depends on who you talk to but most people seem to think you need one on the intake elbow, especially for higher boost levels, to prevent throttle plate damage

of course the factory BOV is on the y-pipe to prevent damage to the turbines

I'm getting my new Blitz BOV mounted directly to the y-pipe to clean up the underhood "clutter" (also eliminating the annoying y pipe to IC intake tube coupler/junction with a flanged connection, and the M2 pipe sucks anyway)

do I REAALY need another BOV on the Greddy elbow? I'm only running 13 psi

 

no.

 

you dont NEED two. having more than one is simply nice. thats all. the blitz bov mounts horribly though. you have to screw bolt it in from the bottom. . . so youd have to stick your fingers in whatever you mounted it to and tighten it that way. . . i highly doubt any of us wanna mess with that. i dont understand why its made that way either. your best bet is to make a flange that mounts to the craplog flange that they send you. this would allow you to freely make a new mounting setup. all youd have to do is countersink the bottom side of the "new" flange. bolt it into the blitz flange. make sure that the countersunk screws are atleast flush with the flange face. make a gasket to go between them. then make another flange to match YOUR flange. this newer flange will have threaded holes in it and will be the actual piece that is welded to WHATEVER pipe you desire. THIS way you can bolt the bov to the flange with ease.

im sure the original intent of the blitz flange is to weld a tube to it and then have that welded to the pipe you decide to have it mounted to. . . but thats ugly. . . my way is better.

you want the bov next to the tb in order to get SAFER REACTION. its not the throttle blades that get damaged. . . its the boost backing up and messing with the turbos. . . causing compressor surge. so having it next to the tb gives you safer operation. since air compresses the first place for it to compress against is the CLOSED THROTTLE BLADES. keep your bov close to the point that its gonna compress against and you have less worries.

13psi can still cause damage to the turbos. i was getting surge at 5psi due to an incorrect installation.

having two is safety. not neccessity.

paul

 

thanks Paul

so why did Mazduh mount the BOV on the y-pipe then?

must be the same engineers that designed the IC, y-pipe primary turbo studs (WHY did they use studs instead of bolts???), and fuel filter location

anyway, I don't see how a backpressure (surge) is going to harm the turbos when the BOV is in either location...sudden throttle plate closure causes a pressure wave to be driven back through the piping and IC, kind of like "water hammer" if you are familiar with that phenomenon....as long as the piping and IC has flexible connections I really don't see it being a problem

agreed it will be a pain to mount on the y-pipe, maybe I'll be forced to go with the elbow....you're buddy David is working on it for me

 

i figured that was you


i see your point. the difference i see is that liquids arent able to be compressed. so a "sudden wave" isnt going to go all the way to the turbos as quickly as it will go to the throttle body elbow. its going to lose speed due to the remainder of the compressed air behind it.

to be honest, you wont notice a difference in performance. its only if youre really picky that you might do this. the difference i always see is "ease of work". its not easy to adjust things and work on the bov in the area that you are wanting david to weld it to. its A LOT easier to do adjustments on it at the TB elbow.

also, i went over that flange idea with david. . . and he thinks its a good idea as well. hehe.

im gonna find some pics of how davids is setup so you can see how hard it might be to mess with that mounting point.

paul

 

i thought i actually had pics of the twins installed on his car. . . ill take pics tonight and post them. its a very tight squeeze. you can see by the pictures that the pipe that comes from the 2ndary will go right over the bov. . . and on top of that its very close to the fenderwell. i think going to the TB elbow is the best idea.

paul

 

nice pics!

 

NIce pics what kind of upgraded twins are those?

 

I run dual Blitz BOV's - sure sounds cool

 

now how about them twins!

i run two bovs on my setup, simply because i like the sound it makes better.

 

those are some experimental bnr twins. . . well find out what they do on july 11th.

paul

 

Wow, thats a beautiful setup. I wish mine looked that good.

 

thats MONTHS of work

 

Oh my god those look awesome Who says you need to go single to have all that bling under the hood. And it does look like a lot of time and hard work went into that setup. NICE!!

 

Beautiful work!! Looks like a part that fell off the Terminator

 

lol

I'm sure Paul can attest to the fact that David spends countless HOURS on his car polishing, powder coating, and replacing every nook and cranny, every fastener (stainless steel), all the wiring, and every possible underhood component for maximum bling.....every time I call him he is getting something else powder coated or polished...some people are a little obsessed life is too short for me to spend that much time under the hood of an FD

but all I know is, I want to buy his car when he sells it! I'd just replace those three spoke wheels, ha

 

we took your advice

I just talked to David and I'm going to have it flange mounted on the elbow....thanks

 

With the volume of air thes big twins should put out ,he thinks both blow off valves are needed to keep the units spooled up between shifts . One valve in the correct location should do for the stock twins . The y pipe set up , with the bolt up flange should work and look very well for you .

 

why would having 2 bov's help keep the units spooled up between shifts? Seems to me 2 bov's will vent twice as much charge air as one so if your wanting to keep more charge air in your pipes you probably should stick with one as long as you dont have compressor surge.

Am I missing a point here???

STEPHEN

 

good point Stephen, under acceleration you would want to keep as much pressure in the system as possible at all times

power shift with an electric air shifter the drag guys use

 

SPO ,think about it ,you shut the throttle and the air backs up and slows the turbos down . this is slow compaired to exhaust gas speed ,but is still right under subsonic . Most people do not shift gears fast enought to get done before the air has its effect on the turbo speed . You must be , of course,shifting mad quick,yo .David has put air shifters on motorcycles,there is one still in storage . So do not give him any ideas for more to do or to make . I for one am ready for him to finish . I want to ride .

 

ahh I want a polished efini y pipe so bad! Looks killer.

 

That is a bit more then a stock efini y pipe,but who will notice . He thinks the modified efini pipe and the pipe attached , to the innercooler , are two of the best looking parts of the set up . He would THANK YOU for the comment.

 

duboisr. . . did david tell you about his "money pit"????? hahaha, ill try to post pics of it tonight!!!!

paul

 

the set-up in those pics, with bolted and flanged connections, is the way it SHOULD have come from mazda, if they were just such a cheap *** manufacturer

all the cheap plastic stuff on the stock car is nothing short of embarassing