BC Coilover spring rates

[dcrobbo]

What are the recommendations on spring rates from you club folks, who have fitted BC coilovers to reasonably standard weight 240Z's, that would mainly be used on our lovely british roads! as I see that they offer 3 options:
NISSAN 240Z 260Z S30 (51MM) (WELD IN) (70-73) 3/3KG.MM
NISSAN 240Z 260Z S30 (51MM) (WELD IN) (70-73) 4/4KG.MM
NISSAN 240Z 260Z S30 (51MM) (WELD IN) (70-73) 3/4KG.MM

 

[Rob Gaskin]

I had 250lb front and rear on my trackday car and it was ok for the road (sporty). I wouldn't go any higher.

I don't know how that translates to kg.mm.

Those blue front ones on your Sam are 250lb.

 

[Kieronpollock]

Would love to understand the maths on this. I have D Faulkner installed on mine - 254mm (10”) Free length, 58.5mm ID with 350lbs front and 275lbs rear and married to my T3 suspension with tyre and wheel combination that pretty much gives stock overall diameter and result is a lovely sporty ride, not too harsh at all.

 

[Rob Gaskin]

Would love to understand the maths on this. I have D Faulkner installed on mine - 254mm (10”) Free length, 58.5mm ID with 350lbs front and 275lbs rear and married to my T3 suspension with tyre and wheel combination that pretty much gives stock overall diameter and result is a lovely sporty ride, not too harsh at all.

Do you have MSA antiroll bars? I did. However tbh I think the front one induced a bit too much understeer on tight corners.

 

[Kieronpollock]

Stock front anti roll bar connected to the T3 lower control arms
Rear is the T3 sway bar set up

 

[Alphabettispaghetti]

spring rates depends on the dampers also.

 

[AliK]

Do you have MSA antiroll bars? I did. However tbh I think the front one induced a bit too much understeer on tight corners.

The late Mr F (God bless his soul) was always trying to convince me to have his uprated ARBs - which I very nearly did. But what put me off was the fact that you need to strengthen (especially at the front) the mounting points.

What he said made a lot of sense. He used to say that “for a great handling road car you want a soft suspension set up with stiff roll bars.

I often wonder about 40+ years of metal fatigue and how much our cars can take without going pop when being pushed hard on a track or somewhere.

 

[Rob Gaskin]

The late Mr F (God bless his soul) was always trying to convince me to have his uprated ARBs - which I very nearly did. But what put me off was the fact that you need to strengthen (especially at the front) the mounting points.

What he said made a lot of sense. He used to say that “for a great handling road car you want a soft suspension set up with stiff roll bars.

I often wonder about 40+ years of metal fatigue and how much our cars can take without going pop when being pushed hard on a track or somewhere.

View attachment 61226

Yes, I beefed-up my chassis legs.