Could someone help to clear in my mind how the feckin restrictor works, it's stoping me sleeping

I have a Classic MY95 series Mcrae, it has the 3 pot solenoid as shown below (Thanks to Mr Power for pic )


The restrictor is located in the vent tube from the solenoid to the air box, i've heard many people talk about opening up the restrictor if the car is modified (de-cat or ecu) to stop overboost, but i cant work out the reason, a bigger hole means the actuator will vent quicker and hence rise boost quicker and i would have thought give more overboost/fuel cut problems??

Or are the early classics different? I would have thought reducing the hole size would give you a smoother delivery and more controllable boost on a modified scooby.

But then i could have this all completely wrong, someone please help a newbie scooby owner rest.

Cheers.

 

hi all, Just wondering if anyone has answer to this as i have a boost problem which could be related to the restrictor.

thanks

 

Hi mate,when i first bought my scooby (MY94 STI) it was fitted with a dual blitz boost controller but without the electronic gizmo, so i had to reconnect the boost pipes back to the 3-port solenoid although the restrictor you mention has been removed on mine and it was boosting to 1.2bar with no fuel cut-running on optimax (not sure if early STI's do that?) but since the hemel fire ive had to use tesco 99 but ive been hitting fuel cut at 1.3bar peaking at 1.5bar and resulting in my gearbox going BANG .

So ive purchased a dawes device to limit my boost to a healthly 1.1 bar which i'll fit after my expensive gearbox re-build.

Hope that sheds some light mate!

 

and resulting in my gearbox going BANG .

So ive purchased a dawes device to limit my boost to a healthly 1.1 bar which i'll fit after my expensive gearbox re-build.

sorry to hear that m8

how much for the rebuilt gearbox? just out of interest

 

sorry to hear that m8

how much for the rebuilt gearbox? just out of interest[/quote]

It's gunna cost about £800+vat that includes a new 3rd and 4th gear ratio although the company did say jap boxes (mainly 2nd and 3rd) arnt very strong so there going to fit a uk spec 3rd and 4th!

Look after your box mate!