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Roll Centre Adjustment For Lowered Cars


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#1 HazleNut21

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Posted 07 November 2020 - 03:38 PM

Hi,

 

Looking for some more knowledgeable people than me to help me out here. I hear/read a lot about roll center adjustment on lowered minis, and the parts out there that are designed to rectify this issue. Now I sort of understand the theory behind it, but am wondering if it's totally necesarry on absolutely all lowered cars? By that I mean, would deviating from the stock ride height by a relatively small amount require the use of these adjusters, or is it for cars that have been lowered by a substantial amount? I suppose I am wondering where the threshold lies, and any other general advice around this topic.

 

Any information would be much appriciated :) Thanks,



#2 nicklouse

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Posted 07 November 2020 - 05:35 PM

Not needed. Also what the benefits are is not quite what they say. They raise the roll center ( as they say correct the roll center to what it was) what they do is keep the wheel going negative in bump. But you have to be very very low to need them. Anything on the road will not be needing them.



#3 Cooperman

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Posted 07 November 2020 - 07:21 PM

As Nick says, they are really just for race cars which are much lowered for the smooth tracks.



#4 Ethel

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Posted 07 November 2020 - 11:40 PM

Saw this & wondered if the OP has a MINI of the BMW variety.



#5 PoolGuy

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Posted 08 November 2020 - 06:46 AM

Maybe he’s been tempted by Endaf’s shiny offerings https://www.owensfab...uct/suspension/



#6 HazleNut21

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Posted 08 November 2020 - 02:48 PM

As Nick says, they are really just for race cars which are much lowered for the smooth tracks.

 

 

Not needed. Also what the benefits are is not quite what they say. They raise the roll center ( as they say correct the roll center to what it was) what they do is keep the wheel going negative in bump. But you have to be very very low to need them. Anything on the road will not be needing them.

Cheers guys, much appreciated!



#7 Cooperman

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Posted 08 November 2020 - 07:39 PM

Does anyone seriously want to lower any road car these days with the increase in 'speed cushions' all over the place.
I saw a stupidly lowered VW recently which had stopped in front of a speed cushion near where I live. It was too low to cross the cushion and was waiting until he could pull to the centre of the road so they there was one cushion on either side. There must have been 6 vehicles waiting behind him. To me that represents an unroadworthy vehicle for modern roads.

#8 Midas Mk1

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Posted 08 November 2020 - 09:22 PM

Ive got  Owens roll centre adjusters, noticed the difference on my road car. 

 

As for the low comments, oldddddddddd. 


Edited by Midas Mk1, 08 November 2020 - 09:23 PM.


#9 nicklouse

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Posted 08 November 2020 - 10:25 PM

Ive got  Owens roll centre adjusters, noticed the difference on my road car. 

 

As for the low comments, oldddddddddd. 

So what do you see as a difference? 
 

what is the height from the road to your subframe bottom arm area? 



#10 unburntfuelinthemorning

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Posted 15 November 2020 - 12:15 PM

 

Ive got  Owens roll centre adjusters, noticed the difference on my road car. 

 

As for the low comments, oldddddddddd. 

So what do you see as a difference? 
 

what is the height from the road to your subframe bottom arm area? 

 

Well that ended the discussion! 



#11 PoolGuy

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Posted 15 November 2020 - 01:41 PM

Many years ago we did some modelling of Miglia suspension with a view to optimising the roll centres. Allan Staniforth’s book on suspension was an invaluable source of info and it enabled us to build a very simple model which showed the effects of raising and lowering the front roll centre. We found the exercise worthwhile, but I think that adjustments to the ackerman and reducing the bump-steer were probably more beneficial.



#12 nicklouse

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Posted 15 November 2020 - 02:13 PM

Many years ago we did some modelling of Miglia suspension with a view to optimising the roll centres. Allan Staniforth’s book on suspension was an invaluable source of info and it enabled us to build a very simple model which showed the effects of raising and lowering the front roll centre. We found the exercise worthwhile, but I think that adjustments to the ackerman and reducing the bump-steer were probably more beneficial.

What did you end up with doing to the Ackerman angle in the end? 



#13 Midas Mk1

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Posted 15 November 2020 - 08:43 PM



Ive got Owens roll centre adjusters, noticed the difference on my road car.

As for the low comments, oldddddddddd.

So what do you see as a difference?

what is the height from the road to your subframe bottom arm area?
Well that ended the discussion!
Don't have time for wasters.

It’s not a discussion when the above has an attitude problem.

Edited by Midas Mk1, 15 November 2020 - 08:55 PM.


#14 Steve220

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Posted 15 November 2020 - 09:47 PM



Ive got Owens roll centre adjusters, noticed the difference on my road car.

As for the low comments, oldddddddddd.

So what do you see as a difference?

what is the height from the road to your subframe bottom arm area?
Well that ended the discussion!
Don't have time for wasters.

It’s not a discussion when the above has an attitude problem.

He won't change mate.

#15 nicklouse

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Posted 15 November 2020 - 10:24 PM

 

 

 

 

Ive got Owens roll centre adjusters, noticed the difference on my road car.

As for the low comments, oldddddddddd.

So what do you see as a difference?

what is the height from the road to your subframe bottom arm area?
Well that ended the discussion!
Don't have time for wasters.

It’s not a discussion when the above has an attitude problem.

He won't change mate.

 

What? I genuine question? Fine you can’t say. Keep you info to yourself.  You may or may not have noticed I actually have some fitted. You may also know there are two different sizes available depending on usage. You may also be interested in they raise the roll center of the front axel as in some cases the roll center is below ground level. 
 

but we will never know how these have helped your set up.






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