VOLVO
240 SPORTS HANDLING
©
by Anthony
Hyde, Australia 1/2001 updated
3/2003 |
The aim of this article is to fill the 'literature void'
with relevant Volvo sporty type information for all experience levels.
Pic -Mike Saccone ITB 242
|
The road and track handling of your 240
can be enhanced significantly, Volvo's R-Sport division proved this
years ago with uprated gas shocks, swaybars and chassis brace products.
A few aftermarket suppliers continue today to develop parts using modern
designs and materials such as polyurethane. Reward for the sporting
driver is less bodyroll for flatter cornering, and increased steering
precision. |
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 sports 2nd hand parts through private sale and recyclers - you might
find a bargain!
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:
Super
Pro / Super Flex Bushes
(Australia, Europe, USA), 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)
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. The
part # is 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 - fit them. By
reducing ride height, you lower the centre of gravity of the sprung mass, 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 in Europe, and Kings Springs in Australia. Expect these to lower your front
end between 1"-1 1/4".
FRONT
STRUTS: (Dampers/Shock Absorbers)
Many users agree that Bilstein
are the premier after-market choice for 240, 740 and 940 McPherson strut front
ends 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 Quadrant
Suspensions are Bilstein specialists.
Koni
is also a popular after-market choice offering an enticing 5 way adjustable
'Koni Sport' (yellow version) for the 240, #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) and Kings
Springs (QLD).
FRONT STRUT and EXTRA
LOW SUSPENSION ISSUES:
For performance driving and
motorsport use, 1982-on struts with the larger diameter stub axle are
recommended over earlier 242/244/245 model years. How to identify: Stub
diameter for the outer bearing (the Small one) increased from Ø19 to Ø22 and
inner bearing (the Big one) diameter from Ø31.8 to Ø35. The casting of the
stub axle to strut body (the most important dimension for strength) increased
from Ø42 to Ø45, an increase of 3 mm in all dia's. This strut tube also
features a tighter inside dia meaning the strut insert is a lot tighter fit
compared to earlier versions.
ISSUES WITH EXTRA
LOW and ADJUSTABLE
SUSPENSION:
A) If
you lower a 240 MORE than say an IPD lowered spring height or 1.5",
you will need modified struts, ast your strut's piston and valve body will also
sit correspondingly lower in the tube. As road dips appear on the horizon you
will breath-in as the strut travel will no longer be enough before bottoming out
occurs. 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
'coil-over-strut' system,
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 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. Ensure the bottom of the collar/spring is
well placed and will not interfere with your rim and 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 worse thanks to the long standard strut tubes. You soon
notice as you adjust the chassis down there is not much suspension travel
available before the strut tube bangs into the top upper strut bearing.
It's time for major strut surgery, more suspension travel needs to be created!
The Volvo outer strut tube needs to be reduced in length or height - (for
example only, say 2"). Method - cut off x length from the top of the
steel strut tube 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, plus the threaded collar might need to moved
and welded. Next step is to have the struts shortened (not again?), then
revalved to suit the new short springs you might need to purchase (not again?).
This modification will then enable the front end to be lowered properly. Other
issues then arise, bump steer, tie rod angles.
The austute 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 advice above, then seek an opinion
from a specialist.
Strut tube with welded collar |
Click image
to enlarge |
|
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. For
example, the 240 Volvo strut tube outside dia is odd in size approx Ø53
mm and some threaded collars are Ø54 ID (2 1/8"), so a sleeve or
custom made collar can be required. Coil-over spring inside dia
is typically Ø65 mm.
Small Dia Springs
- There is typically a choice of spring rates for road and track use. Kings
Springs in Australia
have an massive range of ProSport springs to choose from.
I have experience with linear springs #KPS-185 (175 lbf/in, 300 long,
65mm ID) (good on road, too soft for track) & stiffer #KPS-187 (225
lbf/in, 250 long, 65mm ID) (stiff on road, good on track).
|
REAR Shock Absorbers:
(Dampers)
When comparing on-road performance between inexpensive Volvo heavy duty
oil shocks vs expensive Bilstein oil/gas, the value of high
performance rear shocks on the 240 is not clear cut. This is in contrast with
the enormous benefit that Bilstein can make to front end 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, I find them stiff in short stroke compression -
meaning they bang over the bumps. Re-valving is the answer, I asked for -
softer on compression, firmer on rebound. See link to Dave Bartons's figures at
end of article.
Koni (Made in Holland) is a popular
performance alternative to Bilstein, and offer a sporty (yellow)
3 way adjustable 'Koni Sport' rear shock, #26-1129 Sport. 240 owners
prefer the middle 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. A Koni distributor in
Melbourne, Australian is Toperformance
Products.
Shock Absorber BOLT
(Lower) -Do you hear a knocking 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 sleeve
length 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.
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, combined with 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).
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.
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, the top sitting free around a cup/hat, and this means
that changing rear springs 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
Motorsport Use - at the track you are
required to have an empty boot, so after removing the spare tire/tyre, toolbox,
jack, a minimal fuel level, the rear ride height rises up another 1/2" or
more being far from optimum - hence lowered springs are a head start. Under hard
braking, the front springs compress and the rear chassis lifts up which can
upset handling balance.
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 are the only components 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
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
Bare in mind that the combination of stiff front
springs, large dia. swaybars, performance struts (eg Bilstein/Koni) and low
profile tires/tyres can give a harsh ride.
NEGATIVE
CAMBER: performance driving requires
some front wheel negative camber to at least avoid heat build up and excessive
wear to the outside edge of the tire/tyre. The 240's existing adjustment slots
are minimal and as there's plenty of spare metal you can increase adjustability
by hand-filing a longer slot on the arc. On a standard height chassis this will
increase negative camber to around -0.5 degrees. 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. With standard upper strut bearing
mounts the limit to negative camber is when the spring touches the inner strut
tower when the steering is turned. 17 mm equals a one degree increase.
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.
STRUT
TOWER & LOWER CHASSIS BRACES:
Strut towers on 240/740
Volvos are quite high due to the cars relatively high stance and long suspension
travel. As part of an overall handling package a number of suppliers sell strut
braces to triangulate the towers. If your improving an early 240, fit a set
of firewall to tower chassis braces. The under-car 'lower chassis
brace' (pair) are also recommended as it adds more bracing to the
crossmember, this brace being standard fittment on early 264s. I tried out the
lower chassis brace at the track and agree that 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. MVP, IPD, SAM and small
manufacturers.
UPPER
STRUT BEARING MOUNTS:
STANDARD:
This bearing is a critical upper pivot point for steering and suspension. The
mount would require replacement if the internal bearing is tight or notchy in
rotation, or the vulcanised rubber surrounding the top section is peeling away
or deteriorating. Original Volvo parts are recommended. Usually around 1 deg
negative camber can be obtained using a standard mount, and is quite driveable.
Up to 2 deg negative with slotting.
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 did 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.
 |
 |
| Top View 'offset centre' left
hand strut bearing mounts GpA |
Underside View -2 to -4 deg |
SWAYBARS:
(anti-roll/anti-sway bars)
SWAYBARS
and quality front strut inserts are among the first practical improvements
owners can make. The 240 Turbo spec 23 mm Fr/R Set are 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 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 and are quite expensive.
A ride trade-off with the big 25 mm bars is that suspension rides harder on
bumps due to their rigidity, and from the front bar more resonance 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 27 mm (1 1/16") and
larger diameter bars, increased understeer can be an issue.
Polyurethane bushes are recommended for both the two main support bushes
and the sets of doughnut bushes on the ends of the bar - Sources: IPD, Super
Flex, Energy Suspensions. 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.
Swaybars and handling - To quote from Volvo enthusiast Balu Vandor
"In general, adding roll stiffness (with stiffer springs and/or swaybars)
to the back will bring handling closer to oversteer, while adding roll stiffness
to the front will bring 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."
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 length. 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 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 (or REACTION RODS) and BUSHES:
240 series rear suspension is
very similar to a four link design being quite reasonable for differential
control. Newer style rods with stiffer bushes can give increased security on
higher speed corners, and better diff location control under acceleration.
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 is far too much compliance for
performance use.
Newer type torque rods
feature a much larger round bush of stiffer design. For 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. Super Flex
and Energy Suspensions also offer poly torque rod bushes.
It's really worth upgrading to the newer rods, a parts recycler being a good
source.
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 Volvo Cup bush (x2) from SAM #95086520, or
modern polyurethane varieties that are coming onto the market, eg. Super Flex.
Due to the large bush diameter and long length, removal and installation of the
two bushes requires a Volvo special tool to 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 on 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.
Standard Volvo rubber bushes are good and rigid, no argument. Polyurethane
bushes are stiffer again so can make an improvement and are offered by 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 is free to slide along the
fixed sleeve and will most likely butt up against the axle which itself is OK,
but this means the sleeve is then too long. A remedy is to shorten the sleeve to
38 mm and to put a big washer on 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-axle location, an adjustable panhard rod can be fitted that
uses a L&RH thread system (of eg. 3/4" dia) sourced from a suspension
manufacturer/shop, (in Australia - Whiteline #KTB180). I tried a 4 mm shorter
rod length and noticed a handling improvement. 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.
BALL JOINTS: The
manual steering ball joint assembly has less caster requiring less steering
effort than power steering ball joints (79->). Ball joints from the power
steering version have increased caster compared to manual steer models. This
enables steering self-centering at the expense of greater steering effort - not
a problem with a power steering pump.
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 SPACERS: Visit
my web page CUSTOM
REAR WHEEL SPACERS
| WHAT
ABOUT THE DRIVING POSITION ? |
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 slop is
passed, the car takes a 'corner set' and they can 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
*
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,
Return to Volvo
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