Forge DV Spring?

[ian_jemo]

Hi all

Just been reading up about the different springs you can get with the forge DV. Which are designed for how much presure your car makes.

What colour spring should you use for the S2. I just wanted to check as mine doesn't seem to make much of a sound at all. The spring in mine is blue but don't know where to find out which one is recommended.

Thanks

Ian

[Jon441cc]

The blur spring is rated for 23-30 psi

[ian_jemo]

Thanks

What PSI does a standard S2 run at?

[Jamo]

You should be using the green spring in a standard or chipped S2.

[ian_jemo]

Cheers jamo you'r a star.

How much will the spring cost, I presume I can order it from forge and I take it you can just order a spring

[Jamo]

http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=0007&product=FMDVSU110

[Jamo]

Hi all

Just been reading up about the different springs you can get with the forge DV. Which are designed for how much presure your car makes.

What colour spring should you use for the S2. I just wanted to check as mine doesn't seem to make much of a sound at all. The spring in mine is blue but don't know where to find out which one is recommended.

Thanks

Ian

Also you DV wont make a sound if it's the recirc type unless your using a to atmosphere version?

[ian_jemo]

Cheers again.

No wonder the DV didn't sound right.

Thanks

[Efini]

So could this be the reason for my strange DV fluttering I wonder, because when I opened it up today I found a green spring (0.3-1bars).
I'm currently running 1.7bars so I'm now off to try the blue spring.

[A80Avant]

im running on 1.5-1.6 bars and use the blue spring.am i doing the right thing?

[Matt_D]

Just a quick calcualtion:

Green - 5 - 15 PSI or 0.34 - 1 Bar

Yellow - 15 - 23 PSI or 1 - 1.58 Bar

Blue - 23 - 30 PSI or 1.58 - 2 Bar

Red - 30 + PSI or 2+ Bar

I have the yellow spring running at 18psi/1.2 Bar

PapVas you are right between the two spring rates.
Does your car peak at 1.5-1.6 Bar or does it hold boost at that level ?
Might be worth emailing Forge direct.

[A80Avant]

my car peaks at 1.5-1.6 and then gradually drops to 1.2 i think
i may be having a boost leak though due to a test i did recently,although the car seems to be running beautifully though!

does anyone know the mtm chip what bar does it doe besides 1.5-1.6 overboost?

[Jamo]

You don't want the same rate spring for boost being generated.
I wouldn't have above a green or yellow. IIRC Blue caused surging.

[A80Avant]

jamo,you mean for the S2 or the RS2?can you explain this?

[Jamo]

If the pressure rating of the spring is the same as the boost being generated in the system then the DV won't be pushed opened by the air.

The spring should be weaker than max boost so that it can be pushed open. Too weak a spring and it will creep open on boost generated by the turbo. Too strong a spring and the DV will not open leaving trapped air in the system which can cause turbo stall.

Dump valves are fitted to the engines of turbo charged cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia, the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to inlet of the turbo.