM2 listed, but also using a tire pyrometer that has a memory function has been great for me as well.
I have pulled into the pits in traffic situations and quickly hopped out and done Outside/center/inside measurements of all 4 tires. Then right back out onto the track. After the session I add this data to my logs for the day. I average 2 logs of tires per track day. I also have done this for over 15 years as a competitive Solo 2 driver as well. Every car and driver is different (tires, suspension, skill, etc) I'm a big believer in getting camber "right" especially on the front axle. On R compounds I'll bet the car wants at least 3.4-3.6 neg up front. On 200's ZMP and others swear by 2.9-3.1.... Same goes for cold and hot tire targets. Soo many variables...
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01-11-2020, 09:22 AM | #9 |
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I also have a different view based on some track days. I use the temperature as indication when I need to do a cool down lap, as MPSS start feeling greasy right around 95C. I noticed consistency in this behavior and now as I see temps reach that mark, even while the pressures are ok, I slow down and let them cool off.
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05-16-2023, 03:10 AM | #10 |
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An old thread but this info will be of value to anyone with an LCI and likely OG. Knowing the CS & M2C TPMS have a lower psi value threshold before you get kicked into Comfort mode with the 130kph max speed limit I just had some updates done to my ecu, using ista he updated the TPMS modules (& some other unrelated modules while at it). Previously pressures below 28psi would automatically force me into Comfort with a 130k speed limit, occasionally even 28 wouldn't work. Was a pain having to pit, doing another TPMS reset & hope pressures were up enough.
Now I can start on 25psi, get the pressure warning during reset but car stays in Traction Off (or select any mode for that matter). Have only tried it on street but I was able to drive for over 4km with 3 tyres showing 25psi & a rear 24psi, as long as I got a tyre to 26 by 4km I could continue unaffected (if all still at 25 after 4.1km it kicked into Comfort with the 130 speed limit). Obviously getting pressures up on track won't be an issue. My car is an LCI July 17 build, previous iStep was F020-18-11-531 (updated by dealer Decembe 18 as part of the faulty dash recall). New iStep is F020-22-03-552 |
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05-16-2023, 05:55 AM | #11 | |
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Also, the 28 psi threshold is not automatic at 28 psi. The Ecu seems to account for outside air temps as well. Last track day when it was in the 40s in the morning I was down to 27 psi with no warning. In the afternoon in the 70s I got the warning. |
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05-16-2023, 08:20 AM | #12 | |
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05-16-2023, 09:56 AM | #13 | |
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Different ambient temps would explain why in the past I was occasionally kicked into comfort at 28. Temp today was around 21C when I was driving at 25psi |
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05-16-2023, 04:00 PM | #14 |
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Any chance of this update locking the ECU/DME from being able to be flashed with a tune like BM3?
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05-21-2023, 11:46 AM | #16 | |
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Big shout out to daap1193 who did this update for me remotely and it only took 10min all in! His brake coding is also awesome if you haven't done it yet: https://f87.bimmerpost.com/forums/sh....php?t=1885341 Send him a PM! |
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05-21-2023, 08:02 PM | #17 |
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As an added piece of information, a modded GT2RS driver that I’ve spent some time with at an event runs nitrogen in the tires to keep pressure from building too fast as tire temps rise. He brings a 5 gallon tank charged with it to the event if he needs to add any.
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05-23-2023, 07:45 AM | #18 | |
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05-23-2023, 08:17 AM | #19 | |
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05-23-2023, 08:31 AM | #21 | |
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But still, none of us here are in high enough levels of racing to worry about the less than 1/2-psi difference bn a cold to hot compressed air tire and a cold to hot N2 inflated tire. Especially for HPDE. |
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05-23-2023, 08:37 AM | #22 | |
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