Need suggestions on intake piping.

That spinning thing that makes all of the cool noises. OE and Aftermarket.

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BoneIslandScooby
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Need suggestions on intake piping.

Post by BoneIslandScooby »

I have toyed with several ideas for coffee cup mod on intake. The easiest I came up with, however, is a stainless silicone hose joiner with three ports on it that allow you to install a 90 degree hose barb. I have a doubt about it, however. The three ports are 1/8"-27 NPT female threaded holes. Now it seems one of the vaccuum hoses that goes to the original intake silencer gets plugged when you install a Manual Boost Controller, so that leaves two hoses going to the "Coffee Cup Mod". One of these hoses is nearly 1 inch in diameter, while the other one is about 3/8 inch. I'm talking about O.D. My question is, how sensitive will the engine be to the size of the orifice that is allowing these hoses to connect to the intake tract? Will a restriction cause a problem? How freely do they need to flow?
Last edited by BoneIslandScooby on Thu Apr 24, 2014 10:06 pm, edited 1 time in total.
ride_child
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Re: Need suggestions on "coffee cup mod"

Post by ride_child »

smaller outlet goes to the purge system and isn't really necessary. the bigger one goes to the pcv system and that one i wouldnt mess with too much, i would try to use that same size or as close as you can get.
Kris

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BoneIslandScooby
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Re: Need suggestions on "coffee cup mod"

Post by BoneIslandScooby »

ride_child wrote:smaller outlet goes to the purge system and isn't really necessary. the bigger one goes to the pcv system and that one i wouldnt mess with too much, i would try to use that same size or as close as you can get.
On the original intake silencer, three hoses come out of it. The big one goes to PCV. The tiny one goes to the factory boost control solenoid and gets blocked off, when I install the Manual Boost Control. Is the medium sized one the one you are talking about, which is not necessary? Is all this correct?

What happens if I decide to use an air/oil separator in place of the PCV system?
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Re: Need suggestions on "coffee cup mod"

Post by cj91legss »

The large hose (3/4"-1") on the Intake resonator is for the Idle Air Control Valve.
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ride_child
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Re: Need suggestions on "coffee cup mod"

Post by ride_child »

yea i meant the smaller of the two you were talking about. you had already mentioned going to the mbc so you wouldnt need the one in the back going to the factory boost solenoid.
Kris

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Legacy777
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Re: Need suggestions on "coffee cup mod"

Post by Legacy777 »

BoneIslandScooby wrote:On the original intake silencer, three hoses come out of it. The big one goes to PCV. The tiny one goes to the factory boost control solenoid and gets blocked off, when I install the Manual Boost Control. Is the medium sized one the one you are talking about, which is not necessary? Is all this correct?

What happens if I decide to use an air/oil separator in place of the PCV system?
As CJ clarified the big 3/4" opening on the resonator box is for the IAC valve. You will need something with that size on your coffee cup mod.
Josh

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BoneIslandScooby
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Re: Need suggestions on intake piping.

Post by BoneIslandScooby »

I have changed the focus of this thread to include all intake piping. I need to know what are the things that are plumbed into the factory rubber turbo intake elbow, which connects to the cast metal 90 intake tube bolted to the intake housing of the turbo. What sizes are the hoses plumbed to it? Is it necessary for the intake elbow to be flexible, rather than rigid? As far as I know the coupler between the intercooler and the intake manifold is 2.75". Can anybody confirm this? How big is the VF11 90 degree intake tube (what size silicone hose will fit)? I'm talking about the cast metal 90 degree intake tube bolted to the turbo's intake housing here.
Legacy777
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Re: Need suggestions on intake piping.

Post by Legacy777 »

Have you looked at this? It has all the hoses and sizes

http://surrealmirage.com/vrg3/vacuum/ej22t_vacuum.png

It would certainly be helpful if the intake elbow is flexible. If it is not, you'll need some sort of flexible piece between the turbo and intake box since the engine moves during acceleration/deceleration.
Josh

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BoneIslandScooby
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Re: Need suggestions on intake piping.

Post by BoneIslandScooby »

I knew you had to have something like that. Thank you so much. You are an invaluable resource. However, here I'm talking about the actual compressor inlet and outlet sizes (which I think I now have a pretty good handle on), and also the hoses or sensors that are plumbed into the rubber 90 degree intake elbow going down into the turbo from the air box.

Do you think that it would be sufficient to have two straight silicone couplings (reducers) going to the turbo, in addition to the one OEM rubber coupling coming from the air box? In the case of a later style turbo, there would be two silicone couplings AND the silicone 90 degree bend attached to the Turbo intake. That should have enough give, right?
BoneIslandScooby
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Re: Need suggestions on intake piping.

Post by BoneIslandScooby »

I think I found my answer: It is found in the following thread: http://bbs.legacycentral.org/viewtopic.php?f=1&t=48276
vrg3 wrote:Maybe this'd be a good time to list what we know about the dimensions of the stock boot.

Off the top of my head:

The entire boot is made of (originally) flexible material and meant to slip over the outer diameters of rigid pipes.

The large fitting at the elbow is 19mm ID, meant for the bypass valve. In stock form, there's a 19mm steel coupling stuck in it to connect it to the hose. 19mm is very close to 3/4".

The other two are 12mm ID, for PCV fittings. Each of them have plastic fittings stuck in. The one that points to the driver's side of the car is a little funny; it has a part that sticks into the boot that's kind of spoon-shaped. 12mm is close to 1/2".

The inlet of the entire thing (the end that attaches to the resonator) is 65mm ID; that's close to 2-1/2". The outlet (the end that attaches to the turbo's compressor elbow) is 55mm ID, kind of close to 2-1/4".

The solution to this may be to just use a 90-degree silicone elbow and move all the fittings to a coffee-cup-style resonator replacement.

Hm. Here's an idea:

Install an MBC so you don't have to worry about the stock boost control valve plumbing. Then, put a check valve in the hose going to the middle fitting of the charcoal canister, so you can get rid of the auxiliary purge plumbing.

Now, get a piece of 3-1/8" pipe (the elbow coming off the MAF has an 80mm ID, close to 3-1/8"). Weld/solder/braze/epoxy/whatever on two 3/4" OD elbows (one for the IAC and one for the BOV), and a couple of 1/2" OD fittings for the PCV (probably one elbow and one straight). This will replace the resonator and everything that used to attach to the stock boot will attach to it.

That new fancy pipe connects to the turbo's compressor inlet with a 3-1/8"-to-2-1/4" 90-degree reducer elbow.

And, of course, you could play with the diameters a little. You could probably get away with a 3"-to-2-1/4" elbow which would be easier to find, for example.
Can anybody confirm the 2 1/4" size" I thought the VF11 had a 1.75" inlet size.
Legacy777
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Re: Need suggestions on intake piping.

Post by Legacy777 »

BoneIslandScooby wrote:Do you think that it would be sufficient to have two straight silicone couplings (reducers) going to the turbo, in addition to the one OEM rubber coupling coming from the air box? In the case of a later style turbo, there would be two silicone couplings AND the silicone 90 degree bend attached to the Turbo intake. That should have enough give, right?
The main issue with the 90 degree inlet going into the turbo is that if it's not of sufficient quality it can collapse under full acceleration. I believe Todd, (Wtdash) has had this issue before and may be able to provide more details.
Josh

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BoneIslandScooby
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Re: Need suggestions on intake piping.

Post by BoneIslandScooby »

I am now conceptualizing what I'm going to do with the intake elbow currently going into the turbo. I know that these are hard to find (if not impossible), so I was thinking of going with 5 layer silicone from www.siliconeintakes.com. I thought I'd get a smoother transition into the turbo as well. I just need to figure out what to do with all the stuff that's plumbed into it. I'm thinking of using rubber grommets in holes drilled into a 3" stainless steel tube, in order to connect some of these things. I have to find the right sizes. Has anybody tried this?
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Re: Need suggestions on intake piping.

Post by camped69 »

2 90's with a joiner from the turbo into a custom coffee mod. The joiner should prevent collapsing.

You will need to trim the turbo side of the bottom 90, it's tight in there. Assembling the 2 90's, then attaching to turbo may help when installing.

I went caveman on mine when inserting the joiner. The 90 was catching on a sharp piece of the intake manifold casting. But that was the easy part compared to fabbing up the coffee mod.

The wandering bung my welder calls it. It 2 1/4" exhaust pipe expanded to 3". Working on version 2 now. Determining what direction to go and rounding up all the parts took the most time. Good Luck! Image
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