Dunlop Optical Tracking Gauges

[bzzzracing]

Hi,

Have just bought some old gauges with no instructions.

Can anyone tell me how they work or can anyone send me a copy of their instructions?

Thanks.

Richard.
bzzzracing@aol.com

[StephenRae]

Set one pair of pointers to wheel centre height, set the second set to match them, put them together and looking through the eyepiece you can zero them in, set the bit with the magnifier by loosening the screw and away you go!....don't forget they read backwards when checking the rear toe in.

[graham bahr]

to check ther accuracy in the first place put the two sets of gauges together, as if your putting them on a car but without one if you see what i mean, and check they read zero

[Tim Falce]

Once you have them all set up and lined up on the car, transfer the reading off the white gauge under the magnifying glass onto the round dial which should be set to your wheel size. The reading can then be transfered to inches or mm.

[bzzzracing]

Thanks for the guidance. Will give it a go.

[kingsley]

hi, good luck with your tracking gauges, but bear in mind they are not that practical for tracking up race cars, as they measure total toe and not toe per wheel.

[zefarelly]

I've just found a set of these in my late fathers workshop, a box and brackets, frames, a mirror and all sorts, I'll have to have a play with it when I get a spare few hours !

[dtype38]

Originally Posted by kingsley

hi, good luck with your tracking gauges, but bear in mind they are not that practical for tracking up race cars, as they measure total toe and not toe per wheel.

Just had a similar issue with my car and a borrowed set of Dunlop optical gauges. My steering doesn't self centre just rolling it around in the garage so its difficult to know if just one wheel is out. My solution (FWIW) is a cheap (£20 or so) lazer level. Simply centre the steering wheel and wedge it in place, then hold the lazer level across a front wheel rim and get a mate to measure the offset of the lazer at the back hub (or wheel rim). Do this both sides and it will give you a relative measure of toe in for each front wheel. This can then be adjusted to the same both sides before checking total toe-out (more usual than toe-in for a racing car I think )

[kingsley]

The easiest and cheapest way is to attach a pole across the front and across the rear, then run a lenth of fishing line down both sides of the car attached to the poles, make sure that it is centre line to the wheel.
Then centre the lines by measuring from fishing line to centre of wheel..should be the same on opposite wheel.
Once that is done you can measure all four wheels individual toe settings, by taking a measurement from front of rim to line and then rear of line to string....hope that makes some sort of sense..

[Mackmot]

The pole idea is great until it gets battered about a couple of times in transit, then it messes everything up. The only way to know that you are accurate everytime is to use dunlops. First wrap a string around all 4 wheels and put a 20mm block between it and the tyre sidewall at the front to lift it away from the rim. Get a mate to sit in it and hold the steering wheel straight. Then measure from the rear edge of the front rim and the front edge of the rear rim, to the string on each side and even the distances up side to side. once you know both wheels are pointing in mirrored directions you put you dunlops on and check the amount of toe. Adjust the same number of flats or turns on each side, wiggle the steering wheel and check the string again to make sure you havent done one more than the other, then check your dunlops again.

Hope that makes sense.

[spook]

I have a set of Instructions for the optical wheel aligner. I will endeavour to get them scanned asap and post here if anyone still needs them. They are not very detailed, and most of the previous postings have covered the technique quite well, but there is nothing like have the "original instructions" (or a scanned copy at least).

I also have a Camber/Caster Gauge without instructions. Can anyone help with instructions for these?.

[kingsley]

only rock ape racing will batter set up gear about in transit...if you wrap string just around wheels you have no datum..you could be crapping down the road...and you have the same pronlem once you go back to your gauges...of all the race teams I have worked in I have never seen a set of dunlops! throw them away


camber gauge....erm set to zero on structual item..ie door post put on wheel take measurment,

[zefarelly]

I guess it won't help if you have buckled rims or a lot of run out !!!

will the dunlop gauge check castor angle as well ?

[Spinner]

The fishing line idea is not that accurate, if more measuring from the hubs because if you have different cambers the hub centres will be slightly different! The only accurate way is the plum bobs from the centre of the car and work out from their does take about 4 hours to set up though.

[dtype38]

Originally Posted by Spinner

The fishing line idea is not that accurate, if more measuring from the hubs because if you have different cambers the hub centres will be slightly different! The only accurate way is the plum bobs from the centre of the car and work out from their does take about 4 hours to set up though.

Alternatively take your car down to the local aftermarket rims and tyres megastore (I've used my local branch of Elite) and ask to put it on their lazer wheel alignment rig. That will give you a very accurate camber, castor and toe measurement individually on each wheel, as well as measurements of axle-to-axle alignment and offset. BTW, ask for the values relative to a zero datum, and not to the manufacturers spec. like they usually do. Anyway, I got charged £25 last time I went a couple of years ago, which I thought was money well spent.

[Peter Mallett]

Originally Posted by zefarelly

...................will the dunlop gauge check castor angle as well ?

NO!

However it does set your tracking to suit THE CAR as it is. Sorry for the caps but aren't we getting a bit theoretical here?

Any chassis guage will need to accommodate the shape of the chassis to start with, hence all this BS about string and 50mm blocks goes out the widow when you want to get your historic/club racing saloon to go flat through Craner curves and its just done a season of racing in CTCRC or HSCC! Even without impact metal bits move!

[Tim Falce]

[kingsley]

Spinner..thats clutching at straws lol..if I was to charge customers 4 hours just to set the car up so that I can do a set-up I would never have any customers!

yes dunlop gauge will check caster, feel free to email me, zefarelly I will give you a contact number if you like.

[Peter Mallett]

Originally Posted by kingsley

yes dunlop gauge will check caster, feel free to email me, zefarelly I will give you a contact number if you like.

I'm surprised because we use a separate guage for caster.

[zefarelly]

hmm interesting . .I think I might add a few bars to the roll cage to reduce chassis flex a little further, then 'optimise' my front suspension. . . all within the regs of course !

[Peter Mallett]

[Off Topic]No need to add bars just tie those you've got to the body. You can buy the connectors from rollcentre or SD and they bolt up to weld nuts so its not a "welded in cage".[/Off Topic]

[zefarelly]

not sure how legal that is . . .but then half the cars we race with have fully welded multipoint cages anyway !

[R59]

When you're setting up with your dunflop gauges, don't forget to do it on flat ground.

What sort of car do you have? FWD? RWD?

That all makes a difference to the settings.

Any road up, forget the lasers, these old tools of the trade are still the best.

Coupled with a piece of string, you can set a car up straight and square.

Rob.