GFB DV+ Install and Review

Started by NOWAY1, August 16, 2013, 08:50:44 PM

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NOWAY1

I was fortunate enough to receive a GFB DV+ the other day and finally had time to do the install this evening.  As I expected, it was a fairly straightforward job consisting of getting out three 5mm hex bolts, removing the upper portion of the boost control valve, and assembling the DV+ on the original solenoid and putting it back on.  I wish I could give a unbiased review, but as you will see in the following pictures the diaphragm of my diverter valve was torn in three places so the increase in performance was significant. 

For those that aren't aware of this, the DV has an upper basket which is made of plastic and rubber and this is considered a "perishable item" which is expected to wear out and need replacing periodically... at a quoted cost of NZ$169 or NZ$208 plus 1.5 hours of labour for a total of NZ$327-390 dependent on which valve you require.  This upgrade gives you a non-perishable valve without the performance issues of the stock valve (they tend to leak even when brand new) for NZ$175.  I reckon any reputable tuning shop would only charge an hour for the install and clearing codes.

I should first give a few tips and pointers if you plan on doing this install yourself.  You WILL need a hoist.  I couldn't imagine trying to get the bolts out laying under the car on jack stands and don't recommend it.  DO NOT attempt this install with a hot engine.  The space is cramped and you're between the turbo and engine so you'll get burned.  I was being a tough guy and did it anyways and have quite a few burns and blisters on my forearms to prove it.  The bolts are hard to reach and harder to see so you'll need a short handled rachet, a 10cm extension and a 5mm hex bit as well as a good source of light.

The DV can be found at the back of the engine next to the turbo.  It's black with a cable attached to the bottom of it and in a location right above the drivers side drive shaft.  In the photo below I've disconnected the cable from it so you can see it better.  The bolts are located evenly around it.


When you've removed the three bolts the DV comes right off with no force needed.  You can now inspect your diaphragm for tears.  You can plainly see one of the three tears in mine below.


Installation is extremely simple.  Remove the upper part of the DV (on left in pic) and insert the replacement piston with a bit of engine oil on it for lubrication, then put the replacement DV+ housing on top.  One of the three bolt holes on the original DV solenoid has a female indentation which lines up with a male nub on the DV+ which you should ensure is lined up.


Once that simple task is over, your new upgraded DV+ is ready to be reinstalled, just make sure the connector is facing downwards like it was originally and use the three extended bolts provided.


We finished up the job clearing codes and resetting the ECU and went for a drive, which saw my fairly stock GTI spinning tires and taking off like a rocket without using launch control.  I'll be putting it on the dyno tomorrow and posting the results.

ranton-inc

Gaining HP from fitting a DV.

Unlikely

Reclaiming Lost HP due to a Leaking DV ... More likely.

Good Luck for the Dyno.

NOWAY1

Actually, the manufacturer warned me of the possibility of a loss of power, which is why I'm holding off on any comments until I run it on the dyno. Today's testing showed that most cars are fine except mk6 Rs and other cars running high boost. If this does prove to be an issue an ecu remap/tune may be required.

Quote from: GFBPlease note that our own testing has uncovered some interesting things about the factory valves on the 2.0t FSI and TSI engines that it pays to be aware of. Cars fitted with the ?revision G? diverter (diaphragm type) typically have no problem, and your car should fall into this category.

We have found that cars factory fitted with the ?revision D? diverter however may show an increase in boost pressure due to the fact that the revision D diverters leak quite significantly (contrary to popular opinion that they are better). Depending on the level of modifications, these cars can show a power loss as the ECU tries to correct for the higher boost.

The ECU typically has numerous methods of safeguarding the engine, which is to reduce boost pressure, retard timing, close the throttle, open the diverter, or any combination of these. When a car is tuned, often one or more of these safeguards are overlooked or not set up to take advantage of all the boost entering the engine.

We?re doing more work into this effect, since we?ve had a couple of cars tuned with the revision D valve that have actually lost power after fitting the GFB valve due to ECU intervention because of the higher boost pressure th at results. We?ve proven absolutely that these valves hold boost over and above the factory revision D, and it?s concerning that some cars are unable to make the most of the boost because of the leaky factory valves.

Quote from: GFBThe guys here are doing some dyno testing today and we are doing a video, have been getting some interesting results. Apparently the GTI mark 6 and below are good, however some Golf R 6?s may need a retune. The ECU does not know what to do with the extra air and seems to be opening the valve to let it out when it senses high boost.

We are getting this feedback from other dealers/tuners in SIngapore as well about the retuning particularly on cars running high boost. The tuners in Germany just seem to retune them anyway.

NOWAY1

Only pulled 125kw on today's dyno so my ecu definitely didn't know what to do with the dv+. Will get a tune asap and update.

polo_GTI

Thanks for the review. If it's at the wheels - sounds pretty reasonable to me? On a cold day like today too!
NZ '06 Polo GTI 9n3 REVO Stage2 / H&R springs / Whiteline adjustable sway bars / EBC / SS brake lines / APR mount / Uprated bushes / Forge DV / 3" Downpipe / ECS flywheel / 4barFR / Seat intake / K&N / Forge strut
NZ '06 Golf GTI DSG, Xenon, Leather, Reverse sensor / Bluefin Stage 1

wsnownz

Quote from: polo_GTI on August 17, 2013, 05:48:04 PM
Thanks for the review. If it's at the wheels - sounds pretty reasonable to me? On a cold day like today too!

Yeah I agree. They seem to get anywhere between 120 and 130kw at the wheels.

NOWAY1

Quote from: polo_GTI on August 17, 2013, 05:48:04 PM
Thanks for the review. If it's at the wheels - sounds pretty reasonable to me? On a cold day like today too!
It was a hub dyno and a Skoda Octavia vrs (exact same engine, etc, with stock DV) pulled a 147, which is what a stock GTI should get if the Skoda got that.  I had a look at the stock DV diaphragm and there's perforations in the diaphragm it to allow a certain amount of pressure to release, which I think the DV+ lacks in its design.  My ECU was fault free, unlike the Skoda so there's nothing "wrong" with it, and it just got checked out by a mechanic last night as well so can't really do anything except point out what I was already warned about in the emails from GFB.

HaNs

We have actually seen the solenoid fail so its worth testing it when it's out of the car. Didn't throw any codes but was way down on power

polo_GTI

Quote from: Blue on August 17, 2013, 07:23:06 PM
It was a hub dyno and a Skoda Octavia vrs (exact same engine, etc, with stock DV) pulled a 147, which is what a stock GTI should get if the Skoda got that.  I had a look at the stock DV diaphragm and there's perforations in the diaphragm it to allow a certain amount of pressure to release, which I think the DV+ lacks in its design.  My ECU was fault free, unlike the Skoda so there's nothing "wrong" with it, and it just got checked out by a mechanic last night as well so can't really do anything except point out what I was already warned about in the emails from GFB.

Hub dyno will read higher than the rolling dyno on wheels - but won't read same as what's at the crank. If Skoda is producing 147kw at the hub - means it's likely tuned or the machine has an optimistic reading. So it is either your power is down (if that Skoda is truly stock), or you need to also look at the rest of Hondas and see what they were making.

The numbers look correct to me - and Skoda may have been tuned (ECU) without the owner realising it?

GFB DV+ should not make more than 5kw difference even if the ECU is not registering it correctly. What boost / PSI was the reading at the dyno?
NZ '06 Polo GTI 9n3 REVO Stage2 / H&R springs / Whiteline adjustable sway bars / EBC / SS brake lines / APR mount / Uprated bushes / Forge DV / 3" Downpipe / ECS flywheel / 4barFR / Seat intake / K&N / Forge strut
NZ '06 Golf GTI DSG, Xenon, Leather, Reverse sensor / Bluefin Stage 1

NOWAY1

Quote from: polo_GTI on August 18, 2013, 04:20:45 PM
Hub dyno will read higher than the rolling dyno on wheels - but won't read same as what's at the crank. If Skoda is producing 147kw at the hub - means it's likely tuned or the machine has an optimistic reading. So it is either your power is down (if that Skoda is truly stock), or you need to also look at the rest of Hondas and see what they were making.

The numbers look correct to me - and Skoda may have been tuned (ECU) without the owner realising it?

GFB DV+ should not make more than 5kw difference even if the ECU is not registering it correctly. What boost / PSI was the reading at the dyno?
Honestly the possibilities for my low power that day are endless. GFB have given a very likely explanation that the ecu getting reset the night before didn't give the computer time to calibrate to the additional pressure. I checked my vid of the dyno and can't make out anything on the screen but I'm planning on talking to them tomorrow to get my printout.  Another possibility is inexperience with the car. Who knows, time will tell.

For a very real review of the DV+ the throttle response is excellent and the acceleration is smooth as silk.

22

Hey mate,

Any further news/updates on the DV+?


Cheers

NOWAY1

Yup they've been working hard at solving leak issues and are sending me a new piston and spring.  Not really looking forward to another install but hoping it fixes the issue.

http://www.gfb.com.au/whats-new/latest-news/68-important-updates-to-dv-t9351