3.2 VR6 OEM+ intake manifold project.

[zetarhopike]

Looks like I was wrong about the intake being not variable, I've got to ask where you found those pics? I spent the better part of an hour looking for something like that...

[need_a_VR6]

There was a very good article published recently that compared a bunch of intake bellmouth designs. The quick synopsis is that when you compare round to oval bells, the oval profile flows less per a given area, even compared to a 'simple' round bell. There are gains to be had optimizing the round bells further with elliptical profiles, etc. I'll link it up once I find where it was hosted.

[fourthchirpin]

why dont you make a flange that converts from 3.2 on the head side and 3.6 on the manifold side.

take this flange and weld it up to this with transition runners.

[fourthchirpin]

Quote, originally posted by need_a_VR6 »

There was a very good article published recently that compared a bunch of intake bellmouth designs. The quick synopsis is that when you compare round to oval bells, the oval profile flows less per a given area, even compared to a 'simple' round bell. There are gains to be had optimizing the round bells further with elliptical profiles, etc. I'll link it up once I find where it was hosted.

what about round vs. square.

[RipCity Euros]

You could do something like this, but retain the OEM changeover.

[need_a_VR6]

http://www.profblairandassocia...t.pdf

[Issam Abed]

I made a flange for Phil@Dubsqaured before for his 3.6 NA project.

Josh that flapper motor has to go.

[VR6ix]

I have ideas floating around in my head exactly the same as PowerDubs... but for a 12-valve motor, which does NOT have the constraints of the coils sticking out the top of the head. Basically, a new upper manifold that incorporates the resonance chamber but has shorter runners, either trumpeted into a plenum or with ITBs...

... and most of my idea was based on fab'ing a custom cowl-induction hood. Inspiration directly from factory cowl induction hoods on Camaros, Chevelles, etc. One for clearance and Two for the cowl-induction benefits. Three for blowing past the 200whp "limit" on the 12v and Four for doing something way out of the box. Five is making it all work in a 4-seasons car, rain, snow, etc. I'm currently at Step #-1, so this topic is interesting to finally see posted.

If I get real ambitions I'll try to model it up in SolidWorks before 2011 happens, but I'm only at the "quasi-enlightened layman" knowledge level regarding legit tuning and the physics behind everything. Topic Watched to say the least! Good luck!

[Brake_Dust]

signing in to read later

[Slampig]

watching this.

[R32Freddie]

Quote, originally posted by Slampig »

watching this.

x2

[Nemesis-Brad]

I originally talked to Josh about this , if someone can draw this part up I'll offer my fabrication and welding skills to make the first prototype up .

[PowerDubs]

I've had several people ask me to draw it or measure.

The person doing the fab needs to have a stock manifold as well as a head/valve cover to test fit along with any measurements.

[PowerDubs]

Guys.. to do this complete custom intake manifold will cost a lot of money. I have no problems with that, It will just take a while to come together.

I've got an idea that may be doable for CHEAP that might make exactly the difference I'm looking for without having to spend thousands on a complete new manifold.

I've got to go out for the afternoon/evening, but I might have progress pictures / details later tonight or sometime tomorrow.

The answer was right in front of me the whole time in this picture.

[newcreation]

Well what might that be Josh the answer that was infront of you the whole time???

[stirfriedx9]

looking at that picture im thinking you need two stock plastic manifolds to make this work. cut the top off of one right at the top, then cut the top off the second one halfway down around the seem where the two halves of the manifold join together. put that top onto the other, and presto...you increased only the height of the runners and plenum. the problem is molding the two halves together, so that they dont leak. thats my guess anyway....

[Det. John Kimble]

Quote, originally posted by Slampig »

watching this.

Definitely watching this thread

[R32_alex]

i've been refreshing this page like 40 times a minute sitting at work here getting excited for results. Hopefully your idea works out for you Josh. definitely watching this thread. More power to you

[grammaticus]

Quote, originally posted by R32_alex »

i've been refreshing this page like 40 times a minute

x2

[PowerDubs]

I had time to get some work done on it last night. I've been out all day and have to go back out this evening.. but I might be able to get some more work done on it later tonight.

I found out something else last night I wasn't expecting that may be inherently wrong with EVERYONES manifolds..and could be a super simple easy fix.. I just need to do a couple measurements and test fits. I don't know if this 2nd part will make any true power difference at all...but just knowing it is wrong bothers me.

[newcreation]

Can't wait to see what you have found or thinking about cause i am not sure have my spare in front of me and apart

[VW-FF]

Trying to be patient, refresh, refresh, refresh, ugh nothing lol

[need_a_VR6]

Quote, originally posted by PowerDubs »

I found out something else last night I wasn't expecting that may be inherently wrong with EVERYONES manifolds..

Jesus #$@)* Christmas Secret Squirrel spill the beans and then I can tell you if you've had your head in your ass lately or it's a good idea.

[R32_alex]

if you paypal $10 he will tell you.

[Saabstory02]

Subscribed; this is better than Days of our Lives

Joking aside though; I just want to say thank you to you for all your work, experimenting and effort in pushing these motors beyond the limits with NA power. Oh yeah, and I want to know what you found that's wrong with my manifold as well!


Modified by Saabstory02 at 6:45 AM 1-27-2010

[R32_alex]

I imagine the 08 r32 manifolds would be slightly different. no?

[Saabstory02]

There may be slight differences, but without removing both and measuring they appear to be pretty much the same.

Besides, he did say everyone's...


Modified by Saabstory02 at 11:48 AM 1-27-2010

[PowerDubs]

Quote, originally posted by Saabstory02 »

I want to know what you found that's wrong with my manifold as well!

Sorry...I should have clarified. It would be impossible for the MK5 to have the issue I was speaking of.

[Saabstory02]

Quote, originally posted by PowerDubs »

Sorry...I should have clarified. It would be impossible for the MK5 to have the issue I was speaking of.

No worries, either way I've learned more about the R's intake in this thread than in 7 months of ownership

[newcreation]

HMMM come on guy

[PowerDubs]

Hey guys.. getting a lot of PMs wanting to know whats going on.

I was going to wait until I had some pictures to explain everything, but that won't be until tomorrow at the earliest. I had to go buy a right angle adapter for my dremel..

Add to that a plastic welder, and we have a nice smelly low budget project going on.

First up is the simple thing I was surprised about.

The manifold I am using for my project is like new, came off a very low mileage car. While I was working on it the other night, I stuck my finger in it to wipe away some shavings and I discovered the changeover valve doesn't line up!!

It is off enough that it makes a lip on one side and a drop off on the other .. factor in both openings on the rod and and the pulses moving back and forth and you have 4 spots on EACH runner that disrupt airflow.

Should be easy enough for me to measure how far off it is and shim it.

Now on to part 2- (the actual modification that I am hoping will make a difference.)

What are the 2 main things that effect where the power is tuned on an intake manifold?

Runner length and runner diameter.

I can't do anything with the stock manifold about runner diameter.. but I can about the runner length. Look in the resonance port. I can shorten the 'high speed' runners roughly an inch 'just' by grinding them away. Should kick the peak power up 500rpm or so.

[need_a_VR6]

Won't the distance from the port outlet to the power port plenum wall (the part removed from the metal one) be a factor in resonance tuning? Planning on just cutting out the dividers in the resonance ports down toward the changeover valve?

A customer of mine actually had documented track gains removing the changeover rod totally. I'm wondering now if it's misalignment that could be a factor that when it's removed it can have stronger wave reflections.

I still think you should plastic weld two of them together vertically for more port area.

[climbingcue]

Quote, originally posted by need_a_VR6 »

I still think you should plastic weld two of them together vertically for more port area.

I thought that would also be the best idea...

[Brake_Dust]

Quote, originally posted by stirfriedx9 »

looking at that picture im thinking you need two stock plastic manifolds to make this work. cut the top off of one right at the top, then cut the top off the second one halfway down around the seem where the two halves of the manifold join together. put that top onto the other, and presto...you increased only the height of the runners and plenum. the problem is molding the two halves together, so that they dont leak. thats my guess anyway....

who has a band saw?

[PowerDubs]

I have a small band saw, but trying to increase the main runner size would be extremely difficult and LOTS of cutting and grinding, test fitting...and the odds of getting the parts back together and sealed solidly is unlikely. If someone thinks they can pull it off.. DO IT. I've decided not even to try it (and I'm pretty adventurous)

Shortening the 'high speed' runners as I am doing is something most people could do themselves if they are handy...and I think it should make a positive difference.

Quote, originally posted by need_a_VR6 »

Won't the distance from the port outlet to the power port plenum wall (the part removed from the metal one) be a factor in resonance tuning?

It is my understanding that pulse reflection occurs at the end of runners / opening of plenum. The area 'opened up' by shortening the runners effectively becomes additional plenum area. In theory this will also benefit us.

Quote, originally posted by need_a_VR6 »

A customer of mine actually had documented track gains removing the changeover rod totally. I'm wondering now if it's misalignment that could be a factor that when it's removed it can have stronger wave reflections.

Well, if the rod was removed totally there are a LOT of changes going on to the airflow. It wouldn't surprise me if the now empty rod chamber acts like a mini plenum initiating the pulses earlier than with it in place. The issue I would have is the associated turbulence from the other side and edges. Also, the low end would suffer..not that it would matter on a track.