Anyone used any wheel alignment companies in the Poole/Bournemouth area. I’ve made some enquiries and so far established that Christchurch Tyres and Mike Stokes have the equipment but not sure who to go for??? Any recommendations?
Type your postcode here>…http://www.alignmycar.co.uk/ and it will find the nearest Hunter machine to your addy… The machine costs loads so only the serious would be listed.
If you need helps with settings let me know.
Christchurch Tyre Company come up on alignmycar as they have the Hunter gear. Mike Stokes have got a new John Beam V3D Digital Imaging Four Wheel Alignment System so I’m not sure where to go.
Advice on settings would be much appreciated. 2004 Mk 2.5 Sport used on road by wife as a gently driven “fine day” hack and by me for a quick burst on some of our twisty B roads. ride height front is 345mm rear is 370mm and tyres are 205x45x16. Thanks.
This is not OEM so they will need to type the data in…
sedate/ fast-road calibration
Rear
Camber: -1 degree 14’
Toe: +30 total
Front
Camber: -34’
Castor: +6 degrees 17’ or as near to
Toe: +8’ total
Thanks Tony
Any difference between the John Bean and Hunter machines or will they both do the job equally well?
I assume the +30 rear toe is minutes? Did you mean +8’ front toe as I wondered if that was a typo and should be +18’ as it is so different to the rear figure??? Sorry to appear to be questioning your figures as I know you are the expert in matters relating to MX% alignment but I am bit of a worrier so just wanted to double check!!!
Purely out of curiosity, I’m also wondering about the toe settings. Tony very kindly e-mailed me some OEM settings for my MX5, the ride height on which is slightly lower (10mm front, 15mm rear) than the one we’re talking about here - and the castor/camber settings are broadly similar, but the toe settings in his post above are much more on the rear and much less on the front than the ones he gave to me.
Don’t get me wrong, I’m not for a moment suggesting that any of Tony’s figures are wrong - but I’m genuinely curious as to why a small change in ride height should mean a fairly large change (well, it looks quite significant to me - perhaps I’m reading too much into it!) in toe settings. I appreciate the explaination might well be a bit too technical to go into in any depth here - but a potted version would be very much appreciated, as I like to understand these things!
The difference between the John Bean and Hunter machinesis the opperator…
The toe positions are correct if i were to advance the chassis… Fast road (domestically) needs to respect tyre wear, so a less agressive camber is compensated by toe to induce saturation grip limits, it’s a hard call but historically those positions work.
Advance the chassis? Sorry to sound a bit dim, but what does that mean?
Every example is unque, let me explain…
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Ok I’ve mentioned this before but in order to truly
understand chassis dynamics we must understand both sides of the Car vs Driver
partnership. We must essentially listen to the chassis’s side of the story and
then the driver’s side of the story. When we get this right we produce a
capable chassis that is easily exploitable by the intended driver.
The human element of chassis dynamics is without doubt the most important and
the hardest aspect for engineer’s to understand, the consequence is that this
area of the science is often totally ignored and leads to drivers being blamed
for poor skills or lack of commitment, either that or an acceptable outcome is
eventually totally fluked via hours of trail and error.
The driving process:
• Step one: A driver looks at the oncoming road and estimates the required
inputs to complete the task at hand, we make this estimate based on a model of
the car held in our memory, the more accurate this model the more accurate our
initial guess.
• Step two: An “Open Loop” input is made according to our guess
• Step 3: Then “Closed Loop” trimming modifies these inputs to take account of
emerging conditions or errors in the initial guess
There are 3 main channels of feed back used for “Closed Loop” driving
- Visual feedback
- Inner ear (yaw rate, lateral acceleration etc) feedback
- Muscle tension or Steering wheel torque feedback
It is through these communication channels that a car can speak to a driver.
Ok firstly, the drivers eyes….
Processing visual stimuli is actually quite a complex procedure and incurs a
delay of around 600msec in most people between seeing and understanding, so
that’s a maximum update rate of around 1.8Hz
Driving by your eyes alone is only possible if no quick action is required.
• If the roads and bend radiuses are known and learned
• And of course as long as no chassis control task’s are required
The inner ear….
Processing the yaw and latt acc information from the inner ear is a far simpler
process and is therefore faster but even so this feed-back process still
suffers a delay of around 300msec so this loop can actually update at around
3.2Hz which is pretty fast.
Muscle tension in the drivers body….
The task of moving the steering wheel is a function carried out by the brain
stem, the brain stem works automatically to maintain the correct steering angle
by varying your arms muscle tension. Changes in the steering resistance cause
the brain stem to get confused and flag up the problem to a higher part of the
brain that is responsible for processing the overall task of driving the car.
This form of feedback is extremely fast at around 100msec so this can provide
you feedback at 10Hz (ten times per second).
Some interesting points to note:
• A driver’s in-head car model is almost exclusively linear
• Excessive anxiety in a driver can easily cause the steer torque mechanism to
be completely “swamped” by muscle tension and therefore useless.
• Inexperienced drivers are frequently unable to interpret inner ear signals or
are too confused to act on them so they are discarded by the brains automatic
information filters in the brain stem
• A surprising level of confusion exists in the inner ear between yaw and
chassis roll, this lead some drivers to “dislike” body roll
• Many drivers are found to revert back to an entirely visual driving strategy
in emergency circumstances
• Many drivers are overwhelmed and lose control even though the car was capable
of completing the maneuvre
• A maximum practicable hand steering wheel rate is around 1100 degrees /
second –but not for long
• Typical hand wheel rates are much slower - < 100 degrees / second in
“Sensible” driving
Team MX5oc you need to sort this “cut/ past” id issue, i had no tags in the post?
Could you tell me what the best settings are for fast road/track on a Mk1 fitted with AGX adjustables, Eibach springs and 195-50-15 tyres would be please?
Fast road/ track
Rear
Camber -1 degree 50’
Toe: +40’ total
Front
Camber: -50’
Castor: As high as possible and even
Toe: +8’ total
Thx WIM [Y]
Your welcome.
We still have advanced fast-road and track, difference being tyre preservation.
Hi Tony - finally just fitted my P5 suspension and will obviously need alignment. Main aim is to get good tyre wear as well as the usual good handling. Will never go on track but I am a fast enthusiastic road driver doing about 60 miles a day commuting in the little black number. I have been experimenting with ride heights gradually getting higher as I try to get to a point where I dont get the tyres rubbing the insides of the arches over the worst speed humps and on hard cornering. At the moment I’m on 330 front and 335 rear but I dont want to go too high as it looks too 4x4 (previously driving with something like 50mm less front and back - mean looking but ouch:-). Can you recommend alignment settings for this set up please? Currently even on high shock settings it is sometimes a bit ‘jouncy’ on B roads and on low ones its a bit sofa like.
Cheers BB
p.s. its a mk1 using Mk 1 mounts with the P5 shocks/springs