GustavOllufsen

I'm sure this has been discussed, but does anyone know of a company that makes an improved Y pipe design? I went non sequential so I do nto need the CCV to be in the pipe. just very simple and smooth flowing pipes that merge into 1 and hook up to the crossover.

Also if anyone knwos of a modified version of the rear intake pipe. I don't think I could even breath throught hat thign with all it's bends and knicks and twists. I just want completely tubular and simple piping on both sides of the compressor housing.

I have hardpipe intake piping going to the rear piece and front plastic elbow.

Section8

iTrader: (6)

I don't know about the rear pipe, but the Efini Y Pipe is the only other Y pipe i know of.

Mahjik

iTrader: (1)

Search for Garfinkle here on the forums. He modifies the Y-Pipe to remove things that aren't needed for non-seq. I'm not sure how much he charges for it so you'll just have to call and ask.

GustavOllufsen

perhaps I'll get some aluminum intake piping and cut the flanges off all the pieces and tig em on or something lol

Mahjik

iTrader: (1)

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/my-modified-y-pipe-done-garfinkle-375981/

axr6

Mahjik

Looking at the link that you provided, the Y pipe is a super piece of work. I'm wondering what they did to replace the BOV? In non sequential applicatons the factory BOV valve is used (Efini Y-pipe uses one too) and also paralleled with the old Charge Conrol valve for a second BOV. This pipe has none of that. Where is the relief in this system?

Albert

Mahjik

iTrader: (1)

Greddy elbow.

axr6

Yes, that makes sense.

I'm not very knowledgable regarding BOV issues so, my question is:

What is the BOV protects? Turbos or the engine?

If it is to protect the turbos (as I think it is) from a spike (pressure shock) upon closing the throttle plates when lifting off the accelerator, would it not make more sense to place it as close to the turbos as possible without buffering it through the IC? (as in the factory applications)

Not?

Albert

Improved FD

mine looks just like that....David does nice work....BOV on the elbow (best place for it)

Mahjik

iTrader: (1)

There is a large debate about it. Yes it's to protect the turbos from when the plates close (and the air has no where to go but back). The theory is to remove the air from the system as soon as possible so that would be closest to the plates when they close.

However, Mazda located it close to the turbos for a reason. So, IMO, it's more preference.

Improved FD

Mazduh also created a plastic AST for a "reason"

the reason? cheap!

Mahjik

iTrader: (1)

They did a lot of things cheap so it didn't end up like the NSX (a lot of money for not a lot of car).

axr6

Thanks Mahjik. As a simple minded Electrical Engineer, I would logicly choose a location for the BOV as close to the pressure sources as possible (like the factory). But, like I said I'm an electrical person, not one into flow dynamics.

Albert

afterburn27

iTrader: (5)

I *think* Rich (GoodfellaFD3S) has a custom rear turbo intake pipe. I dn't remember seeing good pics of it before though. Might want to ask him.

GARCO MOTORWORKS

The people in the know tell me to put the BOV near the throttle plates because that is where the air starts to back up when you lift off . Why wait for the air to back up the distance to the turbos to keep them or it from slowing down .The air is moving in the direction toward the throttle ,vent the air there and stop the air column from changing direction three times per gear shift . On my car I have an Efini pipe that is modifed for flow and the two stud flange has been cut off and my flange is located lower ,to clear the shock tower bar, and it has 5 bolts to stop any leaks,or warping .I have also replaced the lower flatened end of the rear turbos air intake pipe with a cast elbow with 4 bolts instead of the stock two .The front air pipe is also a cast alum elbow with 4 bolts . All safety wired and polished . The turbo to Y pipe connection is no longer the stock warped two bolt flanges .I made new flanges with V- band clamps . No leaks, good flow , BNR 3rd stage supersized one off , and three spoke wheels . Life is good .

rynberg

Yep, Chuck Westbrook (cewrx7r1) had them made, IIRC. I would actually like one to see how much of an improvement there is....feeding the BNRs with that little bent OEM pipe is head-scratching.

cohbra

iTrader: (13)

The best location for mounting your BOV is going to be as close to the plates as possible. I used to do a lot of research and prototyping work on fully automated flow test benches for a previous employer. As a result, I gained a lot of knowledge in flow dynamics.
The reason it is best to put the BOV at the plates is really quite simple... Due to the velocity of the air traveling perpindicular to the BOV, you will actually develop a negative pressure in relation to the rest of the intake piping during acceleration. This is due to the Venturi effect. However, if the BOV is located at the end of the line, where the plates are, you will still have the same effect when the plates are wide open, but when they start to close, the pressure will be relieved much quicker. This is the point in the system where the highest pressure will occur after the plates close due to the momentum of the air.
Having the BOV on either end is still better than having it somewhere in the middle though. If it were in the middle, what you end up with is a lot of reflection. This is basically a wave of air traveling back and forth in the intake system bouncing off of the plates on one end and the turbos on the other.

Edit:
I should also add that the benefits gained by locating the BOV close to the plates can be negated by having a longer run on the vacuum line that actuates the BOV. For this reason it is important to keep this line as short as possible to allow the BOV to react more quickly.

axr6

Thanks for the great explanation. It makes sense as you have described it.

Albert