Ohlins Tuning Guide
Overview: What this guide covers
This guide pertains to Öhlins ‘Road and Track’ kits, Öhlins ‘Dedicated Track’ kits, and 3DM Motorsport ‘TrackDay Series’ kits.
Suspensions are VERY complex. Please note this guide is intended to be a BASIC tuning guide and covers information at a relatively high level. Just like there are several ways to brew coffee, there are several ways to setup suspensions. It is ultimately the drivers responsibility to figure out what works best for them.
Understanding how the dampers work
Setting up ride height
Adjusting the clicker knobs
Documenting your setup and changes
Understanding How the Dampers work
It is important to understand WHAT the shocks (dampers) are doing in order to understand how to make changes to the handling characteristics of your car.
Dampers create force to control the springs and the dynamics of the suspension/chassis. When the suspension moves we measure it by velocity. When the suspension compresses it is called “Bump” and when the suspension droops it is called “Rebound”. Turning causes the car to roll (outside tire compresses and the inside tire droops) and this is typically a low velocity occurrence of the suspension (aka low speed). Hitting a bump or curb is typically a high velocity occurrence (high speed).
So the more adjustment knobs the better right? The tendency is to want a damper that has a knob for every function… low speed rebound, low speed compression, and high speed rebound/compression so we can fine tune but unfortunately its not that easy. We see it over and over and over again where people install complex dampers, get lost with knob turning and end up NEVER adjusting them ever again. The best laid plans get derailed by complexity. Its important to keep it simple and keep good notes.
Öhlins dampers are competitive, not complicated. They are setup out of the box with force curves oriented to YOUR car and towards performance driving. The clicker predominantly adjusts low speed rebound (the most important) and low speed compression is matched as necessary. This low speed adjustment helps dial in the “dynamic balance” of the car, in other words, how the car reacts when you turn. It also helps dial in grip through the turn by keeping the tire contact patch optimal over small undulations and ripples in the pavement. The Dual Flow Valve (DFV) replaces the need for high speed adjustments, it allows the damper to soak up bumps without upsetting the car and lets the tire return to the ground quickly.
What about range of adjustment? There are typically two different use cases for aftermarket dampers and their adjustments: combo street/track cars, and dedicated track cars. It sounds enticing to buy a damper that can control a large range of spring rates to encompass multiple use cases but this approach is a major compromise. They typically end up with a small adjustment range for the springs you settle on limiting your adjustability and tuning capabilities from track to track. Everyone is a little bit different, or perhaps a lot different, which is why Öhlins offers two distinct kits, the ‘Road and Track’ and ‘Dedicated Track’, each of which are capable of handling a window of spring rates for their particular use case. No need to have your dampers re-valved if you want to make small spring changes to suit your driving style or car setup.
Setting up the Ride Height
Spring Pre-load vs Height Adjuster: (Stroke Position versus Ride height)
When installing an aftermarket suspension, one of the bonuses is the ability to lower the car. This is good because it lowers the center of gravity (CG) and ultimately creates a better handling car. Most Öhlins suspension kits separate the spring pre-load from the height adjuster.** It is important to note the differences.
(** Some kits only have a preload adjuster due to limitations of the vehicle design.)
Spring Pre-load Adjustments
Spring pre-load will determine where the damper is located in its stroke travel at ride height. The more you pre-load the spring the less the damper will compress before it attains ride height. This can be bad as this will limit droop travel. The less you pre-load the spring the more the damper will compress before it attains ride height. This can be bad as this will limit bump travel.
The weight of the car and spring rate will both affect ride height. You should try to set the stroke position somewhere in the middle of the usable stroke travel.
Ride Height Adjustments
Once spring pre-load has been set, the ride height adjuster can be used to set the vehicle ride height. Ride height is determined by many things such as wheel/tire clearance to the spring perch and fender, or even by desired “stance”. Be carefull with lowering the car too much especially with MacPherson strut cars.
Ride Height Setup on MacPherson Strut Vehicles
As stated above, when installing an aftermarket suspension, one of the bonuses is the ability to lower the car. This is good because it lowers the center of gravity (CG) and ultimately creates a better handling car. However, it is not that simple, especially with a MacPherson strut car such as a BMW, Porsche, Subaru, etc. It is a two fold problem…
First, the cornering balance of the car is determined by the weight transfer difference between the front and the rear axles. Weight transfer is controlled via springs, ant roll bars, dampers, and roll moment. Roll moment is a part of the geometry equation where it is the distance between the center of gravity (CG) and the roll center (RC). On MacPherson strut cars, the roll moment typically gets exponentially larger the more you lower the car. Therefore the more you lower the car, you will need to increase the spring or anti roll bar rate to compensate.
Second, MacPherson strut design places the damper very close to the wheel and tire. The more you lower the car the closer the spring perches get to the tire in a “coilover” scenario.
As you can see, it is important to watch how much you lower your car as this can create all sorts of problems ranging from geometry issues, wheel/tire clearance, and shock travel problems (bottoming or topping out).
Adjusting the Clicker Knobs
When adjusting the clicker knobs you should feel a click as you turn them. With Öhlins dampers you always turn the knob as if you were looking at them. Clockwise is ‘stiffer’ and counter clockwise is ‘softer’. When adjusting the clicker knobs it is important to start from the “zero” point. To find the zero point, turn the knob to full stiff (clockwise) until the knob stops. If it stops on a click that is considered click zero. If it stops halfway between clicks, turn it counter clockwise until you feel the first click and this will be considered click zero. Now that you have found zero, turn the knob counter clockwise until you have reached the desired number.
Settings for Öhlins Road and Track kits and 3DM TrackDay kits
Clicks 1-10 are ideal for track use. This firms up the damper to control the spring for track use. Start with click 5 front and rear and adjust softer or firmer to suit your needs. It is important to make small changes to dial in your car.
Clicks 10-20 are for street use. This softens the damper to allow for a more compliant ride on the street. Start with click 15 and adjust soft or firmer to suit your needs.
Settings for Öhlins Dedicated Track Kits
Öhlins Dedicated track kits have been developed both on a shaker rig and on the race track. The instruction manual will give you a baseline clicker setting out of the box for your particular vehicle. We recommend starting with those and adjusting softer or firmer to suit your needs.
What determines how I change the clicker knobs?
This is very complex. There is no magical answer to where the knobs need to be set, no matter the brand of damper. It all depends on your driving style, car setup, and what part of the track you are having problems, for example turn in versus mid corner versus track out. Your best bet is to try different settings and feel what the car does. See “Documenting Your Setup and Changes” below about logging your settings. We are always an email or phone call away if you would like to discuss your application. Contact Us
Documenting Your setup and changes
As with any subject of complexity, you should incorporate some minimal form of documentation or you will get lost quickly and end up not utilizing the capabilities of your suspension. It can be something as simple as a pocket notebook, a note taking app on your phone, or something as complex as a custom formatted excel workbook. The important thing is to find something that works for you and is sustainable. These notebooks from Öhlins are a great way to document settings and changes you make from session to session.