The decision has been made and finalised. My car will most definitely be a lot more track focused now. Why? Because I have just committed to a set of Nitron NTR Race Coilovers with Eibach Spring upgrade.
These are a serious set of coilovers that I have thought long and hard about for some time; even before I found out that J's Racing had commissioned Nitron to build a set of dampers for one of their S2K race cars. Getting these would make my car harsh on the road but awesome on track, primarily due to the high spring rates and matching valving. There is definitely compromise involved as you can't have a comfortable road car with race suspension, it goes against physics!
The NTR Race model is a 3-way adjustable damper, capable of adjusting rebound, and high and low speed bump. To put into perspective how performance orientated these are, typical aftermarket coilovers are only 1-way adjustable, only allowing you to adjust the Rebound, or rebound and bump together with one adjuster. Of the latter, you may be thinking how on Earth can you adjust two types of setting with a single adjuster when damping forces are not linear?
Exactly! (will explain more on this below) However, in the real World it's not really an issue for the majority of applications. There is typically a large bias towards the rebound adjustment as it has the largest effect on damping out of the three.
Think of 2-way and 3-way dampers as the next level up in damper tuning, not 1-way as a bad application for adjusting damping, because they are not! I was just being facetious earlier, a lot of competition drivers/ some race teams use 1-way (for budget reasons though) :p
To give a greater understanding of how these 3 damping forces affect a car's handling, I'll give a quick overview of what rebound, high speed and low speed bump is (as explained by Nitron):
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When a damper is compressed this is known as the compression stroke or ‘bump’, when it is extended this is known as ‘rebound’. The amount of force that the damper generates during these movements is usually different in each direction and is often stated as a ratio, for example a 3 : 1 ratio means the rebound force is 3 times the bump force. However, things are never this simple. As the damper movement speeds up the force it generates increases, if the bump and rebound forces were totally linear it would be possible to plot an exact bump to rebound ratio. Generally, damping forces do not increase at a constant rate with an increase with speed, and so the bump to rebound ratio varies for different shaft speeds. 3 : 1 maybe the ratio at medium speeds, but at lower speeds this could be 1 : 1 for example.
Low shaft speeds can really be thought of as the chassis moving around, i.e. diving, rolling and squatting, and combinations of these. As a car is driven through a corner, the chassis will take a variety of different attitudes as it goes from straight to straight. These are all low speed shaft movements as far as the shocks are concerned.
High shaft speeds are where the wheels encounter something that rapidly disturbs their steady state, and the chassis will hopefully remain stable, i.e. a bump.
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Typically, dampers are either monotube or twintube. Nitron dampers utilise a monotube design .
I won't go into the details of why monotube is better as I am far from being a suspension technician; Google both, there is lots of literature out there. I will however list out the advantages over twintube:
- Lighter
- Greater heat dissipation
- Greater sensitivity to small shaft movements
- More consistent damping and greater resistance to fade during long periods of use
- Can be inverted to reduce unsprung mass
Additionally, the Race versions have remote canisters that are hose mounted to the main shock.
All dampers require something to compress internally to allow the rod to enter the body, in the case of a gas monotube this is achieved using a floating piston and a compressible volume of nitrogen.
A damper with a remote reservoir on a hose onto the side of the shock allows the length of the main shock absorber to be reduced by moving the floating piston assembly to the side, and a much larger volume of nitrogen may be used which has a more consistent pressure during the rod stroke.
As the piston rod is pushed into the top of the body tube, an identical volume of oil is displaced into the remote reservoir. Placing valves in the head of the remote reservoir canister allows the damping rate to be varied in compression as oil is passed through it during the compression stroke. An additional benefit is the ability to cool the nitrogen by mounting the reservoir where there is cooling airflow and away from sources of heat, this will keep the nitrogen at a more constant pressure and help with consistent damping.
Anyway, the order has been placed, and they should be built within a few weeks. I will have a long and steep learning curve to understand and apply in a practical sense the optimum settings for different tracks, but then that's half the fun ^_^
They look practically the same as these in the pictures below. (They belong to a couple of race EP3's. One of which I'll be on track with tomorrow at Silverstone)
