Most valves come pre-adjusted to the correct setting for your vehicle. The two possible extremes that may require adjustment are a valve that is too stiff for your application or a valve that is too soft.
If the valve is too stiff, your vehicle will generally exhibit some level, large or small, of compressor surge (also known as turbo flutter). This sound may accompany a delayed (and short in duration) release of the air charge from the valve, or it may be present with absolutely no opening of the valve at all. If these conditions are present, then the valve should be adjusted softer. In general, compressor surges can cause damage to the turbocharger and should be reduced or eliminated whenever possible.
If the valve is too soft, then your vehicle will generally suffer by having a valve that is open when it shouldn’t be (such as at idle) or from an extended air charge release (possibly in excess of 3 seconds). If either of these conditions occurs, then the valve should be adjusted harder.
Suppose the cap adjustment does not sufficiently correct an unwanted condition noted above. In that case, another spring will likely need to be selected for your application. It’s also important to be aware that although we advise against it, some turbo kit builders will design a kit using our valve to have a certain level of “acceptable” compressor surge. If you are concerned about an issue such as this, then the best course of action is to reach out to the team responsible for designing the turbo kit.