New Diaphragm BPV announced

[Nige_RS4]

Spotted these on AW last week ..... http://forums.audiworld.com/s4/msgs/2650852.phtml

If anyone is about to bite the bullet for Forge piston jobbies, maybe you will consider these instead and let the forum know how you get on?

Direct link to APR site .... http://www.goapr.com/VW/products/r1.html

[MarkB]

Interesting. Be good to see how these fair after a few miles on the road

[S4TAN]

Way ahead of you - ordered a pair last friday - they'll be delivered tomorrow .... (and fitted about 15 mins later)

[ZeroK66]

Thinking I popped a DV at or before Santa POD so plan on getting some new ones. Where you order yours from S4TAN?

[S4TAN]

Where you order yours from S4TAN?

Awesome GTI have 10 in stock ... well 8 now after i ordered 2 of them £85 each (excl VAT) ...

[GrahamS4]

Way ahead of you - ordered a pair last friday - they'll be delivered tomorrow .... (and fitted about 15 mins later)

[S4TAN]

I'm a marketing mans dream! Seriously though; i've read a lot recently about the pros and cons of piston DVs and diaghragm DVs ... i've got some HyperBoost HX DVs fitted currently, but they need servicing reasonably regularly as i've found the lubricating grease dries out relatively quickly (they get louder the drier they become) and this can cause the pistons to stick .... and perish the O-ring seals (which can cause leaks)

So i read up on these new APR DVs and liked the sound of 'em ... the rest, as they say, is history ...

I'll let you know what i think of them ...

[Dippy]

I'll be waiting for the report then. I couldn't see any reference to spring tension in the APR ad. One thing I have found is that "one spring fits all" is simply not true.

[S4TAN]

I couldn't see any reference to spring tension in the APR ad

Likewise - but I blithely went ahead and bought 'em anyway! Received them this morning - the spring pressure is at least equivalent to the 710Ns, but the DV itself is quite a bit larger ... I must say they look very well made (for what that's worth) ... will try to fit them later today but woke up with the "Mother of all Colds" this morning and am not too inclined to stand in my garage fitting them ...

Will take some snaps when fitted to give an idea of size etc ...

[S4TAN]

Ok - fitted now. Been out for a good old thrash - the valves are very good indeed on first impressions; really quiet and "seem" very fast (according to the feel of the car on gear shifts and how quick my boost gauge needle moves from boost to vac and back to boost again)

Loads quieter than the HX's that the APRs replaced - and a lot smoother in operation (no 'thump' that i used to get with the HX's when they closed)

Not seeing any loss of boost on the gauge - and the vac reading is the same as before.

So; overall - very pleased (so far)

[DavidT]

Great, can you try them against 710N's now please Julian ?

[S4TAN]

can you try them against 710N's now please

Will do - but i'll leave the new ones in for a week or so to get used to the 'feel' of them - then i'll try the 710Ns to see if there's any noticable difference.

[DavidT]

can you try them against 710N's now please

Will do - but i'll leave the new ones in for a week or so to get used to the 'feel' of them - then i'll try the 710Ns to see if there's any noticable difference.

That would be super, thank you.

Do you have VAG-COM now ? I 'think' you would be able to see differences in logs ? - someone correct me if I'm wrong.

[S4TAN]

Do you have VAG-COM now ?

No - I'm a luddite ...

[Nige_RS4]

Do you have VAG-COM now ? I 'think' you would be able to see differences in logs ? - someone correct me if I'm wrong.

You are wrong! (2-2)

Well, I imagine that under lab conditions maybe, but real world it would be harder to measure the difference in response times (unless your original ones are faulty), especially as the difference between the best and worst BPV's is measured in milliseconds and it takes most of us ham-fisted drivers 0.5 seconds to change gear, so unless we can keep the gear change times constant, the response of the BPV's will change marginally.

It could be used to measure whether it holds boost, but even the faithful 710N seems to hold 1.5bar with ease.

I think we'll have to rely on individual feedback based on ASDA (@rse sensitivity dyno analysis)