Boost and less boost

[scotta]

Question!

Car - 2008 Ed 30 manual with 17k on it.

Sometimes when i give the car a bit bean its quick and pulls really hard and other times it doesnt feel as quick. It seems to do the same if you go for a gear change - ie pulls hard then change gear then not so much pull as if its waiting for boost. Had it serviced couple of weeks ago and they checked for fault codes in the ECU but there was nothing.

I was thinking possibly a dump valve issue?

any other thoughts?

[joesgti]

what mods do you have? have you taken off your DV in the past?

I had a similar problem but ive got a boost gauge so i know when the slightest thing goes wrong. Mine was only boosting to 10 psi then let off the accelarator, then plant it again and im back at 22psi.

I found out my DV was mounted the complete wrong way by awesome  

So if you have had you DV off then thats the first place to check!  

[scotta]

car is totally standard - as far as i know!

[Aparoon]

Still check the dv, its right at the front of the engine bay so it's really easy to get off and check for any tears 

[john_o]

delivery can be variable , even on a working properly std car 
however only within a relatively small margin (few psi)
dont suppose you put normal unleaded in recently?

anyways, just to be sure , find a local person with VCDS , and get some logging done on boost/fuel etc
That will tell you if its doing what it should

DV , PCV etc can all cause boost issues btw

one of the main reasons I would recomend fitment of a boost gauge works well and continuosly tells you how the cars getting on.

[scotta]

delivery can be variable , even on a working properly std car 
however only within a relatively small margin (few psi)
dont suppose you put normal unleaded in recently?

anyways, just to be sure , find a local person with VCDS , and get some logging done on boost/fuel etc
That will tell you if its doing what it should

DV , PCV etc can all cause boost issues btw

one of the main reasons I would recomend fitment of a boost gauge works well and continuosly tells you how the cars getting on.

Its been run on V-Power since i got it last year.

Was thinking about replacing the DV with one of the new piston types anyway and installing a panel filter

[FamilyDub]

Unless you're remapped (or planning to remap), the OEM revision 'D'  DV is good enough. It's £47ish - part 06H 145 710 D.

Or a pukka forge motorsport version...
 

[john_o]

without knowing that the DV is your issue , you may be compounding the error tbh. (by adding another variable)
work out whats wrong then fix or improve that.
VW valve thats currently used is sufficient , and I'm not a big forge DV fan tbh.

dont even think about further mods until this is resolved 

[scotta]

Unless you're remapped (or planning to remap), the OEM revision 'D'  DV is good enough. It's £47ish - part 06H 145 710 D.

Or a pukka forge motorsport version...
 

Thats the one (The OEM one) i was thinking about mate 

[WhiteGTI]

Question!

Car - 2008 Ed 30 manual with 17k on it.

Sometimes when i give the car a bit bean its quick and pulls really hard and other times it doesnt feel as quick. It seems to do the same if you go for a gear change - ie pulls hard then change gear then not so much pull as if its waiting for boost. Had it serviced couple of weeks ago and they checked for fault codes in the ECU but there was nothing.

I was thinking possibly a dump valve issue?

any other thoughts?

Right, this might be the reason it might not, but judging from your symtoms it sounds exact to how my car behaves...and I know for a fact that my DV (forge item) is fine.

Turn off your ESP (obviously only where it is safe to do so), then drive it as you describe. You should notice that the car does not hesitate.

The ESP system seems to restrict the car - particularly after a fast gear change under hard acceleration, and the ESP light does not flash to alert the driver that its working. It seems to work in the background. I found that as soon as I turned it off, the car would perform as requested. (this was done on the same road, 1 minute apart, same road conditions etc).

Try it, you may be surprised!

[scotta]

Question!

Car - 2008 Ed 30 manual with 17k on it.

Sometimes when i give the car a bit bean its quick and pulls really hard and other times it doesnt feel as quick. It seems to do the same if you go for a gear change - ie pulls hard then change gear then not so much pull as if its waiting for boost. Had it serviced couple of weeks ago and they checked for fault codes in the ECU but there was nothing.

I was thinking possibly a dump valve issue?

any other thoughts?

Right, this might be the reason it might not, but judging from your symtoms it sounds exact to how my car behaves...and I know for a fact that my DV (forge item) is fine.

Turn off your ESP (obviously only where it is safe to do so), then drive it as you describe. You should notice that the car does not hesitate.

The ESP system seems to restrict the car - particularly after a fast gear change under hard acceleration, and the ESP light does not flash to alert the driver that its working. It seems to work in the background. I found that as soon as I turned it off, the car would perform as requested. (this was done on the same road, 1 minute apart, same road conditions etc).

Try it, you may be surprised!

Tried this the other night up slight  hill.

2nd planted - bit wheelspin then it gripped and pulled hard till the redline
fast change to third back on full power pulling still but not as hard till redline
fast change to fourth boost seemed to come back and pull harder again.

When i say fast change i mean  power off, clutch in, shift, then clutch out and power back on - not a full bore hard shift

[john_o]

can happen, when it next 'doesnt pull as hard' try going on and off the throttle again, bet it goes quicker then..

[cmdrfire]

This sounds suspiciously like what's going on with my car. But I haven't investigated it yet, for various annoying reasons.