I am getting a lot of questions from forum members about the GFB DV+
It's a good product, but I think it's a bit misunderstood. Let's take a look at it.
The GFB DV+ is a direct replacement part for the stock diverted valve. It differs only slightly in design from the stock part, but significantly in quality of components.
So what is a Diverter Valve? In the old days it was called a bypass valve, or a blow off valve, but it's a little more sophisticated. The diverter valve is an ECU controlled valve that relives air pressure in the intercooler and associated piping by opening up under specific conditions and venting that air back into the turbo's intake port. It does this in two situations. First it opens up when the car is on boost and the driver closes the throttle. Second it happens of the ECU feels it needs to open the valve to protect the engine. For example it would do this if the boost line came off of the wastegate actuator, or some other malfunction caused an overboost. (I'm simplifying here)
The factory diverter valve works pretty well. It responds fast enough to offer the protection it should, and when it's closed it doesn't leak too badly. However it does leak, meaning that the turbo has to work a little harder than it otherwise would to create air pressure that's wasted.This leaking causes a very small delay in the time it takes the turbo to spin up, and costs a very small amount of power when on boost.
The GFB valve when closed leaks less than the stock valve. Thus the turbo can spin up a little faster and at least in theory power on boost will be a little higher. However as compared with a stock valve that's in good condition and operating properly, the differences are very slight, so slight that only people really in tune with their car will have a chance of noticing.
Now, IF the stock valve, which is pretty low quality, isn't perfectly healthy, you will notice a difference when swapping in the GFB part. When you hear about someone putting in a GFB and raving about the improvement, it's usually because there was something wrong with the stock valve. The GFB valves seem to last forever so they give very consistent reliable performance.
In the 500 Abarth world the GFB valves are very popular. They are also very popular on a lot of other European turbo cars. It's a good product, just don't expect a big change in power as compared with a properly working stock valve.
We have them at EC, they are here: https://shopeurocompulsion.net/colle...o-fast-bits-dv