Coil spring compression over time & getting new springs made

[Quintet]

Hello Piston Headers. Although I have been a long time lurker this is a first post so please be kind.

I’m a fan of old Japanese cars and I’ve just bought a 1996 Daihatsu Domino. Remember them? It’s a tiny (think classic Mini size) 5 door hatchback. Unfortunately the car has a broken front coil spring. I’ve removed this but a replacement is no longer available. There are some specs on the internet relating to out of stock aftermarket springs which seem the same as mine - except overall length. This spec says:
Coil diameter 95mm
Wire diameter 9.5mm
Free length 313mm

My old spring is 20mm shorter. Would this be accounted for simply by natural compression caused by siting under the weight of the car for nearly 40 years? I’m inclined to think so but I’d be interested to hear if anyone has any direct experience or a different view.

Also, has anyone here actually had new springs wound? I’d be interested to hear about your experience or if you can recommend a company to do this.

Thank you.

[Quintet]

The car is 1986 not 1996. Doh!

[Kawasicki]

I doubt it. Spring steel should stay elastic and not deform over time, unless it has been massively overloaded.

At car companies they often fit a range of springs to one model to maintain rideheights fairly equal irrespective of spec. Maybe your new spring is for scar with a different spec?

[GreenV8S]

I've read that springs left under load do gradually sag and it seems plausible, but I've never noticed it myself on car springs.

I imagine that getting a custom spring would would be hugely expensive. They're normally wound hot at a foundry and getting somebody to set the machine up for a small run seems like it would tie up some expensive equipment and people.

If you know the dimensions and rate you may be able to match them against an existing standard spring. Or replace them as a pair and just accept that the ride height will change a little.

[E-bmw]

GreenV8S said:

I imagine that getting a custom spring would would be hugely expensive. They're normally wound hot at a foundry and getting somebody to set the machine up for a small run seems like it would tie up some expensive equipment and people.

I thought so until I needed to change the springs on a previous track day car.

I took the OE spring to "springcoil" in Sheffield told them what I wanted & £135 later I had exactly what I wanted, a pair of springs that fitted with a different rate.

[stevieturbo]

If you took down the good spring, a spring shop should be able to make you a pair the same, or a little heavier etc as needed.

[Quintet]

Hello again , and thank you everyone for the quick replies, it's much appreciated.

Yes, lots to think about there. I'll have a chat with the suggested Springcoil company and see if I can pick their brains a little. Maybe I'm overthinking this - even if I order to the assumed correct length (20mm longer than what came off) then the car isn't really going to sit much higher than before. Or I could just spec the reduced length. Or a halfway compromise. I'll have a chat with them - maybe they have a factory spec to hand.

[tapkaJohnD]

Most spring manufacturers offer a vast range off the shelf. And for probably less than a bespoke set.

I would replace both, just to be sure they match.
John

[FiF]

E-bmw said:

GreenV8S said:

I imagine that getting a custom spring would would be hugely expensive. They're normally wound hot at a foundry and getting somebody to set the machine up for a small run seems like it would tie up some expensive equipment and people.

I thought so until I needed to change the springs on a previous track day car.

I took the OE spring to "springcoil" in Sheffield told them what I wanted & £135 later I had exactly what I wanted, a pair of springs that fitted with a different rate.

Just to say I have also had a short run custom springs made, not automotive as it happens, while originally expected a silly price yet enquired on the off chance, surprisingly economical solution. Good service.

[stevieturbo]

Quintet said:

Hello again , and thank you everyone for the quick replies, it's much appreciated.

Yes, lots to think about there. I'll have a chat with the suggested Springcoil company and see if I can pick their brains a little. Maybe I'm overthinking this - even if I order to the assumed correct length (20mm longer than what came off) then the car isn't really going to sit much higher than before. Or I could just spec the reduced length. Or a halfway compromise. I'll have a chat with them - maybe they have a factory spec to hand.

For such an oddball...I doubt they would have the specs.

but it would be easy for them to measure yours to replicate or alter as desired.

[Kawasicki]

you don´t need the specs, as long as you have a spring it is fairly easy to copy.

Does the new spring have the same number of turns and the same wire diameter as the old spring. If it does then it is the same stiffness... which means that all you have to do is get the new spring set to the same length as the old one, which isn`t difficult.

[GreenV8S]

E-bmw said:

I took the OE spring to "springcoil" in Sheffield told them what I wanted & £135 later I had exactly what I wanted, a pair of springs that fitted with a different rate.

That's about what I'd expect to pay for off the shelf parts. Do you reckon these were made specifically for you?

[E-bmw]

GreenV8S said:

E-bmw said:

I took the OE spring to "springcoil" in Sheffield told them what I wanted & £135 later I had exactly what I wanted, a pair of springs that fitted with a different rate.

That's about what I'd expect to pay for off the shelf parts. Do you reckon these were made specifically for you?

100% I know they were as it was quite clear when seeing them & seeing the difference in ride height/spring rate from old to new that they were different & achieved exactly what I was asking for.

They even asked me the colour that I wanted.

[stevieturbo]

GreenV8S said:

That's about what I'd expect to pay for off the shelf parts. Do you reckon these were made specifically for you?

getting springs made is not that expensive.

I've a place near me that does it too, and they are surprisingly cheap.

One huge shocker was for an L200 pickup where the leaf springs are well known for breaking. Mitsubishis own just don't seem to last and are very expensive. A friend fitted some to a jeep a few years ago, and about 3 years later they had broke again.
He then looked for alternatives and the spring works near here made a set that really were far cheaper than even Mitsi's own "economy" range and so far have lasted without problem.

He did also get a set of regular wire springs done a few years back for a project too and again price was very keen.

https://www.northbelfastspringworks.co.uk/

[PhillipM]

GreenV8S said:

I've read that springs left under load do gradually sag and it seems plausible, but I've never noticed it myself on car springs.

I imagine that getting a custom spring would would be hugely expensive. They're normally wound hot at a foundry and getting somebody to set the machine up for a small run seems like it would tie up some expensive equipment and people.

If you know the dimensions and rate you may be able to match them against an existing standard spring. Or replace them as a pair and just accept that the ride height will change a little.

Nah they're pretty cheap, as above I always have Springcoil knock me customs up for the buggy and they're pretty cheap.