A newbie-ish question about BPU - Restrictor Ring and Boost Controller

[Sheefa]

OK guys,

 

Just need this cleared up really. I understand the need for a RR on a J-spec if going BPU etc. I think I have a 1.2bar one fitted. I understand this stops over-boost and is simply a metal drilled disk inbetween the Decat pipes.

 

What I don't understand is how using a Boost Controller actually enables you to raise the boost say beyond 1.2 bar. Surely the RR is still restricting the boost down to the safe 1.2 limit, so how can the BC help up this past the set diameter of the ring?

 

It seems like it's a case of trying to get a larger 4 litre bottle of cola through a hole the size cut to fit a 3 litre one!

 

Thanks,

 

Greg

[Ric]

The boost controller can raise it,

 

All a RR is to stop the normal boost creeping away over 1.2 bar via a restriction of exhaust gases, you would see an increase in egt's if using a boost controller to up the boost past that

 

all the a boost controller does is force the turbos to run at whatever pressure you have set by changing the vacumes to the acutatiors or wastegates, not sure which. so they open or close later than they should

[Gee]

I have a similar question. I have just fully decatted my J spec TT and already have a Blitz NUR Spec R exhaust. I am only seeing 12/13psi with this fitted along with a 1.2bar RR.

 

Am I better to remove the RR and see how the boost reacts or will I keep it fitted and just raise the boost using a boost controller?

[Nic]

I have a similar question. I have just fully decatted my J spec TT and already have a Blitz NUR Spec R exhaust. I am only seeing 12/13psi with this fitted along with a 1.2bar RR.

 

Am I better to remove the RR and see how the boost reacts or will I keep it fitted and just raise the boost using a boost controller?

 

A restrictor ring will not give a specific boost reading, it is a bit of trial and error to get the correct diameter hole.

 

Try opening up the hole in RR so there is less restriction.

 

This is assuming you don't have a boost leak somewhere, which I woudl check first.

[wez_p]

I have a similar question. I have just fully decatted my J spec TT and already have a Blitz NUR Spec R exhaust. I am only seeing 12/13psi with this fitted along with a 1.2bar RR.

 

Am I better to remove the RR and see how the boost reacts or will I keep it fitted and just raise the boost using a boost controller?

 

many people have reported on lower boost than expected. i've read that some people have enlarged the restrictor ring hole a bit at a time to increase the boost limit gradually, rather than trying it without the restrictor ring and risk the overboost. have you also got a fuel cut defencer in case of overboost, just as a precaution if you do decide to just remove the restrictor ring?

 

a boost controller would be a more expensive way of increasing the boost really, if it's just the restrictor ring that's a little small, but you would be able to adjust the boost whenever you like