Tracking ... the age old problem

[CRC]

No, not yet, but I have spent a couple of hours today knocking up rig to hold a laser level.

Made it out of an old aluminium spirit level of the sort that bricklayers use and a cheap and cheerful beam laser.

I would think it might work, but will have to wait till evening as I can't see the laser in bright sunlight.

Whether or not it will be good enough to measure accurately enough remains to be seen.

Will keep you posted.

[jimbof]

Good effort.  Fingers crossed it pays off for you

[CRC]

I'm beginning to wonder if it is actually possible to do this even if the problems with accurately aligning the laser can be overcome.

The main reason is that once the toe has been measured and set in the normal position, then the car needs to be lifted to measure the toe angle again.

As the tyres will still be on the ground when the car is lifted, I'm pretty sure that the friction between the tyres and the ground will stop the wheels turning properly and showing a true reading.

That would explain why the tyre centres always place the front wheels on those circular turntable plates ..... to allow the tyres to turn in or out easily.

Also, the toe setting angles are expressed in minutes, which is one sixtieth of one degree, and you need a long distance to amplify this into a measurable distance on a projection wall.

I can see now why there are a lot of expensive alignment systems out there .... just a shame so few know how to use them.

[CRC]

Well, as an update, I found that I could see the laser pretty well in the twilight, so I had a go.

 

The first picture is the rig I knocked up, and the second are the results.

 

I set the laser onto the wheel rims and level with the centre of the wheel and used a steel rule on the centre of the rear wheels to measure where the beam was. The reason for that is that the rear wheel centres should both be at about the same height as the front and both sides should be the same distance between wheel centres.

 

The results are puzzling me at the moment, especially when I leant the laser on the rear wheels and shone it forward .....

[Tdi1.9]

Is part of this confusion caused by you expecting the rear wheels to be parallel, whereas in reality they have a slight toe in?

[CRC]

I'm starting to think that this is a lot more difficult than I thought, and trying to set everything up exactly right is very difficult.

 

Note that the straight edge of the level has two screws screwed into it so that they can rest on the rims of the wheel and the slighest difference in height of those two pins will cause a the beam to be not exactly parallel with the wheel.

 

I tried to find a long straight parallel surface to adjust the screws with, so brought it indoors and placed it against the wall and shone the beam along it and measured the distance out in several places  .... only to conclude that builders aren't that good at building straight walls

[rum4mo]

I seem to remember that my VW main dealer could not reuse the clamping bolts with the shaped shallow "locking" head, so got creative with a grinder on the heads of the hex headed bolts he used instead - I sorted that out later by getting new bolts and nuts ordered in for me and fitting them, the "modified" bolts might have gripped the casting long enough for him to reassemble the steering rods, but I'd doubt if they wold have been able to resist turning a year or two down the line!

Edited 6 July, 2016 by rum4mo

[CRC]

I'm pleased to report that though I've not actually managed to get the car alignment done exactly as specified with the raised toe spec, I've finally ended up with a car that now feels exactly right ... or at least as "exactly right" as I can imagine it can be.

 

To recap, I'd had the tracking done with a "fairly low tech" laser system, and though it had improved things, it never really felt exactly right.

 

The tyre weren't showing any undue wear characteristics, but the car felt "nervous" on a straight road, I was finding that I was having to make a lot of small adjustments (always away from the keb) and  that the car seemed unduly prone to being affected by the camber of the road. It was effectively destroying the enjoyment of driving. Also the steering wheel was always slightly to the right on straight roads.

 

I'd tried without success to find a place with the knowledge and experience to do the raised toe method, and was a little concerned that even if I did, the clamp bolts would be seized solid resulting in a big bill and a delay while new track rod arms were sourced and fitted.

 

My attempts at knocking up a home made laser system had shown that it's debatable if that can really be made to work, given that it needs to be accurate to 1 minute (that's one sixtieth of a degree of angle).

 

Anyway, I was passing a tyre place near my place of work and noticed that they had a a Hunter 3D camera aliginment system, so thought I'd go in and risk a bit more abuse in the name of progress, but to my surprise, it was a very good experience.

 

The guy who used the Hunter machine was what can only be described as an "alignment enthusiast", with years of experience, keen to learn and he tells me that they open up the workshop in the evenings so that local Subaru and MX5 owners clubs can come and have their alignments done using the various "trick" parts that are available these days.

 

Though he'd never heard the expression "raised toe", he invited me through and looked on the Hunter screen and was amazed to find the "raised toe" icon and the instructions for how to do it (including the picture of the VW height spacers). He seemed genuinely embarrased that he hadn't heard of it and apologised that he didn't have the spacers to actually do the procedure, but that he would talk to the boss and see if they could look into it.

 

He then offered to check the current alignment on mine and see if it needed adjustment in the normal position, as that is the first part of the alignment procedure anyway, and that he would guarantee to get it as good as he could and would take it on a test drive afterwards to check that it met his own standards before asking me for any money.

 

Seemed fair to me, so he went through the procedure and the before and after results are shown on the graphic, with everything now being pretty much exactly right apart from the front camber which can only be adjusted by brutality and shifting on the subframe mounting bolts. He did say that they had tried this with an Audi once and after a day had to give up and get a Audi to do it. The rear was perfect as were the ride heights.

 

The difference in how the car feels is amazing ..... it's a joy to drive again, the steering is so much more responsive, the cornering is better, the feedback through the wheel is better, the car tracks straight and true and the steering wheel is in the correct position. Also, even though the raised toe procedure wasn't done, the car feels perfect under heavy acceleration and braking, so I figure it must be somewhere handy to the right position.

 

The cost was £36 and I'm well pleased with the price, the results and the service quality.

 

I can therefore wholeheartedly recommend DCM Tyres Wessex Ltd (on the trading estate in Shaftesbury, Dorset)  if you want a good alignment done and are local to that area.