aggressive dump!

[Sanj]

So My mechanic and I replaced the N75 valve, did the N249 delete, replaced the injector seals and did the catch can mod, Car feels so much better to drive now, the pick up is much more noticable, however.......

the Dump feels very aggressive now with a flutter...... almost like putting our hand over a pipe, let the pressure build up alot and then let go.... its not smooth like before.

dont get me wrong it sounds good, however is this actually how its meant to sound?

Sanj

 

[Inertiauk]

It shouldn't flutter, this seems to suggest the N75 isn't opening properly..

 

[Sanj]

It shouldn't flutter, this seems to suggest the N75 isn't opening properly..

Thanks, faulty valve maybe? I might try putting the old one back and see what happens.

 

[s3dave]

Make sure the ends on the n75 have not been squashed with the clamps...

 

[badger5]

why would n75 effect direct plumbed DV? (it is direct now? N249 deleted?)

If you have aboost gauge is your boost level the same or higher? (does it feel quicker, more torquey)

n75 plumbed wrong could give you uber boost (in a dangerous to engine kind of way)
N75 boost feed is into middle pipe, long pipe to TIP and the other goes to turbo..

 

[superkarl]

N75 not opening properly? Eh? It's just a solenoid that opens the wastegate, so what does it have to do with flutter.

Increased dump noise would be pretty normal, don't forget in deleting the n249 you've got rid of a lot of hoses and crap between the dump valve and mani, so its alot more direct, more reliable and more responsive, you may also have had a leak amongst the n249 pipe/box work.

As for flutter, this can either be put down. to compressor stall (maybe an over stiff dv spring, unlikely tho as you havnt changed springs) or just the sound of the dump valve. due to how much boost you are running. It's a tricky one tho, no one seems to have proven tht mistery yet.

 

[Inertiauk]

why would n75 effect direct plumbed DV? (it is direct now? N249 deleted?)

If you have aboost gauge is your boost level the same or higher? (does it feel quicker, more torquey)

n75 plumbed wrong could give you uber boost (in a dangerous to engine kind of way)
N75 boost feed is into middle pipe, long pipe to TIP and the other goes to turbo..

Oh yes, I pretty much wasn't awake when I read this and mixed up N75 and 710N so I should have written.... 'It shouldn't flutter, this seems to suggest the 710N (or whatever DV in place) isn't opening properly..'

When I read OP and read N75 my head converted it to DV, so I thought that's what they changed.

Need to not post when i'm up late. Sorry Sanj.

Worth checking your DV is operating as it should ... http://www.vaglinks.com/Docs/Misc/VAGLinks.com_DIY_Testing_a_Bosch_Diverter_Valve.pdf

 

[Sandip]

My car had never fluttered but ever since i changed my vac lines from dv to manifold and fpr to manifold i have had flutter. Also tried 2 DV's and made no difference

On full boost i get the normal tssssh but pottering around i get flutter, superkarl heard mine. It's a mystery to me on why it started in the first place

 

[Sanj]

why would n75 effect direct plumbed DV? (it is direct now? N249 deleted?)

If you have aboost gauge is your boost level the same or higher? (does it feel quicker, more torquey)

n75 plumbed wrong could give you uber boost (in a dangerous to engine kind of way)
N75 boost feed is into middle pipe, long pipe to TIP and the other goes to turbo..

Yep Bill its direct now, N249 deleted, unfortunately I only just got the Torque app working again, so couldnt tell what sort of boost i was running, I am going to be playing around with the app this weekend and will do some tests, but it def feels much more torquey, more reponsive.

Ok will check the N75 tonite if i get home early, cheers.

N75 not opening properly? Eh? It's just a solenoid that opens the wastegate, so what does it have to do with flutter.

Increased dump noise would be pretty normal, don't forget in deleting the n249 you've got rid of a lot of hoses and crap between the dump valve and mani, so its alot more direct, more reliable and more responsive, you may also have had a leak amongst the n249 pipe/box work.

As for flutter, this can either be put down. to compressor stall (maybe an over stiff dv spring, unlikely tho as you havnt changed springs) or just the sound of the dump valve. due to how much boost you are running. It's a tricky one tho, no one seems to have proven tht mistery yet.

Yeh, i need to get the car smoke tested again for any leaks so thats on the list. Hmmmm interesting, I have a yellow spring on the way, so will service the valve and test against it.

Oh yes, I pretty much wasn't awake when I read this and mixed up N75 and 710N so I should have written.... 'It shouldn't flutter, this seems to suggest the 710N (or whatever DV in place) isn't opening properly..'

When I read OP and read N75 my head converted it to DV, so I thought that's what they changed.

Need to not post when i'm up late. Sorry Sanj.

Worth checking your DV is operating as it should ... http://www.vaglinks.com/Docs/Misc/VAGLinks.com_DIY_Testing_a_Bosch_Diverter_Valve.pdf

Hahaha I know what you mean, no worries mate, thanks for the link.

My car had never fluttered but ever since i changed my vac lines from dv to manifold and fpr to manifold i have had flutter. Also tried 2 DV's and made no difference

On full boost i get the normal tssssh but pottering around i get flutter, superkarl heard mine. It's a mystery to me on why it started in the first place

Cheers Sandip, yeh its very strange, just dont want it to have any adverse effects!

 

[LiveWire]

My car had never fluttered but ever since i changed my vac lines from dv to manifold and fpr to manifold i have had flutter. Also tried 2 DV's and made no difference

On full boost i get the normal tssssh but pottering around i get flutter, superkarl heard mine. It's a mystery to me on why it started in the first place

I also never had any flutter before I did the N249 delete, but as soon as I did the flutter appeared.

But I get a slight flutter whilst changing gear on full boost, dont get any flutter at all when pottering around!! (other way round to what you get)

 

[Sandip]

I also never had any flutter before I did the N249 delete, but as soon as I did the flutter appeared.

But I get a slight flutter whilst changing gear on full boost, dont get any flutter at all when pottering around!! (other way round to what you get)

I bypassed the N249 a few years ago and the flutter is a recent noise after changing the vac lines lol

It is a strange one,i've tried to cure it by changing the dv but still the same so i'm just going to keep driving it and enjoy it.....if i do cure it in the near future then i'll definitely tell everyone lol

 

[Inertiauk]

Which DV do you run Sanj and Sandip ?

710N or 007p (which spring) ? or something else ?

 

[Sanj]

Which DV do you run Sanj and Sandip ?

710N or 007p (which spring) ? or something else ?

Im running a 007p with a green spring at the moment, I've just ordered the yellow spring, although i dont know what PSI im running at the moment, should find out on the weekend.