Wheel Alignment TCS

[Dilkris]

The attached is from the manual but else where I have seen other figures quoted, specifically 1 degree negative camber all round and 1/4" toe in to rear. Can somebody kindly advise what I should be setting it at. (Note: Not for track use)
Finally, not wishing to ask a couple of stupid questions, where is the toe in dimension actually measure from, the edge of the wheel rim or tire? (In other words at what radius from the center of the axle of the wheel.) and is the toe in measurement (ie: for example 1/4") measured per wheel or between the 2 meaning 1/8" per wheel?     

[EuropaTC]

First thing, I think the specs you've quoted for the rear suspension might be for the S2 and not the TC.   

My manual quotes 1/4" to 1/8" (6.3-3.2mm), the spec shown in your image allows a zero toe in which I think most folks would consider a very bad idea. I take that as total toe as for the front toe specs although I've seen instances where folks say it's per wheel. Taking the numbers as "per wheel" means up to 1/2" total rear toe in which is more than I've seen on any car before.  The mid engined cars I've owned have all been around 1mm toe in but they have also been a more rigid suspension design with less rubber than the Europa.

Personally I aim for between 1mm & 3mm per wheel.  IIRC it's a touch below 2mm at the moment, I don't think I've had it below 1.5mm per wheel but I'd need to go through the files.

If you are using the string box method I measure between the string and rim. I use the rim because it's a machined surface whereas the rubber of a tyre isn't always so accurate.  I have seen where folks have drawn a chalk line around the tyre tread circumference and used that as the datum but for me, the wheel rim is preferable.

[BDA]

What I find really interesting is the difference in the specs. TC front camber is supposed to be 0 to +30’ as opposed to the S2’s 0 to +/- 30’.

Rear toe for a TC is 1/8” to 1/4” (I’m now convinced that is for each side so 1/4” to 1/2” total toe in) while the S2 is 3/16” to 0” (I’m not sure how to read that?) I agree with EuropaTC that 0 rear toe is a bad idea and for the same reason.

I’ve always been surprised that +30’ of front camber is within spec and now I’m wondering if it’s a typo and should be +/- 30’.

About rear toe: somebody long ago, probably from the Lotus distributor I used to hang around very early in my car nut career, told me that Europa TCs came from the factory with a lot toe in at the rear. I, and maybe the guy who told me that, assumed it was a matter of sloppy workmanship and/or for extra safety. Yes, it I was for safety and no, it was not sloppy workmanship.

[Dilkris]

 

Specs for the TC from the manual are indeed:-
Front: Camber 0 Degrees -  +/-30 Minutes Negative; Toe In 1.6 - 4.8 (mm) or 1/16" - 3/16" so average 3.2mm
Rear : Camber 1 Degree  -  +/-30 Minutes Negative; Toe in 3.18 -6.35 (mm) or 1/8" - 1/4" so average 4.8mm

Your 1mm - 3mm toe in per wheel appears to make a lot of sense.

Yes using the string method, but working from a center line from the chassis - (the track width of the front and rear I believe is not  common) - and yes working off the rim face but am using 1m extensions bolted to the wheel in order to magnify the dimensions I am chasing. Will post again with pictures on this approach.

Many thanks your feedback.   







     

[Dilkris]

Thanks BDA - just read your post !! All points noted - it appears we are all singing off the same hymn sheet.

[BDA]

This site is a great help with the string alignment method: https://robrobinette.com/DIYAlignmentCalculator.htm

[Dilkris]

This site is a great help with the string alignment method: https://robrobinette.com/DIYAlignmentCalculator.htm

Excellent - many thanks

[Clifton]

Toe is total both sides. On a light front car is good at 0-1/16" total toe is on a 22-24" is good. I use toe boards with a steel edge, I string it to get thrust/rear toe but boards to check after that. The book says 1/16 to 3/16" front. No way that is per wheel. 2 x 3/16 = 3/8". You would kill your tires pretty quick and have a car that wanders. 3/16-1/4" total on the rear. 

[Dilkris]

On a light front car is good at 0-1/16" total toe is on a 22-24" is good.

What does this mean? I assume you are referring to the diameter of the overall tire yes?

Interestingly, there appears to be a lot of differing opinions on this subject as to whether the toe in as quoted in the specifications is per wheel or overall. 

[EuropaTC]

Interestingly, there appears to be a lot of differing opinions on this subject as to whether the toe in as quoted in the specifications is per wheel or overall. 

Yes, there's equal votes for whether the manual is for total toe or per wheel. All I can say is try it and see how the car feels. When mine had a lot of rear toe, it did scrub tyres although it felt quite stable !
In case you haven't seen it before, Tim Engel wrote his views on Europa geometry. He's of the opinion that the rear specs are per wheel, the front specs for total toe. He also favours toe out at the front, not something I've tried although I have run with zero front toe in the past. But he's certainly got lots of experience with Europas, both S2 & TC, so his views are worth noting even if you decide not to go his way.
Brian

[Clifton]

On a light front car is good at 0-1/16" total toe is on a 22-24" is good.

What does this mean? I assume you are referring to the diameter of the overall tire yes?

Interestingly, there appears to be a lot of differing opinions on this subject as to whether the toe in as quoted in the specifications is per wheel or overall. 

If you are using a toe plate/board that is 24" long against each wheel/tire. I use two of the same brand tape measurers, one in front, one in back. Front measurement is 1/16" less than the rear measurement, it's 1/16" toed in. There is a degree to inch conversion here too. New cars spec in degrees.
https://robrobinette.com/ConvertToeInchesToDegrees.htm

 There's no misunderstanding on toe. No one runs these number per side, 3/8" - 1/2" total toe in. You can try though. If it's toed in, you will murder the outer edge's. Excessive toe kills tires faster than camber.

This is an Elise but the weight is similar to a TC. Ariel Atoms are lighter and run similar.
https://wiki.seloc.org/a/Geo_Setups

I run 0-1/16" total toe in front, 3/16-1/4" total toe in rear. In the non summer on season, I race it monthly and also drive it everywhere I can yearly. I run the same alignment for everything. One hand at 130mph, threshold braking on track, autocross, it's perfect.

Here's a link on how I string mine and a link to a better string to use. You must string it get get the rear inline. If the fronts off, you just have a crooked steering wheel. If the rear is off, you can have 1/4" total but only on one side and not know with just boards. You don't want one 1/4" and the other side zero.
https://www.lotuseuropa.org/LotusForum/index.php?topic=6184.msg66794#msg66794

[Dilkris]

Thankyou everyone for your input - Clifton I was intrigued with your toe plate board approach - BDA the link to the software, as much as I was fascinated and impressed by the trigonometry, I was not clever enough to download, (computers and I do not gel very well and generally just increase my blood pressure...).
I have plenty to be going on with now - as regards the suggestion of running the car down the road to see how she feels, I fear I am a long way away from this - I recently got the car standing on her own wheels for the first time in some 20 years and the present alignment challenge is simply a learning curve for me and to get her somewhere near - when the day comes that she is capable of driving down the road I will obviously repeat the operation - but with some confidence.     

[BDA]

BDA the link to the software, as much as I was fascinated and impressed by the trigonometry, I was not clever enough to download, (computers and I do not gel very well and generally just increase my blood pressure...).

There’s nothing to download. You just enter the measurements in the spaces provided and click on the calculate button.

I should have made more clear that I believe the front toe spec is total and the rear spec is for each wheel. I believe that big rubber bush at the pivot of the radius arm is the reason for the “extra” toe and that if you have a more solid setup (eg. spherical rod ends or spherical ball joints as Serge fabricated in one of his videos) less toe in would be needed.

Before I dialed in more toe in (from probably 1/4” total) driving at 90 on the highway was a white knuckle experience. It’s now, MUCH more relaxed.

[Dilkris]

There’s nothing to download. You just enter the measurements in the spaces provided and click on the calculate button.

Durr.....   I get it now.... sorry, I'm old

[BDA]

The bad part is that there's no cure and it's a degenerative condition.      BUT it's better than the alternative!