3.2 VR6 OEM+ intake manifold project.

[PowerDubs]

Received a helpful PM-

"Great find Josh on the change over rod. From what it looks like. The rod can move well over .100" within the tube. It looks like the openings are off by .100" and there is still additional room for the rod to move further. I was thinking about making a spacer real quickly on the lathe to see how it will fit inside there. I am going to try to make it out of delrin..."

I'm glad to see others interested in this.

I'm about to head downstairs after I eat and see if I can make some progress. I'll take some pics while I'm at it.

[need_a_VR6]

You're correct the main pulse from the 'open pipe' is determined only by the runner length but there's a secondary wave from the plenum wall and distance and plenum volume are factors. This is why some plenum manifolds can make more power then ITB's for a given runner length and diameter.

I look forward to the testing.

[XXX008XXX]

just use a short runner!!!!!

[PowerDubs]

Took some prelim pics after working with the new angle attachment for my dremel.

While working to keep what I think would be a favorable knife edge to the splitters, I did a quick rough measurement and I was able to shorten the divider 5/8ths.

Of course now that I am thinking about how the manifold breathes up from one runner, across and down the next.. I might flatten / round off that knife edge close to what the factory had in there. Funny how while working the grinder, I forget what I was working on and went straight for head port design.

This is the initial rough cut. I'll 'polish' everything up once all the major chop work is done on all runners. Looks better in real life than in the pics. I've got shavings everywhere..

Note the dividers are not straight because the runners themselves are angled if you look at the outside of the manifold.

[R32_alex]

Quote, originally posted by XXX008XXX »

just use a short runner!!!!!

I believe that was not Powerdub's intention. One of the first things to try is to modify the stock plastic manifold and see what happens rather than shelling out thousands. Josh might be onto something.

[need_a_VR6]

If you filled the outer part of the manifold with epoxy or jbweld you could probably make them quite a bit shorter yet.

[XXX008XXX]

Quote, originally posted by R32_alex »

I believe that was not Powerdub's intention. One of the first things to try is to modify the stock plastic manifold and see what happens rather than shelling out thousands. Josh might be onto something.

josh knows i am busting on him.

[PowerDubs]

Quote, originally posted by need_a_VR6 »

If you filled the outer part of the manifold with epoxy or jbweld you could probably make them quite a bit shorter yet.

They can't be removed entirely as the air needs to be directed into the ports on the roller. I already have to patch over the depressions on the outside between runners as it is.

I have finished the dremel work. Now I just need to hit the insides with some fine sand paper and it will be ready to seal back up.

Having never used a plastic welder before this ought to be interesting.

[newcreation]

Guess i'll be opening up my spare manifold for some fun as well.Nice p/m from whom ever is making that shim i got that measurement today but i don't have a lathe to work something that small.Hopefully if he can make them.I am down to pay for that to be made since i can't do it on the lathe at work.

Another thing is it worth porting the lower half of the runners from the head up to the changeover might do it anyhow when i'm in there


Modified by newcreation at 5:48 PM 1-28-2010

[dubnick32]

my buddy has a g35 and the higher flow achived on the intake manifold is achived by putting a 5/16 approx gasket in. they get 20 whp from this without a tune. this is what he says anyway. i wonder if this would work on our engines. anyone herd of this?

[newcreation]

I heard of it.Did it on my buddies Z see there manifold is in sections.Its a plenum spacer and its made for the Rev up engine which is 06 up.

[DannyLo]

interesting.

definitely love the passion you have man

more people need to be like you

I kind of want to do this to a 2.8 manifold if i can find a cheap one.

[need_a_VR6]

I got a spare 2.8 manifold if you want to go gutting.

[DannyLo]

how much do you want for it? There's one on ebay for $80 right now i'm thinking of scooping up

[need_a_VR6]

I was asking 150 shipped but willing to deal.

[fourthchirpin]

he still needs to pick up my exhaust manifolds lol.

[DannyLo]

haha the exhaust manifolds i'm going to have to pass on...for now at least. i don't feel like taking the whole car apart again just to get them off the car and put other ones on.

Although an intake manifold could be a fun project i could do and then install in a short period of time to test...plus i could reinforce it for boost in the process with maybe some epoxy and rivets

[fourthchirpin]

its all good.

[PowerDubs]

Quote, originally posted by dubnick32 »

higher flow achived on the intake manifold is achived by putting a 5/16 approx gasket in. they get 20 whp from this without a tune.

I remember reading something about a plenum spacer on that engine having good results.

20whp? I'd be ecstatic with 5.. hell even if there isn't a power 'gain'.. I'll be happy if it extends the peak power say 500rpm.

I've received a couple PM from people who aren't clear on what I did so I threw this together-

[R32Freddie]

Quote, originally posted by PowerDubs »

I remember reading something about a plenum spacer on that engine having good results. 20whp? I'd be ecstatic with 5.. hell even if there isn't a power 'gain'.. I'll be happy if it extends the peak power say 500rpm. I've received a couple PM from people who aren't clear on what I did so I threw this together-

Wow! Awesome! Let us know how this works out please.

[foffa2002@home]

Quote, originally posted by PowerDubs »

I remember reading something about a plenum spacer on that engine having good results. 20whp? I'd be ecstatic with 5.. hell even if there isn't a power 'gain'.. I'll be happy if it extends the peak power say 500rpm. I've received a couple PM from people who aren't clear on what I did so I threw this together-

plenum spacers only work on alu manifolds
No heat transfer addin plastic to plastic

and in your case adding another 1/4th inch isnt going to help at all.

Btw is it possible for you to remove an inch or so in lenght on the upper part of th mani?

I did this port n polish on my MK4 and it basicly didnt even give me 0.5hp.
basicly dyno error was larger then the gain.

i did the upper part and port match vs the head.

bit easier with the 2 pice early verision plastic manifold.

[PowerDubs]

Foffa, he is not talking about a phenolic spacer on an aluminum manifold. He is talking about a spacer that increases the actual plenums volume which can (and does) make a difference on some engines.

Can't shorten the upper runners on this engine since the main plenum and TB will hit the valve cover.

[foffa2002@home]

Quote, originally posted by PowerDubs »

Foffa, he is not talking about a phenolic spacer on an aluminum manifold. He is talking about a spacer that increases the actual plenums volume which can (and does) make a difference on some engines. Can't shorten the upper runners on this engine since the main plenum and TB will hit the valve cover.

plenum spacer mounted n the TB ?
To make a difference it need to be atleast 30% of the plenum size.

Yo can remove 1 inch of runners in the front resonance chamber on the R32.

We did it 6 years ago.
Then just plastic weld it together.

or casco "marine" glue it

[PowerDubs]

Quote, originally posted by foffa2002@home »

plenum spacer mounted n the TB ?

no- http://www.nicoclub.com/articles.php?id=274245

[newcreation]

Josh those are the exact spacers i installed on 2 of my buddies 350z's

[CaptainQualude]

This is sort of like the BMW S52 intake manifold swap for the S50 intake manifold. When are you going to mount the ported manifold & test it?

[PowerDubs]

Quote, originally posted by CaptainQualude »

This is sort of like the BMW S52 intake manifold swap for the S50 intake manifold. When are you going to mount the ported manifold & test it?

Do you have links to those posts? I like reading about stuff..

I still need to weld this sucker back together and install. I should be able to knock that out in the coming week. The dyno is the easy part.

[lil_kano]

in terms of our manifold where would you add a spacer? in between the upper and lower half?

[PowerDubs]

??

Our manifolds have no upper and lower half.

I was just saying how shortening the dividers was effectively enlarging the changeover plenum and someone posted how an increased plenum on a different car had positive results.

[lil_kano]

Quote, originally posted by PowerDubs »

?? Our manifolds have no upper and lower half.

that i know, which is why i was asking. sorry, miss-communication.

Quote, originally posted by PowerDubs »

I was just saying how shortening the dividers was effectively enlarging the changeover plenum and someone posted how an increased plenum on a different car had positive results.

ok, i see what you're saying now.

so what kind of effective increase in the plenum are we talking?

look forward to the results!!


Modified by lil_kano at 12:46 PM 1-30-2010

[foffa2002@home]

Quote, originally posted by PowerDubs »

no- http://www.nicoclub.com/articles.php?id=274245

Nice

But it feels like this work with your plenum is going to be lots of work for basicly dyno error like power gain.

Are you going to test both the plastic ported and then a single plenum with issams stuff?

Make sure to get som nice angle stacks and not just straight pipes

like the http://www.g-e-t.biz ones

[PowerDubs]

Quote, originally posted by foffa2002@home »

But it feels like this work with your plenum is going to be lots of work for basicly dyno error like power gain.

It might be a waste of time, but we will never know until we try.

I hate to bring it up over and over again for those that are sick of seeing it, but on my old 16v, I modified the upper part of the intake manifold by increasing the plenum size and shortening the runners 1.5 inches and achieved what I think is favorable results for such minor changes..and on a virtually stock engine. (chip, catback, oem euro intake cam)

[foffa2002@home]

Quote, originally posted by PowerDubs »

It might be a waste of time, but we will never know until we try. I hate to bring it up over and over again for those that are sick of seeing it, but on my old 16v, I modified the upper part of the intake manifold by increasing the plenum size and shortening the runners 1.5 inches and achieved what I think is favorable results for such minor changes..and on a virtually stock engine. (chip, catback, oem euro intake cam)

hard work is free.
Buts its alot of work

Try to get INA to sponsor your car or similar.

Leebro migh also do something nice for it.

90MM maf and the larger GM TB and moved air box with battry delete.
And a VW MK1 radiator and 70C thermostat

[newcreation]

yepp ina 80mm plug and play TB from gm

[CaptainQualude]

Quote, originally posted by PowerDubs »

Do you have links to those posts? I like reading about stuff..

I could if you want, but it's a more primitive setup (non-variable) & just a pure bolt on mod. You're removing one & bolting on another that has more surface area where the port meets the head.It looks the same, but flows much better for upper RPM power. It's really just old school technology.