Dr Bones Riddle Me This.....

[Tony-Bones]

To reserect this thread

Decided the back was too hard as it was jumpin off the ground, not good.

Jacked the car up and measured the spring length with no load on, slackened the spring off till it was free, e.g. no compression and measured the "free length" to get the amount of compression on the spring. The measures were 190mm compressed (no Load) and 225mm free length.

Wound the spring back up to 200mm e.g. 10mm longer than before and about a 1/3rd less pre-load. Thinks the car will drop 10mm so lengthend the strut 10mm to compensate. Back on the wheel and off the jack car is 10mm higher. No prob strut back down 10mm.

Other side did the same, 200mm on the spring but left the strut alone, back on the wheels and the car has dropped 10mm and the wheel is tucked under the arch, so extend the strut 10mm and back to normal.

Before I started I measured from the bottom of the top strut flange to the middle of the wishbone bolt both were 500mm now I got 500mm one side and 510mm on the other but the wheel centre to arch is the same with the car on the wheels.

What is going on?

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Reflect back to the height measurments i did before any adjustments, we had a 10mm diparity then on the trim height?......... Ready for this...! I do see this type of problem geometricaly every day with convertibles were the 'frame' twists, it may just be the case here that you have the oppertunity to re-aligin the parallelograms.

[MacRS200]

To reserect this thread

Decided the back was too hard as it was jumpin off the ground, not good.

Jacked the car up and measured the spring length with no load on, slackened the spring off till it was free, e.g. no compression and measured the "free length" to get the amount of compression on the spring. The measures were 190mm compressed (no Load) and 225mm free length.

Wound the spring back up to 200mm e.g. 10mm longer than before and about a 1/3rd less pre-load. Thinks the car will drop 10mm so lengthend the strut 10mm to compensate. Back on the wheel and off the jack car is 10mm higher. No prob strut back down 10mm.

Other side did the same, 200mm on the spring but left the strut alone, back on the wheels and the car has dropped 10mm and the wheel is tucked under the arch, so extend the strut 10mm and back to normal.

Before I started I measured from the bottom of the top strut flange to the middle of the wishbone bolt both were 500mm now I got 500mm one side and 510mm on the other but the wheel centre to arch is the same with the car on the wheels.

What is going on?

←

Reflect back to the height measurments i did before any adjustments, we had a 10mm diparity then on the trim height?......... Ready for this...! I do see this type of problem geometricaly every day with convertibles were the 'frame' twists, it may just be the case here that you have the oppertunity to re-aligin the parallelograms.

←

Car has developed a strange noise at the back like a rattle but sometimes like a metal on metal creaking noise. Could be it be that?

[Tony-Bones]

No. this 10mm difference is it the NSR.

[MacRS200]

No. this 10mm difference is it the NSR.

←

NSR strut is the 500mm one and OSR is the 510mm one with both springs the same length. I'm just puzzled, again :duh:

Could always compress the springs back to the original length and then it should be a case of 2 struts the same length. But then the car will be back to hopping around with the hard springs

[Tony-Bones]

No. this 10mm difference is it the NSR.

←

NSR strut is the 500mm one and OSR is the 510mm one with both springs the same length. I'm just puzzled, again :duh:

Could always compress the springs back to the original length and then it should be a case of 2 struts the same length. But then the car will be back to hopping around with the hard springs

←

In summery:-

1: NSR strut 500mm

2: OSR strut 510mm

3: both coils same length

4: Body height 'level'

[MacRS200]

No. this 10mm difference is it the NSR.

←

NSR strut is the 500mm one and OSR is the 510mm one with both springs the same length. I'm just puzzled, again :duh:

Could always compress the springs back to the original length and then it should be a case of 2 struts the same length. But then the car will be back to hopping around with the hard springs

←

In summery:-

1: NSR strut 500mm

2: OSR strut 510mm

3: both coils same length

4: Body height 'level'

←

Yup that's it

[Tony-Bones]

No. this 10mm difference is it the NSR.

←

NSR strut is the 500mm one and OSR is the 510mm one with both springs the same length. I'm just puzzled, again :duh:

Could always compress the springs back to the original length and then it should be a case of 2 struts the same length. But then the car will be back to hopping around with the hard springs

←

In summery:-

1: NSR strut 500mm

2: OSR strut 510mm

3: both coils same length

4: Body height 'level'

←

Yup that's it

←

Maths in the house...To be 'continued':-

[Monster-Mat]

i can explain all this Verbally no problem.......see you at JAE

[Tony-Bones]

i can explain all this Verbally no problem.......see you at JAE

←

I must admit this 'coilover' area i need an educational kick up the *****. thing is Matt this is 'not' my field' recovery and writting geometry for me is home.

[MacRS200]

Ok susssed it out.

Jacked up the front and measured the springs and struts. The NSF strut was 10mm longer than the OSF, diagonally opposite the shorter OSR!

So decided to make the OSF 10mm longer and shortened the OSR by 10mm.

Now equal lengths on each side and she now sits perfect :D

[Tony-Bones]

Ok susssed it out.

Jacked up the front and measured the springs and struts. The NSF strut was 10mm longer than the OSF, diagonally opposite the shorter OSR!

So decided to make the OSF 10mm longer and shortened the OSR by 10mm.

Now equal lengths on each side and she now sits perfect :D

←

dont forget 'negative' camber lowers the car? and to date the front geometry is not set, if we put theory in to place now the trim is stable the geometry should be a matter of fact.........should?