Post by: pudding on December 15, 2017, 11:41:05 am
I just wanted to alert you to a design flaw I've discovered with the GFB DV+. Please check yours next time you service it. Gently pick at the edges of the orange silicon pad to feel if it's separating from the brass piston. Don't go at it full gorilla, just give it gentle probing. Everyone loves a good probing, right?
For reference, mine was bought in 2014 and is genuine, and the pad has come away from the piston completely in 2 places. I think it's a vulcanizing problem and could do with improving. I have alerted GFB Australia. You may or may not care, just thought I'd mention it because if that pad comes off completely and finds it's way into Mr Turbo's throat, I don't think he will like that very much.
(https://farm5.staticflickr.com/4541/39053776531_94343fbb5a_b.jpg)
Post by: 19TW80 on December 15, 2017, 12:04:03 pm
Post by: lukemk5gti on December 15, 2017, 02:05:27 pm
Their sh*t response to your query is disappointing though.
They should sell the brass piston as a replacement part but then that goes away from their "fit and forget".
Did you go back to Rev D or G?
Post by: Octoparrot on December 15, 2017, 03:34:17 pm
Post by: pudding on December 15, 2017, 03:49:30 pm
It doesn't affect the sealing under boost, but when you back off the gas and it dumps the waste boost, the turbulent air pressure is eventually going to rip the pad off completely. Well, it did on mine...in 2 places. At stage 2+ tuning, that's 25+psi of pressure we're talking about. On a KO4 engine, that pressure will push the separated along the dump pipe until it eventually find it's way into the turbo.
I have a revision G in it at the moment and the throttle response is a bit lazier as a consequence!
I thing I did notice is the surface the silicon pad is bonded to is completely smooth. Surely some kind of knurled surface is better for adhesion?
I should add I have not cleaned mine with any harsh chemicals, just a dry cloth. But regardless of that, a properly bonded component should come away like that in the first place.
Post by: ghuk on December 15, 2017, 05:11:05 pm
Thanks for the heads up. I had a GFB Diverter Valve+ fitted by AMD Tuning just over a year ago as the OEM part was shot. Therefore will get my garage in Leighton Buzzard to check it every service.
Can you keep us updated with any response? Maybe a bit of pressure on social media from a few of us might do the trick if it's stone walled.
Crikey, the last thing I need is that part failing and causing futher 'issues'. I've spent over £3k so far in 2 years of ownership getting my car up to scratch.... :slap:
Post by: pudding on December 15, 2017, 05:56:30 pm
Besides the silicon pad thing, I didn't find it to be fit and forget. Occasionally the piston would start binding, causing part throttle surging. I had to strip it down, clean it and reoil it and then it was good again. Had to do that every 6 months or so, or when I could feel the part throttle getting funny on me.
Post by: MIJ_JAGGER on December 15, 2017, 06:05:00 pm
appreciatedOr are you just "trolling" again
Post by: ghuk on December 15, 2017, 06:24:03 pm
Will do! I hope this hasn't come across too dramatic and alarmist. If it's happened to me, it's sure to happen to someone else...unless I am the unluckiest man in the world and got the one and only dud :grin:
Besides the silicon pad thing, I didn't find it to be fit and forget. Occasionally the piston would start binding, causing part throttle surging. I had to strip it down, clean it and reoil it and then it was good again. Had to do that every 6 months or so, or when I could feel the part throttle getting funny on me.
Very interesting that you mention this Pudding as I've had the same impression with mine on a couple of occasions, almost like the piston was sticking. Hmm.........
I'm not technically minded but potentially can you not re-attach the silicon strip with some sort of bonding agent? Just a thought....
Post by: AJP on December 15, 2017, 08:57:21 pm
I don't have any experience of the GFB valve myself - it's one of those things nearer the bottom of the never ending list for me. Probably because I've had no problems running a rev G at decent boost levels for a while now. I've never found it lacking in terms of boost response, so it's probably a case of 'if it ain't broken...' in my case.
That said, there are loads on here running the GFB. And undoubtedly loads thinking it is that fit and forget part we're led to believe. Hopefully if there is a design flaw that's affected all the valves it's something that can be acknowledged and resolved by GFB.
Keep us updated mate.
Post by: jhook661 on December 15, 2017, 09:06:22 pm
I'm not convinced by these I've had 3 now and they've made the car feel different....
Post by: r5gtt on December 16, 2017, 12:43:48 am
Post by: pudding on December 18, 2017, 10:32:57 am
The last couple of checks the bond had let go very slightly, but it didn't concern me at the time. The last check and what prompted this thread, the separation had spread drastically. Once that much air pressure gets under the slightest lift in the bond, well, we all know what tornados do to roofs!
Brett from GFB ('Go fast Brett' on youtube) came back to me and was extremely pleasant and civil about it. He said they improved their tooling and bonding process in 2014 and suggested mine was an older model that pre-dated the improvements. Mine is the only failure he's seen out in the field but alluded to it happening in testing prior to the 2014> changes. I wasn't seeking compensation or to kick up a big stink about it, merely to pass on some customer feedback and he was grateful for that :smiley:
Anyway, that mega glue I used in my other thread seems to have done the trick, but please do check yours chaps when you get the opportunity.
As for the performance of the DV+, since switching to Revo 2+, I can't say I notice any improvement with the Revo Intake. Perhaps a very slight sharpening of the throttle response.
When I had a custom map with the factory air box, that's when I really noticed the DV+. It was way more responsive than the OEM diverter valves. I don't understand why, but it just worked the best. The DV+ does seem to cause some part throttle surging/shunting at urban speeds with very light throttle. I think that's because the OEM valve is very keen to dump ALL of the air when coming off the throttle, whereas the DV+ keeps some pressure in the manifold, which I guess some ECU tunes don't account for? Not sure.
Post by: r5gtt on December 18, 2017, 01:25:18 pm
Will get GFB out for checking and whilst there I'll pop the Rev D in and drive it around for a while to see how that area up with boost as I've never had a normal working dv in mine since my original was torn and losing mega boost. :happy2:
Also didn't think these GFB were fault proof as that rubber diaphragm was always going to come off at some point!.
Post by: pudding on December 18, 2017, 01:39:25 pm
Post by: Bernhard30 on December 19, 2017, 11:03:42 pm
Recently fitted a GFB DV+..only just bought it from AKS so I guess it's the later version.
This was put in to replace a split diaphragm on my old version which was looked to be causing a check engine light. From memory the fault code PO277..'running too lean at idle'.
Bit of a strange question but does the DV+ work just like a standard DV and so would not prompt a CEL on the dashboard. As even with DV+ in use..the car lasted only about 20 miles before the engine light came on again..so the fault still exists..but wanted to check.
Feels a bit like a boost leak/air leak perhaps ..but just wanted to check from those with DV+ experience.
Cheers
Post by: Dan_FR on December 20, 2017, 07:59:32 am
You can occasionally get the code for a mechanical fault with the valve due to the way the DV+ works, but it would not put the EML on
Sounds like you still have a leak somewhere, as a fault DV wouldn't cause that error anyway.
http://wiki.ross-tech.com/wiki/index.php/18619/P2187/008583
Post by: lukemk5gti on December 20, 2017, 10:15:30 am
Hi guys,
Recently fitted a GFB DV+..only just bought it from AKS so I guess it's the later version.
This was put in to replace a split diaphragm on my old version which was looked to be causing a check engine light. From memory the fault code PO277..'running too lean at idle'.
Bit of a strange question but does the DV+ work just like a standard DV and so would not prompt a CEL on the dashboard. As even with DV+ in use..the car lasted only about 20 miles before the engine light came on again..so the fault still exists..but wanted to check.
Feels a bit like a boost leak/air leak perhaps ..but just wanted to check from those with DV+ experience.
Cheers
Split in your turbo house around the connection point is my first guess
Post by: r5gtt on December 20, 2017, 06:11:15 pm
No worries mate! Having a decent DV makes a big difference in these engines!It definitely does mate :happy2:
Post by: Bernhard30 on December 20, 2017, 06:26:28 pm
Hi guys,
Recently fitted a GFB DV+..only just bought it from AKS so I guess it's the later version.
This was put in to replace a split diaphragm on my old version which was looked to be causing a check engine light. From memory the fault code PO277..'running too lean at idle'.
Bit of a strange question but does the DV+ work just like a standard DV and so would not prompt a CEL on the dashboard. As even with DV+ in use..the car lasted only about 20 miles before the engine light came on again..so the fault still exists..but wanted to check.
Feels a bit like a boost leak/air leak perhaps ..but just wanted to check from those with DV+ experience.
Cheers
Split in your turbo house around the connection point is my first guess
Thanks guys. Will check it.
Correction to my earlier question..my fault code was/is P2177.