VOLVO 240 SPORTS HANDLING
© by Anthony Hyde, Australia 1/2001 - latest update 1/2014


Pic -Mike Saccone ITB 242 (S40 front spoiler)

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 race cars sported trick items like alloy suspension components, carbon fibre composite diffs, light-weight body panels.
IPD, SAM and many 'privateer' manufacturers continue to invest in making Volvo aftermarket parts for people like us, using modern designs and materials such as polyurethane. Even Volvo dealers still stock 242GT springs and swaybars .... at a price.
Reward for the sporting driver is less bodyroll for flatter cornering, better traction, increased steering precision and better looks. The aim of this article is to fill the 'literature void' with relevant Volvo sporty type information for all experience levels.

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 with 2nd hand parts from private sale, Ebay 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 in this article:
Kaplhenke Racing (USA), IPD (USA), Energy Suspensions (USA), shox.com (USA), SAM (Sweden), and your local Volvo dealer for small diameter bushes, Kings Springs (Queensland, Australia)



240 Rack & Pinion Steering (version in pic is manual steer)
Typical Power steering ratio was 17.2:1

 

Link: Steering rack webpage info.

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 use, myself & others found this springs spring-rate matched up well with front Bilstein struts. A similar spec spring was used in the 1979 242GT. A BLUE slash of paint on the front spring indicates Ø13.5 mm wire diameter. Part No. - In a few cases, a faint part # can be found near the start of the first ring.
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 of lowered springs. By reducing ride height, you lower the centre of gravity of the 'sprung mass' (mass of car above springs), always beneficial for better cornering performance. On a few occassions I have carryied bush rocks and placed them on passenger and rear floor areas - the 240 cornering performance was noticeably better due to the lower centre of gravity.
For a 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 ( IPD Sports springs 35% stiffer, free length = 11.84" ), 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 - see web ARTICLE courtesy of Turbobricks.

Difference between Linear and Progressive rate springs - Information from www.stockcarproducts.com/spgtech.htm
Linear Springs: If a spring's rate is linear (most racing springs have linear rates) its rate is not affected by the load put onto the spring. For example, a linear rate spring rated at 500 lb. per inch will compress 1" when a 500 lb. weight is placed onto the spring. If another 500 lb. weight is put onto the spring the spring will compress another inch. At this point the load on the spring has increased to 1000 pounds. The rate of the spring, however, remains constant at 500 lb. per inch.
Progressive Springs: If the load put onto a spring increases the rate of the spring, the spring is said to have a progressive rate. Keep in mind that the load (or preload) put onto a progressive rate spring can greatly increase the rate of the spring. Progressive rate springs are made by varying the spacing between the springs' active coils. During compression the close coils bottom out and deaden. This reduces the amount of active coils and spring rate increases as a result. Springs that are designed to include coils of different diameter or are wound using a tapered wire will also produce a progressive rate.


FRONT STRUTS : (Dampers/Shock Absorbers)
Many users agree Bilstein are the premier after-market choice for 240 / 740 / 940 McPherson strut front suspension, being noted for keeping the heavy Volvo front end well balanced & under tight control. They combine oil and gas with quite firm valving, and 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 are a hugely 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 TUBE ASSEMBLY 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 pipe/tube 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 buy 4 mm (5/32") diameter split pins.
- The strut tube angle of inclination measures 12 deg relative to the stub axle.

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 too far (As a guide the IPD lowered springs reduce height by 1.5"), the struts remaining length of stroke to work in is reduced. As road dips appear on the horizon you will breath-in as the strut suspension travel might not be enough to prevent momentary bottoming (clunking) out. For strut brands that can be dismantled &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 height or '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.
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 height / length (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, and when you've got a handle on the subject seek a specialist opinion.


Strut tube with welded threaded collar

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.

In the last few years many suppliers offer an aftermarket Coil-over-strut solution ready to go. Kaplhenke Racing (USA) has an impressive range of Volvo suspension upgrades to make your mouth water. In Australia DVS Performance . In Sweden SAM.

If doing it yourself, the Volvo 240 strut tube is an odd diameter 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 springs are often based on an inside diameter of around Ø65 mm. Eibach springs are smaller with inside diameter of Ø61 or Ø63.

Small Diameter Springs - There is typically a good 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 current choice is Eibach springs for the front, Kings on the rear.

Lowering the car a bit more than usual means both the suspension arm and the steering tie-rod arms are facing upward and this affects the suspension movement and roll centre. The best product available for a 240 I have ever come across to correct this issue is termed Quick Steer Roll Correction and is made by Kaplhenke Racing (USA), highly recommended.


BALL JOINT - Lower :

Power steer - the lower Ball Joint assembly as seen left in the picture is forward offset by 10 mm to increase castor. What this means is the strut is moved forward at the bottom and so the angle of the strut is inclined at a greater angle to the chassis (increases the Volvo's positive castor angle)

Manual steer - Manual steer ball joints seem to have no offset. The caster on the manual ball joint assembly enables steering self-centering at the expense of greater steering effort.

Part number superceded update - The number cast into the P/S ball joint components is LH side #1330 821 = Volvo # 274 118, RH side #1330 820 = Volvo # 274 119.


CASTER : This is essentially fixed on a 240 chassis (subject to balljoint type used). 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 :

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 and pushed in the inner guard a bit to give more spring clearance. The limit to negative camber adjustment is when the large coil spring touches the inner strut tower when the steering is turned. When setting up for max neg camber, keep rotating the non-concentric strut assembly to ensure the spring won't rub the chassis when turned.
Moving the upper strut mount 17 mm equals a one degree increase in negative camber.

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, others are happy with zero degrees.

<- Pic shows 3.5 to 4 degree negative camber for serious track days that is subject to high tyre loads. Some camber offset gives a more even tire/tyre wear across the whole width, rather than scrubbing out the outer edges during hard cornering.


Click to enlarge:
This lowered 240 inclined the control arm and steering rod 10 degrees

Click to enlarge:
Installing the Kaplhenke quick steer roll correction part gives a perfect 0 degrees


UPPER STRUT BEARING MOUNTS : Bolts onto chassis and locates the top of front strut inserts (shocks)- The Volvo VADIS sysyem describes them as: Shock absorber anchorage # 1272455 (all years of 240)
STANDARD: Inside the upper mount, an large 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 when rotated. Original Volvo parts are still the best by far - you get what you pay for. 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. A standard Volvo mount combined with small diameter springs / adjustable ride height also works very well as some ride quality is preserved.

UPGRADE: For the 240 and 740 a good example of an adjustable camber and caster kit is avaialble from numerous suppliers. A top place to start your research is Kaplhenke Racing (USA). Typically they increase negative camber adjustability to around -2 deg. This is a very good head start to reducing outside tire scuffing. Serious track use can require -3 to -4.5 deg. They are a sports item, so expect a bit more feedback and clunk through suspension. Three Noltec pictures below supplied by Ashley Saunders (Australia).

Noltec Strut top mount
Click all to enlarge

Noltec Bottom

Noltec Strut parts
MOTORSPORT: GpA racing 'offset centre' upper strut bearing mounts with spherical metal bearings are available from SAM and 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. The bearing offset from centre is 26mm. A more road friendly setting can be achieved if the 3 mount screws are moved across 13 mm (so the bearing centre offset becomes 13mm) and this can achieve -1 to -3.5 deg. There is no rubber or poly bushes to absorb loads, just a strong spherical steel bearing.
Top View 'offset centre' left hand strut bearing mounts GpA
Underside View -2 to -4 deg, offset is 26 mm


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.
In Australia all 240s have the upper braces from tower to the firewall, and most used ones have a bend in them. They weren't made with a bend, they have flexed and that demonstrates the tower does move. I selected 2 perfect ones for my 242GT sports machine and after time went to remove the left one. To my surprise it had locked in hard and now sported a good arc like most others out there.
One of the ultimate strut brace designs is made by
Kaplhenke Racing (USA) as it features triangulation not only between the towers, but to the firewall as well. The tubing used is similar to a rollcage.
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 (and importantly the engine sump plug) in the event of an excursion. This under brace was standard fittment on the early 264 6 cyl model. 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 also available from a number of sources eg. IPD, DVS Performance,SAM and many home manufacturers.
REAR SHOCK ABSORBERS : (Dampers) Boge / Bilstein / Koni
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 the OEM Volvo (Boge) shocks in vg condition rate well with me. This is in contrast with the enormous benefit that Bilstein can make to the 240/740 front end control and overall chassis handling.
Bilstein rear shocks are strong when it comes to controling big movements, 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. Expensive re-valving is the answer, In words ask 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 - file off any burrs and fit a new nut. 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 the top screw is skewing 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. Volvo uses a slash of paint half way up a spring to identify. For example a
RED slash indicates Ø12 mm wire diameter and a BLUE slash Ø13 (Ø12.95) mm wire, blue being a stock wagon 245 spring with rate 224 lbf/in. The heavy duty wagon (probably ambulance spec) uses 13.7 mm wire with rate 290 lbf/in.
The 240 rear springs are only secured at the bottom of the pigtail, the top sitting free around a spring seat cup/hat. This means changing a rear spring/s can be done in minutes, especially if they are shorter length springs.
IPD Sports springs Rear free length = 13.44" (342 mm). A longer spring = more compliance. By comparison, a short stiff spring jolts over bumps, but the rest of the time the chassis feels in tight control with no floating. Typical rear spec is 2" lowered, 20% stiffer.
Go too low and the tailshaft universal joints 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 - this is achieved by fitting adjustable Torque rods, and also 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. - If your competitive you'll have a minimal fuel level - So we are now looking at the rear being up at least 1/2" (12.7 mm) or more being far from optimum. You will wish for adjustable height platforms on the rear. For years I thought it was a hard task, but after plenty of research into suitable parts it turned out pretty easy. Now there are suppliers with Volvo specific bits.*
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 secure shorter rear springs is to fit a strap (eg. seat belt material) so when the rear 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, as 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 4 point chassis 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 - for club motorsport a front spring rate of 400 lbs is talked about, then this equals 70N/mm in the Eibach catalog.
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.


SWAYBARS : (anti-roll bars)
SWAYBARS and quality front struts are among the first practical improvements 240/740 owners can make. Going up from 19 mm to 21 mm bar gives noticeable improvement, a 49% increase in torsion. From 19 to 23 is 115%, 19 to 25 is 200%, 21 to 25 mm is 101%. 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, (44% torsional change) 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: 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 'D' shaped support bushes plus the doughnut bushes on the swaybar ends. Sources: IPD,
Noltec, Super Flex, Energy Suspensions. Some original rubber swaybar bushes are no longer availabel eg 23 and 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 and hillclimbs - 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.

A large diameter front 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.



REAR END COMPONENT SECTION - VOLVO 240 HANDLING UPGRADES


The Volvo solid live rear axle needs to sit square to the vehicle chassis so the car tracks in a straight line, and all the links assist with this (panhard rod, trailing arms and torque rods).

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.
a) 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 compliance in this small bush for performance use.

b) Newer style torque rods, 1983 onwards, feature a much 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. 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 - 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 threaded section is the solution (you want to make the rod shorter by say 5-10mm) and there are many suppliers for Volvo. 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)
Two bushes- the big one that fits the Diff and the small that fits into the front of the trailing arm. 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). Poly bushes have fallen out of favour as they tend to bind up the suspension resulting in the lifting of the unloaded wheel. Once more the ultimate solution is made by Kaplhenke Racing (USA).

Link to Poly bush material failure pic - product was from Noltec in Australia. No issues at all have been experienced with quality SuperPro brand that is a light blue opaque colour -

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. So unless you can acess the trick tool and have some mechanical knowhow, his is best done on a garage hoist, so let your mechanic raise a sweat on this job.
TRAILING ARM BUSH ANALYSIS - I'll start with a question - why do the 240 large diff tube bushes cop such a beating and wear out to the point of collapsing in extreme ways when they don't carry the weight of the vehicle ?
- Note the the entire weight of diff and about half of the weight of the four trailing arms and the panhard rod are "un-sprung weight". The rear coil spring & tyres carry the mass, about 46% of the vehicle weight - being approx 300kg on 'each' rear wheel.
Most of the vehicles rear end life is spent obeying the steering direction of the front wheels, be it very minor to very major directional changes.
As the solid rear axle has no in-build steering, the major wear and tear on the big bushes is from having to twist sideways, plus the additional back and forth twisting movement as the suspension goes up and down, so forces come from many angles. Hence they cop a 3D beating to the point of collapse.


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). Hint: to reduce the chance of the nut undoing, secure a wide nylon tie around the shaft thread(s).


REAR FENDER CLEARANCE IMPROVEMENTS : link to article describing modifing the 'rear fender outer edge' to create wide wheel clearance.
WATTS LINK Volvo 240: (non standard enhancement)

To keep readers minds alert, I include a gem of a modified 240 rear setup. Matt Veal from AcuForm, Canberra, Australia, went all the way with his track 242GT-T. One day I hope to have a drive to feel the difference in rear handling.

Keen eyes will notice the location of the rear mounted combination shock / spring. Shocks are AVO-PF120-085 12" items, spring length to suit ride height requirements.


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
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 the 240s didn't feature one. Its worth fitting one to place your left leg on as this can reduce twisting of your upper body whilst cornering, and you will be quicker getting to the clutch and break pedals. Upside is you then focus more 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!' with an impressive amount of driver feel.
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 11/2008
* 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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