mazdaspeedjay
Member
OK i'm going to try this today or tomorrow and let your know how it works. this is a trick i learned when i owned my SRT4. What it is a something called a vacuum restrictor you can get them at your local autozone is where i got mine from. it looks like a white plastic vacuum T fitting but without the T part. it's a straight connector used to connect two pieces of vacuum line together it's open on one end and has a brass restrictor in the other end. the way you used this on the SRT4's which i think will work the same way on my mazdaspeed3 is you take vacuum line going to the top of the waste gate leave everything else stock like. you cut the vacuum line going to the waste gate on the speed 3 i know there's two one on top and one on bottom so i'm going to try the top first and place a T fitting inline. you hook up the vacum line going to the waste gate on each end of the T fitting but take the vacuum restirctor place a small piece of vacuum line on the end without the brass restrisctor on it and the other end of the vacuum line from the restrictor to the middle fitting on the T fitting.
Now on my SRT4 this is used to help hold boost longer in the top end because the vacuum restrictor works to bleed some of the pressure going to the waste gate helping it not open so easy. BUT the brass opening is SOOO small that it doesn't bleed enough to make the waste gate over boost if installed correctly. Now if installed stock the restrictor will only and maybe increase boost 1 PSI if any at all but you should notice that it holds boost longer in the red line and top end. I used this also as a home made boost controller here's how. I bought three of these vacuum restrictors one i left alone. the second i drilled out the brass end just a hair bigger and the third i drillled out the brass end even a little bigger then that. what that did was give me three stages of boost and all it took was a simple unplug one restrictor and plug in another takes two seconds no turning knobs or pushing buttons and messing with gains. the way to increase boost is you must have a AWESOME drill set find the size drill bit that fits perfect with no drilling. to increase boost goto the next size up and drill out the brass end. BE CAREFUL IT"S ONLY PLASTIC AND SOFT BRASS.
The bigger you make the hole the more pressure will bleed off and the more boost you'll run. This worked GREAT on my SRT4 better then my $50 manual boost controller and worked alot better with the factory systems no over boost or PTM ( partial throttle boost ) that alot of manual boost controllers can cause. i HAVE NOT TRIED THIS ON MY MAZDASPEED3 YET I JUST REMEMBER THIS FROM YM SRT4 DAYS AND I'M GOING TO GIVE IT A WIRL ON MY SPEED3 BUT I THOUGHT I'D SHARE THIS CAUSE IF THIS WORKS THE WAY IT DID ON MY SRT4 FOR THE MONEY YOU CAN'T MAKE A BETTER BOOST CONTROLLER AND IT WORKS VERY WELL WITH THE FACTORY SYSTEMS. I WILL TRY THIS TONIGHT OR TOMORROW AND LET YOU KNOW HOW WELL IT WORKS IF IT EVEN WORKED AT ALL.
This will either work great or fail big time. but in theory it should work the same as my SRT4 did on my stock waste gate and was the best bang for the buck cause putting it back to stock was simple and if i wanted more boost i just unplugged one and poped the other one in and each restrictor only cost like $2 from autozone and they usually give you 1-2 per pack. IF you do not have a boost gauge or something to monitor boost don't be stupid and try this any time you mess with boost levels you must have something to monitor it so you know if you're over boosting without having the computer tell you so.
Now on my SRT4 this is used to help hold boost longer in the top end because the vacuum restrictor works to bleed some of the pressure going to the waste gate helping it not open so easy. BUT the brass opening is SOOO small that it doesn't bleed enough to make the waste gate over boost if installed correctly. Now if installed stock the restrictor will only and maybe increase boost 1 PSI if any at all but you should notice that it holds boost longer in the red line and top end. I used this also as a home made boost controller here's how. I bought three of these vacuum restrictors one i left alone. the second i drilled out the brass end just a hair bigger and the third i drillled out the brass end even a little bigger then that. what that did was give me three stages of boost and all it took was a simple unplug one restrictor and plug in another takes two seconds no turning knobs or pushing buttons and messing with gains. the way to increase boost is you must have a AWESOME drill set find the size drill bit that fits perfect with no drilling. to increase boost goto the next size up and drill out the brass end. BE CAREFUL IT"S ONLY PLASTIC AND SOFT BRASS.
The bigger you make the hole the more pressure will bleed off and the more boost you'll run. This worked GREAT on my SRT4 better then my $50 manual boost controller and worked alot better with the factory systems no over boost or PTM ( partial throttle boost ) that alot of manual boost controllers can cause. i HAVE NOT TRIED THIS ON MY MAZDASPEED3 YET I JUST REMEMBER THIS FROM YM SRT4 DAYS AND I'M GOING TO GIVE IT A WIRL ON MY SPEED3 BUT I THOUGHT I'D SHARE THIS CAUSE IF THIS WORKS THE WAY IT DID ON MY SRT4 FOR THE MONEY YOU CAN'T MAKE A BETTER BOOST CONTROLLER AND IT WORKS VERY WELL WITH THE FACTORY SYSTEMS. I WILL TRY THIS TONIGHT OR TOMORROW AND LET YOU KNOW HOW WELL IT WORKS IF IT EVEN WORKED AT ALL.
This will either work great or fail big time. but in theory it should work the same as my SRT4 did on my stock waste gate and was the best bang for the buck cause putting it back to stock was simple and if i wanted more boost i just unplugged one and poped the other one in and each restrictor only cost like $2 from autozone and they usually give you 1-2 per pack. IF you do not have a boost gauge or something to monitor boost don't be stupid and try this any time you mess with boost levels you must have something to monitor it so you know if you're over boosting without having the computer tell you so.
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