FAQ Performance Dampers

Tuning philosophy

Does ZF SACHS have a particular tuning philosophy for chassis?

Yes, ZF SACHS regards the following core aspects as important when tuning a chassis:
Sporty but stiff damping, optimum vehicle handling, better position on the road compared to series chassis and good vehicle controllability when driving at the limits. All modifications are made taking into account driving safety, everyday suitability rounded off with driving comfort while at the same time keeping the vehicle body load to a minimum.

PERFORMANCE Lowering

What is the lowering rate with the PERFORMANCE sets?

The lowering for our complete sets fluctuates between 30-45 mm.

This lowering rate superbly combines the goal of a sport-tuned chassis with significantly improved driving performance based on handling, road position and controllability, as well as the necessary requirements with regard to driving safety, everyday suitability, driving comfort and keeping the vehicle body load to a minimum.

Added to this is the improved appearance and the fact that all the wheel/tire combinations approved for the vehicle are used. The exact toe-in and camber settings stipulated by the vehicle manufacturer are also possible after the PERFORMANCE sets have been installed (note: this is important in particular for vehicles in which readjustment of the camber is not possible due to the steering knuckle/shock absorber module, e.g. E46, Ford Focus, etc.).

How does the lowering rate at ZF SACHS compare with that of competitors?

As part of ZF SACHS? tuning philosophy, the absolute lowering rate is not important (see the point regarding the lowering rate of PERFORMANCE sets). The lowering specified by ZF Sachs is the actual lowering to be implemented for the vehicle modification. Our sales pitch does not focus on the lowering rate. The exact measurement of the lowering is made using the distance between wheel hub and fender cutout (before/after). Subsequent measurement of the vehicle height, based on the data in the vehicle documentation may lead to large inaccuracies.

Does the installation of the PERFORMANCE set have any effect on the vehicle load?

A vehicle with a PERFORMANCE set is completely suitable for daily use. Even with the maximum permitted load, the prescribed residual spring travel is still ensured.

PERFORMANCE Sports Shock Absorbers

When should ZF SACHS sports shock absorbers be used?

PERFORMANCE sports shock absorbers should be combined with spring kits when lowering by up to 50 mm (for details, see spring certificate).

For sporty drivers who don?t want to lower the chassis, the PERFORMANCE shock absorbers are an optimum supplement to series springs.

Does ZF SACHS use shortened PERFORMANCE shock absorbers?

The extent to which shortened sports shock absorbers are used in a vehicle when lowering depends on the lowering springs used (spring part certificate) and the axle geometry of the particular vehicle.

The general use of shock absorbers that change in length when lowering should be avoided because the necessary travel of the shock absorber is reduced. The shock absorbers in the ZF SACHS PERFORMANCE line are shortened to some extent from technical necessity.

The required spring pre-tension is ensured in the PERFORMANCE shock absorbers through the use of high-quality and adequately dimensioned tension stop springs. Tension stop springs are used in the following marques/models in particular BMW, Mercedes Benz, VW Passat; Audi A4/A6, Ford Mondeo etc.).

Can ZF SACHS PERFORMANCE shock absorbers be adjusted?

No, ZF SACHS tunes individual shock absorbers and complete chassis optimally to the vehicle. With a separate damping force adjustment, the balance between front axle and rear axle is no longer ensured. A modification to the damping forces carried out by someone without the appropriate expertise may impair safety.

Lowering Springs in the PERFORMANCE Set

What is the tuning of the springs like?

The spring tuning is designed for the PERFORMANCE set by leading spring manufacturers in line with ZF SACHS? tuning philosophy.

Is ZF SACHS the spring manufacturer?

The springs are procured from Eibach and H&R.

Does ZF SACHS also sell ZF SACHS lowering springs in the PERFORMANCE line?

ZF SACHS does not sell any ZF SACHS lowering spring sets in the PERFORMANCE product line. The individual sale of lowering springs is limited to the Aftersales trade. Nevertheless, lowering sets from other manufacturers are available as trade products through the subsidiaries in Germany and other countries.

PERFORMANCE Product Rage

What are the technical details of the PERFORMANCE products?

Shock absorbers:

for example:

• induction-hardened, chromium-plated and polished piston rod
• seal and guide unit with coated, friction-reducing guide bushing
• working cylinder formed from a single piece
• shock absorber piston with friction-reducing components
• race-proven oil
• working piston and piston valve with a progressive / degressive design of the characteristic line to improve the running characteristics
• springs and valves made from special steel for precisely setting the damping force
• use of access striker springs as additional tension damping force assistance
  

Springs:

for example:

• use of high-quality chromium-silicon spring steel wire
• shot-blasted with steel balls for maximum fatigue strength
• testing for block strength to prevent subsequent spring setting losses
  
  

How extensive is the product range?

The range includes approx. 200 PERFORMANCE sets and approx. 200 sports shock absorbers. More than 250 vehicle models are covered by the PERFORMANCE range. After new vehicle models are launched, new sets and shock absorbers are continuously introduced into the range.

Is the complete set accompanied by a part certificate?

Our PERFORMANCE set is accompanied by a part certificate for the technical acceptance. Depending on the PERFORMANCE set, the part certificate relates either to the complete set (shock absorber and spring) or to the springs. This is not important for the vehicle acceptance.

Why should I buy a ZF SACHS chassis rather than one from a competitor?

ZF SACHS has outstanding expertise and a great deal of experience in series manufacturing and the development of chassis technology for series vehicles. This is supplemented by ZF Sachs? unique expertise in all categories of motor racing (F1, rally sport, touring vehicles, 24 h racing, formula sport etc.). Together with the high-quality production of parts, ZF SACHS provides excellent prerequisites for the area of chassis tuning.

In particular, the experience from the series business makes optimum chassis tuning possible for the particular ZF SACHS philosophy (see point regarding tuning philosophy).

Many competitor products are purely copies or are put together in very small series, the core competence often lies in other areas.

What distinguishes the PERFORMANCE set from the sporting set?

The PERFORMANCE range is the logical development of the chassis tuning segment at SACHS. PERFORMANCE products are geared specifically to private car drivers and are developed at ZF SACHS Race Engineering.

The tuning philosophy, compared to the old sporting sets, has been adapted to customer requests for greater residual comfort.

From now on, PERFORMANCE shock absorbers can be purchased individually and may be combined with other lowering springs.

What can be said about the use of threaded chassis?

Threaded chassis originated in motor racing sports and are used to enable different wheel loads to be set. This is primarily used for adapting the vehicle to the requirements of the various racetracks.

The advantages in terms of driving can only be transferred to road driving to a limited extent. An incorrectly adjusted chassis may even present a safety hazard. Nevertheless, the threaded chassis is an interesting product, particularly for specific fields of application.

In the future will threaded chassis be available from ZF SACHS?

Threaded chassis are in the planning for specific applications and will be introduced in due course.