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Exhaust System On But No Change!

WOG BOY

By WOG BOY,
in General Automotive Discussion

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**RB2530** Proficient

**RB2530**

Posted
Posted
Did the R33 GTS-T's come with a boost restrictor that you can remove to gain a SAFE Factory boost increase like the GTR R32's? The Brass Boost restrictor I think its called..?

If so, remove it and you sould get up to 7 psi...

Yep they come with a solenoid that opens at 4500rpm...When is opens it bleeds enough air to add extra 2-3psi of boost...it feeds back into air intake just after afm so that the air calculation is not stuffed up...From memory stock boost is 5 psi below 4500rpm and jumps to 7or8 psi above 4500rpm...Most people just remove it or permanently short the terminal to ground which holds it open all the time...Its really basic and I dont know why Nissan bothered with it...but anway they did...

I ended up replacing mine with a hydraulic needle control valve (now have EBC)...Its was better than a standard bleed valve because it passed all bled air back into intake...whereas normal bleed valves bleed air to atmosphere and are therefore technically illegal...

Goosy Collaborator

Goosy

Posted
Posted

Before you do what **RB2530** says, how do you know your car is running just 5 psi of boost ? Do you have an aftermarket boost gauge, or are you just reading off the stock one one the dash ? Cause I hope you know that's not in PSI, but in mmHg. (where 5 mmHg = 'round 9.5 PSI)

(OO)SKYLINE(OO) Grand Master

(OO)SKYLINE(OO)

Posted
Posted
Yep they come with a solenoid that opens at 4500rpm...When is opens it bleeds enough air to add extra 2-3psi of boost...it feeds back into air intake just after afm so that the air calculation is not stuffed up...From memory stock boost is 5 psi below 4500rpm and jumps to 7or8 psi above 4500rpm...Most people just remove it or permanently short the terminal to ground which holds it open all the time...Its really basic and I dont know why Nissan bothered with it...but anway they did...

I ended up replacing mine with a hydraulic needle control valve (now have EBC)...Its was better than a standard bleed valve because it passed all bled air back into intake...whereas normal bleed valves bleed air to atmosphere and are therefore technically illegal...

Right, I see! You know Jap cars LOL! The more buttons to push the better LOL!

Before you do what **RB2530** says, how do you know your car is running just 5 psi of boost ? Do you have an aftermarket boost gauge, or are you just reading off the stock one one the dash ? Cause I hope you know that's not in PSI, but in mmHg. (where 5 mmHg = 'round 9.5 PSI)

I believe the Stock Boost Gauge reads in -0.7 to +0.7 Bar

i have an aftermarket boost guage.....and its reading less than 5psi

Did you say your car was stock except the new exhaust you put on? Check out to see if the restrictor is still there... Ask you mechanic if your not sure...

WOG BOY Community Regular

WOG BOY

Posted
  • Author
Posted
Did you say your car was stock except the new exhaust you put on? Check out to see if the restrictor is still there... Ask you mechanic if your not sure...

which restrictor are you talking about?

(OO)SKYLINE(OO) Grand Master

(OO)SKYLINE(OO)

Posted
Posted

Hey WOG BOY!

which restrictor are you talking about?

**RB2530** explains it. I will post a pic to show you where the Solenoid is (But It's From a GTR R32... I Think R33 GTS-T's Might Be Different?) But to give you an idea.

Yep they come with a solenoid that opens at 4500rpm...When is opens it bleeds enough air to add extra 2-3psi of boost...it feeds back into air intake just after afm so that the air calculation is not stuffed up...From memory stock boost is 5 psi below 4500rpm and jumps to 7or8 psi above 4500rpm...Most people just remove it or permanently short the terminal to ground which holds it open all the time...Its really basic and I dont know why Nissan bothered with it...but anway they did...

I ended up replacing mine with a hydraulic needle control valve (now have EBC)...Its was better than a standard bleed valve because it passed all bled air back into intake...whereas normal bleed valves bleed air to atmosphere and are therefore technically illegal...

Where it is circled in RED is, I believe is the Boost Solenoid. Inside there is whats called a Brass Boost Restictor, which can be removed to gain a Safe Factory Boost increase of about 2-3psi.

80419876vr3.jpg

**RB2530** Might have a pic of what the R33 GTS-T one looks like.

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