My Esprit S1 import finally arrives!

[williamtherebel]

2 minutes ago, Jeanvm said:

The car looks very nice. Those wheels very cool. With the gear linkage I would check all the moving parts. A little adjusting can do the trick.

Thanks Jean. Wheels are 15" so am going to change back to the 14" Wolfrace wheels. Yes, I'll be checking all the gear linkages. 

[skiing]

I really like those wheels actually! - creaking from front could be springs / anti roll bar fixings? - the front end of mine was creaky etc. until bushes were done and sorted by Sparky - especially anti roll bar ones.

[gvy]

It looks as if the car sits at the right hight, isn't it? Shouldnt be any lower in my opinion.

 

[drdoom]

That's a smart looking motor car, Lez!

Regarding ride height your latest pictures don't entirely address the question and, while the earlier pics of the car from that PDF set I posted earlier do show the car at a somewhat raised front end, one can't be sure whether the car had been settled onto its normal ride height. Those  shots had been taken either inside or just outside the vendor's garage and it was likely inside the garage where the suspension photos were taken, the car on a lift or jacks. Now that the car has been driven perhaps compare its present stance with those older pics.

Cheers

[williamtherebel]

15 hours ago, skiing said:

I really like those wheels actually! - creaking from front could be springs / anti roll bar fixings? - the front end of mine was creaky etc. until bushes were done and sorted by Sparky - especially anti roll bar ones.

Yes, Im going to check the springs next, but as you suggest will check the anti-roll bar bushes as well. Cheers.

13 hours ago, gvy said:

It looks as if the car sits at the right hight, isn't it? Shouldnt be any lower in my opinion.

 

I will double check next time I go to the garage. It may be that now its had a drive it may have settled a bit. However if its the same as before the springs def need changing. will be in touch.

9 hours ago, drdoom said:

That's a smart looking motor car, Lez!

Regarding ride height your latest pictures don't entirely address the question and, while the earlier pics of the car from that PDF set I posted earlier do show the car at a somewhat raised front end, one can't be sure whether the car had been settled onto its normal ride height. Those  shots had been taken either inside or just outside the vendor's garage and it was likely inside the garage where the suspension photos were taken, the car on a lift or jacks. Now that the car has been driven perhaps compare its present stance with those older pics.

Cheers

Im going to check the ride height again the next time I go to the garage. I will compare and take some more photos for you experts to comment on!!

[GTK]

Looks great Lez! 

Just a thought about the gears slipping, and only thinking of it because it was on my radar over the last week, I read that gear selection can be compromised if the engine/trans mounts are bad. Makes sense to me, so maybe it follows that with bad mounts under load the box could be jolted out of gear? Might be useful info if linkage adjustment doesn't do the trick.

[williamtherebel]

Thanks for the thought. However I have just replaced the engine mounts and the gearbox bushes so wouldn't have thought that could be the problem - however you never know. Will investigate and report back.

[drdoom]

Lez,

To pick up on George's points, do be mindful of the possibility that the gearchange linkage may have been previously adjusted to cope with the trans displacement withered mounts might well have wrought. So in restoring things with a healthy set of mounts it seems possible that the linkage was consequently put out of sorts, therefore in need of adjustment.

Cheers

[williamtherebel]

On ‎30‎/‎10‎/‎2018 at 19:05, gvy said:

 

Lez,

Years ago , I bought a set of brand new front springs from SJ sportscars for my UK esprit S2.2. The reason , my car sat to low and I thought new springs would solve this.

After installing these new front springs, I had the feeling the car sat even lower???? So I decided to change again to the former ones. Since then I solved the problem by adjusting hight to my likes with a stainless steel ring ( made to an exact fit) and the right thickness of rubber ring in the spring seat. All is fine since.

However.

Maybe these brand new SJ springs ( never used in the corner of my workshop)  will sit right on your car ( lower it) and your higher springs sit right on my car ( that is without the rubber donuts).

Your S1 should lower and my S2.2  should lift......

I have no idea about what shipping would cost between Belgium and  UK, but we could just change out our springs to give it a try. I can send mine to you, so you can try them and then you can decide if they are ok, keep them and send me your higher ones in return,  if not ok , just send them back to me.

 

 

 

 

Geert

Hi Geert, Just taken the springs off this afternoon and measured them. The height is exactly the same as yours i.e 34.5 cm. However , yours has 9 coils whilst mine has 11 (or 12 depending how you look at it!). So Im presuming that my wheels will sit higher because the springs will be stiffer. If you are still happy to swop I will get them parcelled up and sent off. Cheers. 

[williamtherebel]

Oh dear, having a senior moment! I meant the car will sit higher - not the wheels!

 

 

[gvy]

Lez,

A bit strange,

Watch this video:

Now in the formula, you can see that the more coils a spring has , the less stiff it will be. ( That is what I always learned in the past also).

Very important is the diameter of the actual springwire. Mine are 11.4mm.

so:

d=11,4mm

OD=112mm

D=OD-d=100.6mm

n=8.75-1= 7.75 (only one closed end on my coil)

= 21.22 N/mm

 

Could you do the same math on your spring before shipping, because it looks like yours could even be less stiff then mine depending on the d?

I guess your spring will be:

d=?

OD will be the same as mine?

n = I count 12 - 1 = 11  (yours has also 1 closed end as mine)

Geert

 

Edited November 8, 2018 by gvy

[drdoom]

Geert's got it right, the more the coils all else remaining equal the softer will be the spring. The compressing of a coil spring primarily results in a torsion force on the free coils, far less a bending force. So if one pictures a coil spring to be a compactly arranged torsion bar it is perhaps easier to see why the greater number of free coils would be softer. To compare these 2 sets of springs, Lez, you'll need to determine the wire diameter and work through the above formula for a start. To accurately anticipate the change of ride height through a change of spring you'll also need to measure and calculate the wheel rate.

On the other hand, the photos make clear that there is no flattening or grinding flat of the top coil, so Giniw's remarks critical of cutting a part coil don't seem applicable in this application. Cutting something off the free end coil will result in a measure of rate increase, an increase in stress of the spring wire itself, and something of a reduced ride height. It's unclear to me that your car sits unduly high at the front, taking what one can from the photos. There are ground clearance specs for the Esprit in the factory manuals, by the way.

Cheers 

[williamtherebel]

17 hours ago, gvy said:

Lez,

A bit strange,

Watch this video:

Now in the formula, you can see that the more coils a spring has , the less stiff it will be. ( That is what I always learned in the past also).

Very important is the diameter of the actual springwire. Mine are 11.4mm.

so:

d=11,4mm

OD=112mm

D=OD-d=100.6mm

n=8.75-1= 7.75 (only one closed end on my coil)

= 21.22 N/mm

 

Could you do the same math on your spring before shipping, because it looks like yours could even be less stiff then mine depending on the d?

I guess your spring will be:

d=?

OD will be the same as mine?

n = I count 12 - 1 = 11  (yours has also 1 closed end as mine)

Geert

 

Hi Geert As you say this is strange. I was working on the car again today and took a measurement of the diameter of the wire. Its the same as yours.(11.4mm) I didn't measure the OD but would presume its the same as yours??. Im not going back to the car until next week, but will double check next time im there. However if it IS correct then I am in a quandary. The car def. sits too high compared to UK models as can be seen by my photos comparisons but if its not the springs Im not sure what it is. I will have to do some more research and get back to you. I will also take what @drdoom has told me into account.

14 hours ago, drdoom said:

Geert's got it right, the more the coils all else remaining equal the softer will be the spring. The compressing of a coil spring primarily results in a torsion force on the free coils, far less a bending force. So if one pictures a coil spring to be a compactly arranged torsion bar it is perhaps easier to see why the greater number of free coils would be softer. To compare these 2 sets of springs, Lez, you'll need to determine the wire diameter and work through the above formula for a start. To accurately anticipate the change of ride height through a change of spring you'll also need to measure and calculate the wheel rate.

On the other hand, the photos make clear that there is no flattening or grinding flat of the top coil, so Giniw's remarks critical of cutting a part coil don't seem applicable in this application. Cutting something off the free end coil will result in a measure of rate increase, an increase in stress of the spring wire itself, and something of a reduced ride height. It's unclear to me that your car sits unduly high at the front, taking what one can from the photos. There are ground clearance specs for the Esprit in the factory manuals, by the way.

Cheers 

Hi Tim thanks for the info. Sorry to be a bit thick but can you tell me what the "wheel rate" is? l'll also check out what the manuals say.

[Giniw]

On 09/11/2018 at 00:28, gvy said:

Now in the formula, you can see that the more coils a spring has , the less stiff it will be. ( That is what I always learned in the past also).

Actually it's easy to understand why, once you figure a coil spring is just a compact shape of a straight bar.
If you imagine a straight bar (the spring before it's coiled), it's easy to understand that for a given force at one bar extremity, it will flew more if it's longer, hence the upper flexibility (mm/N) or lower rate (N/mm).

Of course because of its coiled geometry, a coil spring is also working in torsion so you cannot predict the rate with just the length of the straight bar, but you get the idea ^^

20 hours ago, drdoom said:

so Giniw's remarks critical of cutting a part coil don't seem applicable in this application

I agree that the upper coils of the springs on the photo https://s3.amazonaws.com/tlf/tlf/forums/aws_uploads/monthly_2018_11/1080405839_frontsprings1.JPG.d21fd8aa538b7f2dd51993a5d6956acb.JPG look rather regular indeed, so maybe it's a bit less disastrous to cut it. But honestly I probably wouldn't bother too much adapting those strange springs as they don't look standard anyway (I am telling that from the others photos as I don't know the real shape of a S1 spring, I have never seen any)

(@drdoom > I just noticed you said about the same thing that my first paragraph, except I didn't know which stress was preponderant but anyway... :D)

[Giniw]

6 hours ago, williamtherebel said:

can you tell me what the "wheel rate" is?

I suspect the wheel rate is actually the rate measured at the wheel (taking into account the suspension geometry), as opposed to the spring rate which is only interesting when you compare springs alone on the bench.

Indeed if you want your wheel to travel 100mm for a force of 250daN, that does not imply you have to chose a spring rate of 2500/100= 25N/mm. It would be OK if you put the chassis directly onto the bare springs though! Basically, the suspension geometry modifies the force applied to the spring so you need to know that particular coefficient I suppose ^^

(but that is just a guess, I am not a suspension expert so we'll see whether drdoom confirm!)

 

 

Also, for those who don't know, please keep in mind all springs don't have a fixed rate, depending on the geometry a spring totally can have a spring rate depending on the force applied to it (non constant coiling diameter, non constant wire diameter, ...) so the above formula only applies for simple springs.

[drdoom]

I'm no expert on anything but I do try my best to acquire sound knowledge. Geert, Giniw and I are all concurring in these considerations, I'd say.

Lez, little doubt you will find that the coil diameter of your springs matches that of Geert's. The seats at both top and bottom perches are sized accordingly and, additionally, there's practically no chance any alternative street spec springs were ever produced in numbers for the Esprit. That said, my pal who'd cut a bit off the OEM set to happy effect had first tried a set produced to his spec by a reputable local firm. It was when these non-OEM springs sagged badly that he resorted to the shortened originals. Can't speak for what went wrong with the custom set as they were produced by the same firm I very successfully had produce uprated springs for my classic Elan.

If your springs don't serve as desired I cannot see why it would be amiss to cut something off in order to shorten and firm up. It's not as if they are irreplaceable, and I'd venture you have no plans to rallycross the car. I'd take perhaps 3/4 coil off using a metal cut-off wheel on a high speed angle grinder, appropriate safety gear for hands and face/eyes. That is what my S2 will ride out on when the restoration is wrapped up.

Wheel rate derives from the simple spring rate by way of the suspension motion ratio. To illustrate motion ratio, picture how when the tire/wheel move up or down a given distance relative to the chassis the bottom spring perch moves in step but to a lesser degree, as the distance from lower arm pivot (bush) centerline to perch C/L is less than the distance pivot - wheel C/L. More technical than is needed for our purposes as hack engineers.

[Giniw]

41 minutes ago, drdoom said:

Can't speak for what went wrong with the custom set

Hard to tell obviously but a properly made coil spring shouldn't sag much over time. After the coiling is done at the factory, they are (should be) compressed to block height so that it's sure they won't sag more in their normal use. So theoretically that initial sagging is taken into account during the spring design (they are made a little bit taller during the coiling process). Maybe the initial compression to block height has not been done for that set you are talking about? (sorry, it's a bit off topic!)

[Giniw]

20 minutes ago, drdoom said:

If your springs don't serve as desired I cannot see why it would be amiss to cut something off in order to shorten and firm up. It's not as if they are irreplaceable, and I'd venture you have no plans to rallycross the car.

I tend to agree but personally the Lotus handling is a key value of the brand so that is something I really would want to sort out properly. Plus it could be dangerous if the springs coil are suddenly contacting each others during a compression (apparently there are more coils in the same height of a stock spring, so ...)

But I agree he has nothing to lose to experiment with the springs if he's being cautious.

[GTK]

 

Gents I just took the front springs off my car. They are 35cm long [one is actually 34.9cm] and have 10 coils. I didn't measure the gauge of a coil. I believe them to be Federal spec but have no evidence of that other than the car riding too high.

Just to say, I was watching that stiffness calculation video above and had already seen this coil counting how to, below, and one contradicts the other with regards whether closed ends make a difference to coil count. I can imaging arguments for both schools of thought, but which is right?

 

[gvy]

But anyway,

We were discussing that the possibility in swapping my springs to Lez's springs would be a solution to lower Lez' s car.

I am sure , with all specs known , it will not.

Both springs have the same overall diameter, Both springs have the same wire thickness , Both springs have the same height , My new springs have 8.75 rotations, Lezs have 12 rotations.

In the end my springs will be the stiffer ones and set his car even higher. No need to make the shipping costs to send them from Belgium to the UK , I think.

Geert.

@GIWI

I think, seen the construction of both our springs, they are fixed rate so the formula does apply.

@Lez and drdoom

I think , seen the construction of the springs, it is safe to say that you can cut a piece of the upper part of the spring.

Only one remark : in this picture of your car , I dont think your car sits high. Watch out, dont make it to low, it is not nice to drive . believe me I know, I did all sorts of things to make my s2.2 sit a bit higher.

Geert

Edited November 10, 2018 by gvy

[drdoom]

The flattened coils are not to be counted as the kinematics don't task them as they do the free coils, as I have read.

Just got off the pot and took a look here and there for something helpful to add, so offer the following: from the S1/S2 Lotus Shop Manual front coils Federal are 10.5 coils, 34.6 cm overall length and 63.63kg/cm rate ( 140 lb/in  for us old-timers ), Dom/Euro are 9 coils, 35.3 cm length and 55.14 kg/cm rate ( 121 lb/in ). Coil diameter for both is 10.0 cm. Also, I checked what my S2, 78/07/100S, was fitted with at Factory and, lo and behold, the front coils would have numbered 9 before I cut 1 free coil off. I will attach  pictures of my untouched car at rest, plus a shot of prepped springs for reference. Note that my car was fitted with A/C at Factory, sold into Canada originally yet not fitted as Federal. Interesting.

[drdoom]

Lez, where one is to commence the count of free coils from the bottom end is the point at which the wire has ramped into upward incline, separated from the perch, bench or floor as the case may be. Your count of 11 or 12  equates to 10.5 if you take another look at your posted pictures, in light of this.

Cheers 

[drdoom]

By the way, for Lotus Manual specs to be correct regarding the front spring rates, the Federal springs must be made of thicker wire. They are effectively longer, 10.5 coils versus 9 for Dom/Euro, so must either be of thicker wire or otherwise would be of a softer rate. No getting around that. Still, Lotus information has not always been ironclad, anti-roll bars for example. Over on the V-8 Esprit forum there has been discussion of a-r bars found fitted which did not agree with the Factory specs. When I pulled apart a 1964 Elan for restoration it most certainly had a 5/8 a-r bar from factory yet you will find no reference to such a thing in any literature on the cars. All references are to 11/16 bars.

[williamtherebel]

On ‎10‎/‎11‎/‎2018 at 17:19, gvy said:

But anyway,

We were discussing that the possibility in swapping my springs to Lez's springs would be a solution to lower Lez' s car.

I am sure , with all specs known , it will not.

Both springs have the same overall diameter, Both springs have the same wire thickness , Both springs have the same height , My new springs have 8.75 rotations, Lezs have 12 rotations.

In the end my springs will be the stiffer ones and set his car even higher. No need to make the shipping costs to send them from Belgium to the UK , I think.

Geert.

@GIWI

I think, seen the construction of both our springs, they are fixed rate so the formula does apply.

@Lez and drdoom

I think , seen the construction of the springs, it is safe to say that you can cut a piece of the upper part of the spring.

Only one remark : in this picture of your car , I dont think your car sits high. Watch out, dont make it to low, it is not nice to drive . believe me I know, I did all sorts of things to make my s2.2 sit a bit higher.

Geert

Hi Geert, I measured the OD this afternoon. It measures 11.5 so its probably the same as yours. However, with everybody kindly offering information and advice I have got a bit sidetracked regarding my original point. Namely I have a federal car that sits too high due to the USA regulations for headlight height, compared to UK models. If I order the springs from SJ or Lotusbits they would just send me the springs you have. So, if you are still willing I would like to take you up on your original offer. If I send you the cost of the p&p you could send me your springs. I can fit them and see what they looks like. If they don't lower the height I will send them back, paying the return p&p of course. However if they do lower the car, then it would follow that my springs would benefit your car and I could send you my springs. OR, if you didn't want my springs, perhaps I could purchase your springs which would save me removing them again. What do you think? You can PM me if you like. Cheers.

[williamtherebel]

On ‎12‎/‎11‎/‎2018 at 03:37, drdoom said:

By the way, for Lotus Manual specs to be correct regarding the front spring rates, the Federal springs must be made of thicker wire. They are effectively longer, 10.5 coils versus 9 for Dom/Euro, so must either be of thicker wire or otherwise would be of a softer rate. No getting around that. Still, Lotus information has not always been ironclad, anti-roll bars for example. Over on the V-8 Esprit forum there has been discussion of a-r bars found fitted which did not agree with the Factory specs. When I pulled apart a 1964 Elan for restoration it most certainly had a 5/8 a-r bar from factory yet you will find no reference to such a thing in any literature on the cars. All references are to 11/16 bars.

Yes, As you say, interesting, but even more confusing than before. Therefore, I am going to see if Geert will send me his springs and I will fit them and see what it looks like. I think it is worth taking the chance because If I got UK springs from SJ or Lotusbits, presumably they would send me the same ones that Geert has.