Nordschleife

I've driven without TPMS and with TPMS. I won't order a car without it now. If I'm driving at very high speeds, I want to be warned if there is a change in pressure. I have been horrified to see the shredded interior of tyres which look fine from an external inspection.

As far as most of the people complaining are concerned, they are beefing about the system doing what it is designed to do - its indicating a significant change from the baseline pressure.

At the track remember to reset your baselines through the day. To make all this easier, fill with N. Like real racers.

I have been used to TPMS in various forms since the introduction of the 959 (ghastly system). Because I do a lot of high speed running, I habitually buy new tyres and rims on a regular basis, everything has to be perfect as the speeds rise.

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how long do your tires last on avg. robin?
why the need to regularly change rims?

as far as tpms goes at barber's they made it sound like it uses wireless technology that interferes and gives false readings when around other
porsche's w/ tpms?
we were told to disregard any readings but "flat", and then to just let them know at next pit, and they would check it out.
but that most likely the tire was fine.
i had several low readings including a flat, but tires were fine.

Nordschleife

Jeff

I have been on track with 20 plus identical cars with tpms without interference. Possibly this was because the people looking after the cars had made sure the sigs were different, I didn't think to ask. I think its very easy to 'Äblame' anomalies upon 'wireless interference', I see people doing this all the time, but very rarely do they turn up with kit to track down the source of the interference.
Possibly they were providing students with a reason for the occurance of 'transients'.

When a front goes through, it will set off the TPMS. In Munich we get Föhn wind effects that set it off all the time. Its a matter of a moment to reset the base line.

How long tyres and wheels last is dependent upon what is going on, rather than amount of use.

Sometimes avoiding curbing tyres and rims is impossible. This is the basis upon which I replace tyres and rims. Sometimes when driving fast there is a temptation to drop a wheel over the edge of the road on the inside (like being on rails, ) or Italian hill villages, or pot holes, you know the thing.

When I get wheels rebalanced, I ask the guy what he thinks, if we need too much weight I'd rather replace the wheel. I can tell you all sorts of things start flexing at speed unless balance is perfect.

I do recall on guy (from Massachussetts as it happens) jumping into his brand new car and curbing three wheels within 20 metres of getting into the car because he wasn't used to tight European city streets.

I don't get uptight about this, I just replace. Do I want them repaired - NO WAY - try driving down the road at 200 mph and start thinking about what will happen if you have a tyre or wheel failure - don't think about it for too long, you may never drtive again!

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i just read that tpms uses the abs communication system so it doesnt use wireless!?
going to have to talk to those guys at barbers!?
. . . or maybe i didnt listen? possibly they disabled the systems,
so they give false readings?
brian or colm would know.
i'll know after going back in a couple weeks.

i hate having to worry about curbing the wheels and tires all the time.
i think i'll adopt your attitude! **** it . . . have to buy another!

Nordschleife

There are two kinds of TPMS system in use in the US.

One is totally useless and crap, it uses the sensor from the ABS system to calculate the circumference of the tyre and to extrapolate from that the assumprion that if the tyres are a different diameter, then the pressures must have changed...... This is about as sensible as dangling a wedding ring by a thread over a pregnant woman's stomach to predict the sex of the baby.

The other system uses the valve stems to broadcast the reading from the sensor inside the rim. You can tell whether pressure sensors are fitted and operatrional by looking at the valve stems.

I think the guys at Barbers were pulling your leg.

How about starting up a subscription service with Tirerack and BBS?

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eclou

All Porsches used the Beru wireless system. Only lower end Audis (A3) and older Mercs use the ABS sensor system. There is a great technical document here:

http://www.beru.com/download/produkt...satz_tss_e.pdf

I have purchased and installed a new set of sensors in my new wheels. Very easy job to do

mitch236

I guess these work on a case by case. Mine are off a couple of pounds from my Longacre guage but are consistent which is the only important issue. As long as they are consistent and I know the delta, I can use them. I ignore the yellow triangle that tells me I have a flat.

Nordschleife

Here is a much more current description of how the system works -

http://www.beru.com/download/produkt...tss_3gen_e.pdf

once you understand how it works, you have to ask yourself, why would you ever be without it

also see page 24 of this document -

http://www.beru.com/download/produkt...rung_tss_e.pdf


which reveals an alternative way of turning the system off - carry a fifth active sensor inside the car.



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mitch236

Ok, but that won't get rid of the warning light? Is there a way to reset what the default optimal pressure is without a PWIS?

amaist

TPMS is great for driving at high speed without too many curves. Like public road driving in Europe. On the unlimited autobahn it is almost essential.

At the track it can go crazy unless you keep playing with it. If you have enough experience you will feel the loss of 5 psi pretty quickly so TPMS is not that necessary. And always check the pressures with a gauge after each session. So far TPMS proved inaccurate in comparison with a good gauge.

I heard that on the C6 Z06 if TPMS is tripped the car goes into some limited mode. On the track that is a PITA.

Nordschleife

So why do so many race cars have it?


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amaist

Maybe they get a more accurate system then. From many reports I heard so far the Porsche mounted TPMS is not accurate.

Do you think race cars start popping warning lights when the normal changes in pressure happen during the race? They have track oriented systems.
TPMS is a street oriented system.

pcar964

I'm sorry, but a tire with a defect like a "shredded interior" wouldn't be avoided with a TPMS... When the tire gives, it gives - until that point, the only indicator is possibly an out-of-round situation, which you would obviously feel. And in actual fact, you would FEEL a drop in tire pressure almost immediately, especially at high speeds - so the TPMS is pretty much useless to anyone who is paying attention while driving. imho

Nordschleife

Well what do you think?????
'We have fitted a TPM system that does issue warnings' - really useful.

Sure, like everything else to do with motorsport there are more expensive ones available. I can say that they integrate extremely well with the Bosch monitoring and telemetry system.

Driver checks with pit and resets if required.

I fail to see why people get so uptight about these systems. Worsr case, if you get a false warning you are only 200 miles from fixing it when you stop for gas.

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Bob Rouleau

TPMS is mandatory in the USA since low tire pressure was linked to roll-overs in certain SUVs driven by people who have no feel for the vehicle.

On high end race cars, everything is monitored but I suspect tire temp is monitored more closely. I have seen tire pressure control systems on F1 cars - very slick. They are set to the optimum pressure (for the day/track) and automatically bleed off excess pressure if there is a build up due to changing conditions. Very neat but very-very expensive. A long session behind the safety car would cause a drop in pressure but the tire temperature monitors would pick that up as well.

Mooty, my dealer says he can turn off TPMS - I wonder if this is an artifact of the different software load for Canadian cars. Perhaps it is not allowed in the USA and legit (for now) here? When my 18 inch wheels show up I will know for sure because I did not buy the monitoring gizmos.

Best,