The road and track handling
of your 240 can be enhanced significantly. Volvo's R-Sport
division proved this years ago suppling enthusists with
upgraded items like hard-rubber bushes, gas shocks, stiffer
springs, large diameter swaybars, steering wheels, chassis
brace products. Volvo GpA machines sported alloy suspension
components, carbon fibre composite diffs, light-weight
panels, but these are specialist track items.
©
by
Anthony
Hyde,
Australia 1/2001 -
latest update Nov 2007
Improvements cost money, and
in most cases are worth it. Improved handling is welcome and very
noticeable if you have just replaced worn out bushes, bars and
springs with new components. To assist you, a number of new part
suppliers are listed in this article. Also keep an eye out for
R-Sport & IPD 2nd hand parts through private sale and recyclers -
you might find a bargain!

Pic -Mike Saccone ITB
242
IPD, SAM and many Privateer manufacurers continue to invest
in making Volvo aftermarket products supplying parts using
modern designs and materials such as polyurethane. Even
Volvo dealers still stocks 242GT springs and swaybars ....
at a price.
Reward for the sporting driver is less bodyroll for flatter
cornering, and increased steering precision. The aim of
this article is to fill the 'literature void' with relevant
Volvo sporty type information for all experience levels.
Enhancement is achieved with upgrades to : Front & Rear Coil Springs, Front Struts and Rear Shocks, Strut Tower and Bracing, Swaybars and End Links, Negative Camber, Upper Strut Bearings, Trailing Arm Bushes, Panhard Rod, Torque Rods, What about the Driving position? And more.
WEB
SITES for Volvo 240/740
products
mentioned throughout this
article:
IPD
(USA), MVP
(USA), Energy
Suspensions (USA),
shox.com
(USA), EuroSport
Tuning (USA),
SAM
(Sweden), and your local Volvo dealer for small diameter
bushes, Kings
Springs
(Queensland, Australia)
POLYURETHANE
BUSHES
Informative
product information and a wide range of poly bushes in more
advanced material to suit Volvo's can be found at the
Noltec
Australia website. Other poly
suppliers are Super
Pro / Super Flex (Australia,
Europe, USA), and IPD
(USA) for Volvo suspension bush kits.
In my experience with both Volvo rubber and poly bushes, the poly is
fine but the centre steel bush is drilled oversize, or simply
imperial tube sizesare used, eg 1/2" or 12.7 mm. For example, an M12
suspension bolt measures 11.9mm in diameter, but bushes are often
12.5 or more. Too much slop / clearance for my liking. If your fussy,
remake the steel bush.
FRONT
COIL SPRINGS:
Standard
height - Volvo's sit rather
high, ready to take on all terrain, so if you wish to retain ride
height, less 15 mm, and improve handling, then genuine Volvo heavy
duty front springs #1229337-9 being 35% stiffer than stock are hard
to beat. In a number of cases, the faint part # can be found near the
start of the first ring. In use, myself & others found the
spring-rate matched front Bilstein struts very well indeed. A similar
spec spring was used in the 1979 242GT.
Lowered
- If you rarely venture off the tar and are keen to lower your 240's
ride height to more modern settings, or desire a more aggressive
look, there are plenty of suppliers that sell them. By reducing ride
height, you lower the centre of gravity of the 'sprung mass' (mass of
car above springs), always beneficial. With the McPherson strut 240
front end, ensure the lowered front springs minimum free length is
near 335 mm so as to be fully captured when the wheel is raised off
the ground. Some suppliers are IPD in the USA (35% stiffer), SAM
& Eibach in Europe, and Kings Springs in Australia. Expect these
to lower your front end between 1"-1 1/4".
Coil-over
small diameter springs
are mentioned further down the page.
700/900 series Volvo with big wheel and lowered spring can cause a factory defect to be revealed - ARTICLE courtesy of Turbobricks.
FRONT
STRUTS: (Dampers/Shock
Absorbers)
Many users agree
Bilstein
are the premier after-market choice for 240, 740 and 940 McPherson
strut suspension, being noted for keeping the heavy Volvo front end
under tight control. They combine oil and gas with quite firm
valving, are rebuildable with long product life. Although
non-adjustable (to the user), specialist dealers can revalve bounce
and rebound settings or de-stroke for lowered suspension (eg to
'Sprint' settings). If you already have a lowered car, then
'Bilstein Sprint' struts feature a shortened stroke to reduce
the possibility of bottoming out on road dips. USA suppliers - IPD
and shox.com. In Australia, Sydney
Shocks with SPA Shock Dyno, and
Quadrant
Suspensions are Bilstein
specialists.
Koni
is also a very popular after-market choice offering an enticing 5
way adjustable 'Koni Sport' (yellow version) for the 240
front strut, #8641-1245 Sport, (sourced from Holland). All
struts and dampers are oil based and adjustable on rebound. 240
owners with Sport Konis' report the harder setting being the best for
front end handling. In Australia, Koni distributors are
Toperformance
Products (Melbourne),
Proven
Suspension (Sydney). For
those seeking a standard strut, KYB seem a popular inexpensive
alternative to Volvo (Boge) units.
Rear Shocks are covered further down the page.
FRONT STRUT
UPGRADE:
For performance driving
and motorsport, the 1982-on struts feature a larger diameter
stub axle and are recommended over earlier 240 model years.
How to identify: Stub diameter for the outer bearing (the
Small one) increased from Ø19 to Ø22 and the inner
bearing (the Big one) from Ø31.8 to Ø35 - the
transition diameter from stub axle to strut body (the most important
dimension for strength) increased from Ø42 to Ø45 -
therefore all changes feature a diametrical increase of 3 mm. The
82-on strut tube also features a reduced inside diameter, meaning the
strut insert is a lot tighter fit compared to earlier versions.
Split Pin for stub axle Nut (wheel bearing adjustment) - For
best fit use only 4 mm (5/32") diameter split pins.
ISSUES WITH
LOW
and
ADJUSTABLE
HEIGHT SUSPENSION:
Volvo
240/740/940's use McPherson strut
suspension, also known as a
'coil-over-strut'
system.
A) If you lower a 240
MORE than say an IPD lowered spring height or 1.5", you will
need to reduce the strut length, as the strut's piston and valve body
will also sit correspondingly further into the strut body. As road
dips appear on the horizon you will breath-in as the strut suspension
travel might not be enough to prevent momentary bottoming out. For
struts that can be modified, shortening the stroke will overcome this
issue. The following web page link to ALUFORM
shows the components inside a front Bilstein strut.
B) Further lowering requires fitting an Adjustable Ride Height system, usually with smaller diameter springs, essentially a custom fitment typically used in motorsport. The basis of a 'coil-over-strut' system is a screw threaded collar welded onto the outside of the strut tube replacing the fixed lower perch, and then fitted with a smaller diameter coil spring. The stiffer the spring you select means the higher the chassis will sit up again as stiff springs reduce little in height. Choosing the length of a spring becomes an issue because you want the final chassis height to be well within the range of your threaded collar, plus ensuring adequate clearance ( approx 10mm) between the bottom of the spring adjusting collar and your tire.
C)
By this stage you could be
keen to fit an Adjustable
Ride Height front end and
have researched the
spring length issue. With
a Volvo 240 the situation gets more difficult due to the long
length of the thick walled steel outer strut tubes. You soon notice
as you adjust the chassis down there is equally less suspension
travel available. Coil-over-strut
system Adjustable
Ride Height -
Benefits of adjustability - allows you to set ride
heights eliminating ride height differences between
passenger and driver sides; to fine tune heights for optimal
corner weight distribution; and to setup additional negative
camber as much smaller diameter springs are used. SAM in Sweden can
supply Volvo specific kits, with more general kits being
available in most countries from good suspension shops but
expect some mods to suit your Volvo. Noltec,
Australia, has Coil
over hardware
Kit #N44502. With reference to the hardware chart, none of
the threaded tubes (internal diameters) comes close to the
Volvo
240 strut tubes odd size
at approx Ø52.6 to Ø53, so a sleeve or custom
made collar will be required to build up to Ø54 ID,
the ID of the closest coil over threaded collar. Coil-over
spring inside diameter is typically around Ø65 mm.
Eibach springs are smaller with inside diameter of
Ø61 or Ø63. Small
Diameter Springs -
There is typically a choice of spring rates for road and
track use from world suppliers. Kings
Springs
in Australia have a massive 'website range' of
ProSport coils to choose from. My 2005 choice is
Eibach springs, based on their ERS system of a main spring
plus a tender spring. The tender is strong enough to hold up
the car and to give a little suspension movement before
going to block. Main #160-60-70 (400 lbf), Tender
#60-60-60 Performance driving requires
some front wheel negative camber to reduce excessive wear on
the outside edge of the tire/tyre mostly caused by
road/track friction & abrasion forces tearing off
over-heated rubber molecules. The 240's existing adjustment
slots are minimal in width, and can easily be extended
inboard by drilling / hand-filing a longer arc as there's
plenty of metal to spare. With standard ride height only
about -0.5 deg negative can be obtained. Lowering the
suspension will achieve additional negative of at least 1
degree. With effort I achieved -2 degrees each side on a
lowered 1980 chassis using standard upper strut bearing
mounts. The limit to negative camber adjustment is when the
large coil spring touches the inner strut tower when the
steering is turned. It's worth mentioning that
when the McPherson strut is turned, a small increase in
negative camber occurs. With a wheel alignment, less toe is
required, some people report a little toe-out assists
cornering, others settle for a little toe-in. <-
Pic
shows 3.5 to 4 degree negative camber for track days.
This camber offset gives even tire/tyre wear across the
whole width, rather than scrubbing out the outer edges
during hard cornering.
It's time for major strut surgery - more
suspension travel needs to be created ! The
Volvo thick wall outer strut tube needs to be reduced in length or
height - (eg around 2.125" or 54 mm). For example, one strut
modification procedure a specialist might perform is to cut the thick
walled tube well below the existing top threaded section, then
cut-out a length of tube (eg 55 mm) well below the thread. The
threaded top section piece can then be TIG welded back to the tube,
(tack with strut insert in place). The coil-over threaded collar is
then slipped over the shortened strut and welded into position at
either end to give a strong reinforced tube.
An alternative method might be to cut the strut tube as required and
arrange for a new thread to be cut (tapped) inside the tube to suit a
new threaded collar. Only a specialist will have the large diameter
fine pitch tap to cut the thread, but any weld must be far enough
away from the proposed re-tap area, otherwise the tap will blunten
fast.
Next step involves shortening the eg. Bilstein strut's 'outer tube'
by the same amount as the outer strut tube holder, (let the shop
select the removal point). Your struts will require revalving, and
repositioning of the internal bump stop to suit the new short springs
(more new springs - not again). This modification will then enable
the front end to be lowered properly. Other issues for consideration
are bump steer, tie rod angles.
The astute reader might notice that if you started with
A
then moved onto
B &
C you would have been through
a few sets of springs and had your Koni or Bilstein strut length
changed a few times as well. Plan as best you can from the above
advice, then seek a specialist opinion.

Strut tube with welded threaded
collar
I have experience with linear springs # KPS135 - 300 lbf/in
@ 200 long, Inside Diameter 65 mm, coil spacing 20 mm, 5.5
active coils, 11 wire dia, compressed 84 mm. Helper springs
are required. Also tried (175 lbf/in - good on road, too
soft for track), stiffer 225 lbf/in, and 300 lbf/in (stiff
on road, good on track). Ride characteristics can be altered
with strut valving changes inside a rebuildable strut like
Bilstein & Koni.
Link:
Additional pics and info on a MVP coil over-strut
installation is found on Dave
Barton's web page.
BALL
JOINTS:
'Power steering' - the P/S version ball joint assembly features
increased castor being forward offset by 13 mm (1/2") to the control
arm axis (therefore
an increase in the Volvo's positive castor
angle) .
- And with an x deg caster angle inclination a lot of strut housing
negative camber can be set without issues.
The cast part number on ball joint components is LH side #1330
821 = Volvo # 274 118, RH side #1330 820 = Volvo # 274
119.
'Manual steering' - The
caster on the manual ball
joint assembly enables steering
self-centering at the expense of greater steering effort .
CASTER:
This is essentially fixed on a 240 chassis. Caster is Positive
between 5 to 6 degrees, depending on your setup. Angle goes to rear
(feedback welcome on this point). 740 specs 4.5-5.5°. Adjustable
camber and caster kits eg Noltec are mentioned further down this
article.
NEGATIVE
CAMBER:

Moving
the upper strut mount 17 mm equals a one degree increase in
negative camber.
UPPER
STRUT BEARING MOUNTS: mount
on top of front struts-
STANDARD:
Inside the upper mount, an internal bearing provides a critical pivot
for both steering rotation and suspension support. The front chassis
weight at each front wheel seems to go through the mount bearing. A
worn mount is evident by distortion and lifting away of the
vulcanised rubber surrounding the top section, or worse, the internal
bearing becomes tight or notchy in rotation. Original Volvo parts are
recommended, but cheaper units are readily available nowadays.
Usually around 1 deg negative camber can be obtained using a standard
mount and is quite driveable. A bit under 2 deg negative can be
obtained with a combination of more slotting of the arc and lowered
springs.
UPGRADE:
For the 240 and 740 a good example of an adjustable camber and caster
kit is made by Noltec
Australia, and one or two other suppliers around the
world.
The Noltec unit seem well made
and I estimate they increase negative camber adjustability to around
-2 deg. This is a good head start to reducing outside tire scuffing,
but for regular track use around -3 to -4.5 deg is req'd for even
tyre wear. They are a sports item, so expect a bit more feedback and
clunk through suspension. Three Noltec pictures below supplied by
Ashley Saunders (Australia).
MOTORSPORT:
GpA racing 'offset
centre' strut bearing mounts are available from SAM to enable a
-2 to -4 deg negative camber setting. Group A rules specified that
the original mounting points must be preserved - these mounts
achieved that. The SAM catalog details them for the 240, being
normally combined with a smaller diameter spring in a coil-over
suspension. Coil-over has been discussed in the Front Strut section.
Bare in mind when SAM say their upper strut mounts give -2 to 4 deg
negative camber, -2 is the lowest angle you can go back to. There is
no rubber or poly bushes to absorb loads, just a strong spherical
bearing.

Noltec Strut top mount
Click
all to enlarge

Noltec Bottom

Noltec Strut
parts


REAR Shock
Absorbers: (Dampers)
When comparing on-road performance between inexpensive Volvo heavy
duty oil shocks vs expensive Bilstein oil/gas, the
value of standard Bilstein high performance rear shocks on the 240 is
not clear cut, so this speaks well for OEM Volvo (Boge) units. This
is in contrast with the enormous benefit that Bilstein can make to
240/740 front end control & chassis handling. On very undulating
surfaces with big dips, Bilstein rear shocks give superb control, but
this is not typical of road or good track surfaces. In my opinion,
the valving on rear Bilsteins seems better suited for use as a rally
shock than a road shock. For general road use, myself and others find
them stiff in short stroke compression - meaning they bang over
the bumps. Re-valving is the answer, In words asked for - softer
on compression, firmer on rebound. See link to Dave Bartons's figures
at end of his article.
Koni (Made in Holland) are a
popular performance alternative to Bilstein, and offer a 'Koni
Sport' rear shock being yellow (not the red standard type).
This YELLOW
type is 3 way adjustable #26-1129Sport. 240 owners prefer the 1
or 2 softer setting. Your specialist suspension supplier will need to
order them. A web article comparing Koni Red vs Yellow models is at
the Tirerack
site (search Koni). A Koni distributor in Melbourne, Australian
is Toperformance
Products. REAR
SHOCKS BILSTEIN
(blue/yellow) KONI Sport
(yellow) Shaft diameter 11.0 mm 9.7 mm Body diameter 50 mm 40.4 mm Weight 1,520 g 1,320 g End welds fused superior quality Width of mount
bushes 34.5 mm 42 mm
I own both brands and currently favour the Koni Sport for the REAR
on bitumen road & track.
KYB brand is often mentioned by owners as a good inexpensive standard replacement unit.
Shock Absorber
BOLT(S)
(Lower) - Do you hear a
rattle type noise at the rear? - really pay attention to the bottom
shock absorber mounting - the steel spacer sleeve next to the shock
can indent into the inner wall of the trailing arm, or the spacer
sleeve can bruise on the ends, which means there is a tiny bit less
length and hence play - resulting in a rattle. A thin shim washer or
an undamaged replacement sleeve can help solve this issue.
Pay attention to the screwthread condition on the long fastening bolt
(screw) (and locking nut) as the bolt's thread is often damaged from
knocking through the trailing arm holes during shock removal and
fitting, or from over-torquing. Tech hint - use two bolts to
assist aligning either end, and a small trolley jack to raise the
trailing arm so the bolt pushes through without damage. New Volvo
Bolt (screw) #970986, Lock Nut M12 #971084 (same M12 lock nut is used
for top and bottom shock mounts).
(Upper bolt) - take a look at your shock from the rear. Is it tilted outward ? If yes its screwing your shock bush at both ends, & if your fastidious, skimming around 2mm of the bolt outer flange will correct this.
REAR COIL
SPRINGS:
With lowered springs from sources such as IPD, SAM or KINGS a
reasonable height reduction is achieved. Even with lowered rears, the
rear end sits higher than the front which is a pity as on a 240 as a
low rear looks aggressive, and if cornering hard reduces load on the
front tires.
If you require a standard height rear spring, Volvo have three wire
diameters (hence stiffness) to choose from, see your dealer.
The 240 rear springs are only secured at the bottom of the pigtail,
the top sitting free around a cup/hat. This means changing a rear
spring/s can be done in minutes.
A longer spring = more compliance. A short stiff spring gives a poor
ride and control over bumps. Author's favourite rear spec:
2" lowered, 20% stiffer - suit 240 Volvo from
ALLSPRINGS, Moorebank, Australia. Go too low and the tailshaft
universals complain as the diff nose angle goes down with the
suspension. If lowering more than a set amount you will need to
raise the front nose of the diff - achieved by adjustable Torque
rods, and fit an adjustable Panhard bar (more info in the subject
sections).
Motorsport & Ride height -
at the track you are required to have an empty boot, so after
removing the spare tire/tyre, toolbox & jack, the rear ride
height rises. - More again with a minimal fuel level - So we are now
looking at the rear being up at least 1/2" (12.7 mm) or more - far
from optimum. Under hard braking, the front springs compress down and
correspondingly
the chassis rear pitches up even
higher which upsets handling and braking balance. Stiffer front
springs will reduce this 'nose-dive' and if your car is lowered
springs this is of benefit as well.
Like the case with the front coils, to keep captured, aftermarket
suppliers are restricted to a minimum spring length. One method used
to safely fit shorter rear springs is to fit a strap (eg. seat belt
material) so when the axle assembly is raised, droop is reduced to
keep the spring located. With two holes at either end of the strap,
they can be securely attached under the hat at the top, and at the
base under the trailing arm secured by springs bolt, washer and
retaining nut. This will also remove strain from the shock absorber
shafts, that on a standard car the welds on the shaft ends are the
only component that hold up the enormous weight of the rear-end when
off the ground or on a hoist.
Coil Spring Rate
Conversions:
To Convert
lbf/in to N/mm (Pounds-force
per inch to Newtons per millimetre)
lbf/in x 0.175 = N/mm, Example: 100 lbf/in x 0.175 = 17.5 N/mm
To Convert N/mm
to lbf/in
N/mm x 5.714 = lbf/in or N/cm x 0.5714 = lbf/in
For road registered cars, bear in
mind a combination of stiff front springs, large dia. swaybars,
performance struts (eg Bilstein/Koni) and low profile tires/tyres
will give a harsh ride.
STRUT
TOWER & LOWER CHASSIS BRACES:
Strut towers
on 240/740 Volvos are quite high to enable long suspension travel. As
part of an overall handling package a number of suppliers sell
strut braces to triangulate the towers to the chassis
firewall. If your improving an early model 240, fit a set of
firewall to tower chassis braces. The under-car 'lower
chassis brace' (pair) are also recommended as they add more
bracing to the crossmember, and provide a skidbar to protect the
underside of the front end in the event of an excursion. This under
brace was standard fittment on the early 264. I tried out the lower
chassis brace at the track and agree it was of benefit. With all
three braces fitted, a typical response is "just a little bit more
held together".
Braces are available from a
number of sources eg. IPD, SAM and many home manufacturers.
SWAYBARS:
(anti-roll bars)
SWAYBARS
and quality front struts are among the first practical improvements
240/740 owners can make. Even a 21 mm bar offers noticeable
improvement over a 19mm bar. The 240 Turbo spec 23 mm Fr/R Set is a
good combination for resistance to body roll and offer an improvement
over standard 240 sizings. I found the next size up - IPD's popular
aftermarket 25-26 mm Fr/R combination gives the 240 added
manoeuvrability in autocross/hillclimb situations as well as flatter
front cornering. Volvo still sell new 23mm bars being quite
expensive. Currently I swap between a 21 a 23 mm rear bar, as the
turbo power twist on the tires combined with a 25mm rear does cause
some oversteer.
A ride trade-off with the big 25 mm bars is the suspension rides
harder on bumps due to their bar rigidity, and more resonance/fine
vibration can be felt in the steering wheel. The angle on the ends of
the IPD 25 mm bar is better suited to lowered suspension than
standard bars. Tech note: My Front & rear IPD swaybar
diameters measured 25.7 mm or 1.015", being much closer to 26 mm than
the advertised 25 mm size. With even larger 27 mm (1 1/16") plus
diameter bars, increased front understeer can be felt. IPD bars are
cold formed using 4040 steel.
Polyurethane bushes are recommended for both the two main
support bushes as are the sets of doughnut bushes on the bar end
eyelits . Sources: IPD, Noltec,
Super Flex, Energy Suspensions.
Some original rubber swaybar bushes are no longer availabel eg
23,25mm. Users' report that the firmer red/black/yellow coloured poly
bushes (termed Nolathene in some countries) are better for the bar
support bushes and are quite easily adapted. Note Volvo changed the
main brackets 3 times, so you might need to use earlier brackets to
suit the readily available "D" poly bushes.
Swaybars and handling - To quote a Volvo enthusiast Balu Vandor "In general, adding roll stiffness (stiffer springs and/or swaybars) to the rear end will bring handling closer to oversteer, while adding roll stiffness to the front brings it closer to understeer. The stiffness of a swaybar increases with the 4th power of diameter, so even a small increase in diameter should bring noticeable results. The handling balance can also be fine-tuned by changing the tire pressures in the front and rear tires in comparison to each other."
Big Front Bars in
AUTOCROSS -
Contributed by Jon Rush, USA
In the Stock class in Sports Car Club of America (SCCA)
autocrossing, the rules restrict you to only front anti-roll bar
changes. Springs and rear bars can't be changed from what is factory
supplied. To improve autocross handling, we frequently install a
large front bar alone. A large front anti-roll bar does several good
things and one bad thing.
The large bar keeps strut suspensions out of the bad portion of the camber curve, keeping the outside-front-tire contact patch flatter to the pavement. This keeps you from wearing out the shoulder of your tire and can improve front grip. A big front bar also makes the car much more responsive in side to side transition maneuvers. For rwd and awd cars, the big front bar helps put power down too. The big front bar shifts more of the total roll resistance work to the front and keeps the body flatter. Therefore, the inside rear tire has more loading and it will be less likely to spin or lift off the pavement.
The downside is that
you will get more understeer in steady state cornering. In autocross,
so little time is spent in steady state and so much of your time
improvements come from being able to transition quicker and put more
power down sooner, that the tradeoff is well worth it.
Swaybar 'END
LINKS' - ADJUSTABLE: End
Links attach the ends of a front swaybar to the control arms. If your
car is fitted with lowered suspension, adjustable links can give an
effective upgrade to handling. Standard Volvo end links are rubber
bushed and not adjustable in height. Without adjustability, a lowered
cars swaybar 'ends' are likely to have quite an upward angle on them
- far from optimal. In one case a reduction of 20 mm (over 3/4") was
required to level the arms on both swaybar-ends.
Adjustable links consist of a threaded rod that screws into a steel
spherical bearing replacing the bottom rubber bush. Positioned along
the threaded rod are Nyloc nuts, and as per standard you position the
original small doughnut bushes and cup washers either side of the
sway bar ends.
Bearing shops can supply spherical rod end bearings in metric
sizes (bore 10 mm) and price depends on quality. The bearings
with a thin PTFE lining are good as there self lubricating. Grease
versions can suffer additional wear in the gritty road wheel
enviroment.

Spacers optimised (SEE
PICTURE) - pay attention to the angle of the 'End Link' where it
mounts into the control arm relative to the above sway bar hole, as I
found it positioned best with a thin spacer one end, thicker the
other, rather than equal width spacers.
On good road surfaces, slower corners could be taken at higher
speed. i found the difference quite noticeable, with ride and
tracking being uncanny in smoothness. Took me days to understand the
change, it's as if the swaybars exert more control, being consistent
with a reduction in play, and the improved end link angle. On rougher
roads there seems to be a small steering reaction on bumps. As there
is no lower rubber bush anymore, more road vibration is
transmitted.
So far as finishing off a swaybar upgrade, this optimum positioning
is to me fine tuning, the icing on the cake. As mentioned in
Swaybars,
poly doughnut bushes are ideal. MVP
are a source of Endlinks.
|
TORQUE
RODS (REACTION Rods / Upper trailing arms) and BUSHES:
240 series
rear suspension is very similar to a four link design being quite
reasonable for differential control. Newer style - later model torque
rods when fitted with stiffer poly bushes do give increased security
on higher speed corners, and offer better diff location control when
accelerating out of corners.
Two types of Volvo torque rods exist and function to keep the rear axle/differential square to the chassis and to limit diff windup or rotation. The older type rods, (1975-83?) are fitted with very flexible small diameter curved bushes (also called butterfly or dog-bone due to shape). Replacement butterfly bushes are expensive and very tricky to press in, but the problem is, there's far too much bush compliance for performance use.
Newer style torque
rods feature a round and larger rubber bush of stiffer design.
For further bush upgrades, IPD offer an excellent two piece
polyurethane unit that features generous side wall diameters, ideal
for keeping the axle better located in dynamic use. Noltec, Super
Flex and Energy Suspensions also offer poly torque rod bushes. An
option to fitting poly bushes is much harder rubber bush for newer
torque rods as used in Volvo Cup competition (x4 req'd) are
available from SAM #1273622RF
It's really
worth upgrading to the newer rods,
1984 onwards - a parts recycler being a good source.
Adjustable torque
rods - If lowering your car more than usual, the diff nose will be
pointed down more than is acceptable for efficient rear uni joint
function (do you hear a grumble sound when de-cellerating). You will
need to shorten the torque rods to bring the nose up again - an
adjustable thread section is the solution. Under sudden acceleration
the diff nose rises a (disturbingly) large amount.
TRAILING
ARM BUSHES: (2x
long trailing arms locate the differential/rear wheels to
chassis)
The small
Volvo bush (at front of arm) is rigid and recommended, but the
large rear bush mounted in the Dana diff 'rear axle bracket'
can be improved by upgrading to a more rigid harder rubber version
having has less bush flex. Suitable for road cars is the harder
rubber bush used in Volvo Cup competition (x2 req'd) from SAM
#95086520 (old Volvo number on bush is #1205796). Modern polyurethane
varieties such as Notec (my favourite) come with a steel outer
sleeve. The Super Flex bush requires you to use the same original
steel outer sleeve and its no simple task removing the vulcanised
innards !
Fitting - Due to the large bush diameter and long length, removal and
installation of the two bushes requires a rather special
multi-piece Volvo tool to first remove and then fit the one
piece bush into the axle brackets. This is best done on a garage
hoist, so let your mechanic raise a sweat on this
job.
PANHARD
ROD:
This critical steel tube
keeps the chassis from swaying from side to side as it links the
rear axle to the chassis so movement to one another is relative
over a wide arc. Trailing arms, torque rods and springs assist the
axle attach squarely to the chassis. Therefore, its most important
panhard rod bushes are in top condition with no play whatsoever.
Standard Volvo rubber bushes are good hard and rigid, no argument.
Polyurethane bushes are an alternative and offered by Noltec,
SuperFlex, with Nylon offered by SAM - racecars use
uniballs/rosejoints. Tech hint - if upgrading the chassis end
panhard bush to a poly unit with steel sleeve, it is recommended you
check the play/clearance between the steel sleeve and the securing
bolt. A tighter tolerance steel sleeve might need to be made eg. 12.0
mm ID. Tech hint - For the axle attachment end bush, if
upgrading to a poly unit with steel sleeve (where a standard rubber
bushes are vulcanised to the steel sleeve), a point to consider is
the poly bush is free to slide along the fixed steel sleeve and will
most likely butt up against the axle which itself is OK, but this
means the sleeve is then too long (ie the poly is not being clamped
into position. A remedy is to shorten the sleeve a bit and put a
larger outside diameter washer at the nut end. From an alignment
perspective, if you lower the chassis with shorter spring height, the
panhard rod sits closer to a level position, meaning the rod is at
its optimum position, moving the chassis a little further left,
relative to the axle.

For more precise side positioning of
the chassis-to-tire location, an adjustable panhard rod can be
fitted that uses a L&RH thread system (eg. 3/4" dia) sourced from
a suspension manufacturer/shop, (in Australia - Whiteline #KTB180).
Before modification, do your math then hacksaw out a section on the
large dia tube (eg 80 mm length), suggest near LH end for adjustment
accessability. Machine 2 off supplied nuts on the O.D. for most of
their length so they press into ends of rod tube (27.1 mm dia) and
have welded-in professionally.
A suggested adjustment reference point is the chassis-rail
near the top of rear spring hat, measure inside of tire/tyre to
square chassis rail (not inside of guards), make equal, and if
required obtain a thrust wheel alignment.I tried a 4 mm shorter rod
length and noticed a handling improvement. The Dana diff centre
offset is to the right with an offset from chassis centre of approx
32 mm (don't centre the diff, leave as is and use the tire to chassis
rail left to right comparison).
TIRES/TYRES:
Use the best you can afford. Per dollar, better quality tires with
low slip angles will improve your driving and reduce lap times more
than engine work will.
WHEEL OFFSET
& Wheel SPACERS: Visit
my web page for information on measuring wheel offset & spacers
OFFSET
& REAR WHEEL SPACERS
THE
SEAT: Original equipment
seats are comfortable, but don't hold you so well when cornering,
especially if a leather or vinly fabric. Volvo cloth and aftermarket
seat types provide more friction. To stress the importance of good
seat, compare these two scenarios; Imagine driving quickly along a
winding road or racetrack. Your body is moving from side to side,
bum, shoulders, back and head all trying to keep straight (to stop
moving your even pressing your arm into the door trim) - you haven't
got close to the control required for precise cornering!
Compare this to SITTING-INTO a body hugging sports seat, where
your firmly located and as road input requires you just move/rotate
the steering wheel for precise cornering - driver input is efficient
as your not compensating for excessive body movement, you can instead
concentrate on driving well.
SPORTS
SEATS: There are
several brands to choose from e.g. Recaro,
Sparco, Cobra, available in either a one piece or reclinable
design. If your going racing the seat must be a one piece.
Some have brackets to suit a Volvo, others need to be
adapted. Since I required adjustability, the very low in
height Volvo seating rails were ideal, enabling new seat
securing brackets to be attached on top. Position the L
shaped seat brackets in a position to suit your seat width
and drill new holes in the L bracket. Volvo R-Sport offered
quality seat covers with high side bolsters to keep the
driver well positioned. On the 2nd hand market these are
sought after items, and are still available new from Volvo
but at a premium price.
STEERING
WHEEL: A large diameter wheel
has added mechanical advantage when turning, but your arms also
rotate further around on the large arc. A smaller diameter
wheel requires less exaggerated arm movement, and I believe less
movement enables more precise driver input whilst cornering. Most
Volvos have power steering, so to turn a small steering wheel
requires little effort.

FOOT
REST: Most modern cars have
them standard, but I'm yet to hear of one standard in a 240! Its
worth fitting one to place your left leg on as this can reduce
twisting of your upper body whilst cornering. Instead you can
focus on accurate steering input.
FINAL
WORD: As most of us have
experienced with a standard 240, once the initial sway is passed, the
car takes a 'corner set' and they usually handle sharply. After
improvements described in this article, a typical drivers comment is
'the car now
goes around corners like its on rails!'
2nd
FINAL WORD: This
is from a Road&Track comparison test of sports sedans, Aug
1991:
After completing one of the twistiest, most challenging portions of
our [test] loop, we came away with respect for this upright
rather boxy live-rear-axle sedan that could keep pace with cars of
obviously more sporting intent. "It's your worst nightmare," said one
of us, "to be going along at a really good clip and see this *Volvo*
right on your bumper." [thanks
Mike Justeen]
Hope you enjoyed the content of this article.
©
Anthony Hyde, 2001- Updated
9/2007
*
I have no links with any of the companies listed, other than having
purchased some of their products.
*
DISCLAIMER
*
PLEASE NOTE any information
offered on this web page is free and without guarantee. Should you
choose to perform any of the procedures listed on this page, you will
be doing so of your own free will, and I will not be held responsible
or liable for any damages that might occur from using information
obtained here. The information stated here, is to the best of my
knowledge, accurate. However, in order to safeguard myself legally, I
make no claims that it is in fact accurate in every, or any detail.
Further web
reading:
Bilstein
Re-Valving figures -by Dave
Barton 245 Turbo
Front
Suspension Theory
Physics
of Racing - weight transfer,
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