Intake plenum and 911 throttle body

[Ben006]

As I said, I do that only as a hobby and because I have enough free time right now. Nothing worth getting in trouble for!

And if anything happens, I can always go back to the original straight tube shape that worked great and that has nothing to do with IPD patent.
(the only reason I used a wedge on the new version is to stiffen the 3D printed part. It's not needed for the aluminum part).

I went to the foundry yesterday, and I think I can do an aluminum part for a price close to the 3D printed part, the only difference is that I need, like the shifters, 10 or more person that want one to start.
I'm not done with all the costs yet so I can't tell you a price. Should be around 300$.


Also, I found the datasheet for the 3D printed material: https://www.shapeways.com/rrstatic/material_docs/mds-strongflex.pdf
The plenum operates at a temperature way lower than those value, so it's safe.

If you are interested in having one in aluminum, you can send me a PM.

Thank you!

Ben.

[Ben006]

Sooo...
Just to be sure, I've send a mail to IPD.

We'll see!

[The Radium King]

Originally Posted by Ben006

And if anything happens, I can always go back to the original straight tube shape that worked great and that has nothing to do with IPD patent.
(the only reason I used a wedge on the new version is to stiffen the 3D printed part. It's not needed for the aluminum part).

well, I agree that the wedge is not required - there are some flow analyses that have been posted on this forum that show that the flow naturally splits there and there is no need for the divider.

the true problem is with the inside radii when the flow splits - too sharp a curve and the flow delaminates. so, the primary focus would be to make a plenum that has larger inside radii, as the OEM tube has a very sharp bend in it.

the other issue is that you are limited to a smaller throttle body; 67 mm on the S models. it would be nice to be able to use a cheap 76 mm throttle body take-off from a 996/997/Cayman. you need a different plenum for that, however.

the thing is, the OEM 997 plenum at $40 new meets all these needs, so the only real benefit of an aftermarket piece is to match the secondary diameters to the intake runners. That is a benefit, however, as is anything that makes it easier to install the part. with that in mind then perhaps consider the ducting between the throttle body and airbox as well, so that you can sell as a kit and add some value to your product.

personally, I think the real market is with the 996/997/Cayman guys. these cars have bigger engines and can actually benefit from the 83 mm GT3 throttle body. unfortunately, there is no OEM plenum that will drop in (the GT3 intake is configured differently) and the aftermarket stuff is at IPD prices.

[Ben006]

Thanks for the advice

I just received an e-mail saying that IPD's mailbox is full, so they didn't receive my mail... we'll see Monday.


My main goal was to make a plenum that easily drops in place of the old one, without complex intake tube, stretched boots and a almost factory look.
I didn't like the 911 plenum solution, even is it's the cheaper and that it still gives result.

For the intake tube, I don't think I will include it in a kit (unless people really want to, I can figure out a way) as it would just add complexity for me (waiting for more deliveries that might be lost... like what happened with the ball bearing for my shifters).
Two of these:
US 3" to 3 1 8" 76mm 80mm Silicone 90 Degree Elbow Reducer Pipe Hose Red | eBay
+
one of these:
3" 76mm 15deg Aluminum Turbo Intercooler Pipe Piping Tube Tubing L 610mm | eBay
Will make a perfect intake tube! that's what I use:

EDIT: I've just checked, I can have that cheaper if I have at least 10 people.

As you said, the benefit with my plenum is the inside radius, I can't have them smoother!

I first went to the Y shape because the 3D printed part wasn't stiff enough in the version I tested (but still perform perfectly!).

For the 987.1, I think the use the same dimension as the 986 ? And the 987.2 is too big for me :/

Now, I will work on figuring out how to make it out of aluminum (the fittings, small details that will make it easier to produce etc...) and how to make the 3D printed part stiffer without the Y shape.
In case IPD answer negatively.

If you would be interested in getting one, PM me so I can see how many are interested

Ben.

[BrokenLinkage]

1) re: IPD. I don't think I would poke that skunk. Their counsel will undoubtedly ask you to cease production and alledge infringement, whether legally correct or not, just to protect their future rights.
2) while I like the idea of aluminum as a more durable material, won't it result in more transfer of heat from the engine compartment to the incoming stream of air, thus decreasing density?
3) I'm interested.

[The Radium King]

Originally Posted by Ben006

If you would be interested in getting one, PM me so I can see how many are interested

i am interested in one for an 83 mm throttle body - i think i'd pm'd you about this quite a while back - but still need to get you the dimensions; i'll try and do that in the next few weeks.

[Ben006]

Originally Posted by BrokenLinkage

1) re: IPD. I don't think I would poke that skunk. Their counsel will undoubtedly ask you to cease production and alledge infringement, whether legally correct or not, just to protect their future rights.
2) while I like the idea of aluminum as a more durable material, won't it result in more transfer of heat from the engine compartment to the incoming stream of air, thus decreasing density?
3) I'm interested.

For peace of mind, I think I will still ask them. The T design is out of their patent, so they can't say anything about that

Aluminum is stronger, but yes, nylon doesn't conduct heat like aluminum does, they both have their pros and cons:
3D Printed Nylon:
-No production run needed
-can easily be made to suit 76 and 83mm TB
-doesn't conduct heat well
-cheaper

Aluminum:
-Strong and durable
-Better surface finish (can be media blasted to achieve the perfect finish)
-A lot more expensive
-conduct heat well

Originally Posted by The Radium King

i am interested in one for an 83 mm throttle body - i think i'd pm'd you about this quite a while back - but still need to get you the dimensions; i'll try and do that in the next few weeks.

I remember, you have a 911 engine right ? I need the inside diameter and width of the cross tube and the inside diameter of the gt3 TB's exit.

Right now, I have a little something that might be interesting, I'll post another thread

Ben.

[Ben006]

I'm done with the last version.
It does not infringe the patent, and should resist, it's thicker than any of the other.
Pretty sure two persons (two like me at least^^) can step on it without breaking it.
Problem, now it cost way more to make... but still under 300$ !

Try this link, you should be able to see it: Porsche Boxster Intake Plenum (F3SH5ZNFE) by Ben006
I'll continue to update it until I now what I'm allowed to do or not.

[Ben006]

I should get an answer from IPD tonight!

Then, last verifications and I'll make the new prototype according to what they will say !

ben.

[Ben006]

Hi!

I received the answer from IPD yesterday, and its... no.

Well, good thing I already started the new version!

So now, this week end I'll check the final dimension, and order the part!
It should take a week to arrive.
Then I'll use it for a while, I'll probably do a track day with it next month.
But if I see nothing abnormal during the first weeks, I'll make it available and you'll be able to grab one!
Since I need to re-check some things, I can't tell a price right now, but expect it to be around 260/270$ (without the throttle body and intake tube).

Thanks guys!

Ben

[Ben006]

Here is the final version... now I just need to print it...
It's stressful!

[Ben006]

I should receive it in 10 to 12 days!

For those who are still sceptic... the oil filter cover is also nylon (15% or so glass fiber), and has no problem with the oil temp and high pressure

[Ben006]

Guess what's there!






It feels even more solid than the old one!

I need to clean it before trying it.
It should also fit even better since the TB will be 6mm further back and will clear the starter solenoid perfectly!

Ben

[Leebherron]

Nice work !!

[cbadbox]

Looks good! I continue to follow this and your shifter thread.

[Ben006]

OKAY!

This morning I woke up with a headache... but I couldn't wait more!

So...



Yep, I put my dirty fingers all over it!



For comparison:



So, first, I have some modifications to do, to make it easier to fit, nothing major, but still (it stretches the boots too much to my liking, and the PCV fittings are too close to each other.)

The fact that it's 5mm shorter makes the intake tube very easy to fit, and there's lot of clearance now.

I had to turn the cross tube a little because the stiffening ribs were hitting the valve mechanism... takes 30sec, but took me 15min of driving to figure! The howling noise after 5000 was missing, and the engine was very linear.

I drove it for around 20minutes, the mid range torque is still present, I haven't pushed it too much, I want to go gradually. (And I don't want a ticket...)

Today is a hot day with very low humidity today (35% right now) which isn't that great for power... so, doesn't matter anyway.


I checked after a bit of driving:


It's actually cooler than it was when it sat in the sun while I was working! So, not worried about temp problem! I'll still check after longer drives.

I'll drive it as long as my AOS survives (remember last time? ^^), and check it regularly.
By the end of the week I should be able to tell any gain in power (the last one did, so this one should).

I did take a video... but I'll take another one where I don't film my license plate...

Ben

[Ben006]

Hi!

The idle is finally stable
But the AOS is starting to give up... again.
It's OK, it only affect idle a bit, it's not too bad now.

Like the last time, the sound is very nice!
After 2000rpm it has the same power, maybe a bit more. And after 3000rpm it definitely has more power.

I'll check if everything is right this evening when the sun won't cook me alive.

The only thing I don't like about it... is the wind noise at part throttle, I drive without the insulation on the cover now (so I can access it quickly) and its noisy...
I'll try with the insulation back on tomorrow.

Again, I feel like a tune/remap would really work great with it, but I can't afford it right now.

Ben.

[Ben006]

Hello!

After a week of driving it (~260 miles) the idle is now very stable, just as stock.

The power as greatly increased from 2000rpm through redline, it's really noticeable!

Below 2000rpm, it's different as expected. between 1300/1500 and 2000rpm, it feels like stock, and below that there's slightly less, but it's completely out of the operating range so it doesn't matter much.

I checked it everyday (we had a quite hot week this week) and no problem detected.

So, testing continue next week

and May 24th I'll do a trackday with it.


Ben

[Ben006]

Litlle update:
My gas mileage hasn't change 24.9mpg.
Usually I'm between 23 and 25.5mpg.

I took one of my friend for a ride, and he also noticed the increase in power, it's not only in my head

testing continues! (Can't wait to be Tuesday...)

Ben.

[Ben006]

Hi guys!

Another update

I did a track day with the plenum yesterday... it was perfect, didn't have any problem, and made consistent power all throughout the rev range with a beautiful noise!

I have to visually check it, but since the car still runs great, there shouldn't be any problem.

The testing will continue until the end of June at least.

My gas mileage hasn't change significantly either.

For comparison: A stock 986 S
https://www.facebook.com/benjamin.nenert/videos/10209542163249346/?l=3024385774512079470

Mine with the plenum, headers and mid pipes:
https://www.facebook.com/benjamin.nenert/videos/10209542163369349/?l=3745880025100679306
https://www.facebook.com/benjamin.nenert/videos/10209542163289347/?l=3187950946171532859

I'm very please with it so far!

Ben