Too much toe in

[aceparts]

A bit last minute (for a track day) I've discovered my car was set with 30 minutes of toe in total (0.15 degrees each side) instead of 5 minutes total +/-5

Porsche 993 btw.

Typically, how much do I need to wind the track rod in to get somewhere closer to ideal? I was thinking 1/6th of a turn each side.

Should I even bother?

Cheers!

[aceparts]

bump!

[BertBert]

Sorry, can't answer the how many turns question, but isn't 30 minutes, 0.5 of a degree?

[BertBert]

So if the correct total toe is 5 minutes and you have 30 minutes, then the difference on each side is the difference between 2.5 and 15 mins.

By my dodgy maths at the wheel rim on an 18" wheel that is about 0.8 mm difference.

The distance of the end of the steering arm from the axis of turn will be less that 9", so lets say it is 6". You will need to find about 0.5 mm.

The pitch of the adjuster is likely to be 0.75, 1.0 or 1.2mm. Assume it's 1.0, then you need 1/2 a turn.

I can't convince myself that it's going to matter hugely though.

Bert
PS you can probably tell what era I went to school as I am so confused by which units to use

[aceparts]

Yes, 0.5 degree. By my calculations on the 18" wheel rim that is 1.8mm of total toe in or 0.9mm on each wheel.

The optimal setting (5mins) or 0.08 degrees which is 0.32mm total or 0.16mm each side. So I'm toeing in by .75mm each side. As the steering arms are 2/3rd the way in that's about .5mm each side.

Our calcs match!

Next question. What's the point in worrying about 1.5mm at the wheel?

[DiscoColin]

aceparts said:

Next question. What's the point in worrying about 1.5mm at the wheel?

I might get corrected on this one, but I think that you have increased braking stability at the expense of increased wear on the inner track of the tyre.

[BertBert]

It certainly doesn't feel a bad thing having a tad too much toe in. It's not like going from toe in to toe out.
Bert