My Forge dump valve on a MY00 UK is making stupid chirping noises!

With just the blue spring it was quite loud and the car shudders on part throttle!

Yellow spring makes everything feel worse!

I've tried the blue spring with two shims and shuddering is not as noticeable, but it's still making a silly chirping noise on gear changes or backing off on the throttle (albeit it quieter!)

Should I stick more shims in, get a red spring (and maybe some shims) or just send the fecking thing back? [img]images/smilies/mad.gif[/img]

Bearing in mind the car is MY00 with full de-cat peaking at about 1.1bar (still running the 802 ECU)

[Edited by Andy Tang - 5/2/2003 6:22:07 PM]

try the red spring m8 (ive got 1);)


mines my98 with blue spring i put the red 1 in, it, ran ok but i could c the pipe blowing up like a balloon

will swop u 2 or 3 shimes for my red spring:D U SHOULD B OK WITH A RED SPRING M8,CAN SEND U THE RED 1 TO TRY IF U WANT M8

HOPE THIS HELPS M8

[Edited by scooby-si - 5/2/2003 7:53:49 PM]

tango give us a call later on

sorry to hijack the thread, i have the same noise of my Forge V4 which has a blue spring in.forge have sent me today a set of shimms,red and yellow springs..

What are the shimms for....?

And what effect does changing the spring have, blue,red,yellow...

the stronger the force on the valve, be it with shims or a stronger rated spring, the faster it snaps shut and the harder it is to open

i have a TAS piston recirc one and its adjustible, i have set this at 18psi which seams a good balance

seams to drive through the gears a lot nicer and punchier, my standerd one was fooked and leaking

Andy, your standard TD04 turbo is quite tough and the compressor wheel should be able to tolerate a red spring. This will reduce the volume of the dump valve when it opens because it will open less. It will also open in fewer situations - really from full boost to a pretty sharp lift off. The stronger springs also reduce the chattering and on some cars juddering you get when they open-close-open-close several times from a gentle lift off. The juddering may be in part due to the pulses of air going the wrong way through the MAF sensor.

I've never got it as smooth as the OEM, but the worry is they leak, and also they drop the boost quicker between gearchanges. If only the Forge one would open and close more smoothly - it's not just mine - all of them I've seen do this.

Thanks John I think you've covered all the things I was worried about! :)

I'll give Forge a call on Tuesday to sort out a red spring! :)

Andy, ive swapped my spring today from blue to red, my dumpy is a VA but i was getting similar effects to you plus it was dumping at very low revs and was very loud.

Put the red spring in and now it seems much better, not as loud and only dumps over 3k revs. Only other difference is the wastgate makes more noise now..

My spec is MY98UK Turbo

K&N 57i Induction Kit
Forge V4 Dump Valve
Dawes Device Boost Controller set at 1.2