PI SportSprings look to me like they will fit YRV Turbo

Not as good as my Teins

Not as good as my Teins Wink

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'12' Plate Mazda MX-5 2.0 litre NC 3.5 Venture Roadster 160BHP
'15' Plate SEAT LEON 184 FR TDI. 240BHP/500nm Torque.
Past: '53' Plate Yellow YRV Turbo Approx. 150BHP

Yep. SPAX and i think PI, A

Yep. SPAX and i think PI, A few other brands do Sirion springs.

Best to just google Sirion springs

But the standards are pretty good, unless you just want it a bit lower.

I know Bob had some made up

I know Bob had some made up by the original manufacturer and yes I think theres room to go lower

Spring type

Interesting to see that these springs are progressive not linear.

The YRV rear springs I bought some time ago from Daihatsu Netherlands (pics in 'Images')are generally stiffer but are also progressive, which is a more sophisticated design.

YRV Tony

Almost all lowered springs

Almost all lowered springs are designed progressive to achieve the lowering effect. So when uncompressed the spring is about the same overall length as originals so it does not become loose in the cups when wheels are off the ground.

Spring design

A very plausible but over-complicated explanation for the use of progressive springs Nathan, but in practise unlikely.

It would be a very unusual supension set-up if you didn't have to compress the springs quite significantly to engage the extended dampers. Even with stiffer lowering springs I would have thought that 25mm lowered ride height was insignificant in this context.

The real reason for the choice of progressive springs is much simpler - just to give a slightly softer ride at low deflections, especially with generally stiffer springs.

Come to look again at the eBay image of the Pi springs, the rears at least don't look YRV compatible. Perhaps the image is just a general example and not YRV specific.

YRV Tony

AS already stated, the photos

AS already stated, the photos are not YRV springs! But VW passat.

Yes of course the springs are compressed for fitting!!

But lowered spring set will often not get the german TUV approval if they are not pretty similar to the originals when uncompressed length.

There needs to be a certain amount of pre-compressed tension.

Progressive can be used to give softer ride when driving flat, And this can be often designed into the spring.

BUT also more often than not with lowered springs there are 2 or 3 very tightly spaced coils that actually bind up and sit on each other when the car is jacked down,

Known as dead coil design.

TURBO SPRING

All i now about the Turbo's springs is that the fronts are a special design to the standards. Assume the rears are all the same.....or maybe they have a slight firmness upgrade?
Daihatsu call it a "Curved offset spring"
Not a perfect cylinder shape but bulging out centraly but only on the side facing the tyre.
YRVTony with his springs background can probably explain this design and the way it firms up with the more pressure it gets.
Wonder why Daihatsu didnt put Turbo Springs on the Sirion rally etc ??

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Current- 04 Silver YRV TURBO
Past- 91 Charade GTti, 89 Charade GTti, 98 1.3 Hi-Jet.
A friend in need is a friend indeed, a friend always in need, an Effin nuisance Wink

Curved Offset Spring?

It’s kind of you Dave to credit me with a ‘springs’ background, but I think Bob and Nathan are more practically sprung than I!

However there are straightforward pointers to a coil springs’s capabilities.

If the spring is wound using a fixed diameter wire and the coils are evenly spaced and of the same diameter, the spring is linear…the spring rate is constant.

If the diameter of a coil is larger than that of the next coil, it is softer in that region of the spring…the spring rate is variable, progressive.

If the spacing of a coil is larger than that of the spacing of the next coil, it is effectively stiffer in that region of the spring…the spring rate is variable, progressive.

From these pointers you can anticipate the type of performance of any shape of fixed-wire coil spring by its appearance.

Think of a coil spring as a wound torsion bar. The visible configuration of the windings indicates the attack angle of the force applied to that part of the spring, smaller angles giving a softer rate.

YRV Tony