Restrictor ring size

[markybhoy86]

Going BPU now, i have a j-spec 1993 TT, what size is the restrictor ring? im fitting a boostlogic exhaust system which is 4" connection so i will be going from 3" onto a 4"- if that makes any difference.

 

cheers

M

[ShamelessTT]

52mm RR = 1.2bar (BPU). Im using a Blitz Nur Spec RX, which is just over 3.1 inche pipe work, so you maybe need to reduce this a couple of mm.

 

Id go for about 50mm then widen IF needed, its really trial and error mate. However you can just raise your boost on your controller if your RR is too small.

 

Si

[jamesmark]

As above, I would rather have the RR small and raise the boost via a boost controller.

[mikeyb10supra]

either way, its a very crude method to control boost...there is no two ways about it. Its really hit and miss. I would suggest fitting a smaller one and playing about with a boost controller....or leaving the 1st or 2nd cat in

[Scott]

I wouldn't advise leaving the 1st cat in as that would cause excess heat.

 

Get a 50mm restrictor ring and up the boost with a controller as suggested, its the best way for the j-specs.

[jamesmark]

or leaving the 1st or 2nd cat in

 

That is the crudest way of doing it imho, and as Scott has said the build up in heat will not do any good.

[Bossco]

50mm seems very small. There are loads of threads on here which say 56mm is around 1.2 bar. I have a 56mm fitted and I get just under 1.1.

 

I might try a 60mm and see where that goes

[Scott]

50mm seems very small. There are loads of threads on here which say 56mm is around 1.2 bar. I have a 56mm fitted and I get just under 1.1.

 

I might try a 60mm and see where that goes

 

That all depends on the exhaust though. My exhaust is quite restrictive (possibly because of the turbine stuck in it) and i only get 0.9bar with a 1.2 restrictor ring in.

 

Can't be sure on the size though. I would go with whatever one averages 1.0bar and take it from there.

[markybhoy86]

right so go 50mm then up the boost using my boost controller ? that whats you recomment ?

 

M

[Scott]

Yup

[mikeyb10supra]

That is the crudest way of doing it imho, and as Scott has said the build up in heat will not do any good.

 

Mine has been fine for 4 years of hard driving and sits at 1.1bar perfectly. restrictor rings are a pain in my opinion, difficult to size without the car overboosting through the colder months and not going to get you through an mot without a battle. And a restrictor is doing essentially what the cat does...cause a restriction so there both going to cause heat build up in a sense