long suffering A30's continuous improvements

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Big Daddy
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Re: Spa Classic 2017 Prep Begins

Post by Big Daddy »

Countryboy wrote:Are we not talking 4/5's of f______L ?
No because getting dynamics to work properly is a subtle art. Small changes can make a huge difference. These springs are just fundamentally wrong... :whistle:

Countryboy wrote:As these springs are stiffer than the 63 year old originals , flatter and have a thicker top leaf, surely the car will be more stable and more planted ?
If you like and you're happy... :mrgreen:

Countryboy wrote:What's the alternative on my budget ?
C'mon crying poverty lacks credibility. Springs are cheap unlike some very expensive engine modifications... :whistle:


But to restate the important factor... :thumbs:
Big Daddy wrote: Although that spring installation would not satisfy me, if you are happy where's the problem :?:
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Countryboy
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Re: Spa Classic 2017 Prep Begins

Post by Countryboy »

Thanks Gents

I am going to give them a go and see how she handles

:wave:
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Countryboy
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Re: Spa Classic 2017 Prep Begins

Post by Countryboy »

Trial fitted the first U bolt with elongated threads
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RenderedContent-9F52DF6F-DB77-42C7-B7B4-B5A4EA1621B1.JPG (108.46 KiB) Viewed 1261 times

You can see the thread I cut as it's slightly darker. I will cut the excess length off all of the bolts before I work on their threads
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David Swain
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Re: Spa Classic 2017 Prep Begins

Post by David Swain »

Looking good Steven, have you run the nuts up the threads already to check them? The diameter of the bolt (And new thread) looks larger in the photo where you have cut the new thread. I imagine that this difference is due to the original thread being rolled, as opposed to the new thread that you have cut.
Very interested to see how this works out, always impressed with your work. :thumbs:
David Swain. Member No. A1743
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A30 van 55 'R.G. Swain', A35 4 Door 59 'Little Gem', A35 2 Door 59 'The Rev' '+1'
Big Daddy
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Re: Spa Classic 2017 Prep Begins

Post by Big Daddy »

Steven thanks for raising this rear shackle angle issue - it's prompted an idea :idea:

Anti-dive and anti-squat geometry is a common feature of many independent suspension designs. But until now I didn't realise that it was possible with cart springs.

If those shackles were inclined forwards at static ride height, they would swing even further forwards under braking but swing backwards into a more upright position under acceleration. So a subtle little tweak providing effective anti-dive and ant-squat mechanisms... :thumbs:

Unfortunately your shackles work in the opposite direction, at least until they go solid... :rol:
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Countryboy
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Re: Spa Classic 2017 Prep Begins

Post by Countryboy »

Big Daddy wrote:Steven thanks for raising this rear shackle angle issue - it's prompted an idea :idea:

Anti-dive and anti-squat geometry is a common feature of many independent suspension designs. But until now I didn't realise that it was possible with cart springs.

If those shackles were inclined forwards at static ride height, they would swing even further forwards under braking but swing backwards into a more upright position under acceleration. So a subtle little tweak providing effective anti-dive and ant-squat mechanisms... :thumbs:

Unfortunately your shackles work in the opposite direction, at least until they go solid... :rol:

BD
When exactly will they go solid ????
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Big Daddy
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Re: Spa Classic 2017 Prep Begins

Post by Big Daddy »

Countryboy wrote:BD
When exactly will they go solid ????
Go to a track day at Goodwood (as you've experienced already). Turn into Madgwick on the adhesion limit which could be 90mph, and then traverse that surface bump part way through the bend. Life could get exciting ... :shock:

Watch the Academy race cars if you don't believe me... :whistle:

Similar excitement could happen at lower speeds on the public highway. Alternatively don't push your car hard into bends. But then what was the point in fitting those new springs in the first place :?: ... :rol:
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Countryboy
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Re: Spa Classic 2017 Prep Begins

Post by Countryboy »

Big Daddy wrote:
Countryboy wrote:BD
When exactly will they go solid ????
Go to a track day at Goodwood (as you've experienced already). Turn into Madgwick on the adhesion limit which could be 90mph, and then traverse that surface bump part way through the bend. Life could get exciting ... :shock:

Watch the Academy race cars if you don't believe me... :whistle:

Similar excitement could happen at lower speeds on the public highway. Alternatively don't push your car hard into bends. But then what was the point in fitting those new springs in the first place :?: ... :rol:

I get the fact that these springs are not the perfect length and I will take this up with their makers tomorrow

Having mechanically forced them through and passed their range of normal travel without metal to metal contact, I still don't see how they will "go solid" I guess I am just simple
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Big Daddy
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Re: Spa Classic 2017 Prep Begins

Post by Big Daddy »

Countryboy wrote:Having mechanically forced them through and passed their range of normal travel without metal to metal contact, I still don't see how they will "go solid" I guess I am just simple
There's compliance in the system - bushes compress and even the metallic parts deflect. Steady state displacement (such as on your jack) is an incomplete picture. Dynamic impact loads tend to cause greatest deflection just when you don't want it.

Ensure there is enough margin in suspension travel to stop it going solid under all conditions. Absence of witness marks is a good indicator... :thumbs:
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Countryboy
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Re: long suffering A30's continuous improvements

Post by Countryboy »

Been busy on and off fitting the rear springs and dampers

Had to buy rose joint covers for the damper drop links . The academy dampers are I am reliably informed, modified Midget ones .

I thought I had finished this job a couple of nights ago but had a disappointing shakedown run . The car sits lower at the rear, as expected with the top of the wheel rim in line with the bottom of the wheelarch.

I guess this ride height along with the thicker than standard top leaf helps reduce body roll. The car did seem to corner flatly and there where no tyres rubbing bodywork .


Over some bumps I had a metallic noise coming from what I thought was the NSR.

I jacked the car up under the diff and could see no witness marks anywhere after a thorough look. I had expected to see these on the over axle pipe of the exhaust but there was nothing. I then placed a second jack under the NSR Spring to axle plate and lifted until the central jack was redundant. Still nothing was touching anything and both rear wheels rotated easily.

I had been a little uncomfortable with the new rear damper setup.

The originals had a step in the link bolt to secure it in the axle locating hole . The new bolts supplied to fit the Rose jointed links were of uniform diameter thus loose in these holes. Also, if I'm not mistaken the holes on the dampers should have a taper fitting bolt ?

Again, standard bolts supplied were loose here.

I cannot use my original links with the new dampers as the arms end up in the wrong place for them . Tomorrow evening the standard damper setup is going back on . I know I mentioned earlier that one was weeping slightly but they were pretty much just a stiff and linear in their action as the new ones. Need to get out in my Austin

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Big Daddy
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Re: long suffering A30's continuous improvements

Post by Big Daddy »

Countryboy wrote:Need to get out in my Austin :wave:
:iagree: ... :thumbs:
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Dave Clark
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Re: long suffering A30's continuous improvements

Post by Dave Clark »

That remark about the link bolts being a rattle fit instead of a taper, combined with the length of the springs AND the crude attachment for the Panhard Rod at the axle end all confirms to me that this stuff is for one purpose only - to make money.

I regret buying the Motobuild Panhard Rod now (which I have not yet fitted) because I am sure I could make something stronger and more effective myself.

Anyone want a Motobuild Panhard Rod ?
Big Daddy
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Re: long suffering A30's continuous improvements

Post by Big Daddy »

Dave Clark wrote:AND the crude attachment for the Panhard Rod at the axle end...
How about the body end :?: ... :whistle:
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Neil Evans
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Re: long suffering A30's continuous improvements

Post by Neil Evans »

Can you swap the arms of your original shocks to the new ones? Robert Prinn is talking of doing this on a commercial basis... :thumbs:
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Countryboy
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Re: long suffering A30's continuous improvements

Post by Countryboy »

Neil Evans wrote:Can you swap the arms of your original shocks to the new ones? Robert Prinn is talking of doing this on a commercial basis... :thumbs:
Neil
I might try this as I have some spares to play with :whistle:
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