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Twincharge???
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2,227 Posts
Discussion Starter #1
I thought the car handled somewhat not as responsive as the car should be so it was sent to Heasman and get it checked out.

Things discovered:
* Camber on the rear wheels is -2deg while it's only -1deg up the front.
* Toe-in (or was it out? can't remember) was completely out from factory
* Rear springs is too soft (well I discovered that on Friday when I had 2 oversized passengers up the back)

Couple of things Doug at Heasman suggested - get the camber adjustable strut top to get closer to -1.5 to -2deg up front depending on how agressive I want turn-in to be. Get the camber adjustable suspension arm for the rear to get a little bit less camber. Something a bit obvious, they wanted to sell me a set of Eibach's :) it make sense though, the Eibach was pretty good in my last couple of cars.

Right now, the car felt like the rear wants to turn while the front doesn't. It isn't balanced.
 

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Boy who made the wolf cry
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10,324 Posts
Hmmmm, that is interesting to hear your thoughts...

I take it you are refering to the MCS??

Maybe the springs are set up for race, rather than the commuter life with passengers in the back?

How much did he offer you eibachs for?

Todd
 

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Twincharge???
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2,227 Posts
Discussion Starter #3
Yep, talking about the MCS.

I was talking to Carl over the weekend about putting the stock spring back in for the time being. He reckons it might upset the MCS's balance. Then again, it's already not so balanced anyway.

Heasman have done a set of Eibach pro-kit and they said the Whiteline felt poor compared to the Eibach's. They didn't quote me a price as I told them I'll toss them out soon-ish for a set of coilovers.

I'll probably shoot Whiteline an e-mail asking them what's the spring rate for the rear spring. It felt soft - it dropped by 1.2cm when I loaded a 70kg fat butt in there then drop a further 1cm when I loaded another 80kg fat butt in there.
 

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my second passion, a tin!
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729 Posts
Custom suspension can have a fair degree of levity from factory setup. Remember factory is designed for everyday safe/regular driving.

My rear is setup with -4deg camber and I think its 0 toe in at front whilst, factory setup is usually toe in at the front. For track I think its 700lb Eibachs all round.

This setup works fine for track and rally for me. I think Robbo had the rear camber taken out for targa on his car and was less than happy.

Then again maybe I'm just a crap driver who wrestles the car from end to end without knowing what is right or wrong:rolleyes: :rolleyes:

Have a chat to Boo as he is running whiteline setups and knows a lot about them.
 

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Twincharge???
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2,227 Posts
Discussion Starter #5
Thanks for the comments Stu. I'll wait and see Boo to make some comments about the suspension setup. Personally I think the sway bars work but have doubts over the spring rate. It's sort of sorted for the time being with the alignments but will need the strut tops and control arms replaced to get more adjustments not to mention need some experiment with spring rates all round.

This is getting more and more expensive everyday! :D
 

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Track Addict
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2,622 Posts
dairyboy said:
Yep, talking about the MCS.

I was talking to Carl over the weekend about putting the stock spring back in for the time being. He reckons it might upset the MCS's balance. Then again, it's already not so balanced anyway.

Heasman have done a set of Eibach pro-kit and they said the Whiteline felt poor compared to the Eibach's. They didn't quote me a price as I told them I'll toss them out soon-ish for a set of coilovers.

I'll probably shoot Whiteline an e-mail asking them what's the spring rate for the rear spring. It felt soft - it dropped by 1.2cm when I loaded a 70kg fat butt in there then drop a further 1cm when I loaded another 80kg fat butt in there.
Hi,

You should speak to Boo. His mini has been the test "mule" for whiteline, and has all variations of the whiteline components thoroughly tested on his car.

The whiteline products are excellent. Think very hard before you take them out and go with the Eibachs, especially if you are considering tracking the car. I know some people who have done exactly the opposite, and are very happy with the result.

The set-up on Carls car sounds like it is optimised for a combination of street and track days.

By the way, your setup sounds pretty mild. I am running -2 front (with camber plates), -4.5 rear. On the track, in my experience the rear springs need to be relatively soft, compared to the front. However, I know that Boo's car, which is tuned by whiteline is running lesser camber numbers, I think around -0.5 front and -2 rear.

I have driven my car and Boos a lot on the track, as well as road, motorkhanas etc, and both are good setups, and both are equally fast, although they get there in different ways ;) There are other factors to take into account as well as the camber settings and spring rates, eg strut bars, stabiliser bars, wheel sizes, tyre profiles etc etc.

I would recommend you get a clear idea what you want to achieve, eg sporty street setup vs street and track combo vs pure track setup, and then go and see the boys at whiteline.

Cheers

Robbo
 

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Twincharge???
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2,227 Posts
Discussion Starter #7
Thanks Robbo.

Yeah should give the Whiteline boys a bell and see what they reckon. Right now I am chasing a setup that's more suited for track than road use but if that means rock hard suspension then so be it. I'm definitely getting the camber plates up front to get a bit more camber then if it still doesn't quite suit my driving style then more tweaking is required.
 

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Un-Banned
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1,999 Posts
robbo mcs said:
Hi,
On the track, in my experience the rear springs need to be relatively soft, compared to the front.
Heard exactly the same thing from Mr. H+R the other day when I ordered some coilovers. He is getting a slightly harder front for me due to feedback from Track goers with MCS's. Too soft at the fronts.
But if tracking is'nt on your to do list, change.
 

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Sponsor and Widget
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1,736 Posts
Hi there,
firstly, i have 17" X 7" rims with 215/45/17's for the track.
My car is usually set up for track whilst not being too uncomfortable to live with.

My best set up so far was Whiteline springs, larger swaybars front and rear, camber adjusters on rear and Koni dampers. This set up was really nice on the track with a very neutral feel allowing you to 4 wheel drift under full power around long sweepers (like turn 1 at Eastern Creek). Have approx -2 deg camber on back and stock on front.

Am currently testing their group 4 coilovers. Awesome suspension but are still re-engineering the springs to get a full range of adjustability. Damn good though.....
At present have approx 10mm drop on standard.
 

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Twincharge???
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2,227 Posts
Discussion Starter #10
Boo, thanks for that.

Do you think it was necessary to fit those Koni's or the factory shocks were doing a fairly good job? Reason being I am not keen on spending on something that won't make much of a difference then later having to spend more money at it.

Looks like I've just got the handling pack fitted, so it's fairly mild by anyone's standard. More mods to come...stay tuned.
 

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Gone Old School
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745 Posts
Evan, i have been in GreenDevil at wakefield and found it had different handling characteristicts to mine... yet there from memory isnt a huge difference.

I have found the Eibachs are great value for money. They are from my understanding not progressive springs like the whiteline.. Ive fitted whiteline springs to mates GTIR's and R32 skylines and found that there are better products available spring wise. I went straight for the Eibach springs as they are a name that go hand in hand with BMW. They have been around a long time and have always had a good name. To my understanding M series BMW's use Eibach springs. ( that in itself says something.)

All of the other Whiteline products like strut braces and swaybars have been excellent, super impressed... but springs... hmmmmm PASS
 

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Twincharge???
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2,227 Posts
Discussion Starter #12
Giles, thanks for that.

Sounds like my suspicion isn't unfound, maybe it really is the spring spoil the party.

List of things to change before the track outing: springs, camber plate, rear lower control arm, front + rear strut brace and C-pillar brace. If those doesn't sort it out then a set of coilovers.
 

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Gone Old School
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745 Posts
hmmmm i think you have to many strut braces listed... there is only 2 Front and C pillar.

I cant remember what swaybar is on yours.... does it have the 3 adjustment points?
 

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Twincharge???
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2,227 Posts
Discussion Starter #14
No idea about the sway bars. I'll take a look tomorrow...

I was having a go with Whiteline's catalogue, they didn't listed any rear strut brace so I assumed there's a C-pillar brace as well as the normal braces. Ah well you learn something new everyday.
 

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Gone Old School
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745 Posts
hehehehehehe thats kewl man....
PS... if you buy one ... they will ask you if you are using it for Racing... say yes.. or they wont sell them to you

Oh and be carefull about insurance and strut braces.. make sure you take the time to read your policy.
 

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Twincharge???
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2,227 Posts
Discussion Starter #16
No insurance hassles at the moment - there's simply no insurance :eek: not a single soul wanted to touch me with this car.

Now here's the funny question - they do have a bar for the Honda Civic that goes where the rear seat belt anchorage goes on both sides BUT also a strut brace on top of the rear strut tower. Don't they have the same for MINI's?
 

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Gone Old School
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745 Posts
dairyboy said:
No insurance hassles at the moment - there's simply no insurance :eek: not a single soul wanted to touch me with this car.

Now here's the funny question - they do have a bar for the Honda Civic that goes where the rear seat belt anchorage goes on both sides BUT also a strut brace on top of the rear strut tower. Don't they have the same for MINI's?

There is not rear strut towers... get under the back and have a look..
its a c pillar that mounts to the area where the seats clip into
I will take some pics tommorow and send them to you
 

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my second passion, a tin!
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729 Posts
Pretty sure Boo has a rear strut brace fitted. Maybe a demo version?

I have used Eibach's for both fixed and progressive rate springs for recent car setup and am pretty happy. Mind you cannot see why with the right setup Whiteline cannot have a similar fixed rate spring.

The factory shocks are pretty good and will serve well, but any upgrade is enjoyable!!
 

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Twincharge???
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2,227 Posts
Discussion Starter #19
Stu and Boo - just one question, did your suspension guys changed the toe-in/out at the rear end or they've just played with the camber settings? Reason being I don't want to buy 2 lots of rear control arms if I could get away with factory toe settings.
 

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Gone Old School
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This is some information for those to understand suspension

The following article is reprinted with the permission of Grassroots Motorsports magazine. For more information from this fine publication, please point your browser to Grassroots Motorsports magazine.

Pointed the Right Way
story by john hagerman
Camber, Caster and Toe: What Do They Mean?

The three major alignment parameters on a car are toe, camber, and caster. Most enthusiasts have a good understanding of what these settings are and what they involve, but many may not know why a particular setting is called for, or how it affects performance. Let's take a quick look at this basic aspect of suspension tuning.

UNDERSTANDING TOE

When a pair of wheels is set so that their leading edges are pointed slightly towards each other, the wheel pair is said to have toe-in. If the leading edges point away from each other, the pair is said to have toe-out. The amount of toe can be expressed in degrees as the angle to which the wheels are out of parallel, or more commonly, as the difference between the track widths as measured at the leading and trailing edges of the tires or wheels. Toe settings affect three major areas of performance: tire wear, straight-line stability and corner entry handling characteristics.

For minimum tire wear and power loss, the wheels on a given axle of a car should point directly ahead when the car is running in a straight line. Excessive toe-in or toe-out causes the tires to scrub, since they are always turned relative to the direction of travel. Too much toe-in causes accelerated wear at the outboard edges of the tires, while too much toe-out causes wear at the inboard edges.

So if minimum tire wear and power loss are achieved with zero toe, why have any toe angles at all? The answer is that toe settings have a major impact on directional stability. The illustrations at right show the mechanisms involved. With the steering wheel centered, toe-in causes the wheels to tend to roll along paths that intersect each other. Under this condition, the wheels are at odds with each other, and no turn results.

When the wheel on one side of the car encounters a disturbance, that wheel is pulled rearward about its steering axis. This action also pulls the other wheel in the same steering direction. If it's a minor disturbance, the disturbed wheel will steer only a small amount, perhaps so that it's rolling straight ahead instead of toed-in slightly. But note that with this slight steering input, the rolling paths of the wheels still don't describe a turn. The wheels have absorbed the irregularity without significantly changing the direction of the vehicle. In this way, toe-in enhances straight-line stability.

If the car is set up with toe-out, however, the front wheels are aligned so that slight disturbances cause the wheel pair to assume rolling directions that do describe a turn. Any minute steering angle beyond the perfectly centered position will cause the inner wheel to steer in a tighter turn radius than the outer wheel. Thus, the car will always be trying to enter a turn, rather than maintaining a straight line of travel. So it's clear that toe-out encourages the initiation of a turn, while toe-in discourages it.
With toe-in (left) a deflection of the suspension does not cause the wheels to initiate a turn as with toe-out (right).
The toe setting on a particular car becomes a tradeoff between the straight-line stability afforded by toe-in and the quick steering response promoted by toe-out. Nobody wants their street car to constantly wander over tar strips-the never-ending steering corrections required would drive anyone batty. But racers are willing to sacrifice a bit of stability on the straightaway for a sharper turn-in to the corners. So street cars are generally set up with toe-in, while race cars are often set up with toe-out.

With four-wheel independent suspension, the toe must also be set at the rear of the car. Toe settings at the rear have essentially the same effect on wear, directional stability and turn-in as they do on the front. However, it is rare to set up a rear-drive race car toed out in the rear, since doing so causes excessive oversteer, particularly when power is applied. Front-wheel-drive race cars, on the other hand, are often set up with a bit of toe-out, as this induces a bit of oversteer to counteract the greater tendency of front-wheel-drive cars to understeer.

Remember also that toe will change slightly from a static situation to a dynamic one. This is is most noticeable on a front-wheel-drive car or independently-suspended rear-drive car. When driving torque is applied to the wheels, they pull themselves forward and try to create toe-in. This is another reason why many front-drivers are set up with toe-out in the front. Likewise, when pushed down the road, a non-driven wheel will tend to toe itself out. This is most noticeable in rear-drive cars.

The amount of toe-in or toe-out dialed into a given car is dependent on the compliance of the suspension and the desired handling characteristics. To improve ride quality, street cars are equipped with relatively soft rubber bushings at their suspension links, and thus the links move a fair amount when they are loaded. Race cars, in contrast, are fitted with steel spherical bearings or very hard urethane, metal or plastic bushings to provide optimum rigidity and control of suspension links. Thus, a street car requires a greater static toe-in than does a race car, so as to avoid the condition wherein bushing compliance allows the wheels to assume a toe-out condition.

It should be noted that in recent years, designers have been using bushing compliance in street cars to their advantage. To maximize transient response, it is desirable to use a little toe-in at the rear to hasten the generation of slip angles and thus cornering forces in the rear tires. By allowing a bit of compliance in the front lateral links of an A-arm type suspension, the rear axle will toe-in when the car enters a hard corner; on a straightaway where no cornering loads are present, the bushings remain undistorted and allow the toe to be set to an angle that enhances tire wear and stability characteristics. Such a design is a type of passive four-wheel steering system.

THE EFFECTS OF CASTER

Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it's tilted forward, then the caster is negative.

Positive caster tends to straighten the wheel when the vehicle is traveling forward, and thus is used to enhance straight-line stability. The mechanism that causes this tendency is clearly illustrated by the castering front wheels of a shopping cart (above). The steering axis of a shopping cart wheel is set forward of where the wheel contacts the ground. As the cart is pushed forward, the steering axis pulls the wheel along, and since the wheel drags along the ground, it falls directly in line behind the steering axis. The force that causes the wheel to follow the steering axis is proportional to the distance between the steering axis and the wheel-to-ground contact patch-the greater the distance, the greater the force. This distance is referred to as "trail."

Due to many design considerations, it is desirable to have the steering axis of a car's wheel right at the wheel hub. If the steering axis were to be set vertical with this layout, the axis would be coincident with the tire contact patch. The trail would be zero, and no castering would be generated. The wheel would be essentially free to spin about the patch (actually, the tire itself generates a bit of a castering effect due to a phenomenon known as "pneumatic trail," but this effect is much smaller than that created by mechanical castering, so we'll ignore it here). Fortunately, it is possible to create castering by tilting the steering axis in the positive direction. With such an arrangement, the steering axis intersects the ground at a point in front of the tire contact patch, and thus the same effect as seen in the shopping cart casters is achieved.

The tilted steering axis has another important effect on suspension geometry. Since the wheel rotates about a tilted axis, the wheel gains camber as it is turned. This effect is best visualized by imagining the unrealistically extreme case where the steering axis would be horizontal-as the steering wheel is turned, the road wheel would simply change camber rather than direction. This effect causes the outside wheel in a turn to gain negative camber, while the inside wheel gains positive camber. These camber changes are generally favorable for cornering, although it is possible to overdo it.

Most cars are not particularly sensitive to caster settings. Nevertheless, it is important to ensure that the caster is the same on both sides of the car to avoid the tendency to pull to one side. While greater caster angles serve to improve straight-line stability, they also cause an increase in steering effort. Three to five degrees of positive caster is the typical range of settings, with lower angles being used on heavier vehicles to keep the steering effort reasonable.

Like a shopping cart wheel (left) the trail created by the castering of the steering axis pulls the wheels in line.

WHAT IS CAMBER?

Camber is the angle of the wheel relative to vertical, as viewed from the front or the rear of the car. If the wheel leans in towards the chassis, it has negative camber; if it leans away from the car, it has positive camber (see next page). The cornering force that a tire can develop is highly dependent on its angle relative to the road surface, and so wheel camber has a major effect on the road holding of a car. It's interesting to note that a tire develops its maximum cornering force at a small negative camber angle, typically around neg. 1/2 degree. This fact is due to the contribution of camber thrust, which is an additional lateral force generated by elastic deformation as the tread rubber pulls through the tire/road interface (the contact patch).

To optimize a tire's performance in a corner, it's the job of the suspension designer to assume that the tire is always operating at a slightly negative camber angle. This can be a very difficult task, since, as the chassis rolls in a corner, the suspension must deflect vertically some distance. Since the wheel is connected to the chassis by several links which must rotate to allow for the wheel deflection, the wheel can be subject to large camber changes as the suspension moves up and down. For this reason, the more the wheel must deflect from its static position, the more difficult it is to maintain an ideal camber angle. Thus, the relatively large wheel travel and soft roll stiffness needed to provide a smooth ride in passenger cars presents a difficult design challenge, while the small wheel travel and high roll stiffness inherent in racing cars reduces the engineer's headaches.

It's important to draw the distinction between camber relative to the road, and camber relative to the chassis. To maintain the ideal camber relative to the road, the suspension must be designed so that wheel camber relative to the chassis becomes increasingly negative as the suspension deflects upward. The illustration on the bottom of page 46 shows why this is so. If the suspension were designed so as to maintain no camber change relative to the chassis, then body roll would induce positive camber of the wheel relative to the road. Thus, to negate the effect of body roll, the suspension must be designed so that it pulls in the top of the wheel (i.e., gains negative camber) as it is deflected upwards.

While maintaining the ideal camber angle throughout the suspension travel assures that the tire is operating at peak efficiency, designers often configure the front suspensions of passenger cars so that the wheels gain positive camber as they are deflected upward. The purpose of such a design is to reduce the cornering power of the front end relative to the rear end, so that the car will understeer in steadily greater amounts up to the limit of adhesion. Understeer is inherently a much safer and more stable condition than oversteer, and thus is preferable for cars intended for the public.

Since most independent suspensions are designed so that the camber varies as the wheel moves up and down relative to the chassis, the camber angle that we set when we align the car is not typically what is seen when the car is in a corner. Nevertheless, it's really the only reference we have to make camber adjustments. For competition, it's necessary to set the camber under the static condition, test the car, then alter the static setting in the direction that is indicated by the test results.

The best way to determine the proper camber for competition is to measure the temperature profile across the tire tread immediately after completing some hot laps. In general, it's desirable to have the inboard edge of the tire slightly hotter than the outboard edge. However, it's far more important to ensure that the tire is up to its proper operating temperature than it is to have an "ideal" temperature profile. Thus, it may be advantageous to run extra negative camber to work the tires up to temperature.

(TOP RIGHT) Positive camber: The bottoms of the wheels are closer together than the tops. (TOP LEFT) Negative camber: The tops of the wheels are closer together than the bottoms. (CENTER) When a suspension does not gain camber during deflection, this causes a severe positive camber condition when the car leans during cornering. This can cause funky handling. (BOTTOM) Fight the funk: A suspension that gains camber during deflection will compensate for body roll. Tuning dynamic camber angles is one of the black arts of suspension tuning.

TESTING IS IMPORTANT

Car manufacturers will always have recommended toe, caster, and camber settings. They arrived at these numbers through exhaustive testing. Yet the goals of the manufacturer were probably different from yours, the competitor. And what works best at one race track may be off the mark at another. So the "proper" alignment settings are best determined by you-it all boils down to testing and experimentation.



John Hagerman is a mechanical engineer who works for the U.S. Army as a vehicle test engineer at the Aberdeen Proving Grounds in Maryland. John started autocrossing at the age of 16 in a Triumph Spitfire and switched to road racing a few years later. Lately, he has been playing with a Sports 2000



and here are the pics that relate to the artical...
 

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