Coilover design
Discussion
I'm thinking about buying an old, small car (not sure what yet) and renewing the suspension for road use.
I've plugged some car models into the KW website, and been surprised when they have kits available.
So, I'm wondering - do KW (and other manufacturers) get their mitts on all the cars they make coilovers in order to design/test/develop an optimum product? Or, do they base things on OEM shock length and car weight etc. and sell kits without testing the end result?
I've plugged some car models into the KW website, and been surprised when they have kits available.
So, I'm wondering - do KW (and other manufacturers) get their mitts on all the cars they make coilovers in order to design/test/develop an optimum product? Or, do they base things on OEM shock length and car weight etc. and sell kits without testing the end result?
GreenV8S said:

Perhaps something is lost in the German to English translation, but the KW website gave me the impression that their solutions were tested for each car. However, some phrases are ambiguous, and I'm not sure how they could develop individual solutions and test them for each model.
So, do their coilovers work better for some cars than others?
The answer is yes and no.
Most manufacturers will have range of common damper bodys and a selection of modular end fixings.
Internally the damping circuits (shim stracks for example) are sufficiently customisable to accommodate the various masses of cars. So the better companies will develop a damping tune per car, initially based on mass and then with road / motorsports testing. Same process for springs.
Others (cheaper) just go down the huge range of adjustment route... So it's possible to completely over damp the suspension so it starts to 'pack down'.
As an aside manufacturer suspension is generally better than low to mid coil over design.
If you're paying 250-500 per corner, and with supply chain profits, think about how much is left to cover design, testing, and manufacture.
Most manufacturers will have range of common damper bodys and a selection of modular end fixings.
Internally the damping circuits (shim stracks for example) are sufficiently customisable to accommodate the various masses of cars. So the better companies will develop a damping tune per car, initially based on mass and then with road / motorsports testing. Same process for springs.
Others (cheaper) just go down the huge range of adjustment route... So it's possible to completely over damp the suspension so it starts to 'pack down'.
As an aside manufacturer suspension is generally better than low to mid coil over design.
If you're paying 250-500 per corner, and with supply chain profits, think about how much is left to cover design, testing, and manufacture.
GreenV8S said:
ph9 said:
I take it that's a "No", then!
If you're lucky, they'll look up the specs of the OEM units and produce something close.The OEMs on the other hand will have put a lot of time and money into fine tuning the suspension.
OEMs do spend many miles testing cars on a wide variety of surfaces so that the suspension can be proven work on glass smooth & horrendously bumpy surfaces whilst being deemed "acceptable" not "perfect", it has to be compromised as a result. Then consider each shock/spring is also still built to a cost and not built by the car manufacturer. BMW do not make shocks they will still go to for example Bilstein with a spec or ironically for the new Mini Works Pro KW developed the kit!
If you buy from the Bilstein range it will likely consist of OEM spec called a B4, most likely the B6 with upgraded internals & adjustable dampening, the B12 adjustable height/dampening/rebound , this is the difference of spending £100 per corner to over £500.
In terms of aftermarket coilovers, yes there are a lot of budget brands that just go to the same manufacture and ask for their shocks to be painted whatever colour, internally they are largely the same as will things like spring rates. Often these budget coilovers have no dampening /rebound adjustment and the method for raising/lowering the height is by compressing the spring which not only adjusts the height but changes the amount of travel available to. Good quality coilovers will have adjustable platforms which allow adjustment to the height without significantly compromising the amount of travel or reducing the available spring motion. Even better coilovers have adjustable platforms that allow you to adjust the steering arm angle & adjustable top mounts that allow the camber, castor to be modified giving complete geometry adjustment.
OP- KW/Weitec certainly have a good reputation and are widely used on a variety of cars from road cars all the way to full blown racing cars which makes me think the notion that KW " look up the OEM spec and produce something close" is seriously undermining the work that they do. The main advantage of any good suspension kit is the adjustability which means you can set them up how YOU want them - be it very stiff, very soft , very bouncy , very slow to react whatever works for you ,your driving style, the types of roads you use etc not just some general " it will do" spec.
ph9 said:
Thanks - it's interesting stuff!
That Northampton Motorsport place looks interesting. The only thing is, I'm at the other end of the country. Also, they say that tracking can easily be put out by hitting a pothole, so I wonder how often alignment needs to be checked and adjusted.
That can happen on any suspension. That Northampton Motorsport place looks interesting. The only thing is, I'm at the other end of the country. Also, they say that tracking can easily be put out by hitting a pothole, so I wonder how often alignment needs to be checked and adjusted.
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