VAP

I have mentioned here the shortest-tightest/thinnest wall elbow you can find for placement between TB and firewall is to ALWAYS be preferred because of space constraints on EVERY 12V platform. I've also mentioned in several places that a softer, more gradual minor radius will outflow that tighter radius TB elbow. What I've neglected to mention, and only for those that didn't connect the dots or put two & two together is that there is benefit to using the tighter minor radius elbow on the TB but to use a more gradual minor radius elbow on the top. Using a 1.5" minor radius or similar on the top elbow results in a just over 18% flow increase in the lower/tighter elbow under WOT conditions and at above 4k RPMs.

I experimented with this 5-6 years ago when designing the S3 Hose kit. But I was strapped with having to contend with what people wanted rather than just "my" needs/wants or forced with making many different styles for many different people and chassis's. It was simply easier for me to make the best-flowing-one-size-fits-all hose kit I possibly could. A big desire for most back then was an induction kit that was mildly OEM-appearing and could also be kept under the engine cover yet offered dramatic flow enhancement over the stock hose/plenum that was OEM on the car. I accomplished that in spades!

Sometimes complacency takes hold and we become comfortable and satisfied with the status quo in spite of long-since giving up on things like engine covers and the OEM look. While the system I designed and sold years ago is good, like everything else in car-building it is a compromise. It was as good as could be done at the time while simultaneously retaining the things "most" buyers wanted. And as a result of Luxus's elbow find yesterday can still be done today EXACTLY as it was 5-6 years ago if desired.

While some are perfectly delighted with a "patchwork quilt" type induction system, that simply won't meet the wants/needs of everyone. That goes double for me. I want/need to have things look as clean, near-OEM and as-good as they work/flow while also being uniform, well-planned and executed using matching components of the same color, wall thickness of EVERYTHING involved from the MAF outlet to the throttle body inlet. Purely MY neurosis!

In helping others search for elbows the last couple days I've also been keeping my eyes open for a more gradual minor radius 90 degree elbow for my own use as my "upper" elbow. Getting it in black is easy, getting it in 2-ply, +/- .110" wall thickness has proven impossible. And since the upper elbow is out in the open and in plain sight I just don't want that shouldered "step" to be so prominently visible in my upper elbow with the hood open. Sure it's a small thing to contend with but to me it's H-U-G-E... flat-out a deal-breaker! I have plenty of black silicone straight .110" wall tubing around for my own use that is identical to the tight black elbow. And of course I could opt for 4-5 ply silicone tubing like Samco et al for the top elbow which would appear identical up top save for the small thin-wall TB elbow hidden below. But that wall thickness causes interference with other things like ISV en route to the TB from the MAF outlet. See? EVERYTHING is a compromise!

So I'm thinking a custom one-off gradual radius thin-wall elbow. And because the components I'm using are also available in red I'm thinking of replacing everything with red just because of my car's color.

A 1.5" minor radius upper elbow with a tight radius elbow on the TB at 328CFM (average 12V flow rate at WOT above 4k RPM) flows 18% better than 2 tight radius elbows used "in-parallel." On my new engine it could easily be twice that!

Having a custom elbow made represents a VERY steep set-up and manufacuring cost involving a new mandrel be made to wrap the silicone on. If a manufacturer will allow me to CNC my own mandrel that could save me thousands of dollars. If they won't allow that then I'll likely have to forget the entire idea as they'll probably want at least $500 just to produce a single elbow for me once a mandrel is produced. I'm willing to do $500 or so for 1 or 2 so I have a spare. But $3-$5k is not even a consideration. Hell, for that kinda money I'd want a one-piece MAF-to-Throttle Body silicone hose-kit... but history shows that can't happen either, least anywhere NEAR that price.

Another option available to me is to find a silicone tubing/elbow manufacturer that's already in posession of a more gradual radius mandrel and have them "wrap to spec" a silicone elbow for me with 2-ply (instead of 4-5-ply) in order to attain the .110" wall thickness. I'll be inquiring about that possibility later today.

Last time I did this I did what everyone else wanted or would buy if I made it. Today I want to do what "I" want and then compare the 2 side-by-side.

Luxus Panzer

<ul><li><a href="http://www.siliconeintakes.com/product_info.php?cPath=3&amp;products_id=37&amp;os Csid=247a034c0d737e502ce932c9605b2a2a">I hope so as I already have one!!!!</a></li></ul>

VAP

as I gave everyone full instructions with the formula on how to do this at the post linked below. Rather than me do the math why don't you give it a whirl and see what you come up with? If you get stuck I'll help.

Trust me, if you're gonna work on cars you NEED to know how to do this. And once you learn and are still shopping elbows you'll be using it again before the day is over.

So c'mon Lux, do some of that math stuff and tell us what minor radius is on that elbow you linked to. Easy-peasy!<ul><li><a href="https://forums.audiworld.com/12v/msgs/74499.phtml">How to measure radii</a></li></ul>

dragon-ryder

I've since choosen to go a different route, but here's a few things I was working on before that may help to give some insight...
<img src="http://img.photobucket.com/albums/v697/anokiernan/Intake%20Plenum/intakeplenumassem.jpg">
prototyped:
<img src="http://img.photobucket.com/albums/v697/anokiernan/Intake%20Plenum/DSC02509.jpg">
<img src="http://img.photobucket.com/albums/v697/anokiernan/Intake%20Plenum/DSC02510.jpg">

Second Iteration comparision (it's pretty obvious which is which):
<img src="http://img.photobucket.com/albums/v697/anokiernan/Intake%20Plenum/intakecomparison1.jpg">
<img src="http://img.photobucket.com/albums/v697/anokiernan/Intake%20Plenum/intakecomparison2.jpg">

The design was optimized via CFD to B4 chassis constraints while remaining compatible with the OEM engine cover (I don't want to give up the CF engine cover P ).

Luxus Panzer

<center><img src="http://www.siliconeintakes.com/images/product/90_3.0_specsheet.jpg"></center><p>I am not to sure how to do this, but following your directions (I think)....

I measured this diagram on my screen and the gose diamater is 3.5"

The Radius (1/2 the circle) of the bend in this pic measures 2.5". This is where I am kinda confused on where to go from here with the mathmatical equation?

dragon-ryder

you can't measure it on your screen since your resolution plays a part in it's display.

VAP

with 1" diamter plug-ins cast to receive dual-ended short tubes with a single bead rolled into them for CCV. Designed for the B4 chassis till I got an estimate on set-up and manufacturing. Was a $24,800 buy-in for setup and 50 (mandatory minimum) pieces from Samco in the UK. No US manufacturer at the time would touch it! And Samco wanted me to build a prototype to send them using elbows and hose couplings to form the final shape. Something I couldn't do because it required more than just simple 90 and 45 degree elbows. However it was price alone that stopped me in my tracks due to the $500 per-part cost. And it was B4 chassis specific... didn't address B5 or C-chassis.

Luxus Panzer

sorry but I do not seem to be grasping this.

I understand that the radius is 1/2 of a circles diamater, but this is where I get a bit fuzzy.

The instructions say to measure the pic on your screen. I do understand how resolution works so I see how this could not work.

me=confused

Luxus Panzer

so did you give up on that design or do you still plan on making them?

VAP

the 12V people as it relates to elbows is "fitment" rather than empirical radius it's perfectly fine/acceptable to do so. The number achieved may not be "exact" to thousandths but it will certainly be within .100" if done carefully unless it's a REALLY small, low res pic that has to be blown up 400% or more to be measured. Those are virtually impossible to scale on-screen accurately especially if visually bit-mapped. However, most I've seen/measured on-screen within the past 5 or so years have ALWAYS been within or less than .100" of the radius I measured/interpolated on-screen and what they turned out to be when they showed up on my door step. And .100" of an inch of radius tolerance has never, even once been such a significant or dramatic obstacle that it posed ANY problem whatsoever in fitment. And it beats the socks off "guessing" if a hose will work without benefit of ANY measuring whatsoever. Additionally it simply KILLS ordering elbows en masse with no earthly idea if their radii allows fitment. Very much a "measure twice/cut once" precept.

Surprisingly enough most silicone resellers, or at least the people answering the phones are unable/unwilling to tell you what their elbow radii are! I've found others that told me only for me to find out after I got them they had given me diameter numbers instead of radius numbers rendering my purchase from them a flagrant waste of time and money. Far better, cheaper and more convenient to measure their product pics on-screen than rely on their spoken information.