Sheet metal intake, questions about runner lengths

I've seen tube belling done on a lathe with an easily made tool.

I think it was one of the crazy Swedes  

In reply to kitsune1324 :

For intake trumpets. What about 3d printing them? (At least two people on this board have) That would slip over (and bond) to the runner protrusions in the plenum.(There hight could be changed individually to equalize flow,think Hilborn mechanical injection ) Forget the filter comment. Was thinking itbs in the plenum. And if stock starved one bank why aren't each side opened to incoming air?

Search for the term "velocity stacks" I can dig up some links tomorrow.

In reply to BarryNorman :

That's a fantastic idea! Do you know what material they used? Since it's in the engine bay, I feel like it may be best to use something like derlin over using ABS as it has a higher heat resistance. 
The problem with my upper intake is that it's heavily modified/ported, and I think there's some blockage where you can't see which is mitigating proper airflow.

Paul_VR6 (Forum Supporter) said:

Search for the term "velocity stacks" I can dig up some links tomorrow.

I found a lot using that search term, but nothing with an ID of 1.5"

Nevermind, i litreally just found one, but it's expensive at $30/each. https://www.treatland.tv/malossi-metal-clamp-style-velocity-stack-38mm-ID-p/malossi-velocity-stack-051510.htm

Yea 20-30$ each is typical and the 1.5" id makes the ones I normally think of way too big.

if I were to print one it would be about $80 each for a low volume but I do polypropylene or nylon12 + vapor polishing. These materials have held up in underhood applications . If someone wanted to buy a few hundred of them the price would drop significantly. 

kitsune1324 said:

In reply to BarryNorman :

That's a fantastic idea! Do you know what material they used? Since it's in the engine bay, I feel like it may be best to use something like derlin over using ABS as it has a higher heat resistance. 
The problem with my upper intake is that it's heavily modified/ported, and I think there's some blockage where you can't see which is mitigating proper airflow.

Carbon Fiber impregnated ABS I believe, at least on the Lamborghini Jalpa project here.  He put them on the ends of Weber style DCNF ITB's and was building an airbox to go around them as the stock one no longer fit with the ITBs.

@80 each for printed stacks I would see if you couldn't get a press mandrel made to flare common tube and do it that way.