FRONT COIL-OVER SUSPENSION:
Available for MGA, MGB&BV8

Our replacement double wishbone, coil over front suspension system has been specially designed to overcome some of the criticism of the original or other alternative options. The wishbones are fabricated using high grade tubular steel that improves the structural strength and rigidity, the springs are positioned closer to the wheel enabling a much softer spring to be used, and together with high quality damper units results in a more supple suspension.

The coil-over damper units are specially made ‘click’ adjustable, re-buildable units with adjustable spring seats to enable the ride height of the car to be changed, and are supplied with a 3 year warranty and individual test reports.  The springs supplied are a standard 2 ¼” I/D which are used on a variety of special and race cars. These can be obtained in a wide variety of stiffness and lengths.

New anti-roll (sway) bar links are supplied fitted with a spherical joint to provide a more positive reaction. The bottom stub axle bolt is replaced with a special high tensile bolt that has a small flat machined on it which carries 2 snail cams, this enables the camber angle to be adjusted simply and quickly. Several shim washers used at the top end of the stub axle provide a small degree of castor adjustment.

All fabricated parts and springs are black powder coated, the dampers are chemically blacked, and nuts and bolts are bright zinc plated.

Standard MGB lower inboard bushes are utilised for the inboard ends of the new top and bottom wishbones. Polyurethane replacements for normal road use are recommended and can be supplied.

Fitting the kit is straightforward, it replaces some of the components normally fitted, and these are:

In order to be able to fit a full size spring/damper unit of this type it is necessary to modify the ends of the front cross-member (chassis outriggers on MGA) to provide clearance. We can do this for you or supply a ready modified powder coated unit on exchange (not MGA). Some customers carry out the modification themselves, which involves cutting off the end of the cross-member and welding in a gusset (supplied in the kit). Also the MGA top trunnion requires modification or alternatively the MGB stub axle assembly can be used.

NB: These kits are suitable for both chrome and rubber bumper MGB. The ride height of a rubber bumper car can be lowered using the spring height adjuster but this will result in a similar amount of bump travel being lost

FRONT CROSS MEMBER ASSEMBLY:
Available for MGB & MGRV8

A “ready to go” fully built cross member using the Hoyle Suspension and Brake kits and modified cross member, the stub axle assemblies, hubs and steering arms are reconditioned using new bearings and bushes. The unit can be supplied with either bolt-on or centre-lock hubs.

This cross member is superior to the RV8 replacement as used on MGB’s. The ride and handling characteristics of the Hoyle system are superior, the braking performance is improved and the unsprung weight reduced by the much lighter calipers. It is also less costly.

INDEPENDENT REAR SUSPENSION:
Available for MGA, MGB&BV8, MGC, & MGRV8

Our IRS unit is a complete replacement for the existing rigid axle, leaf springs, and leaver arm dampers. It was designed to cope with up to 400bhp and fit around the existing body, battery boxes, and fuel tank without modifications being necessary. The installation adds to the rigidity of the cars shell and reduces the un-sprung weight by 55kilos (overall weight same as std axle), this, together with softer springs and high quality dampers, results in a more supple suspension. Unlike the original system each wheel reacts independently to the change in road surface so not upsetting the balance of the car, and the unequal length double wishbones ensure that for hard cornering the small camber change induced keeps the maximum amount of rubber in contact with the road.

The system consists of a new sub-frame that supports the differential, upper and lower tubular wishbones, coil-over dampers, machined alloy hub carriers, and tie bars to the spring eyebolt location. Also attached to the sub-frame are the new stainless steel braided brake pipes and the handbrake cables. All these parts plus all the necessary polyurethane bushes, and nuts and bolts make up the basic kit. Shims, in the form of quick-change C washers, can be fitted between the wishbone pivot yokes and the sub-frame to make minor adjustments to camber and tracking. The dampers used are the same spec as our front system, the fabricated parts are black powder coated, and the aluminium uprights are anodised.

In addition the differential, drive shafts, hubs, stub shafts, drive flanges and disc brakes are sourced from the Ford Sierra or Granada. The half shafts require shortening to retain the standard track dimension and can be supplied, whilst the Ford drive flange can be used for centre-lock wheels with a bolt-on splined adapter, we supply a new flange with MGB stud pattern for bolt-on wheels. All these Ford parts can be supplied as new or reconditioned, or can be sourced second-hand very cheaply. There is a range of differential ratios available (3.1-3.9 Sierra and 3.3-3.6 Granada). The Sierra unit has a 7” crown wheel and can cope with engine power up to 250bhp whilst the Granada’s 7.5” will happily withstand higher output engines. For those with big V8 engine cars that want to drive them hard, or use for track days or competition, both diffs can be fitted with the standard Ford viscous coupling type Limited Slip unit, alternatively a Quaife torque biasing LSD could be fitted.

Fitting the kit is straightforward, once the original axle, springs, and dampers are removed, the unit, which can be pre-built off the car, is raised into position. It is attached to the original damper mounts (4 bolts); the rear spring front eyebolt mounts via the tie bars (2 bolts): and the check strap brackets (2 bolts). The stainless brake hoses mate with the existing pipe-work and dual handbrake cables and their linkage attach to the handbrake drop link. The rear suspension unit can be supplied fully built ready for bolting to your car. N.B. A minimum wheel diameter of 15 inches is necessary to provide sufficient clearance.

The instructions cover setting up both suspension systems, but some customers may find this a little daunting with all the variables available to them (ride height, damping rate, spring rate, and geometry adjustments), in which case we are always available to discuss and advise from our own and other customers’ experiences.

All enquiries to:
Hoyle Engineering Ltd                                            TEL/FAX: +44 (0) 208 393 2555
52 Reigate Road, Epsom, Surrey, KT17 1PX     email: info@hoyle-engineering.co.uk
ENGLAND, U.K.