Ride Height settings

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hippolover

hippolover

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Perthshire
I've searched but can't find the figures. Does anyone know the factory suspension height settings for the P38? Not the distances from arch to ground but what they should be set at when I connect up a Testbook.

I get the feeling the car runs a bit high on standard setting and it does drop to motorway cruise height at the correct speed, etc but sometimes when it is returning to standard it forgets to stop and goes right up to extended height which means a frantic press of the button before the next corner!

I've also noticed the backend is a bit slower to respond to button presses but just put this down to there being a heavy engine up front and an empty boot.

Any advice appreciated.
 
Test Book uses calibration blocks placed in the bump stops and everything is done by the software.
Faultmate and other BBS systems use the centre of the wheel to arch dimensions for calibrating Access, Standard and High .....this disregards difference in wheel sizes.

So..if you want it checked against Test Book specifically, you need the user to have the calibration block sets.
 
I've seen the readings before with the TBook and on standard it was 105 rear and 95 front. 75 front and rear on access mode and 145 front and rear on high (to the best of recollection). I suppose the machine must already be set up to do readings as the settings can be altered by pressing the up and down buttons on screen. I'll plug it in again and see exactly where it's sitting and maybe drop the back end by a few millimetres to see if that helps with the rising problem. It showed 'no faults' last time. Thanks, meantime.
 
Its a Testbook T4, should be pretty up to date with downloads etc as the garage is quite a stickler for these kind of things. If you could get me the figures that would be great. It's not due in til Friday when I get the AC re-gassed after a disastrous re-gas at the garage where I got the car after they fitted a new condensor. They used one of these diy tins (won't be going back there!!!)

PS I also have access to a friend's Launch X431 but that doesn't do the full range of stuff.
 
hippolover said:
I've searched but can't find the figures. Does anyone know the factory suspension height settings for the P38? Not the distances from arch to ground but what they should be set at when I connect up a Testbook.

I get the feeling the car runs a bit high on standard setting and it does drop to motorway cruise height at the correct speed, etc but sometimes when it is returning to standard it forgets to stop and goes right up to extended height which means a frantic press of the button before the next corner!

I've also noticed the backend is a bit slower to respond to button presses but just put this down to there being a heavy engine up front and an empty boot.

Any advice appreciated.
Click to expand...

The front end comes down before the back so it stops the headlights blinding on coming drivers, when the suspension raises the back go's up first followed by the front.
 

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Here are the "Expected" bit values for P38 EAS on Test Book.

Profile Front Rear

High 120-180 105-150

Standard 95-150 85-130

Low 75-140 75-120

Access 50-110 50-100


Obviously, the sensor components are not extremely accurate, but the readings should fall within the above bit values for the height mode selected.

:behindsofa:
 
The values have little to do with the actual heights other than a numerical means to visually monitor the increments you is adjusting it by. An even surface, don't matter if it a 45 degree slope you is on, as long as it is even, the wheel arch method is the way to go. Any given potentometer is gonna report a different value, and this is exponentially increased due to positioning variances on individual suspensions components as well as individual vehicles.
 
As the settings are going to be checked with Test Book...normal measurements (mm or inches) are not used and Hippolover was looking for the bit values that Test Book generates when reading the settings.
 
The thing is though, the values are never gonna be the same across an axle, unless for some reason you is the luckiest bugger on earth and every bit of ya car is perfect down to the thousandts of an inch, which is never gonna happen outa Sollihol, you is gonna get uneven values. If he sets the values to read the same numerical value across axle then there is an exceptionaly high possibility he is gonna be driving down the road lop-sided.
 
I accept that.
You will see from the figures given that they are expected to be within the ranges shown for the various height options.
This is for the reasons given in the post and you have confirmed, that the sensors are unlikely to give the same bit values.
The Test Book method of setup/calibration is to fit the blocks between the axle and body, lower the body on to them and Test Book calculates this as the baseline, all other heights are calculated from this base and applied automatically.
Other systems set the height modes on an individual basis, but use the same reference points basically..axle (Centre of) and Body (Wheel arch), this takes into account different wheel sizes, and the values that are utilised are either millimetres or inches.
 
Irishrover said:
I accept that.
You will see from the figures given that they are expected to be within the ranges shown for the various height options.
This is for the reasons given in the post and you have confirmed, that the sensors are unlikely to give the same bit values.
The Test Book method of setup/calibration is to fit the blocks between the axle and body, lower the body on to them and Test Book calculates this as the baseline, all other heights are calculated from this base and applied automatically.
Other systems set the height modes on an individual basis, but use the same reference points basically..axle (Centre of) and Body (Wheel arch), this takes into account different wheel sizes, and the values that are utilised are either millimetres or inches.
Click to expand...

I was not discounting your statement, just trying to get through to OP that he is better off doing the wheel arch measure, the way we all do.
 
Thanks all for the info and references. When I last saw the Testbook it gave two sets of figures for each wheel i.e. what the actual wheel height figure was and what the car's system was set to. To demonstrate to me what the machine could do the mech pressed a button and put it up at one corner (and down again). In fairness to the settings the car has been adjusted to the 'real' figures were pretty level being only two or three mm away from each other. Yes, that was due to the slightly uneven ground but the other figure for each wheel remained constant which I suppose is the target figure for a Solihull factory floor. I understand the bit about not dazzling other traffic for the front going down first - pretty obvious really but sensible!
 
Does anyone have the 'Standard' height from the centre of the wheel to the wheelarch?
zzr100 gave the dimensions from the road for standard tyres but I have 255/60x18 which are going to alter things a bit. Anyone possibly measure their RR and see what we get? Rave gives the variations from Standard but only states that the standard is set using testbook, not what the standard actually is in real terms.
(Low 1" below standard, Access 2.6" below standard, High 1.6" above standard and extended 2.75" above standard).
 
Here (Again !!) are the heights from the wheel (Or axle) CENTRE to the wheel arch.....


Standard 790mm +/- 7mm

High 830mm +/- 7mm

Access 730mm +/- 7mm



** Low ("Motorway) profile 770mm +/- 7mm

** Extended profile 850mm +17mm/ -7mm


** Controlled by EAS ECU

:behindsofa:
 
Irishrover said:
Here (Again !!) are the heights from the wheel (Or axle) CENTRE to the wheel arch.....


Standard 790mm +/- 7mm

High 830mm +/- 7mm

Access 730mm +/- 7mm



** Low ("Motorway) profile 770mm +/- 7mm

** Extended profile 850mm +17mm/ -7mm


** Controlled by EAS ECU

:behindsofa:
Click to expand...

Irish, sorry to be a pain, but I think that the measurements you've stated are from ground to wheel arch. Not axle/wheel centres unless theres 31 inches at standard height from axle/wheel centre to wheel arch lip (790mm = 31 inches)....:behindsofa::behindsofa::behindsofa:
 
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