fivepint

Hi lads, the brass restrictor, is it a factory piece, i ve been experiencing surging on WOT so decided to check all hoses, noticed the cut and insert of the restrictor is very DIY is this a factory job? what effects if removed will I see/feel?

Cheers

john banks

Sounds like someone has replaced the restrictor at some point - it is brass usually with a thin indentation around the circumference half way down, and as standard a 1.2mm hole on MY99/00.

If you remove it you will reduce the boost level drastically.

fivepint

thx john, i will check the diameter, the indentation rings a bell... on a an unmoletsed car, should the pipe be cut at the restrictor or is it jus pushed into a pipe if ya get my drift???

Cheers

john banks

Should be sealed inside the pipe with no cuts whatsoever.

fivepint

thx again John...

Cheers

fivepint

Hi again, the diameter of the resrictor appears to be nearly 4mm, what kind of effect will this have, should i get another restrictor and reduce it?

Cheers

john banks

What about the orifice through the middle of it?

fivepint

Sorry john, 4mm is the diameter of the hole thru the restrictor (hmm if thats what u'd call it now ) I should have made that clearer... also any idea why some one would modify the restrictor, if u recall i had some surging probs on WOT, ive since cleaned the boost solenoid and checked all hoses relating to the turbo etc... but i havent had a cjanec to retest yet...

Cheers

john banks

It is a MY99 or 00 isn't it? Sounds like it needs a bit of a tidy up if it is?

fivepint

Hi john, its an MY00, only engine mods (AFAIK Im the 2nd owner) are samco intercooler hosing and alloy Y-piece, by tidy up, do u mean replace the hose with a new smaller restrictor in place? any idea why it has been tampered with?

thx agin for the help

Cheers

AlanG

Increasing the size of the restrictor will have an effect on what boost pressure is achieved.

For example, std restrictor in place should achieve approx 0.9/1.0 bar boost on a std car (MY99/00). No restrictor will see boost pressure reduced and/or the car will feel less responsive.

Also length of hoses and position of restrictor can have a marked affect on what boost is seen.

Best bet is to start afresh with a new restrictor and std length 4mm hoses. Especially the hose from the turbo outlet to the 'T' piece.

"Edited to say that the restrictors i've seen tend to be 0.9mm orifice, though appreciate there may be other sizes available. Unlikely to have a 4mm orifice, since the std hoses are approx 4mm ID and the restrictor has got to fit inside this. Maybe someone changed the hoses to something bigger?"

A

[Edited by AlanG - 27/05/2002 15:57:34]

fivepint

Cheers Alan, i will try and repalce it, any idea why someone would want to replace it with something bigger?

Cheers

AlanG

Can't think why, but maybe some peeps can tell us if the silicone hosing has a different bore size to std? (Assuming it's been changed?)

A

[Edited by AlanG - 27/05/2002 16:25:47]