S1 Project car - part 2 - the continuation

[Lotusfab]

Well have had a think two methods, 

Get a straight edge to span between the front and rear hub centres. You lay the track ace mirror or other mirror on this and set the reader at 90 degrees to the straight edge. You then measure the toe other the other side as before. I don't have a straight edge that long!

Use a laser spirit level and steel rule. Set the laser equidistant from the front and rear hub centres and measure the toe in from the laser line. On each wheel measure both opposite rim edges from the beam and divide by 2 to give the toe in.

Maybe there is a table some where that relates shim thickness to toe in for the rear wheels? Should be possible using maths and the arm length to approximate the shim thickness for a given change in toe.

Well I used a spirit level and iPhone tilt app to get the wheel camber. Then were +1,0 degrees on front and +2,+3 on the rear. I figure 1 degree is acceptable on the front, as its within the error on the instruments being used. I have adjusted the rear to 0,0 very easily by tightening the adjustable dampers. Peters settling measurement gave me the above ballpark and a couple more turns on each and it was exact. 

Have measured the rear wheel toe in the left rear 7.75 MM, right 5.5mm. It should be 4 MM. Because if the radius arm length I calculate this is roughly a 12 MM shim and a 4.5 MM shim( of course I may have calculated it or measured incorrectly), it's all new to me! Does anyone who's done this already think it's in the ballpark?

 

[Lotusfab]

Have just learned that only measuring one side is not accurate enough. So have to measure from hubs on both sides then divide to get vehicle centreline then take all measurements from this reference! 

[Rolls]

On 25 July 2016 at 22:27, Freemason said:

OMG I want an S1...

Don't be greedy - I just want an esprit that works!

[Lotusfab]

Mine nearly works! 

Well have spent a day with track ace. It's difficult to set up. But have got some surprising results if they are correct? The front total toe is just under four MM so the mathematical method seems to have worked. The rear is not so easy. I have conflicting info. Using two methods the left rear wheel was 7.5 MM toe in and 10 MM . The right wheel 5 MM and 2 MM. So it's obvious the methods are not accurate enough to align the rear wheel or the wheels are grossly misaligned. The track ace gives two degrees total between the rear wheels. This seems a lot to me? Will have to get them all measured and then use the readings to reset the rear using shims.

[Lotusfab]

Have just been driving for an hour,fantastic fun! For those of you still working on your projects keep going it's all worth it in the end! The drive  seems to be improving as I tweek the suspension. Pretty good on corners now, all the parts seem t be bedding in! ?????. Have to say I thought the steering wheel was getting hot, it wasn't - just my tight grip on it!

[jonroberts]

Are you certain the front and rear hub->hub lengths are the same ? I know the book says the track is the same (59.5") but the wheels are 6J and 7J sizes.  Just wondering if your method is right - if I've understood you correctly  

I used two wooden poles of exactly the same length spanned widthwise front and rear resting on axle stands set at wheel centre height and stretched nylon fishing line front to back them to make a kind of rectangular frame. Got the 'frame' set exactly around the four wheels measured as close to the centre of each wheel as I could, then measured front and rear of each wheel rim distance to the line with a micrometer. Subtract one from the other to calculate the toe in mm.  

The handling is quite sensitive to tyre pressures being correct all round. Book values for the S1 seem low but thats what I've been using.

[Lotusfab]

Don't think the hub lengths are the same, so I revised the method. Lasers are quite tricky a simple string method may have less errors and be better? The Trackace can only measure total angles but can be used to measure change in wheel  angle, if you know how much you need to change it by.

I worked out the vehicle centreline yesterday using the laser spirit level which can draw a flat plane. I put spacers on each hub on the same side then marked the floor with masking tape. Repeated on the other side. I then used the laser to put a straight reference line between the line on each side. Measured half way then marked the vehicle centreline with tape. I then transferred  this centreline to both sides and marked with tape. So ending up with two reference lines of the vehicle centre  outside of each wheel. This is the same as what you did with the string rectangle. The readings for the front wheel s total toe 4 MM. Confirmed with Trackace as 35 minutes = 4 MM at the rim. Great.

Rear passenger side 10 MM, drivers 2 MM. The rim size 14 inches for both, according to the manual? So 4 MM is 35/60 degrees app 0.5 degrees. So the total for the rear 12mm 1.5 degrees roughly. I measured the total angle using track ace which gave 2 degrees. 1/2 a degree error is too much to align properly. May try the string method, what results did you get?

The problem is 10 MM( if correct) would be very large. Because the shims are at the end if he radius arm it's like an amplifier. The shim thickness would be much greater than 10 MM. Steve at S and J said the most he has ever done is a 6 MM, 2x 1.5MM and three 1.5 MM washers 13.5mm total. This leads me to conclude my reading are incorrect. So will take to the shop and get a Hunter system to read all of the angles. With these can use the trac ace to change the toe in on the rear by zeroing the scale with the wheel without shims. Then you can read the change with shims, correcting it by the Hunter reading amount. Will post on here what effect each shim size has. Will then take it back for another Hunter system reading to ensure its all correct. 

Simple!?????????

[Lotusfab]

Well got it checked by Kwik Fit, who have one of the best Hunter Alignment systems,they checked it all and were very helpful - thanks Kwik fit. We recorded settings with two people in the car and empty. It makes a big difference. Surprisingly the first hub method I used was pretty accurate. 8mm out on rear left (I got 7.75mm) and 4 MM on rear right(5.5). Steering toe almost as per Trackace and within limits. The tracke ace measured 2 degrees total on rear the hunter 1.75 degrees, so not a bad piece of kit. The Track ace was almost the same reading for the front toe.

For anyone who has to do this in the future. I needed to reduce toe in on left rear by abou 52 minutes, just under one degree. I have put in 9 MM of shims from S and J and this is too much. So about 7.5 MM of shims will work I think. Will confirm after I have double checked and taken it back to Kwik fit. It's a real pain to release the radius arm and place a 6 MM shim. The 1.5 MM shims are split and so no requirement to remove the arm. Once the 6 MM bit is in its easy to make small corrections using the split shims. 

The rear camber is slightly off. I have heard of placing shims in the drive shaft, but changing the damper setting seem to have a camber effect. The camber is off slightly on the front left. Not sure how to deal with that unless the upper Baal joint is eccentric. Hope this all helps as U couldn't find much about it ion the forums. Will keep retesting until I get to the book values, hopefully quite close now!

[Paul Coleman]

The front upper ball joints are eccentric I believe.

[Lotusfab]

Thanks, was just looking on S and J website, will have to take the ball joint out on mine and see if it's adjustable. If they are anything like the new lower ones that were installed they won't be correct! Slowly creeping towards the end of this project. Took the car on an A road for the first time. Handles very well even with the suspension slightly off. Drives straighter than my Golf, and no emission problems!

[Paul Coleman]

Then when you fit the new ones you'll have to find out if the bump should be pointing inwards or outwards - I can't remember and I'm not even sure it makes any difference.

[Lotusfab]

Just remembered I have really put any inside pictures on! Having problems with the surface to air missile system, nothing seems to happen when I press the button! The periscope screen is stuck in clock mode too!

[Lotusfab]

Here are some pictures of the shims and the radius arm mount. It's very difficult to get it out. I had to partially remove two of the hub bolts in order to move the radius arm enough to get the mount bolt out!

[Rolls]

19 hours ago, Paul Coleman said:

The front upper ball joints are eccentric I believe.

Paul is correct. You should be able to feel thought the boot. From SJ. Also notice one side has the corner ground off. See my post.

[Lotusfab]

Will have a look, thanks.

[Lotusfab]

Latest project to get the suspension correct. Here were the settings. The specs for each setting were in the database. The first set of readings was taken car empty, second two passengers. Posted this to aid anyone who still has to do this. Surprised there are no details on this on the forum? Anyway, these are my cars. I am using a laser spirit level and trigonometry to make adjustments then will get the hunter readings done again.

In a nutshell,

Front wheels

The front wheel toe in adjusted by releasing rubber gromets on steering rack, rotating the steering arms arm after loosening the locknut on the ball joint.

I have old style upper ball joints on front wheels. They have a square drive at the bottom of the joint so you can loosen the lock nut and rotate the ball joint, which is eccentric and this changes the from wheel camber.

Rear Wheels

toe in changed with shims at the end of the radius arms. I have a 6 MM and 1.5 MM shim on the left rear and 2x 1.5 MM shims on the right, may need to adjust this further after the next readings. 

Rear camber I have adjusted by changing the height of the adjustable dampers. About two turns give a degree or so camber change, I think! 

Hope to get a sheet full of green soon!

You can see with two people in the car only one parameter is correct. This is what you are dealing with after a full rebuild!

Still shouldn't be too difficult to sort this, I hope on the retest most of them are correct.

[Lotusfab]

Have been looking through some of the paperwork that came with the car. I found a brochure for Wolfrace wheels that tells you how to keep them good and a copy of the Lotus owners manual. The owners manual answers the question of where to jack up the car and give a lot of the operating data. I thought some of it is quite useful so here's a few pages.

Interesting how the camber and toe vary depending where you look them up?

[Lotusfab]

Think the quickfit data base is slightly off for the earlier esprit. The difference between the handbook and the workshop manual is:-

Rear suspension in the handbook toe in 8 to 10 mm, 

In the workshop manual 4 mm, max. All other data is the same. Surprised this has not come up before? 

I remember in 1977 there were no lasers apart from in Star Wars, so Lotus probably gave mm at rim edge so you could set up the wheels with a string rectangle?

[Lotusfab]

Well, have calculated new figures based on the workshop manual, which has to be the definitive reference. Here's the modified alignment sheet for the S1. I used tables provided by Jon to convert MM to degrees, they are the same readings as those I had looked up before. If anyone sees any discrepancies please let me know, thanks.

heres the workshop manual extract and the amended alignment sheet!

[Paul Coleman]

How is the caster angle adjusted? And how are you going to measure it?

[Lotusfab]

Have bought a ball joint separator to partially remove the top ball joint. The joint has a square drive with a split so you can rotate it and change the front camber. I will reset the camber and hope this has an effect on the castor. The only way I think the caster could be adjusted is to shim the upper wishbone???Don't think this was done on the early cars? As you can see from the above with the amended Lotus limits my right front wheel is set ok. Just the toe needs adjusting. The left I will use a spirit level to change the camber and take it back to Kwik fit and see if it's all within limits. I assume from the lack of info on here car set up to the book limits, apart from front toe in, is not that common?

[jonroberts]

14 hours ago, Paul Coleman said:

How is the caster angle adjusted? And how are you going to measure it?

Using a camber gauge and turning the wheels through 40 degrees and measuring the camber differences.  I suspect that since the top ball joint is eccentrically adjustable the caster could change as the joint moves through a fore/aft movement. If this is the case, then I see it's possible to set correct camber, but with the balljoint in the 'wrong' position - hence incorrect caster. I'm not sure if the joint moves through 360 degrees, or is constrained over a smaller arc. I guess Fabian is about to tell us  ..   I do remember that there is a correct way and an incorrect way to install the top ball joint - something to do with a dot or indent on the joint casting ? I don't remember which is correct but the end measurements are what matters.

[jonroberts]

2 hours ago, Lotusfab said:

Have bought a ball joint separator to partially remove the top ball joint. The joint has a square drive with a split so you can rotate it and change the front camber. I will reset the camber and hope this has an effect on the castor. The only way I think the caster could be adjusted is to shim the upper wishbone???Don't think this was done on the early cars? As you can see from the above with the amended Lotus limits my right front wheel is set ok. Just the toe needs adjusting. The left I will use a spirit level to change the camber and take it back to Kwik fit and see if it's all within limits. I assume from the lack of info on here car set up to the book limits, apart from front toe in, is not that common?

My guess is that when you reset the camber on the left front wheel, it will bring the caster back into limits.  It will likely affect your toe settings as well, which currently show negative instead of positive by the way.

[Lotusfab]

Thanks Jon, have to be honest hadn't spotted the toe was out! Will correct it and post all details of rotating the upper ball joint and its effect together with the rear shims, as soon as I get a little time free to adjust it. I have fitted a 6 MM shim to the left rear and 2x1.5 MM to the right.

[Rolls]

On 5 August 2016 at 08:23, jonroberts said:

. I'm not sure if the joint moves through 360 degrees, or is constrained over a smaller arc. 

It does rotate 360 degrees.