My new SLC

[Keithslippery]

Hi guys picked up a 2001 1.8t cupra last week.

Boosting is not very good on it..
Looking at engine bay it has had vacuum boost pipes changed. They dont look too good.
When it is warm they are very very soft, and it has a forge looking DV but not forge on it but looks ok and seems to do its job. Cant get vag com on it as only have free version. Would the soft pipes cause boosting problems, I will be changing them today anyway, and it seems to have the 249 bypass done...

 

[Keithslippery]

It is bogo standard slc filter tip are standard, there are in the boot three extra springs for the dv after looking on here they are red black and blue the one that is in t is yellow..

 

[Pabs]

Welcome to SCN.

How do you know the boost isn't very good... what do you mean exactly? Is it not smooth power delivery, do you think there is a lack of boost...

Check the DV is functioning properly if possible, perhaps use the forge test to make sure you can hold the plunger in place with a vacuum.

Unfortunately your best bet is to get VAG-COM to check for errors as they don't always throw a CEL, and at least will pinpoint any issues. If you've got no errors, then perhaps see if you can do some logging and check for requested vs actual boost.

The OEM hoses aren't great - if yours are aftermarket then I suspect they'll be better!

 

[Pabs]

Best do a search on here regarding Forge springs. If you've got a yellow one in it, it should be fine. Do NOT go swapping the springs unless you've read up on it. I think the standard Forge spring is green (weakest), with Red being the strongest (Not recommended for use as is too strong in most applications)

Standard TIP/hoses shouldn't cause you any noticable issues, unless it's split.

 

[Keithslippery]

hi pabs.
My brother has exactly the same car standard aswell. his oem pipes are much stronger than mine when warm my does boost but seems to struggle and hold back on the boost compared to his. You can hear the dump valve when you release the pedal it is fully recirculating. the free version of vag com brought up no errors.

 

[Keithslippery]

The red spring s def weaker than the yellow one, its not a froge one remember, you can tell by the thickness of the spring itself. red being the thinest up to black being the thickest and strongest.

 

[Keithslippery]

ok so replaced pipes with some better ones and put weaker spring in dv now seems to be boosting smooth and fine. no fault codes on vag com, but still a fair noise from turbo wooshing type but cant see or find any leaks vag com dont see any either...

 

[Pabs]

Unless you've got your head under your bonnet while you're boosting, it's very unlikely that you'll see a leak. You need to do a proper leak test, sealing the system off and then pressurising to 10psi to locate a leak. Search on SCN for more info - lots of guides/help etc on this.

VAG-COM won't see a leak either - if it's within the tolerances it'll assume all is normal. If it falls outside of those, it'll throw an error.

Unfortunately without more info on DV, or pictures, it's impossible for us to know about the springs either - you only mentioned a colour previously, which is useless info if it's different from the DV's we know about.

Hope you fix it!