One of the most popular vehicle mods is the fitment of lowered springs.
Lowering your car improves aesthetics and can give improved handling. But how do
you lower your car without sacrificing ride quality and ground clearance? Well,
that’s the big question – and one we’ll answer through the course of this
article.
The demo car for this feature is our newly acquired 1997 Mitsubishi Verada
V6. The factory springs had been chopped by a previous owner and the resulting
ground clearance was abysmal. Our aim was to install a new set of springs that
gave a lower than standard ride height but with acceptable levels of ground
clearance and ride comfort. A firm-ish spring rate was also required to aid
handling.
Factory Spring Upgrades?
The first option to consider is whether the manufacturer released a ‘factory
sports’ version of your particular car. This is an attractive approach because
OE sports springs ensure durability, useable ground clearance and an acceptable
ride - in most cases...
In
the case of the Verada, a firmer and lower pair of rear springs was available
from the Magna Sports/Verada GTV. Unfortunately, these springs are only
s-l-i-g-h-t-l-y uprated compared to the Verada and the difference wasn’t enough
for us to justify their purchase. The next option was a set of Ralliart Magna springs. Again,
these are only marginally lower than standard but, based on our drives of the
Ralliart Magna, the spring rate is suitably firmer. Ralliart springs were
seriously considered for our Verada but we couldn’t find any second-hand and
they’re quite expensive to purchase new.
So an aftermarket set of springs was what we needed.
Selecting Suitable Aftermarket Springs
The
Mitsubishi Magna/Verada, like comparable Holden and Ford models, is supported by
a wide selection of aftermarket springs. Manufacturers such as Lovells, King and
Whiteline offer springs to suit. But how do you choose?
Well, first, we’ve gotta tell you how not to choose springs.
Asking for advice on web forums is risky business. ‘Acceptable’ levels of
ground clearance and ride comfort vary hugely and what you might consider
bone-rattling someone else might consider fine... And there are plenty of other
variables including the performance of the vehicle’s dampers, local road
conditions, wheel/tyre size and vehicle weight. You have been warned!
The best place to start is to check out the existing springs.
The first consideration is ride height. It’s common for aftermarket spring
manufacturers to quote approximately how much lower your car will sit after
their springs have been fitted so, if you have any concern about ground
clearance, it’s important to know the starting height. Typically, ride height is
measured from the centre of the wheel to the lip of the guard – this eliminates
any variations caused by altered wheel/tyre diameter. Using this method of
measurement, the ride height of most large passenger cars varies between around
370mm and 430mm.
Determining the rate (firmness) of your car’s existing
springs isn’t as easy. If possible, we recommend removing the springs from the
vehicle and having them tested on a spring rate testing press. As seen here, a
spring rate press compresses the spring using a hydraulic ram and the spring
rate (expressed in pounds per inch or kilograms per millimeter) is shown on a
digital display.
If this approach isn’t practical, you can compare the rate of your vehicle’s
existing springs against aftermarket springs using the following formula...
wire diameter x wire diameter x wire diameter x wire diameter
number of free coils
A higher number means a firmer spring rate.
In the case of our Verada, the standard spring
specifications were available through an aftermarket spring manufacturer and
Mitsubishi Australia. The Verada’s standard front springs are listed at 140lb/in
while the rears are very soft at just 110lb/in – no wonder they’re always
bum-down when towing!
So now you know the ride height and rate of your existing springs – now
what?
The next step is to plough through manufacturer information to find the
springs that deliver a ride height that’s within your desired range. For the
Verada we wanted a subtly lowered ride height and there were a few ‘30mm
lowered’ springs that caught our eye.
With a shortlist of lowered springs, you can select the most attractive set
based on spring rate and the resulting ride characteristics. In some instances,
aftermarket manufacturers will provide you with the rate of their springs.
Alternatively, you can have them tested on a spring rate press or you can use
the spring rate comparison formula to rank the springs in order of firmness.
In our case, we chose a set of Lovells 30mm lowered springs.
The manufacturer told us the front springs are rated at 166lb/in while the rears
are 140lb/in – interestingly, this is almost identical to the spring rate of the
Ralliart Magna (which we know has an acceptable ride). A few minutes on the
spring rate press showed this particular set of Lovells springs to deliver
175lb/in and 155lb/in front and rear respectively. Note that this is the maximum
recorded spring rate which is achieved near the end of compression – the first
couple of inches travels have a softer rate (as we’ll discuss in a moment).
Purchased through Phillcom Rally (www.phillcomrally.com), the set
of four Lovells springs cost AUD$225. This undercuts many other brands which are
closer to AUD$300. Phillcom Rally also offers installation through Midas at
Thebarton (South Australia) for a special price of just AUD$150 – why bother
trying to do it at home without a hoist?
More on Spring Rate Testing...
A spring rate testing machine is a hydraulic press equipped with a load cell
that sends information to a digital screen. The operator has a joystick to
control the vertical movement of the hydraulic ram and there are a couple of
buttons which lock and unlock the access door. Note that the press and spring
are securely contained in a mesh cage - the energy stored in a compressed spring
is potentially lethal.
The test spring is installed into the press between the
top mounting surface and the lower ram platform. If necessary, steel wedges are
used to keep the spring vertical - the spring cannot be tested while
sitting at an angle.
The operator will use the ram to apply some preload to the
spring before testing commences. Depending on the size of spring, preload is
typically 100lb. From its preload position, the operator will then compress
the spring in one inch increments and record the force shown on the digital
display. The spring is compressed as far as possible before the coils start to
bind. In the case of the Lovells springs, we were able to take measurements
across five inches of travel.
The front Lovells springs gave 130 – 135lb/in over the
first thee inches of travel increasing to 150 and 150lb/in in the fourth and
fifth inch of travel. The rear springs gave 155lb/in over the first three inches
of travel increasing to 175lb/in over the fourth and fifth inch of travel. This
is slightly softer than claimed for the front and slightly firmer than claimed
for the rear.
In South Australia, we had our spring rates tested by Industrial Springs.
Cost is just AUD$10 for a pair of springs. For a spring rate test press in your
local area, we suggest contacting aftermarket spring manufacturers.
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Installing a Lowered Set of Springs...
Installation begins by raising the vehicle on a hoist and
removing the wheels.
Starting at the front, the brake line retainer is removed
and the two lower bolts that secure the strut to the hub are removed.
The nuts holding the top of the strut to the body are now
removed from inside the engine bay.
With the upper and lower strut mounts removed, the strut
can be withdrawn from the car.
The strut is secured in a vice and the first step in
disassembly is to compress the spring. This is achieved with a heavy-duty spring
compressor tool which is driven by a rattle gun.
Once the spring compressor tool has removed spring
tension against the upper spring mount, the top strut assembly can be removed.
The front struts of the Verada have a rotating top assembly which contains a
bearing. This top assembly and upper spring mount can be removed after removing
a central nut at the top of the strut.
This photo shows the strut minus the top assembly and
upper spring mount. The rattle gun is being used to release the spring to its
free length.
With the existing spring removed, the upper and lower
spring mounting surfaces (including rubber isolators) should be cleaned.
The new springs can now be dropped onto the strut
paying attention there may be different springs specified from left to right.
The spring compressor reduces the height of the new spring to allow
reinstallation of the upper spring mount and top assembly.
Once reassembled, the strut can be refitted to the car.
Make sure the upper and lower strut mounts are tightened to the specified
torque. The brake line retainer is also reinstalled.
The front wheels are now refitted – and the front is
complete.
With attention now turned to the rear, the back seat of the
Verada must be removed to give access to the upper strut mounting nuts.
On the Veraada, the bottom of the rear strut is released
by removing a single bolt. With the upper and lower mounts removed, the strut
can be maneuvered from the vehicle.
In this case, a single nut holds the upper spring mount
to top of the strut. This nut is removed with a rattle gun to allow removal of
the upper spring mount and spring.
Note that the existing chopped rear springs in our Verada
were so low there was no need to use the spring compressor – with the strut
removed from the vehicle, the spring was too short to reach its upper
mount...
With the strut mounting surfaces cleaned and the new
spring fitted, the upper spring mount can be reinstalled by tightening the upper
retaining nut.
The rear strut can now be reinstalled to the vehicle. The
upper strut mounting nuts are fitted followed by the lower mount. Each is then
tightened to the specified torque.
The back seat and wheels are now refitted and the job is
done. Note that a wheel alignment is recommended to reestablish camber and toe
angles.
Results
After doing our research, we’re happy to say that the Verada’s new springs
are exactly what we were after.
These photos compare the ride
height achieved with the previous chopped springs and our new Lovells springs.
As you can see, ground clearance is improved and, using the measurement from the
centre of the wheel to the lip of the guard, the front and rear now sit at
around 365mm front and rear – up from 360mm and 315mm (respectively) with the chopped springs. The front
mud-flaps occasionally scrape over giant speed humps but we haven’t found any
other problems.
The ride is obviously firmer than standard but it’s in the same ballpark as,
say, a Ralliart Magna or SS Commodore. Perfectly within our range of acceptance.
The dampers are also able to maintain decent spring control – though, even with
standard springs, the Verada suspension feels a bit soft in damping.
Handling? Well, compared to a standard Verada there’s less roll through
corners which improves feel and reduces understeer (in dry conditions, anyway).
Pitch and dive is also much reduced under hard acceleration and braking.
Mission achieved.
So there you have it - fitting lowered springs can cause problems if you leap
into it, but when you do some homework you’re almost assured a positive
result!
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