M20 intake manifold design thread

[B C]

A few of us here are interested in designing an intake manifold for an M20, and a few have already started working on them. 

SOME DISCLAIMERS

UNLESS YOU ARE A NERD, THIS WILL BE AN IMMENSELY BORING THREAD FOR YOU.
IF THIS THREAD SEEMS BORING ALREADY, CLICK HERE  https://user.xmission.com/~emailbox/trivia.htm

1) I do not know everything, especially when it comes to unsteady flow dynamics.

2) I have done a lot of research on intake design over the last 13 years in my free time, but I am still nowhere near an authority/expert on the subject. It is just one that fascinates me and I may have an unhealthy level of interest in it.

 

3) I DO know that even when playing with advanced maths and analysis, that there are still 9302934021 things that aren't being accounted for, or cannot be predicted. If you have done well, and get lucky, you may find yourself in the ballpark of where you need to be. Real world testing, when possible, trumps mathematical analysis all day everyday and 3.14 times on Sunday

 

4) Even when testing a manifold design on a flow bench, there are still at least 2814731 things that aren't being accounted for, or cannot be tested.

5) The only 100% accurate testing and analysis is performed with a manifold installed on a car with proper measurement equipment (dyno, etc)
 

6) The time, cost, and knowledge involved in thoroughly developing the ideal intake manifold is unrealistic for anything short of an F1 team, and even then, they have to draw the line somewhere.

 

7) Assumptions must be made. Whether they are good or not, you must make assumptions. If and when the end product doesnt work as intended, you must re-visit your assumptions and make adjustments.

 

Now that is through,   this thread is for us to exchange thoughts and theories about taming the crab under the hood. 

 

-------------------------------------

 

 

 

[ClassE]

Awaiting my PNP MS box... Once it's installed and tuned to a reasonable level, intake mani is gonna happen.

Hopefully in time for Scooters... But likely will be done after.

[straight6pwr]

this should be awesome.  the dbilas itb intake is pretty much the sexiest thing you can bolt to an e30, so anything that even aspires to it will be awesome as well.

[fporro]

Aloha,

 

Am glad you guys taking on this topic and no, am not trolling, just glad to even if in a comical way manage to stir the pot.

 

running dbilas 44mm itb's and the plate that mate it to the head. it has been shown that 40mm is more than enough for 885 heads. 

 

Here's the short of it, using pvc because ...

 

- ease of manual-ability

- 40mm inner dia (optimal for 885 heads)

- it withstands n/a temps just fine

- you can't blow it apart with n/a psi.

- super light

- creases are minimal and super easy to fill in.

 

you guys should get transarent pvc pipes and plexy glass, make a box, experiment more I say.

see with your eyes what the gazillion of unanswered equations your brains can't visualize.

a aint a sin for sponge bob's sake !

 

1st) setup previously posted here, i concur, crap and thanks for constructive criticism.

2nd)  1/2/3 + 4/5/6, 13 inch runners, sounded nice, ran well.

3rd) 1/3/5 + 2/4/6 (video) resonance at 10 seconds, cutting off at 4200 rpms, on better ms2 itb, tune now.

 

[Bassboy3313]

This is a very cool take on a custom variable length intake manifold (VLIM) that an e21 member on BF has been working on. Possibly some inspiration for you guys.

 

http://www.bimmerforums.com/forum/showthread.php?2144807-Winter-Project-2014-2015-VLIM