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Suspension Coupé
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Author:  Yoda74 [ Fri Oct 16, 2015 12:39 pm ]
Post subject:  Suspension Coupé
Hi Folks,

I have some questions about the suspension of my "93 Coupe.
As you can see on the pics below, All but the wheel at te right front are sticking a bit out off the wheelarch.
The one on the right front isn't, it is quite a bit further to the inside.
What can be the cause of this issue?
On first view the car had no big damages.
The wheels seem to be the same.
I've heard that the suspensionarms are the same as a classic mini, but then lengthened, is this so?
There is very little to be adjusted on the suspension.
Can it be a worn rubber cone maybe?
Or other worn rubbers or bushes?
Worn Wheelbearing? (I feel no play when I pull the wheel)
Maybe the "Bonnet" has not been mounted straight?

Also both front wheels have quite some negative camber.

Who can shine some light this?

Anyone else who has/had the same issue?

Image

Image
Author:  kano nordie [ Fri Oct 16, 2015 7:51 pm ]
Post subject:  Re: Suspension Coupé
Hi Yoda,
I have heard many GTM Coupe owners comment that the body and chassis is not quite correct or in line, with gaps around the bonnet wheel arches being different each side, sorry there is not a lot you can do with the body mouldings.
You can check the chassis/subframe mountings to see how correct they are, (I have heard owners say the chassis was different side to side)
With a long flat metal bar or tube across the car sitting on axle stands, pressed against the front of the front tyre and against the back of the rear tyre at the height of the wheel center line you can now tie a thread or fishing line to the front tube on each side and with the aid of a small weight drape the other end of the tread over the rear tube this will give two straight line each side of the car.
You can now measure from the thread to the wheel rims or even the ends of the drive shafts and the thread to the sills to make sure all is in line and parallel.
If you want to adjust it you will need adjustable suspension bottom arms and tie rods and a camber/ caster gauge to measure what you are doing, as you have negative camber I would guess you have extended bottom arms, or as I used to do cut them, extend them ¼” and weld them back together to give approximately 1.5 degree negative camber.
John
Author:  West [ Fri Oct 16, 2015 9:28 pm ]
Post subject:  Re: Suspension Coupé
Its a case of positioning it so it looks right. Also Fibreglass panels can move and take a set over time. I spent ages with a heater and wedging the rear bodywork on mine to get the rear arches to look right from the rear. Then once right I fixed the boot liner to the chassis to hold it.

Even old Corvettes are different side to side!

Neil
Author:  Yoda74 [ Sun Oct 18, 2015 2:29 pm ]
Post subject:  Re: Suspension Coupé
Thanks for your reaction guys.
This morning I took an other look at it.
If I take a look at the "bonnet" (Dont know how else to call it), at the right Side of the car, the gap between the front of the door and the bonnet is about 5mm, the gap on the left Side is larger, aproximatly 15mm.
The bonnet seems not to be straight on the car.
If I look at the bracket in front of the subframe, which holds de bonnethinge, the one on the right Side of the car seems bend to te right, the one on the left seems bend to the right too. In my opinion, if these brackets where straight, the bonnet would be more straight, the gap between bonnet and left Side door would be less, and the front wheel on the right side would be less to the inside of the wheelarch.
I measured the wheels relative to the bonnet.
On the left Side the upper point of the frontwheel sticks out about 20mm, on the right side the wheel lays back about 25mm.
The straightened brackets and moving bonnet would even this out a bit, not totally I think.
If I want to straighten the brackets, I Will have a Problem is the radiator which lays thight between them, there is almost no space.
Also the bonnetlock on the left Side Will have to move backwards I guess.

Also I measured the angle (camber) the front wheels make, both almost the same, I have to calculate the angle, but I put a spirit level (hope I translated this well) from the floor upwards, against the tire. At the top of the tire I measure about 25mm to the inside, thats quite a bit I think.

Just the things I noted today, hopefully I've written and spelled it in correct(ish) English. Correct me where i'm wrong.

Greets from Holland
Harold
Author:  kano nordie [ Sun Oct 18, 2015 2:50 pm ]
Post subject:  Re: Suspension Coupé
Hi Yoda, I would have to calculate the angle, but at a guess 25mm is about correct, when you think that the bottom arms used to be cut and extended 1/4" (6.5mm for for you) to give approximately 1.5 degree negative camber, much easier to measure with a camber gauge :wink:
John
Author:  Yoda74 [ Thu Oct 22, 2015 3:03 pm ]
Post subject:  Re: Suspension Coupé
Thanks John, I will try to measure the camber-angle this weekend.
Author:  Yoda74 [ Wed Oct 28, 2015 3:33 pm ]
Post subject:  Re: Suspension Coupé
Last weekend I measured the Camber.
I made a simple drawing of the situation, this is the right front wheel.
If I remember right, the angle on the leftside-wheel is almost the same, but I will measure this soon.
As you can see the Camber angle is far to large.
What can be the cause? Lower arms too long seems a possibillity, or can there be other causes?
Wheelbearing seems to be ok.

Image
Author:  kano nordie [ Wed Oct 28, 2015 6:27 pm ]
Post subject:  Re: Suspension Coupé
Hi Yoda,
Jack it off the ground, hold the wheel at the top and bottom with both hands and see if there is any movement on the rubber bushes, especially the inner bush where it fits onto the subfame, if the joints have dried out and broken up with age that would give increase negative camber :(
John
Author:  Yoda74 [ Thu Oct 29, 2015 9:52 am ]
Post subject:  Re: Suspension Coupé
Hi John,

Do you mean the bushes (Number 2) on the low right side of this pic?

Image
Author:  Yoda74 [ Thu Oct 29, 2015 11:19 am ]
Post subject:  Re: Suspension Coupé
Don't seem worn at all :shock: :shock: :shock:

Image

Should I get these ones: https://www.minispares.com/product/Clas ... K3013.aspx
Author:  kano nordie [ Thu Oct 29, 2015 5:54 pm ]
Post subject:  Re: Suspension Coupé
Hi Harold,
I was thinking of the bush’s #2 as being the most likely place to be worn, but any wear or free movement is not acceptable, the car will wander about especially when braking.
If the lower arms #4 have been cut and lengthened there should be signs of the welding and also a little reinforcing plating on the sides of the arm where it is welded to put some strength into the joint, I used to use small bore steam pipe cut into half welded into the H section of the arms, but never lengthened more than ¼” (6.5mm) to give approximately 1.5degree negative camber.
I did not hear of anybody making lower arms for Mini’s with more than 1.5 degree camber.
Just out of curiosity when you drive it how does it behave, any wandering in a straight line or under braking?
I don't have my MiniSpares catalogue with me at home (I browse things like that at work :oops: ) so cannot check what part you are referring to, they do make good adjustable bottom arms, tie rods and all the bushings in different hardness and materials
John
Author:  Steve Shield [ Thu Oct 29, 2015 7:35 pm ]
Post subject:  Re: Suspension Coupé
Hi Harold,

Looking at your photos I was wondering if your car's ground clearance is a bit low -- especially at the front. If it is then the front suspension may be in a part of its travel where the negative camber is increasing. Other's may have better ideas but I think for a road car the minimum ride height should be 4 1/2" at the front and 5" at the rear and if you have speed bumps/rough roads etc you could increase that to 5 1/2" front and 6" rear. These measurements are taken at the ends of the sills from the bottom edge to the ground.

The bushes you identified -- the type that include an offset -- are the best ones to use when geometry is changed from the standard Mini settings.

Hope this helps.

Steve
Author:  Yoda74 [ Thu Oct 29, 2015 8:09 pm ]
Post subject:  Re: Suspension Coupé
Hi John and Steve,

As you can see on the picture the bushes number two seem to have had their best time.
Those have to be renewed.
Tomorrow I'm free from work, so I Will spend Some time in my garage and check if I can find more movement.
Also I Will check if I can find reinforcements on the lower arms, havent seen it yet.
When driving all seems to go well, no wandering, but I have Nothing to compare to, when I was young I drive Some mini's, but that's about 18 years ago, my memory isnt that well. Comparing it to more modern cars I have owned doesn't seem a good idea.
When braking mildly It has no issues, when braking a bit harder it pulls a little bit to the right at first and then straightenes .
And yes it is low, speedbumps are not my best friends.
The front has no Hi-lo's, seems standard, the back has got Hi-lo's and is pretty low.
I Will measure how low tomorrow.
Maybe the rubber cones in the front are worn.

Cheers

Harold
Author:  flapjck1 [ Thu Oct 29, 2015 9:41 pm ]
Post subject:  Re: Suspension Coupé
Adjustable suspension + polibushes = best choice
Author:  kano nordie [ Fri Oct 30, 2015 4:30 am ]
Post subject:  Re: Suspension Coupé
Hi Harold,
Look for any sign of cutting and welding on the lower arms to see if they have been extended, the rubber cones compress with age and would lower the car, good idea to get another pair of HiLo's to fit in the front.
I have made everything adjustable on my car as I expect to run slightly raised ride heights due to our bad roads and will probably start with 5-1/2" on the front and 6-1/2" on the rear, as Steve said measured from the sills
John
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