Great review. I'm pretty sure my diverter valve is torn (rev. G), I can't decide between buying GFB DV+ or just a rev D. If I buy the GFB DV+ kit, do I still need to buy a new DV since the one on my car is broken?
I have installed my DV+ for more than 10 months now. Been to 10 track days. Won more than half of them. Never had a problem nor a soft code (uni re alocation kit). This past week I switched to oem rev D.... Boost levels were similar (a 0.9% lower) but the response and sound does not match the DV+. Tested this because there was so much talk lately. My DV+ is back in my car. That's my story. I could try removing the extra spring of the DV+ but honestly I think the test will not change my current set up.
There was a wave of people who wanted to move back to the OEM DV to see if there was a difference, I've been running the OE DV for a while, time to go back to the DV+. After roll racing an APR Stage 3+ Golf R this weekend I noticed that boost was definitely falling off faster between shifts.
There was a wave of people who wanted to move back to the OEM DV to see if there was a difference, I've been running the OE DV for a while, time to go back to the DV+. After roll racing an APR Stage 3+ Golf R this weekend I noticed that boost was definitely falling off faster between shifts.
Installed the DV+ yesterday and I wish I had done this earlier, throttle response is much quicker and you get to boost quicker as well. I don't know how long I was driving with a torn rev. G because I didn't get a CEL, but this is night and day, very pleased with the construction and response of the car to the DV+.
So I have some boost bleeding at high rpms and some hesitation at the onset of peak boost. logged it and verified my boost values do change during the hesitation period which is causing my afr to change also. So air is escaping somewhere. Pressure tested multiple times and no leak found. I had the hesitation before dv+. Installed dv+ with main spring and problem still there. Removed main spring, problem still there.
My question is even though i have the dv+ installed could i have problems with the system as a whole if my oem valve is faulty. Not the diagphram (rev G) but more like the actual mechanical operation like the actuator that moves the diagphram. In the case of the dv+ this would be the part that causes the piston to move.
I just posted this today. Install coverage and feedback will be posted on IG @becauseryanjacobs. Get yours after the holidays only from @kmdtuning call to place your order at 201-773-9171
The new GFB DVX is a cross between a dual port VTA spacer or BOV and the original DV+. The DVX still uses the factory diverter valve solenoid like the DV+ but now the solenoid is located remotely from the valve body because there isn’t room to incorporate it on the valve. In terms of mounting the remote solenoid, the EA888 has an unused threaded hole next to the vacuum pump where the remote mount will fit. During my install and testing I'll try to locate this and point it out for others otherwise I'll determine another location.
GFB claims that the opening speed response is still within 10% of the DV+ opening time, which is splitting hairs since this adds up to a response speed that is about 0.002 seconds slower than the DV+.
The DVX kit includes a remote mounting block that effectively converts the factory diverter valve solenoid coil to a 2 port solenoid valve and connects to the VTA spacer or BOV with a length of vacuum hose that can be cut or trimmed.
The DVX uses the same piston as the DV+, but the remote mounting block has a selectable spring pre-loaded lever which allows the inner sleeve to rotate, giving the user proportional control of the venting bias between atmosphere venting and recirculation. The goal is to adjust the spring so that the valve closes after venting before the engine drops back to idle (not something that can be done with a VTA spacer or BOV).
The DVX will not allow true 100% atmosphere venting, because GFB left 2mm of the piston travel permanently exposed to recirculation in order to take care of low RPM flutter which caused the P2261 fault code when using the main spring. In the past, if we had this fault code, we had to remove this shorter, wider main spring which would then make the original DV+ operate like the factory diverter. For us manual drivers, the main spring kept throttle response sharper but now with the DVX we should have this back without a fault code.
GFB said the canted design of the valve allows the best flow for both the atmospheric and recirculating outlets. They also said that other dual port valves which bring the air up and out of the diverter chamber can't flow enough in recirculation mode to prevent compressor surge at high boost. Their new DVX design allows the piston to stay low in the chamber so recirculated air has a straight shot into the recirculation port.
When I asked GFB about fuel trims and the concern over metered air being VTA, GFB responded that the only time BOVs can affect fueling is for the brief time the valve is venting, which is typically under closed throttle. A lot of the BOV's on the market today still use the factory diverter valve whose operation is not ideal for atmosphere venting valves. Since the factory diverter opens wide and stays open for at least 2 seconds after the throttle is closed or until the throttle is opened again, they will lose more air to the atmosphere than you would with the DVX. This could be why a lot of us have seen MAF fault codes with full DV spacer or BOV options.
In their testing, they have not seen evidence that the selectable atmospheric vent level affects long term fuel trims because of the shorter, selectable duration of venting air.
