What the Press said in 1977 after the UK launch of the Lancia Beta Montecarlo
Handling
The purpose of building a mid-engined car is to obtain the ultimate in cornering power, and both the handling and the roadholding of the Montecarlo – though not flawless – are of a very high order. Traction in particular, is superb.
The rack and pinion steering is light, even at parking speeds, and precise with good feel; the lock is also good. The car understeers under all normal circumstances for there is insufficient power to break the tail away, though oversteer may easily be provoked by lifting off the throttle in mid-corner. A mere flick of the wheel is then necessary to hold the car on a line that is little affected by bumpy surfaces. Cross-winds make the car wander – but not unstable – at speed.
Ride comfort
The bias of the suspension design is in favour of handling and the ride is consequently firm. But it is rarely uncomfortable, almost all surface irregularities being soaked up before they reach the occupants. However, although the low-speed ride is relatively good for this type of car, at high speeds over indifferent surfaces it becomes rather jiggly. For a car with such high reserves of handling and roadholding the ride quality is very good indeed and of a firm but supple nature. Moreover, there is little roll, even during harsh cornering.
Steering
The rack and pinion steering is heavier than one might expect from a mid-engined car’s rearward weight bias, but on the road it is a delight; quick and accurate with a responsive feedback from the low profile Pirelli P6 tyres….
SUMMARY OF SUSPENSION ANALYSIS REPORT
(prepared for TMH in 1999 by Barney Gerrard*)
• An analysis of Montecarlo/Scorpion suspension using modern techniques
• Measurements and data supplied by The Monte Hospital
• Comparisons between state of the art then (nearly 40 years ago) and now
• Montecarlo rightly praised when launched for its combination of comfort with excellent handling
• McPherson struts – give excellent luggage space and comfort
• Kingpin and Castor angles are high – chosen for straight-line ability
• Ground offset also high (28mm) – prone to braking pull and steering kickback
• Zero Ackermann geometry on S1, improved on S2
• Static toe settings high (4-8mm on rear) by modern standards – tyre technology has since improved
• Small wheels and high profile tyres – major contributor to comfort, although at the expense of steering response
• Anti-roll bars at front and rear on S1, rear removed for S2
• Spring rates firm but not high
• Front Roll Centre is very high – 125mm compared with 35mm for modern sports cars – increases sensitivity to poor road surfaces
• Camber compensation is good (40% front, 24% rear) – higher than normal for strut suspensions (front more typical of double wishbone)
• Less than ideal ‘anti’ properties – 40% pro-dive and 15% pro-squat – resulting in more nose-diving under braking than normal – does not aid driver perception of braking performance but has no real effect on actual braking performance
• Modifications to wishbone and tie rod mounting locations can improve suspension geometry if desired
* Barney Gerrard is a highly-qualified suspension design engineer. Not long after preparing this report he was asked to join the Fiat organisation and moved to Turin. He subsequently joined the Chrysler Corporation and relocated to the USA.
THINGS TO THINK ABOUT
Tyres/wheel size
• Pros/cons of changing width, profile and offset
• Tyre size front and rear – effect on handling
• Effects of adding wheel spacers.
Static set-up
• Effects of toe in and toe out on turn-in and straight-line stability.
• Selection of tow settings given modern tyre technology
• Static camber settings
• Kingpin/castor angles
Bushes
• Role of rubber bushes – handling performance as well as isolation
• How the bushes affect handling
• Handling improvements by stiffening bushes with minimum loss of comfort
• Strut top mount performance – comfort with loss of body control
• Effects of bush deterioration – what to look out for!
Suspension Struts
• Role of dampers in the suspension – weight transfer during turn-in
• Upgrading dampers – balanced increase front and rear
• Importance of up-rating dampers when stiffer springs are used
• Over-damped/under-sprung preferable to under-damped/over sprung
Road springs
• Why have stiffer springs?
• Lowering the car on its road springs
• Selection of complementary front and rear springs to maintain handling balance
• Need for additional damping when spring rates are increased
Anti-roll bars
• Function.
• Effect of anti-roll bar changes on handling
• Sensitivity of anti-roll bar stiffness to diameter changes
Weight Distribution
• Current weight split front/rear
• Potential for modification
Geometry (mounting point location) modifications
• Advantages of lowering Roll Centre Heights
• Changes to front suspension to improve Roll Centre Height
• Relevance of anti-dive and anti-squat to the Montecarlo
• Modifying front/rear suspensions to improve anti-dive and anti-squat
Other modifications
• Strut braces
POSSIBLE APPROACHES TO IMPROVING HANDLING
• Identify whether the suspension is in good shape to begin with – bushes and dampers in particular. Replace old or worn bushes with polyurethane bushes on track control arms (front) and rear wishbone legs (rear) prior to checking toe-in and camber settings.
• Have the static set-up of the car checked – both front and rear toe settings are particularly important owing to their effect on handling.
• Tyres and dampers are the most influential components in the system – decide whether to change wheel size to improve the choice of available tyres (especially for S1 and Scorpion) and/or to fulfil other requirements.
• Select good-quality tyres (Bridgestone, Michelin, Yokohama, Toyo etc) and use the same diameter front and rear.
• Lower profile tyres will provide an immediate improvement in steering response.
• New or reconditioned struts – tired and worn struts cause a significant degradation in suspension performance.
• Consider lowering and stiffening the suspension, requiring new springs all round (to give balanced increases in rate at both front and rear), and adjusting static camber by using a camber adjustment kit. This will result in improvements to the suspension geometry and give handling gains from a lower centre of gravity and reduced roll whilst cornering.
• If very low profile tyres are used, then suspension geometry changes (in particular the front Roll Centre Height) should be considered, either by modifying the suspension mount locations or by lowering the car on the road springs.
• Anti-roll bars are an interesting possibility as a potentially low-cost route to improving handling.
DATA SHEET
Whole vehicle data
Wheelbase 2300 mm
Track (front) 1412 mm (on ground)
Track (rear) 1456 mm (on ground)
Wheel/tyre size 185/70 HR13 5½J (Series 1)
185/65 HR14 5½J (Series 2)
165 HR13 5½J (Scorpion)
Static Laden Radius (SLR) 1715 mm (rotation frequency of 7.5 Hz @ 30 mph)
Kerb weight split 43:57 (front/rear)
GVW definition 2 people + 70 kg luggage
Front suspension
Type McPherson strut
Kingpin inclination 13°
Caster Angle 6°
Castor trail 30 mm
Ground offset + 28 mm
Static toe in 2 – 4 mm toe-in
Static camber 0°± 20’
Toe out/Toe in 32° /32° (zero Ackermann behaviour – S1)
Spring rate 25.9 N/mm
Effective wheel rate 21.9 N/mm
Kerb wheel load 219 Kg
Primary Ride Frequency 1.6 Hz
Wheel deflection @ GVW 22 mm
Rear suspension
Type McPherson strut
Static toe settings 4 – 8 mm toe-in
Static camber 2° ± 20’
Spring rate 30.9 N/mm
Effective wheel rate 27.3 N/mm
Kerb wheel load 290 Kg
Primary Ride Frequency 1.5 Hz
Wheel deflection @ GVW 23 mm