Measure tyre pressure ?

[geartox]

1) which device do you use to control/check the tyre pressure ? digital ? analog ?

2) The Exige does not have a TPMS , did you install one ? 
   Michelin has the CUP2 Connect but for the moment not in good size for us.
 

[philcool]

I use an analog gauge always buy the best quality 

Digital always look more accurate but that's not always the case and I'm old school 

[razad]

I use a small analogue gauge that fits in the pocket so I can check the pressure directly after entering the pits.

I kow the new exiges have tpms since a "low tirepressure" light goes on when pressure is low. Would be nice to be able to read out that signal somehow and see it while driving. Through the obd2 maybe?

[MrP_]

On 14/10/2018 at 09:58, razad said:

 

I kow the new exiges have tpms since a "low tirepressure" light goes on when pressure is low. Would be nice to be able to read out that signal somehow and see it while driving. Through the obd2 maybe?

I think TPM is only a requirement for certain countries, and I think it’s itpms where wheel rotation is measured, but haven’t looked into it

Edit: Actually have now looked into it and it is direct monitoring, with 434mhz wheel sensors part no: A132G6017F. and you also need the receiver B132M0376F. But I thought this was Gulf countries only, so a bit confused. Certainly never seen the light on mine

Edited October 15, 2018 by MrP_

[razad]

1 hour ago, MrP_ said:

I think TPM is only a requirement for certain countries, and I think it’s itpms where wheel rotation is measured, but haven’t looked into it

Edit: Actually have now looked into it and it is direct monitoring, with 434mhz wheel sensors part no: A132G6017F. and you also need the receiver B132M0376F. But I thought this was Gulf countries only, so a bit confused. Certainly never seen the light on mine

When driving on track I have 2bar in the tires hot.
fter after a longer break (lunch) the pressure is about 1,7-1.8. When starting the car I get the "low pressure" light.

What I would like to know is if it is possible to read the signal from the sensors with a reciever fron ebay that you can put on the dashboard.

[MrP_]

25 minutes ago, razad said:

When driving on track I have 2bar in the tires hot.
fter after a longer break (lunch) the pressure is about 1,7-1.8. When starting the car I get the "low pressure" light.

What I would like to know is if it is possible to read the signal from the sensors with a reciever fron ebay that you can put on the dashboard.

As it's the same part numbers as the Evora, then it seems to be reading the pressures as in this picture:

From the quick reading I have done, the signals are fed via the ECM and communicates via Canbus - this is for the Evora, but can't see the Exige being different. As for Canbus decoding, I think you need to look on LotusTalk. And to add although it may be the same parts, as our dash doesn't display the signals the ECM may not relay them, instead just alerting when below 75%

I'm not sure how the ebay displays get a feed so not sure if you can piggy back off the Canbus

[razad]

5 minutes ago, MrP_ said:

As it's the same part numbers as the Evora, then it seems to be reading the pressures as in this picture:

From the quick reading I have done, the signals are fed via the ECM and communicates via Canbus - this is for the Evora, but can't see the Exige being different. As for Canbus decoding, I think you need to look on LotusTalk. And to add although it may be the same parts, as our dash doesn't display the signals the ECM may not relay them, instead just alerting when below 75%

I'm not sure how the ebay displays get a feed so not sure if you can piggy back off the Canbus

I was thinking something like this recieving at 434MHz

https://www.ebay.com/itm/Solar-Wireless-TPMS-LCD-Car-Tire-Pressure-Monitoring-System-4-External-Sensors/253867796136
 

[MrP_]

8 minutes ago, razad said:

I was thinking something like this recieving at 434MHz

https://www.ebay.com/itm/Solar-Wireless-TPMS-LCD-Car-Tire-Pressure-Monitoring-System-4-External-Sensors/253867796136
 

For the money it’s worth a try, if they are simple transmit/receive then you could in theory do it. I’ve just never seen it

[geartox]

I was thinking about the same type of device.

[mark248am]

On 15/10/2018 at 12:15, MrP_ said:

I think TPM is only a requirement for certain countries, and I think it’s itpms where wheel rotation is measured, but haven’t looked into it

Edit: Actually have now looked into it and it is direct monitoring, with 434mhz wheel sensors part no: A132G6017F. and you also need the receiver B132M0376F. But I thought this was Gulf countries only, so a bit confused. Certainly never seen the light on mine

I have the euro spec Cup and when my tire pressure drops i get a warning on my dash

[MrP_]

3 hours ago, mark248am said:

I have the euro spec Cup and when my tire pressure drops i get a warning on my dash

Right, time to let the air out and drive around for a bit!

Edited October 16, 2018 by MrP_

[Lo2zz]

What tyre pressures do people run for road?

[razad]

14 hours ago, Lo2zz said:

What tyre pressures do people run for road?

2.0 front 2.2 rear on Cup 2s
Thats 29/32 in psi.

Edited October 22, 2018 by razad

[LotusPilot]

Responding to the original question, any pressure guage is only as “good” as its calibration - although, generally, price can (but not always) provide a clue as to quality and accuracy of its calibration.  The better gauges generally quote their calibration accuracy.  Garage forecourt pressure gauges are notoriously inaccurate as they are heavily abused and rarely recalibrated.

Don’t confuse the scale resolution with accuracy - although you would hope that improved scale resolution would be coupled with improved accuracy.

Digital guages are, in general, very good for achieving consistency of readings between tyres where they are all checked/set at the same time.  A good, affordable, digital gauge should be able to achieve resolution of 0.1 bar (~0.5lb) or better.  Analogue guages, even with large visual scales, are more difficult to achieve relative consistency between readings; this is a function of both the mechanics of the guage mechanism and parallax errors in reading the scale - neither aspects of which affect digital gauges.  Commercial quality analogue gauges can also be relatively sensitive to temperature - whilst some professional (expensive) kit can be temperature compensated.

Regardless of choice between analogue or digital, set pressures are generally more accurate if you slightly over-inflate beyond the target pressure - and deflate gradually, with the gauge, until the target pressure is acheived.  The best gauges incorporate a valve for this purpose.

If you can find one, Halfords used to carry a “professional” digital gauge in a zipped hard-case.  My personal experience has been that this model has a very reliable pressure-load cell, is very well calibrated, is insensitive to instrument temperature - and has resolution and stated calibration of 0.1bar.  Target pressures for front and rear can be programmed to assist with rapid setting - with audible feedback when the pressure is within 0.1 bar of target.

In summary, a “good” digital gauge can remove many of the limitations of reliable pressure setting - but even a modest digital gauge will allow you to acheive consistent settings.  By contrast, a “bad” gauge of either type is just a bad gauge.

Edited October 26, 2018 by LotusPilot

[LotusPilot]

A corollary to my previous comments with respect to calibration and consistency...

The above comments obviously relate to the use of a single high-quality gauge to set the pressure of all wheels.  The use of TPMS systems that directly measure pressure via independent pressure load-cells (as opposed to wheel speed) should not be relied upon for absolute pressure setting.

Whilst the use of a single external gauge to set pressure will achieve relative consistency between wheels (as the measurement gauge and related calibration are common between wheels), TPMS relies upon seperate sensors, calibration of which will be variable and highly unlikely to be consistent for pressure or ambient temperature.

In general, TPMS should not be relied upon to provide accurate absolute pressure readings.  The primary purpose of TPMS is to provide the driver with early warning of a significant tyre pressure issue, whilst the vehicle is being driven, prior to occurance of catastrophic failure and/or loss of control.  Additionally, TPMS systems that utilise wheel-speed detection cannot detect a gradual pressure change - such as a slow puncture or leakage from a faulty valve or rim seating.

Consistent with good practice, we all check our tyre pressures (and condition) before every journey, don’t we?  😉

 

[geartox]

little pictures regarding my experiences with tyres during the last three years.

 

 

 

TPMS is interesting for road usage to identify quickly a problem. It could be also interesting during a trackday (like the Michelin connect system) to detect pressure changes from an optimal configuration measured previously with a reliable instrument.

Otherwise concerning the CUP2 (only CUP2) 30 PSI front/rear is clearly not a good setup for me 😱😢.  30/32 front and 32/34 rear provide a very good grip and reduce the destruction on the tyre sides.

As I said in a previous post checking tyres before, during, after a trackday is MANDATORY. I know that it could be boring, but you have to.

I didn't find for the moment a good aftermarket TPMS system to buy and test.

Regarding the tyre pressure I used a little digital device from Michelin : 

 

 

 

 

 

 

 

[mark248am]

I use this https://www.amazon.com/gp/product/B00443ZNOM/

Had a good rating and was a good price

[Arun_D]

12 hours ago, geartox said:

 

Otherwise concerning the CUP2 (only CUP2) 30 PSI front/rear is clearly not a good setup for me 😱😢.  30/32 front and 32/34 rear provide a very good grip and reduce the destruction on the tyre sides.

 

 

 

Wow, I thought I was unlucky with my single delamination of a ZZR on the 'ring this year. Thanks for sharing the picture.

Regarding your Michelin experience, I follow the reference below (states an optimum working range of 33-39psi depending on application), and have similar good experience to you. I have started with 33psi all round.

https://www.michelin.co.uk/high-performance/sport-driving-FAQ/checking-tyre-pressure

 

[geartox]

driver61 recommends longacre https://driver61.com/product/longacre-digital-air-pressure-gauge/

[geartox]

New racelogic system to monitor in live tyre temperature :

https://www.vboxmotorsport.co.uk/index.php/en/products/accessories/tyre-temperature-monitoring-system

Integration with video :

https://racelogic.support/02VBOX_Motorsport/Video_Data_Loggers/VBOX_Video_HD2/Knowledge_Base/Connecting_Tyre_Temperature_Sensors_to_VBOX_Video_HD2