Remapped Cupra 1.8T owners...

[lordgibbness]

yet forges actual advice is to leave it green unless you get problems. yellow isnt needed for a remapped car. green should seal fine
how can i be running the equal to the green spring on 320bhp? anything heavier would knacker my turbo

just found this..
http://www.seatcupra.net/forums/showthread.php?t=99417&referrerid=10009

Yeah like I said a lower spring won't cause a problem but a higher one will. Yellow is designed for remap if you look at the boost levels on the forge site. Yellow will give quicker response when you lift off the throttle whereas green will be slower.

 

[Mr OCD]

Yeah like I said a lower spring won't cause a problem but a higher one will. Yellow is designed for remap if you look at the boost levels on the forge site. Yellow will give quicker response when you lift off the throttle whereas green will be slower.

If response is slower would that cause the car to jerk a little when lifting off ?

 

[traumapat]

Yeah like I said a lower spring won't cause a problem but a higher one will. Yellow is designed for remap if you look at the boost levels on the forge site. Yellow will give quicker response when you lift off the throttle whereas green will be slower.

but wont it respond slower when you put your foot down?

i know what your saying about over run on lift off. fitting a yellow spring did help, but the harder, more abrubtly the dv reacts the bigger the pressure difference against the turbo spindle and certainly on some turbos, will reduce their life span.

i would let any map settle and only change springs if it was required.

 

[traumapat]

If response is slower would that cause the car to jerk a little when lifting off ?

other way round id have thought. softer should be smoother if anything

 

[lordgibbness]

but wont it respond slower when you put your foot down?

i know what your saying about over run on lift off. fitting a yellow spring did help, but the harder, more abrubtly the dv reacts the bigger the pressure difference against the turbo spindle and certainly on some turbos, will reduce their life span.

i would let any map settle and only change springs if it was required.

You might be right but I went with what custom-code recommended and wanted it to be a more responsive drive on the throttle.

 

[JamJay]

If anything, i think the LCR runs better with a Forge & Yellow spring than the OEM Bosch valve. I bought the valve with a yellow spring in it, so i don't have a green spring at all. Am I doing damage?

 

[traumapat]

i wouldnt worry jason. im sure if you give forge a ring they`ll send you a green one if your worried. loads of lcr owners running yellow springs

chill

 

[JamJay]

Good news. Well it's off for a remap soon anyway so i'll hold out. Thanks traumapat

 

[lordgibbness]

Green spring for the stock map and yellow for a remap. If you have a green and are remapped all it will mean is that it will dump slower (not feeling so responsive to decelerate). A yellow spring on a stock map will be a little too strong for the boost and might not fully open when accelerating.

I'm going to eat humble pie here - I think I had it the wrong way round...
Looking at this diagram the dv opens to bypass the turbo.

This would mean in an extreme example, a very weak spring would always be open, bypassing the turbo; and a very strong spring would always be closed and would never bypass the turbo.

So I'd guess a green spring on high boost is more likely to bypass the turbo (boost leak), and a yellow spring on weak boost would not open causing turbo damage?

 

[Willie]

That drawing is missleading.
The DV in that drawing is set up in reverse.
The DV Dumps from the turbo compressor side into the intake rather than the other way about

 

[skahigh]

The DV in that drawing is set up in reverse.

It's not Willie, its just shown upside down.

 

[Willie]

Yup thats what I mean.
the traditional way the DV would work is opposite to the way its shown

 

[skahigh]

Yup thats what I mean.
the traditional way the DV would work is opposite to the way its shown

I don't think gravity has anything to do with it does it? Reversed would be if the spring was pointing horizontally rather than vertically.

 

[Willie]

This is getting well confusing, lol

Its all good, lets not confuse each other any more, have a nice day

 

[skahigh]

This is getting well confusing, lol

Its all good, lets not confuse each other any more, have a nice day

Haha, fair enough.

 

[lordgibbness]

A dv should be such a simple thing but somehow its not LOL

 

[skahigh]

A dv should be such a simple thing but somehow its not LOL

Its only confusing because it uses inertia to open the valve. The vac on top of the valve alone is not enough to open it. When on boost there is vac on the the top and on the bottom from the sucking of the TIP, as soon as you let off the throttle the vac from the TIP disappears but the vac on the top remains. It is the change in state that causes the valve to open for a very short space of time before the spring over powers the inertia effect and recloses the valve.

So...

A stronger spring will result in the dump valve opening for a shorter period of time when you let off the throttle. If the spring is too strong it won't open at all and the charge air has nowhere to go but back across the turbo causing the turbo to stall and giving you the chatter noise.

Does that clear things up or make it more confusing?

 

[slim20vt]

ahhhhhhhhhhhhhh im running mine with the yellow spring at 265bhp i dont notice a diffrence with yellow or green ...... but i was told yellow for remap

 

[lordgibbness]

ahhhhhhhhhhhhhh im running mine with the yellow spring at 265bhp i dont notice a diffrence with yellow or green ...... but i was told yellow for remap

That's correct according to forge's spring ratings.

 

[stewbie55]

We were having the same discussion here:

http://www.seatcupra.net/forums/showthread.php?t=215859

If I follow everything correctly then the diagram in the link in post 29 is the "preferred" way to connect the DV and in this case "any" spring will be OK.

My DV is connected opposite to this and in the OE orientation as far as I'm aware, in which case the spring is working against the boost pressure, hence a stiffer spring is required to keep the DV shut on higher boosted cars.