STOCK BIPASS VALVE tested.

[SuperStretch18]

I can confirm via visual check of my boost gauge that I gained boost with the forge valve. Before upgrade, I was limited to 8 psi in 2nd, 14 psi max all gears. Now I hit about 12 psi in 2nd, 16 max all gears. This is a CX-7 mind you, but the difference is night and day. I don't have video confirmation though, so you will have to take my word.

BTW, I am not trying to push the forge valve, it's just what I have on my ride; you will likely see the same improvement with any upgraded BPV...

 

[6262MS3]

Forgive me for this noob question: If the stock bpv is crappy would that play a part in our brutal lag during upshifts? I know a turbo engine will bleed off boost when the throttle's lifted, but other turbo cars I've driven haven't felt nearly as bad. Isn't the bpv supposed to vent the intake backpressure when the throttle's closed to let the turbo freewheel and build pressure quickly when the throttle's reopened after a shift? I refuse to flat-shift as it's so hard on the drivetrain and I like letting the revs match for (mostly) smooth upshifts even when I'm charging through the gears.

 

[SpdFreak]

Is any Forge DV good, or do I need a specific one?

I'm not sure if this is a good deal.

Link

 

[CX-7owner]

No it's not, you cannot use a diverter valve, you the BPV made for the DISI engine

 

[sleeper3]

3 guys here at work have speed3s and we all hold boost around 17 psi in 6th gear. we're all stock too. are you guys talking about something else?

 

[CX-7owner]

Umm, you shouldn't see a steady 17 PSI, I thought the Max on a stock MS3 was 15.6.

Where are you measuring the boost?

 

[aaronc7]

I get 15-16 in 4th gear, and the same in 5th and 6th... but 5th and 6th will spike to about 17-18 for a second first.

 

[sleeper3]

vac line off the bypass valve just like everyone else. I spike to 19 in 6th and one other dude here spikes to 20 but we both settle back to around 17. only in 6th though.

 

[nypest]

what spring on the forge is the best set up for the stock mazdaspeed3 boost lev ?? Blue?

 

[CX-7owner]

Yes.

 

[nypest]

the blue one isnt to firm ? its rated for 23> psi

 

[MidwestSpeed3]

Blue has worked fine for me.

 

[nypest]

do you feel it holding boost better then stock ?

 

[Kosh]

Just because 1 or 2 people's stock bpv isn't holding boost doesn't mean all of them are leaking. Wouldn't hurt to test your own but it doesn't mean everyone's isn't holding proper boost levels.

 

[Haltech]

Just because 1 or 2 people's stock bpv isn't holding boost doesn't mean all of them are leaking. Wouldn't hurt to test your own but it doesn't mean everyone's isn't holding proper boost levels.

What does it matter? The guy wanted to know what spring to use, so either give him the answer or move the hell on without a reply!

 

[Haltech]

do you feel it holding boost better then stock ?

Blue works for me. Remember, each car is different. You can try the Blue with a shim.. or the yellow.. People are running different combo's. Look up the Forged BPV thread. There's a lot of info in there as well.My car holds boost better than stock did.

 

[nypest]

yeah i read the Forge thread but it seem like there are alot of different combos. I am running stock boost but have plans to up to at least 18 so i fugure ill use the blue untill then. I just dont want the blue spring to be to strong when the throttle plate closes thus having bad comp surge.

Haltech what boost you running ?

 

[Kosh]

What does it matter? The guy wanted to know what spring to use, so either give him the answer or move the hell on without a reply!

I was responding to the original post, didn't even make it to the last page before posting. What is your problem?

 

[Haltech]

yeah i read the Forge thread but it seem like there are alot of different combos. I am running stock boost but have plans to up to at least 18 so i fugure ill use the blue untill then. I just dont want the blue spring to be to strong when the throttle plate closes thus having bad comp surge.

Haltech what boost you running ?

Stock boost right now. I didnt like how the car reacted with the MBC and BCD.. I didnt get the map clamp prior to doing this. Like everyone else, im waiting for the next big thing.

 

[Haltech]

I was responding to the original post, didn't even make it to the last page before posting. What is your problem?

Well thats why you should be quoting the posts. This way, people dont take what your saying out of context (spin)