Suspension geometry set-up.

[Chillidoggy]

Took the car to NMS yesterday for a full suspension geo set-up.

I'd previously rearranged the front top wishbone shim washers in the hope that all the adjustment could then be carried out with the ball joint shim plates. As it was, I decided to go 4.5mm/4.5mm fore and aft, which meant me machining four 3mm washers, but proved to be the right choice. Prior to setting off, I removed Rubik's heat shield and replaced it with a piece of temporary Thermal Velocity and wired it in place. I also took a good selection of shims so the car wouldn't be stuck there waiting for any to be ordered. That was a little costly, but at least now I have a shim collection. Very impressed with NMS's engineer Chris, who did the job, a very knowledgeable guy, he's also set up @CHANGESEsprit a few times before. After adding the correct ballast to the car, Chris first proceeded to go round making sure the suspension links were released and set correctly, then go on with the measurement and shimming.

Sadly, the drive home was not the best test, it pissing down with rain and there was heavy traffic, but as we neared home it cleared enough to be able to say that the car feels more planted now, and the faster it goes, the better it feels. Of course I resisted that particular temptation. I hope to be able to exploit the new set up once the weather improves.

My thanks to @tomcattomfor the photos of his shim positions.

[cweeden]

Hi Ian, 

Out of interest do you know what shims you ended up with and where? I will need to do this soon to get the geo in the right ball park before popping the body back on the chassis.

cheers

-Chris

[Chillidoggy]

1 hour ago, cweeden said:

Hi Ian, 

Out of interest do you know what shims you ended up with and where? I will need to do this soon to get the geo in the right ball park before popping the body back on the chassis.

cheers

-Chris

Possibly, but I’m afraid it won’t work like that. The Esprit chassis’ have a manufacturing tolerance and are not laser-perfect, which is why shims are required in the first place. Also, the V8 may have a different geo than the 4-cyl, but TBC.

My suggestion would be to simply put any shims back where you found them, then have the final set-up done once it’s on the road again.

[tomcattom]

3 hours ago, Chillidoggy said:

My thanks to @tomcattomfor the photos of his shim positions.

Forced me to clean a bit more of the extra ballast off my car in the form of the dried mud I'm carying about. I'm sure it must have been rally-crossing in a former life 🤣

[Chillidoggy]

@cweeden

I should probably have explained that the reason I asked tomcattom for photos of his shim washers was because the Esprit should a total of 9mm of castor shim washers on the wishbone shaft, I'd noticed mine was short of that figure on both sides. Because of that, the top wishbones were never going to be in the correct position for castor.

[Jacques]

As I also discovered on mine as well. So, I decided to do it myself, and all angles and setup are now spot on. Took a whole day, but well worth the effort, as we are talking supercar with super performance. A required safety in handling.

Kind regards,

Jacques

[hspeck]

On 30/06/2021 at 23:36, Chillidoggy said:

@cweeden

I should probably have explained that the reason I asked tomcattom for photos of his shim washers was because the Esprit should a total of 9mm of castor shim washers on the wishbone shaft, I'd noticed mine was short of that figure on both sides. Because of that, the top wishbones were never going to be in the correct position for castor.

Hi, I have recently send my car to the alignment shop, but they were not able to get the correct castor.

My castor is now about 1° each side only.

We used 9mm washers at the wishbone to chassis, and 12mm shim plates at the wishbone to top ball joint. However, no matter how we shift them, the maximum that we can get is still a little shy of 1°. We maintained a minimum of 1.5mm between the wishbone and chassis as required in the manual for 1988-1992 Esprit.

My car is the X180, but using SJ's adjustable wishbone, which I presume we will have to follow the manual's settings for the S4.

Any idea what might be the issue?

Thanks.

[Barrykearley]

You need to send it to someone whom knows what they are doing. The parts on the car and the chassis will dictate what the numbers should be. 

[Chillidoggy]

4 hours ago, hspeck said:

Hi, I have recently send my car to the alignment shop, but they were not able to get the correct castor.

My castor is now about 1° each side only.

We used 9mm washers at the wishbone to chassis, and 12mm shim plates at the wishbone to top ball joint. However, no matter how we shift them, the maximum that we can get is still a little shy of 1°. We maintained a minimum of 1.5mm between the wishbone and chassis as required in the manual for 1988-1992 Esprit.

My car is the X180, but using SJ's adjustable wishbone, which I presume we will have to follow the manual's settings for the S4.

Any idea what might be the issue?

Thanks.

 

Given that castor (at least on later models) is achieved solely by the top wishbone position, have you fitted the wishbone arms the correct way round? 

[sailorbob]

Mixing suspension components from different years is likely to have unexpected results. A 1.5 mm castor washer / shim on the SE causes almost 1° of change in castor but on the S4 onwards it is only approximately 0.4°. I suspect the chassis tube for the upper wishbone stud could be different.

Also, the S4 onwards does not specify using a minimum 1.5 mm washer between the upper arm and chassis but a 5 mm clearance instead.

[hspeck]

3 hours ago, Barrykearley said:

You need to send it to someone whom knows what they are doing. The parts on the car and the chassis will dictate what the numbers should be. 

This is the 4th shop that i have been to that is willing to try. Most just told me they can't do it. 

I really envy you guys. We are lacking old school shops that can handle our cars. Most of the shopa nowadays just want to plug in an obd reader and follow instructions on the diagnosis machine. 

1 hour ago, Chillidoggy said:

 

Given that castor (at least on later models) is achieved solely by the top wishbone position, have you fitted the wishbone arms the correct way round? 

If looking at the photo i uploaded, what should i do if i want to increase the castor?  

1st photo is for the drivers side. 

1 is 1.5mm, 2 is 7.5mm, 3 is 4.5mm and 4 is 7.5mm.

2nd photo for the passenger's side we could only get 0°53' when all the shim plates are at 1 side. 

I am thinking maybe it is because we misunderstood the instructions as we are not native English speakers. 

Please kindly advise what we have done wrongly as this has been going on for more than a year. 

Thanks. 

[Chillidoggy]

I think I can see your problem(s).

Unless I'm mistaken, one set of your wishbone arms are incorrect. Check Section CF of the Lotus Service Notes for the correct position. The arms are different, they are not identical. First thing is to get them correctly orientated. Then insert the shim washers. As a guide, I started with 4.5mm at each end of the chassis tube and the remainder could be adjusted at the ball joint with the shim plates to give the correct castor.

It's difficult to see amount of shim washers on your wishbone shafts, see the photo. If your wishbones both need moving rearwards, it looks to me like you have too much shimming at the front in the first photo, but it's difficult to see. Those shims set the initial wishbone position and if it's not even close there's no chance of getting the castor correct.

 

 

[hspeck]

1 hour ago, Chillidoggy said:

I think I can see your problem(s).

Unless I'm mistaken, one set of your wishbone arms are incorrect. Check Section CF of the Lotus Service Notes for the correct position. The arms are different, they are not identical. First thing is to get them correctly orientated. Then insert the shim washers. As a guide, I started with 4.5mm at each end of the chassis tube and the remainder could be adjusted at the ball joint with the shim plates to give the correct castor.

It's difficult to see amount of shim washers on your wishbone shafts, see the photo. If your wishbones both need moving rearwards, it looks to me like you have too much shimming at the front in the first photo, but it's difficult to see. Those shims set the initial wishbone position and if it's not even close there's no chance of getting the castor correct.

 

 

Hmmm.. I didn't realise that the wishbones are different. I will need to check the manual and see if i can find the difference. 

As for the shim washers, i have 2 3mm and 1 1.5mm at position 2, and 1 1.5mm at position 1.

So i should set both to 4.5mm as a start and move the shim plates at the ball joint to adjust. 

Don't have the manual with me now, will take a look tomorrow when i get back to the office. 

Thanks. 

[eeyoreish]

As far as I'm aware, all 4 top wishbones on the X180 are the same (4x X036C6004F according to the parts diagram). I think maybe the S4 onwards is different?

[Chillidoggy]

17 minutes ago, hspeck said:

Hmmm.. I didn't realise that the wishbones are different. I will need to check the manual and see if i can find the difference. 

As for the shim washers, i have 2 3mm and 1 1.5mm at position 2, and 1 1.5mm at position 1.

So i should set both to 4.5mm as a start and move the shim plates at the ball joint to adjust. 

Don't have the manual with me now, will take a look tomorrow when i get back to the office. 

Thanks. 

 

Yes, get the arms correct first! The ones you bought are the later version, and are not identical.

Then if you consider what I said about the wishbone needing to be moved rearwards, the shim washer positioning on the pivot shaft should make sense. If the wishbone is too far forwards, you will never be able to correct it using the ball joint shims alone.

[hspeck]

3 hours ago, sailorbob said:

Mixing suspension components from different years is likely to have unexpected results. A 1.5 mm castor washer / shim on the SE causes almost 1° of change in castor but on the S4 onwards it is only approximately 0.4°. I suspect the chassis tube for the upper wishbone stud could be different.

Also, the S4 onwards does not specify using a minimum 1.5 mm washer between the upper arm and chassis but a 5 mm clearance instead.

Hi, unfortunately the only top wishbone available is those from the newer models, and i thought one should be able to achieve similar parameters using the newer wishbones. 

I believe many has done that. 

However, i did not know about the difference for SEs and S4s. Will keep that in mind. 

And, 5mm, is the total? 

Thanks

Just now, Chillidoggy said:

 

Yes, get the arms correct first!

Then if you consider what I said about the wishbone needing to be moved rearwards, the shim washer positioning on the pivot shaft should make sense. If the wishbone is too far forwards, you will never be able to correct it using the ball joint shims alone.

I can't seem to see the difference.. 

How can i tell? 

Thanks to the folks here who send me the CF section. 

3 minutes ago, eeyoreish said:

As far as I'm aware, all 4 top wishbones on the X180 are the same (4x X036C6004F according to the parts diagram). I think maybe the S4 onwards is different?

I think the wishbone i bought from SJ is also for the S4s.. 

But i may be wrong 

[hspeck]

So I just checked on SJ's, the top wishbones for 1993 onwards are different for the front part and rear part. Both have different part numbers

But for the X180 they seemed to be similar as it comes in a set. 

[sailorbob]

In your 2nd photo for the passenger's side where you say you could only get 0°53' when all the shim plates are at one side you have the upper wishbone arms swapped over to how you have them on the drivers side.

[hspeck]

15 hours ago, sailorbob said:

In your 2nd photo for the passenger's side where you say you could only get 0°53' when all the shim plates are at one side you have the upper wishbone arms swapped over to how you have them on the drivers side.

OK, will do that and try again

Thank you!

[Chillidoggy]

If I read my first Hunter printout correctly, with the LHS wishbones incorrectly orientated it gives approximately 3 degrees of castor. So, simply by changing them around on the LHS will give you approximately 3 degrees, 53' castor on that side. Do the wishbone shaft shim-washers first, then the ball joint shim plates for the final castor alignment. I don't think your wishbone shaft chassis tube is in a different position, but that's an unknown until you do the work, and have it checked again.

Camber - it's just the wishbone plates, but the technician who did my geo did say that any change to castor or camber can potentially affect other settings. Toe setting should be the final job.

Good luck in finding a sympathetic garage!

 

[hspeck]

On 08/07/2021 at 16:41, Chillidoggy said:

If I read my first Hunter printout correctly, with the LHS wishbones incorrectly orientated it gives approximately 3 degrees of castor. So, simply by changing them around on the LHS will give you approximately 3 degrees, 53' castor on that side. Do the wishbone shaft shim-washers first, then the ball joint shim plates for the final castor alignment. I don't think your wishbone shaft chassis tube is in a different position, but that's an unknown until you do the work, and have it checked again.

Camber - it's just the wishbone plates, but the technician who did my geo did say that any change to castor or camber can potentially affect other settings. Toe setting should be the final job.

Good luck in finding a sympathetic garage!

 

I have informed the workshop what I have learned here and he is willing to try again.

Will be going to the shop next Tuesday. Hopefully it can be finally settled!

Thank you!

[Chillidoggy]

49 minutes ago, hspeck said:

I have informed the workshop what I have learned here and he is willing to try again.

Will be going to the shop next Tuesday. Hopefully it can be finally settled!

Thank you!

 

I don't know what wishbone shaft shim washers you have spare, but if do you need any, they are easy to make. It's always worth having some spare before you got to the workshop. You might be lucky and not need any, but equally, you might be unlucky.

[hspeck]

19 hours ago, Chillidoggy said:

 

I don't know what wishbone shaft shim washers you have spare, but if do you need any, they are easy to make. It's always worth having some spare before you got to the workshop. You might be lucky and not need any, but equally, you might be unlucky.

Thanks, i have bought many pieces from SJ as I was not sure how many i needed. I reckon i can use what i have to do 2.5 cars... Hahha

[hspeck]

Just an update on the castor...

As advised by the folks here, we swopped the top wishbone arms on the passenger side and voila.. we can now adjust the castor to 3° each side.. however, after some discussion with the shop, we decided to follow the original specs for the X180 and has set both sides to about 1°15' instead.

Thank you all for the kind advises.

Cheers!

[hspeck]

On closer look, we realised how to identify the difference... These were bought from SJ

In the first diagram, the 2 circled are different. One is raised and the other is flat. 

Another telltale in the office second photo one has a raised part and the other is flat.