New boost issues - when letting OFF the gas...?

[Pabs]

thanks mate - thats quite good I'm assuming thats a standing start?

Does anyone else get the same as gaz? Or do they get same readings from idle and off-boost?

 

[Pabs]

thats the same as mine.

so you get a STRONGER vacuum when changing gear than you do on idle?

Should they all do that?

 

[traumapat]

so you get a STRONGER vacuum when changing gear than you do on idle?

Should they all do that?

when cold mine wont go to full neg vac ... stops a little short. once warm... it flys back to full neg vac. havnt noticed at idle once warm...

ive pm`d you mate

 

[cordobabrendy]

dont read so much into vacuum when on the move, boost is the only one you need to worry about.
when driving along and you take your foot off the gas it should drop straight to around -24 and at idle stationary it can be anywhere around -20 to -26 if you have aircon etc.

 

[Pabs]

thanks brendy - thats confirmed what i needed to know.

I have a feeling my forge dv might be to blame.
When you do the DV test, should the piston drop AT ALL? Mine drops very slightly, but i assume this is normal as the vac seals with my finger over the top.

 

[cordobabrendy]

yea it will drop as your finger and spring arnt solid metal, there will be 2-4mm play, as lng as the vacuum is preserved for a couple of seconds its fine.

 

[traumapat]

yea it will drop as your finger and spring arnt solid metal, there will be 2-4mm play, as lng as the vacuum is preserved for a couple of seconds its fine.

yep mine drops 4mm but holds fast

 

[Pabs]

hmmm so probably not my dv then. can't see what else would be wrong with it tbh.

I just REALLY can't understand why i get the chatter noise - i have your spare n75 installed now brendy (bought it from you ages ago) , so thats already been changed...

Is n249 cheap to replace, do ya know? Don't know what other options i have if bypass makes things worse...

 

[traumapat]

wouldnt be a pipe collapsing would it? sides sucking together? i guess that would increase the vac?

 

[Pabs]

i'd have thought i'd get less boost if that was the case, or a STRONGER vac... but from what i can see i get a weak vac, which then leads to the "chatter" dv noise.

Hoping that bypassing the n249 creates a stronger vac... can't see that happening tho!

I'm gonna need to get to a meet with someone knowledgeable and take em out in my car... get their opinions.

 

[traumapat]

i'd have thought i'd get less boost if that was the case, or a STRONGER vac... but from what i can see i get a weak vac, which then leads to the "chatter" dv noise.

Hoping that bypassing the n249 creates a stronger vac... can't see that happening tho!

I'm gonna need to get to a meet with someone knowledgeable and take em out in my car... get their opinions.

keep us informed

 

[Pabs]

well the hose i have is some red stuff that forge gave me for my dv relocation kit a while back, so i assume its good enough to do the job. Seems quite a lot smaller than the OEM hose..

 

[cordobabrendy]

what about your wastegate, maybe its your turbo thats fluttering?
im having a slightly different problem at the moment, im getting a whirring/turbo spin up noise at around -10 vac then as you accelerate it goes away but im peaking around 10 psi in first and 15 in the rest with a high pitched noise very supercharger like, it might be a leak around the manifold so im going to be otherwise engaged tomorrow!
im going to need to do some logging with vagcom to see how my n75 is faring as it may need replacing too.

 

[Pabs]

oh, let me know how u get on mate. There must be a way to repair these valves? Can't be much to em can there?

I don't understand why these cars aint all the same? Ie n249 bypass work for everyone and not just some...

 

[cordobabrendy]

my n249 looks different to most others, its only a small air reservoir, no switch etc, strange.

 

[Pabs]

surely we don't peak at 20psi in each gear tho? I tend to get higher readings in higher gears.... but i think i get higher than 10psi in 1st...

 

[Pabs]

my n249 looks different to most others, its only a small air reservoir, no switch etc, strange.

eh? really?
The n249 is in front of the manifold isnt it, under the plastic shroud thing. And the reservoir is above the far right coilpack...

Surely if u have different h/w and these are the issue then you'd have had this problem since remap?

 

[cordobabrendy]

i get around 12 in first about 16 is second then full tit 20 ps in the rest though i derperately need to get hold of an sps3 as i think my timing is too advanced vagcom was showing 6-8cf's.

 

[cordobabrendy]

eh? really?
The n249 is in front of the manifold isnt it, under the plastic shroud thing. And the reservoir is above the far right coilpack...

Surely if u have different h/w and these are the issue then you'd have had this problem since remap?

im going to take a pic tomorrow and post it for comparison.

 

[Pabs]

so timing could be the issue?

I've reset my ecu by disconnecting battery, and AFAIK that also reset the revo settings to bog std, ie t6b6.... and i still have issues.

I think i get the same as you RE boost mate.. and currently running t7b6.