NjsGT's build.... with pics!

[NjsGT]

BOV has nothing to do with power output there is no issue with the bov. This is exactly how it acts on a blower car and is not hurting anything.




With a centri blower at idle the blower is pushing alot of air already. The maf is blow thru way down stream of the bov, there is no way it is affecting maf signal. The bov doesnt/cant create a vac leak or effect maf signal even if it was able to pull in air from there while it was open. (which it cant becasue the blower is pushing air out of it all the time.)

Your bov is between the blower and intercooler and the maf is between the intercooler and tb correct?

The bov spring pressure needs to based off vac at idle thats it, not at cruise or deccel. You want a spring thats strong enough to close it at idle or be slightly open at idle. If the spring is too stiff the bov wont open properly, no good can ever come by having too stiff of a spring.

What is your vac at idle?

Yes, bov is between the blower and IC, drivers side.... MAF is between IC outlet and TB....
Hot idle it will pull -22hg -23hg

For the bold print...
I believe that is the prob with the fluttering.... I believe the amount of air trying to get out of the BOV at a cruising speed or -24hg -25hg is enough to hold open the BOV.... Honestly, it seems even with a 11 psi spring, the motor has to go as low as -10hg at a crusing speed for the 11 psi spring to over come the compressed air plus -10hg to finally close the BOV.... That meens I having a lag of about -15hg before boost can come on..... That also makes for the "fluttering" noise since the BOV valve is prob open just to much or maybe even half way.... IDK, this shit is new to me.....

 

[JeremyH]

My a/f gauge will pin out, 16:1 or lean...... I believe thats the injectors pretty much shuting off which is part of the ford tune, all mustang will do that.... JimII did tell me he can add fuel which would get rid of the popping....

And I am considering the bold only because the lack of experiance tuning a car with this setup. The guys at JDM DO know their shit and do awesome quality work along with decades of tuning experiance.... When I popped my hood to see what they did , I was very happy with the type, quality, and amount of care they put into the car..... Some of you guys may know that I am a near licensed master plumber, when I do work on whatever job it may be, someone's home, a school (Jr, you know what Im talkin about haha), or a doctors office I take pride to give them a quality and professional job.... JDM is no different

Yes letting off the gas completely goes into vapor lock and should show lean on your af gauge, but if your getting popping thats becuase either you have an exhuast leak or you have unburnt fuel from running rich just prior to letting off the gas.

 

[Greg Hazlett]

I think there are quite a few of the FI guys that were having "popping" with the FRPP intake.....I know Jeremy and I were having it.

 

[JeremyH]

Yes, bov is between the blower and IC, drivers side.... MAF is between IC outlet and TB....
Hot idle it will pull -22hg -23hg

For the bold print...
I believe that is the prob with the fluttering.... I believe the amount of air trying to get out of the BOV at a cruising speed or -24hg -25hg is enough to hold open the BOV.... Honestly, it seems even with a 11 psi spring, the motor has to go as low as -10hg at a crusing speed for the 11 psi spring to over come the compressed air plus -10hg to finally close the BOV.... That meens I having a lag of about -15hg before boost can come on..... IDK, this shit is new to me.....

This is a good thing.

Doesnt work like that, -2 vac = +1, make sense? It takes -2 inches of vac to cancel out 1psi of presusre.

The bov will instantly snap shut in boost. Yes the most efficient way to operate a bov is closed all the time except when you let off after being in boost. However you will get the fluttering and noise with a blower while crusing.

If your seeing 10psi at the manifold then thats 10psi + 11psi spring pressure for a total of 21psi keeping the bov closed (pushing against that 10psi in the piping)

If you want to get rid of the noise you can go to a softer spring which will keep the bov slightly open at idle or try the foam method like silentscope did.

 

[JeremyH]

I think there are quite a few of the FI guys that were having "popping" with the FRPP intake.....I know Jeremy and I were having it.

He's talking about exhuast popping.

 

[NjsGT]

Yes letting off the gas completely goes into vapor lock and should show lean on your af gauge, but if your getting popping thats becuase either you have an exhuast leak or you have unburnt fuel from running rich just prior to letting off the gas.

Im leaning that way although Ill check the joints on the exhaust for any black blow-out stains....

I think there are quite a few of the FI guys that were having "popping" with the FRPP intake.....I know Jeremy and I were having it.

Do you still get it from time to time? Gregg Ill PP ya abit later... i gotta go cut some grass

 

[NjsGT]

This is a good thing.

Doesnt work like that, -2 vac = +1, make sense? It takes -2 inches of vac to cancel out 1psi of presusre.

The bov will instantly snap shut in boost. Yes the most efficient way to operate a bov is closed all the time except when you let off after being in boost. However you will get the fluttering and noise with a blower while crusing.

If you want to get rid of the noise you can go to a softer spring which will keep the bov slightly open at idle or try the foam method like silentscope did.

Well will the softer spring cause tune issues since it was tuned trying to remain closed? I think the foam is more of a muffler, also SS is running half the boost I am.... Not sure how that would fair trying to get 13+ psi out lol... Might blow a hole right through it LOL

 

[Greg Hazlett]

Sounds good! Have fun cutting the grass in the heat...glad I got the cars washed before 9:00 and it really got warm.

 

[JeremyH]

Well will the softer spring cause tune issues since it was tuned trying to remain closed? I think the foam is more of a muffler, also SS is running half the boost I am.... Not sure how that would fair trying to get 13+ psi out lol... Might blow a hole right through it LOL

Not on a blow through maf, the air gets metered down stream of all of this so it has no effect.


Yup the foam is a muffler, and no its not a restricition. It is designed to flow lots of air through it.

I think you will be happier trying the 8psi spring like Jeff mentioned earlier.

 

[Irishman]

I wasn't saying that the BOV was robbing him of power, just didn't go that route because of the noise of the BOV haha.

 

[JeremyH]

I wasn't saying that the BOV was robbing him of power, just didn't go that route because of the noise of the BOV haha.

Gotcha completely understandable, it is a bit annoying at certain cruise speeds.

 

[Irishman]

I used to love the external wastegate on my STi but now that I'm getting older I don't want to hear it all the time lol (man I never thought I would be saying shit like this). I'm worried the Mondo valve will be to loud.

 

[NjsGT]

I used to love the external wastegate on my STi but now that I'm getting older I don't want to hear it all the time lol (man I never thought I would be saying shit like this). I'm worried the Mondo valve will be to loud.

I think you'll JUST be able to hear it.... When I had my STi, I just chrushed my stock bov and it was pretty loud at 20-21psi... It was also re-circ'ed like your mondo....

 

[NjsGT]

Ok so I busted out the Go-Pro, stuck it on the side of the car and went for a 1st-4th run from a dig..... There is more wind noise then I hoped but you can get a good idea of hows shes running

 

[94tbird]

video is private, make it public so we can see!!!!!

 

[NjsGT]

video is private, make it public so we can see!!!!!

Shit! My bad! Try it now

 

[NjsGT]

BTW, 720p it fella's

 

[94tbird]

go pro cameras rock. I SOOOOO need to get one of these.

 

[cm581978]

Road looks familiar lol

 

[NjsGT]

Road looks familiar lol

Haha, the testing grounds........ shhhh, no more about it