From the user forum for nanocom-diagnostics - that anyone who has one can sign up to and read/post on:
Topic is under the 'Instrument Mode' section with the topic title of 'tyre coefficient/road speed questions'

From part way through the thread:
Having had some further discussion on D2BC, I think the real question is:
Can this setting adjust the dash speedometer? E.g. when changing tyre sizes
Or
Does it only affect the 'nano speed' in instrument mode?

To which the BBS support's (Adrian) reply is:
Hello!

I apologize for the delayed answer, but I've missed this post.
The Tyre coefficient will just affect the Nanocom readings and have no effects on the vehicle. If the tires are of a different size then the vehicle instruments will read and record wrong data.

Kind regards,
Adrian

I would have thought that it would have been worth spending the 5 minutes it took me to look that up before accusing someone that they don't know what they are talking about ...
 
From the user forum for nanocom-diagnostics - that anyone who has one can sign up to and read/post on:
Topic is under the 'Instrument Mode' section with the topic title of 'tyre coefficient/road speed questions'

From part way through the thread:


To which the BBS support's (Adrian) reply is:


I would have thought that it would have been worth spending the 5 minutes it took me to look that up before accusing someone that they don't know what they are talking about ...

Never knew that. Saw the setting and assumed it would affect the car. Pity it is not in the manual.

Thanks for sharing.
 
That is probably the biggest gripe I have with some of the BBS stuff is the manuals, whilst quite well written seem to leave out a few useful bits of information...

I've always gathered that the Instruments part were just showing live data (I've used them a couple of times mostly for watching the engine coolant temp after I did the water pump and wasn't sure I had managed to get all the air out, but had to drive 40 odd miles for work - so had it on so I could keep an eye on things!) But things like the tyre coefficient would be nice to have a bit of a description in there - because I went to look in the manual first and whilst it was mentioned as an option, it isn't acually described in any way, shape or form about it's usage.

I find with the manuals on some of the other modules - Thor engine management for example - whilst have a lot of info, also don't tell you a lot in some respects. Biggest one being fuel trims/adaptive values... Whilst you presume they should sit around 1, they then go to +/- from there it seems - which there is no clue in the manual as to what units it actually is... I've always assumed it is a multiplication factor, but giving the units of measure and some 'expected values' to look for so you have something to base what you are trying to fault find against would be helpful! And whilst the long term trims and current trims go from 1.00 being default when you reset the adaptives, the idle trim resets to 0.00, but again maxes out about +1.5, so the consitency isn't there in my mind. A simple %age value with rich/lean indicated would be far more user-friendly...

Can't have everything I guess... and for the most part if there is a problem with the equipment, and it has to be sent back then they are good and get it fixed quickly - even if it does have to go back to Cyprus!
 
That is probably the biggest gripe I have with some of the BBS stuff is the manuals, whilst quite well written seem to leave out a few useful bits of information...

I've always gathered that the Instruments part were just showing live data (I've used them a couple of times mostly for watching the engine coolant temp after I did the water pump and wasn't sure I had managed to get all the air out, but had to drive 40 odd miles for work - so had it on so I could keep an eye on things!) But things like the tyre coefficient would be nice to have a bit of a description in there - because I went to look in the manual first and whilst it was mentioned as an option, it isn't acually described in any way, shape or form about it's usage.

I find with the manuals on some of the other modules - Thor engine management for example - whilst have a lot of info, also don't tell you a lot in some respects. Biggest one being fuel trims/adaptive values... Whilst you presume they should sit around 1, they then go to +/- from there it seems - which there is no clue in the manual as to what units it actually is... I've always assumed it is a multiplication factor, but giving the units of measure and some 'expected values' to look for so you have something to base what you are trying to fault find against would be helpful! And whilst the long term trims and current trims go from 1.00 being default when you reset the adaptives, the idle trim resets to 0.00, but again maxes out about +1.5, so the consitency isn't there in my mind. A simple %age value with rich/lean indicated would be far more user-friendly...

Can't have everything I guess... and for the most part if there is a problem with the equipment, and it has to be sent back then they are good and get it fixed quickly - even if it does have to go back to Cyprus!


Noticed that. Sometimes contradictory too, hence why I did the Nanocom resync How To.

Suspect many of yhe values are based on 256 with multiplier of some sort but maybe it is not linear response or has an offset.
 
Maybe Martian will work it out once he gets his Nanocom. He seemed to be fairly well informed.
 
I have 2 garmin Sat navs and can use them as a speedo as they dont rely on any information from the car electrics
 
Never knew that. Saw the setting and assumed it would affect the car. Pity it is not in the manual.

Thanks for sharing.

Yes that is true. Pretty pointless function as would be the coolant warning, that can also be changed, if it did not effect the actual instrument.
 
Last edited:
Apologies - I wish I hadn't raised that particular question now but many thanks for your responses - nothing like a bit of healthy debate!

I use my Motorcycle Sat Nav in my Jeep to give me an idea of true road speed as my Jeep also has non standard wheels, (smaller so speedo reading higher than real road speed).

Incidentally I do recall seeing a reference in the Jeep service manual to a switch, (somewhere around the transmission), to select different wheel sizes.

Not wishing to neglect my Jeep chums I have also thrown a rather large cat amongst the Grand Cherokee forum 'pigeons', (they must have them to), as I continue my 3 month quest to source a simple power steering pressure hose!

I have tried jeep parts specialist, (in bothEurope and USA), ordered parts that I have been assured are the correct hose but then had to return them because they are not.

I seem to have a 'parts bin special' as it was built in 1998, (Austria), and it is an ZJ variant, (according to the VIN), but everything about it suggests the later WJ variant and it would appear that nobody else has a power steering system like mine!

I am hoping that would qualify me for a free upgrade - although I would be more than happy just to get hold of a replacement hose!

So P38's are not all bad after all - or perhaps it is just me?!

Back to repairing my compressor, (garage not EAS), as it is too wet to finish my sunroof and reinstall my new headlining!
 
Apologies - I wish I hadn't raised that particular question now but many thanks for your responses - nothing like a bit of healthy debate!

I use my Motorcycle Sat Nav in my Jeep to give me an idea of true road speed as my Jeep also has non standard wheels, (smaller so speedo reading higher than real road speed).

Incidentally I do recall seeing a reference in the Jeep service manual to a switch, (somewhere around the transmission), to select different wheel sizes.

Not wishing to neglect my Jeep chums I have also thrown a rather large cat amongst the Grand Cherokee forum 'pigeons', (they must have them to), as I continue my 3 month quest to source a simple power steering pressure hose!

I have tried jeep parts specialist, (in bothEurope and USA), ordered parts that I have been assured are the correct hose but then had to return them because they are not.

I seem to have a 'parts bin special' as it was built in 1998, (Austria), and it is an ZJ variant, (according to the VIN), but everything about it suggests the later WJ variant and it would appear that nobody else has a power steering system like mine!

I am hoping that would qualify me for a free upgrade - although I would be more than happy just to get hold of a replacement hose!

So P38's are not all bad after all - or perhaps it is just me?!

Back to repairing my compressor, (garage not EAS), as it is too wet to finish my sunroof and reinstall my new headlining!
Can you not have one made using your original ends?
 
Apologies - I wish I hadn't raised that particular question now but many thanks for your responses - nothing like a bit of healthy debate!

I use my Motorcycle Sat Nav in my Jeep to give me an idea of true road speed as my Jeep also has non standard wheels, (smaller so speedo reading higher than real road speed).

Incidentally I do recall seeing a reference in the Jeep service manual to a switch, (somewhere around the transmission), to select different wheel sizes.

Not wishing to neglect my Jeep chums I have also thrown a rather large cat amongst the Grand Cherokee forum 'pigeons', (they must have them to), as I continue my 3 month quest to source a simple power steering pressure hose!

I have tried jeep parts specialist, (in bothEurope and USA), ordered parts that I have been assured are the correct hose but then had to return them because they are not.

I seem to have a 'parts bin special' as it was built in 1998, (Austria), and it is an ZJ variant, (according to the VIN), but everything about it suggests the later WJ variant and it would appear that nobody else has a power steering system like mine!

I am hoping that would qualify me for a free upgrade - although I would be more than happy just to get hold of a replacement hose!

So P38's are not all bad after all - or perhaps it is just me?!

Back to repairing my compressor, (garage not EAS), as it is too wet to finish my sunroof and reinstall my new headlining!

No problem, use this to see how far your speedo is out. Standard wheels are 255/65/16 or 255/55/18. 255/50/19 would also give same standard rolling radius. Just feed in one of those to get standard rolling radius then feed in the sizes you have fitted to get the speedo difference. http://www.kouki.co.uk/utilities/visual-tyre-size-calculator ;);)
 
Tomcat,

I would definitely consider this option if I can fnd somebody local, (presumably an agricultural machinery specialist), should be plenty in Lincolnshire!

I did do some research and, (just like so many things we take for granted), hydraulic hoses are no exception - the critical bit being the dies used to crimp the high pressure hoses to the metal pipes - just sufficiently enough to provide a high pressure seal but not too much to distort the crimps!

Wammer's,

Many thanks for confirming wheel sizes - the non standard wheels/tyres on both of my vehicles are not through choice - they came, (free), with both vehicles!

Despite them being over sized, (my speedo is under reading), I am still surprised at how much space remains between the tyre and the wheel arches, (I have yet to try out my EAS diagnostics/set up diagnostics kit)!

I have a strong feeling that I will be spending some money at Blackbox next month as I am itching to take a closer look at my systems, (if my wife asks I will blame that very nice forum member Grrrr)!
 
Tomcat,

I would definitely consider this option if I can fnd somebody local, (presumably an agricultural machinery specialist), should be plenty in Lincolnshire!

I did do some research and, (just like so many things we take for granted), hydraulic hoses are no exception - the critical bit being the dies used to crimp the high pressure hoses to the metal pipes - just sufficiently enough to provide a high pressure seal but not too much to distort the crimps!

Wammer's,

Many thanks for confirming wheel sizes - the non standard wheels/tyres on both of my vehicles are not through choice - they came, (free), with both vehicles!

Despite them being over sized, (my speedo is under reading), I am still surprised at how much space remains between the tyre and the wheel arches, (I have yet to try out my EAS diagnostics/set up diagnostics kit)!

I have a strong feeling that I will be spending some money at Blackbox next month as I am itching to take a closer look at my systems, (if my wife asks I will blame that very nice forum member Grrrr)!

Speedo will under read with oversized tyres. Speedo works off a standard 8000 beats per mile with standard rolling radius. So as the larger tyres are turning slower for any speed they will not attain 8000 beats per mile so the speedo will register a road speed less than it actually is. If you can follow that.
 
Tomcat,

I would definitely consider this option if I can fnd somebody local, (presumably an agricultural machinery specialist), should be plenty in Lincolnshire!

I did do some research and, (just like so many things we take for granted), hydraulic hoses are no exception - the critical bit being the dies used to crimp the high pressure hoses to the metal pipes - just sufficiently enough to provide a high pressure seal but not too much to distort the crimps!

Wammer's,

Many thanks for confirming wheel sizes - the non standard wheels/tyres on both of my vehicles are not through choice - they came, (free), with both vehicles!

Despite them being over sized, (my speedo is under reading), I am still surprised at how much space remains between the tyre and the wheel arches, (I have yet to try out my EAS diagnostics/set up diagnostics kit)!

I have a strong feeling that I will be spending some money at Blackbox next month as I am itching to take a closer look at my systems, (if my wife asks I will blame that very nice forum member Grrrr)!
Check it out on Google, there will probably be someone mobile. Just had one made up for an commercial mower, £15 cash no reciept.;)And you can call me Alan.:)
 

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