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Ben's Z

Ready to blow my brains out

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Ben's Z    0

I thought I had my AFM mounting licked.  Well I temporarily installed my AC compressor and I have no idea how anyone can get the AFM between the compressor and that big piece of shit dangling off the bottom of the throttle body with the one wire coming off of it. (Whatever purpose it serves)  I can sort of get it in there but any universal cone filter I buy is going to be something off a single barrel stromberg carb. I see no way in hell you can run your IC pipes using the fresh air holes in the core support, (drivers side serving the turbo, passenger side serving the throttle body) keep your AC and get any sort of decent sized air filter on the AFM.  I did however get my IC mounted tonight and it looks pretty good.

post-19549-0-39451500-1362803757_thumb.jpg

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BluDestiny    10

That thing off the TB is the BCDD (boost control decel device). It basically controls your decel fueling so you don't dump gas when you just decide to let off after a wide open throttle run. 

 

What have other people done? I'd imagine just moving it forward more, or even lower. I'd also probably not run the clutch fan and use some slim electric fans instead. 

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Tony D    143

Other people mount it in front of he radiator, upside down...

But that was inconceivable.

So we get this!

 

Woot!

 

And the BCDD has nothing to do with fuel, it has everything to,do with admitting air so you don't get a vacuum spike in the manifold on drop-throttle (oil consumption in city driving and racing...), and also pump enough air into the exhaust that throttle cut injector disable/reengagement doesn't spike HC to,he catalyst due to,over-rich mixtures from lack of air on drop throttle...

Edited by Tony D

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Ben's Z    0

Other people mount it in front of he radiator, upside down...

But that was inconceivable.

So we get this!

 

Woot!

 

And the BCDD has nothing to do with fuel, it has everything to,do with admitting air so you don't get a vacuum spike in the manifold on drop-throttle (oil consumption in city driving and racing...), and also pump enough air into the exhaust that throttle cut injector disable/reengagement doesn't spike HC to,he catalyst due to,over-rich mixtures from lack of air on drop throttle...

Does the air between the turbo and AFM just magically find its way between the two?  I'd love to see how the pipe is ran, you incessantly blather on about this routing method.  

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Tony D    143

The frustrating part is for some reason I can't enter your screen name into the "ignore" list so you inability to surmount basic items and constant prattle goes beneath my radar.

 

I mentioned it, there are PHOTOS POSTED. That you can't visualise it is your issue dude. This stuff ain't rocket science and is documented clearly all over the web. In addition to here. But you don't want to hear what you don't want to hear.

 

That "Ben's Z" won't enter the "ignore" box is more than a mild irritation. Seeing the posts simply compounds it!

 

WOOOT! Cut and Paste! No more issues! Happy day...

Edited by Tony D

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billseph    1

I think the simple fact here is that you're gonna have to put the AFM outside the engine bay. Make some custom piping to extend the stock intake boot to the turbo, or just toss the boot all together and make a full intake pipe from metal. Extending the AFM harness will be a snap after that little bit of intake fab, it's just 4 wires to cut and splice.

I know I'm stating the obvious here, but Tony pretty much said to put it "in front of the radiator" which is a great location for it, it just requires some extra work.

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Or if you wanted the "quick fix"

 

Remove the BCDD.

Block it off.

Become comfortable with the idea of some "crackling/popping" exhaust noises on decel. Especially noticable right after WOT driving.

 

 

But, the "better" fix is to keep the system in tact, and working how it was designed to.... So like Tony and others have said above,  just get creative with intake routing, and put it in front of the radiator support.

 

 

 

 

Or......lose the A/C, roll down windows,  and just drive REALLY REALLY fast, since you live in Tx. 

Edited by OldAndyAndTheSea
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rayaapp2    3

Im afraid I have to side with Tony.

 

If you cannot conceive what he is trying to portray your missing his point.

He laid out what some people do and gave you a hint as to what that BCDD does. Its up to you as to how to execute the resolution.

Many folks have obviously done this swap. If you dont know how to make it all work thats on you. This is a classic case of looking a gift horse in the mouth.

 

If you cannot make your own intake, understand how and why things work, cut and splice wiring, or use what ever creativity you have to solve this problem its not on him or anyone else. And you may not be able to overcome this simple problem.

 

I can come up with at least 5 different ways of solving that issue. Think outside the box. Take that stupid rubber ducting out and start coming up with ways to connecting the two.

 

Its really that simple like it or not.

 

BTW in my last turbo swap I was able to mount the VAFM inside the engine bay near the radiator support and run a K&N filter up front. And I didnt have to extend any harness!

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Ben's Z    0

Decided to reclock the turbo and run the pipe underneath the oil pan. It worked great and is going to leave me more space for the afm. I have a question about cut ic pipe. Do you necessarily need to reflare or swedge the pipe again after you have shortened a piece? I have access to a muffler shop pipe bender so I can do it no problem but didn't know how crucial it was.

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Ben's Z    0

Or if you wanted the "quick fix"

 

Remove the BCDD.

Block it off.

Become comfortable with the idea of some "crackling/popping" exhaust noises on decel. Especially noticable right after WOT driving.

 

 

But, the "better" fix is to keep the system in tact, and working how it was designed to.... So like Tony and others have said above, just get creative with intake routing, and put it in front of the radiator support.

 

 

 

 

Or......lose the A/C, roll down windows, and just drive REALLY REALLY fast, since you live in Tx.

Old Andy: I live in Houston buddy. A/C is shortly behind water in life necessities in this part of the world!

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Ben's Z    0

Well I hadn't really took a look at my turbo intake yet, it was in storage above my garage. The one you see in the picture was just loosely on there and was from my n42 intake.

 

In reference to my bov, I thought excess pressure was plumbed back in to the intake.

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Ben's Z    0

Well I hadn't really took a look at my turbo intake yet, it was in storage above my garage. The one you see in the picture was just loosely on there and was from my n42 intake.

 

In reference to my bov, I thought excess pressure was plumbed back in to the intake.

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NewZed    56

Are you going to use the N42 manifold, or the turbo manifold?

 

I was just comparing a ZX NA W24 intake to an N47 intake.  The dimensions are slighty different, the throttle body mounting boss position is farther back (more room for you) and the throttle shaft also (the distance to the firewal will be shorter).  And the N42 throttle body is bigger than the ZX, with a different bolt pattern.  IIf you're using the N42 intake to mock up for the turbo intake, you might be wasting some time.  Plus, the BCDD is probably hanging from the bottom of the turbo  manifold, that's why there is none on the TB.  Nissan moved it from the TB to the bottom of the manifold with the W24 manifold.

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rayaapp2    3

Are you going to use the N42 manifold, or the turbo manifold?

 

I was just comparing a ZX NA W24 intake to an N47 intake.  The dimensions are slighty different, the throttle body mounting boss position is farther back (more room for you) and the throttle shaft also (the distance to the firewal will be shorter).  And the N42 throttle body is bigger than the ZX, with a different bolt pattern.  IIf you're using the N42 intake to mock up for the turbo intake, you might be wasting some time.  Plus, the BCDD is probably hanging from the bottom of the turbo  manifold, that's why there is none on the TB.  Nissan moved it from the TB to the bottom of the manifold with the W24 manifold.

Its no wonder Tony has an aneurism when he reads these posts.

 

There is no BCDD on the turbo manifolds. period

The ECCS system is more complicated than the NA versions and cuts injectors based on RPM and throttle position so the BCDD is not needed!

 

I have N42 manifolds and the P79 manifolds, and the turbo manifolds. The turbo manifold uses a 55mm throttle body. The N42 I just measured is 55mm as well with the same bolt pattern!

 

I do not have a W24 intake to compare with, but all the manifolds I have all locate the TB in about the same position.

 

The linkage positions for the N42 and the turbo manifold(which do not seem to have a casting code on them) are also the same.

 

Now as for you Ben,

-BOV do not recirc into the manifold. The stock manifold has something to that effect, but its different as the stock L28et did not have a BOV. It uses a check valve at the #5 runner to bleed excess pressure off, but a BOV works a little different. You should be doing a lot of research on how to run a BOV before you proceed, or at least search for pictures of how some folks do it. You may be headed towards disaster if you continue down this path your on. But its your time and money.

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NewZed    56

Can't help you on the different measurements.  I was considering usng the W24 manifold so took side-by-side measurements a couple of days ago, a 1981 P79/F54 engine manifold compared to an N47 from a 78 N47/N47.  The TB diameter and bolt pattern and positioning is definitely different.  The W24 TB from the ZX is surprisingly smaller than the N42, as are the hoses that connect it to the air filter.

 

I didn't say that the turbo manifold was the same as the W24, I offered it as a possibility, since the W24 is different and comes from the same ZX body style.  Which you'd know if you had one to measure.

 

Looks like we're all adding to the confusion.  Check valve (? - check valves don't generally "bleed" pressure), BOV, emergency relief valve (Nissan's term), definitions of each, how they work, where to plumb them and whether or not to use them.   Looks messy.  Yeehah.

Edited by NewZed

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Ben's Z    0

I do know that the best place for a bov is right before the throttle body. I've only owned one turbo car before in my life and only briefly. It discharged excess pressure to the atmosphere. Frankly I didn't want want the blow off woosh, I was trying to push it back into the motor, which I thought was protocol to eliminate the noise, I guess I am wrong.

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Tony D    143

Its no wonder Tony has an aneurism when he reads these posts.

 

-BOV do not recirc into the manifold. The stock manifold has something to that effect, but its different as the stock L28et did not have a BOV. It uses a check valve at the #5 runner to bleed excess pressure off, but a BOV works a little different. You should be doing a lot of research on how to run a BOV before you proceed, or at least search for pictures of how some folks do it. You may be headed towards disaster if you continue down this path your on. But its your time and money.

Ray,

The stock BOV dumps into #4 / 5 intake runner area and works well without increased volume of piping associated with an inter cooler (if at elevated pressures.) it's function, as well as how it functions has been covered previously ad nauseam by yours truly. I believe the Nissanspeak for that valve was "vacuum control valve" and it's off-boost dumping into the plenum (like the BCDD) prevents massive spiking of vacuum in the plenum causing oil consumption issues and uncombistible air deprived conditions lowering HC spiking to the catalyst. Removing it, like removing the BCDD has shown increased oil consumption when driven similarly on vehicles I've tested.

 

Including the 1973 Maroon Roadster with the 82ZXT engine in it that has showed at the last few MSA events...which you can check, Ray...the AFM is mounted EXACTLY where I say, and there is NO harness extension required. Both Ian and I considered this a no-brainier due to the ease of repositioning. Apparently there are incidences of brain deprivation exceeding our wildest expectations as that is where I see a majority of them mounted.

Edited by Tony D

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OhBilly    10

I do know that the best place for a bov is right before the throttle body. I've only owned one turbo car before in my life and only briefly. It discharged excess pressure to the atmosphere. Frankly I didn't want want the blow off woosh, I was trying to push it back into the motor, which I thought was protocol to eliminate the noise, I guess I am wrong.

 

If you are going to recirc your BOV, it should recirc back into your intake, as in pre-turbo.

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NewZed    56

There's Ray's check valve...

 

There could be a better term for what the BOV actually does.  Doesn't seem like it really does much blowing off.  And there seem to be several ways to achieve the desired result.  "Blow-off valve" seems like an over-simplification and should probably not be used to describe anything.  Just a thought - ban the BOV.

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Tony D    143

Just be advised the pittfalls removing the factory unit in lieu of something that functions quite differently and should be sized accordingly. "Dumping it back pre turbo" is a gross oversimplification of what the valve should do when vented that way!

 

The stock unit does it's job seamlessly and silently. As a properly engineered valve should do. The only real way to properly install what most people have nowadays and what should be properly termed "Compressor Bypass Valve" is about the only thing Mr. Corky Bell and I agree upon. BEGI made a great compressor bypass valve (AKA Today "BOV") and Corky's explanation of it's function in 'Maximum Boost' is about the only redeeming quality in the entire text! And that is what a pre-throttle plate valve is for, compressor bypass and overboost control on drop-throttle. Some turbos now have ELECTRIC ones built into the turbo casing. What about "proper venting" in that case? 

 

There IS a better term, it's just through ignorance and popular vernacular, it's been perverted into a basic explanation and oversimplification of what it actually should be designed to do.

 

It's why the Nissanspeak term is "Vacuum Control Valve" -- they found the spiking in the manifold and oil consumption/increased HC Emissions were more important, so this is how they managed to tackle both the issue of drop-throttle surge prevention and compressor speed decrease (blow off function) and preventing the manifold vacuum spike until the pneumatic control system could enact anti-stall and additional air to the engine by opening the AAC.

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