Intake plenum and 911 throttle body

[Ben006]

If you want a good Y shape, you have to have the TB pushed out, i'm working on a new one with a Y !I can't have a Y as large a the one you're showing in the bottom because the space is not wide enough on the 986.
The wedge stabilises the air, maybe the cfd testings of the T alone don't show a big improvement with the wedge, but once on the car with the whole system, it should make a bigger difference.
You want the flow as clean as possible all the way to the valves (the you want turbulences in the combustion chambers).
In a naturally aspirated car, every bit counts

I have my midterms next week so I have to study and will not have too much time to do it this week, but after I will have all the time I need !

[KRAM36]

I think the reason the wedge doesn't help as much is because the wedge actually makes the inside circumference of the tube smaller and less air can get through.

Keep at it! I would like to have one with matching tube diameter to the plenums. The 997 has an OD of 97mm. Much larger then the Plenums opening.

[The Radium King]

i personally think reducing the turning radius of the air ('improving the y shape') is the primary benefit so that the air can adhere as it turns the bend, which will reduce resistance and increase flow volume.

at steady-state flow an area of turbulent air is established where the wedge sits, and turbulent air has less flow resistance than the wedge does, so the wedge is not much of a benefit.

HOWEVER, the flow through the intake tract isn't steady state. it pulses with opening and closing of valves, so the turbulent air wedge is constantly re-establishing itself. in this instance having an actual divider may be of some benefit. unfortunately, the previous offerings available to us were a bit expensive ($260 for pedro to add a wedge to a 997 plenum, or $900 for an ipd unit). further, if the wedge isn't done right, as kram says, it probably does more harm than good as it becomes a restriction to flow. ps, not arguing against Pedro's claimed gains from the technotorque, nor that his pricing is unrealistic, but am wondering how much of the gains he shows are from the 997 plenum vs the added wedge - that would answer the question.

[KRAM36]

More inspiration lol.



Werks1 - Porsche 997 Carrera/Carrera S Carbon Fiber Plenum

[Ben006]

I'm taking your comment in account for the next shot

With the design I have now, the air stays attached to the plenum as it turns (well, just by blowing on it you can feel that the air stays attached to the inside, my test worth not that much but I'm confident )

And the roughness of the material help with that too !

[BYprodriver]

Any concern about nylon contracting when it gets hot?

[Ben006]

nope, the temperature will not rise above critical level for this part, and if needed, a heat shield can easily be wrapped around for protection !

We will see, that is why I want to test it before anything else !

[KRAM36]

Here, look at how this is done. From the TB point the section goes all the way to the top and to the side. No T shape to it at all. This is what you should shoot for. Get rid of the tube to tube design. Actually I would call this a V shape more then a Y shape.

[IMG]http://www.****************************************.com/Images/93174-3.61.jpg[/IMG]

Just need it to have the same OD/ID where it meets the stock Boxster Plenums and accepts a 76mm TB. This picture is for a 996, but it only accepts a 74mm TB.

[jaykay]

Whose engine bay is this? I would like to see your intake pipe arrangement..

Originally Posted by KRAM36

I didn't figure you could. What I would focus on is getting the Y shape better then the 997 piece, if possible shorten the distance from the TB connection to the Distribution T. On the 997 part it puts the TB very far out. I would probably forget about the wedge too.

This is what I would want for a Distribution T that accepts a 76mm TB and has the same diameter tube as the plenums.



One of the problems with the 997 piece is the larger diameter tube, which also pushes the TB further out.

[KRAM36]

That's BYprodriver's engine bay. I will have mine installed in the next 2 weeks, still waiting on a couple of parts to come in, but have my 987 air box modding done.

maf and throttle body diameter

[Ben006]

I'm working on it

Also, I made a heat resistance test today, I bake the T in the oven at 190°F (a temperature that it will hardly see in real life) for 2 hours, after that I tried to bend and compress it, but it held just like when at room temperature So I have no worries at all for the heat now.

[Reebuck1]

When will you be ready to make the 74 mm intake??

[Ben006]

Well, I have yet to receive the hardware et test it on the car :/
the problem is that some supplier are very slow... I think I will switch from metric nuts and bolts to inches so I can find the hardware easily.

as soon as I validate the part and the reliability I will make some for the others

[Ben006]

new shape for the 76mm


and for the 83mm


I don't think I can get more angle in the V without sacrifying the smooth transition between the tubes.

[KRAM36]

Looks nice! When do you think you will get a test in on one?

[Austinsynthetics]

Originally Posted by Ben006

No, these retain the stock TB but add a "divider", the first purpose of my is to use a bigger throttle body.

I took the measurement on my boxster 2.7 wich share its intake with the 3.2, so I already have the measurement.

I can make it any way you want, straight T, with a little turn, divider, no divider, wright anything on it ... etc

Not sure if you're keeping a list, but I'm interested in your design. I also have a 2.7 liter

Thanks,

Brett

[Ben006]

For now the list is this thread

I'm still waiting for some hardware (from various places, to see wich one will be the best, that's why it takes some times).

Ben

[Ben006]

Hi !
Two more parts to get and I can test the T ! I can't wait !

The nuts fit in as designed


I will test it on a dyno the 11th of ... April ... It's a month to wait, but it's the only time I can dyno it. during my school car show !

[KRAM36]

Anymore pictures to share? I'm very curious on what you have going on. I need a different distribution T and the 997 Distribution T is too big, it also has this thick piece I marked in red that hits the top of my starter and I can't get a good down angle on the TB.



I really don't want to change the intake as the car is running like a beast right now. I suppose I could take it back out, shave off that area and reinforce it by melting some wire into it.


.

[Ben006]

now I'm stuck on the testing because I have no place to work :/
I don't need to do much, but I can't do it at home because my 93YO neighbour will report me for doing so ...

Monday a friend should lend me is garage for few hours and I will finally get this thing done !

The only thing I did is a little sanding to smooth the outside and got the EVAP port enlarged a little.

I hate wasting my time like that, waiting.

If anyone want's to offer me a little clean place to work at for a few hours, he's welcome