Measuring racecar toe

[Mecatech]

Hi all,

After a few years of working on racecars I noticed that measuring toe can be a little complicated (at least in my opinion), so I have started work on a new tool and would like to know how other people feel about the issue. If you have experience in measuring toe I would greatly appreciate if you can answer this short survey which should take less than 5 minutes. Thanks!

https://docs.google.com/spreadsheet/...MENmd2Y0d1E6MQ

[Mecatech]

..and if you have any other comments on measuring toe please feel free to post them here!

[Notso Swift]

Can't answer because I don't qualify, living where I do

[GORDON STREETER]

Originally Posted by Notso Swift

Can't answer because I don't qualify, living where I do

Obviously a tiny country like yours doesn't count Notso

[Mecatech]

Originally Posted by Notso Swift

Can't answer because I don't qualify, living where I do

haha should have included an option for all of the above then!

[Copperbottom]

What's wrong with a tracking bar

[GORDON STREETER]

Originally Posted by Mecatech

Hi all,

After a few years of working on racecars I noticed that measuring toe can be a little complicated (at least in my opinion), !

Can you explain please ?

[Notso Swift]

Originally Posted by GORDON STREETER

Obviously a tiny country like yours doesn't count Notso

I see a country and raise it by a Continent!
Understandable when Aussies and NZ'er have had so little influence in the world of motorsport, Brabham, Tauranac, McLaren, Hulme, Gardiner and we haven't got out of the 60's
What do Australia, the UK, Germany and Spain have in common?
Only countries to have the premier FIA championship events from Bikes, Circuit and Rally

What's wrong with a tracking bar

Well you can't really set it up, you can check it but how do you know if you have 2mm on each side or 4mm and 0mm, or 5/-1 (OK if you cant tell by driving you should be banned from getting behind the wheel)

[Tim Falce]

Notso Swift, I've just noticed your toe settings by your country flag, they're way out and I'd be surprised if your car goes in a straight line mate.

Gordon, Mecatech may be struggling as his string may be bent.

[MGDavid]

Originally Posted by Notso Swift

..........
What do Australia, the UK, Germany and Spain have in common?
Only countries to have the premier FIA championship events from Bikes, Circuit and Rally.............

well, you see, somebody thought that to call it a 'world' championship they ought to race somewhere in the lower hemisphere and there aren't too many options ;-)

back on topic, I just use my good friend at Absolute Alignment...

[indigorallye]

Done

[DaveGT6]

String car to get square then use this as a datum. Dunlop gauges sort front toe adjustment, castor and camber. Don't see where the complexity lies? Or am I missing something obvious?

[Mecatech]

Originally Posted by GORDON STREETER

Can you explain please ?

Considering that toe is just a simple angle between the wheel plane and the chassis, I think that it requires a lot of effort to measure it and get it right compared to camber for example. Proof of this is that several different methods have been invented and even with modern technology parallel strings are still used by most teams. Other methods like toe plates, dunlop optical and toe-in bars are simple to use but can't reference each wheel to the chassis - therefore making it possible to have the steering wheel off center or the rear wheels pointing to one side. Laser systems are of course very precise and meet all the technical requirements but they are bulky and relatively difficult to set up, which is why parallel strings are still used even in F1 nowadays. However, parallel strings still have in my opinion a weakness in that taking the measurement (ie measuring from the string to the wheel twice and then doing the maths in your head) is a slow process and it is easy to mistake the magnitude or sign of the result. I have seen this happen even to very experienced professional mechanics and the result can be very confusing on track.

[Mecatech]

Originally Posted by Copperbottom

What's wrong with a tracking bar

The problem with tracking bars is that you can only determine the angle of the front (or rear) wheels relative to each other and you can't tell how they are relative to the chassis centerline. So, you could even have the car crab walking down the straight while the steering wheel is pointing 15º the other way... which is of course not good aerodinamically and distracting for the driver

[dtype38]

Originally Posted by Notso Swift

Well you can't really set it up, you can check it but how do you know if you have 2mm on each side or 4mm and 0mm, or 5/-1 (OK if you cant tell by driving you should be banned from getting behind the wheel)

What if it goes in a straight line fine... but only when the steering wheel isn't straight?

[GolddustMini]

Im not convinced that a string box is particularly prone to error, its as prone as any system that involves human interaction, as the error revolves around poor arithmetic on behalf of the user. Perhaps a simple sliding measure that could be zeroed for one measurement would work, however, this would still have the same human error issue as a ruler and would still require similar equipment however it would rem8ve the requirement for simple math.

[tristancliffe]

Lasers are worse. Same human error issues, but people trust them as though they can never be wrong or inaccurate. As far as I can see, the only way lasers are better is because you can trip over a laser beam. Even F1 teams still use string.

[GolddustMini]

Originally Posted by tristancliffe

Lasers are worse. Same human error issues, but people trust them as though they can never be wrong or inaccurate. As far as I can see, the only way lasers are better is because you can trip over a laser beam. Even F1 teams still use string.

Got to agree with you there, laser beams belong on sharks!

we've got one of those laser levels for corner weight scales, I much prefer the good old spirit level method, because its something physical to work to rather than a red line that is only really visible when it hits something