Does anyone know if i need a restrictor ring when i install ppp to my 02 sti. I will be using the piggyback chip.

cheers

 

You do need a differently sized restrictor with the old daughterboard PPP install. If it's not fitted you'll suffer rather unpleasant boost oscillation when 'on beans'.
From memory it's a narrower diameter than the standard restrictor but I can't remember what the exact size was (1.2mm maybe ) but I was able to get restrictors in a variety of sizes from Knowlesy at Xtreme Scoobies back in the day for about £5.
He's a really helpful guy so might still be able to hook you up with what you need.

Dealers used to be very UNhelpful when it came to suppling bits of the PPP on their own. The restrictor will be a listed part but whether or not they'll supply it is another matter. Maybe they've relaxed a bit with the passage of time....

Cheers,

Stewart.

 

just spoke to extreme scoobys and they say that i have to wait and see what it boosts to with the ppp installed and that it dosnt always overboost.
I wonder could i use a boost controller along with the ppp to control the boost a little better.

 

Fair comment - they don't always overboost/oscillate BUT
With a standard sized restrictor fitted it might not.
With a resized restrictor it definately won't.
IMHO while it's only a 3-5min job to change them, if you get the right thing from the off it's just less feckin' about once the PPP is fitted .


Probably. An MBC serves a similar purpose iirc but can't help as I never used a Dawes or similar on any of my cars. Used to be all the rage so there's probably some useful old threads on them if you search.

Cheers,

Stewart.

 

cheers Stewart, you have been a great help on a couple of my threads now. Xtreme scoobys say they cant recommend a size of restrictor until i see if the car is over boosting and at what psi/bar. Quess ill have to wait and hope,,,maybe its different for sti's and wrx's.

 

You're welcome fella.

BTW, couldn't understand why Xtreme weren't just sending you a PPP spec restrictor - have now done what I should have from the off and 'viewed your scooby' BUT actually read the car spec!!!
I was obviously blind/stupid/temporarily 'cause I utterly did not pick up on the 3" decat and non standard BOV.

So yes, you'll need to see what it's boosting too and whether it oscillates before you can (or even need to?) try resized restrictors. Chances are that with your set up, a PPP sized restrictor might not help anyway.

Happy experimenting - I'm now off to for my stupidity!!

S.