3.0 engines and 3.6 intake plenums

[jamesjedi]

I was reading the PCA rules and came across this;



"3.0 engines and 3.6 intake plenums: 2400lbs"



I have searched and not found anything about it. I am currently building a 3.0 engine (was going to use a 3.6, but have run out of "engine" money). Anyways, what exactly is this, and are there any instructions on how to do it? I do not see it in Waynes book.

THANKS!

James

[rsscotty]

We have done this on quite a few engines. The pictures explain most of it. We use DTA engine management with great results. Jeff @ Rothsport Racing sells all the parts..throttle linkage, adapters to individual throttle bodies, tee piece on intake crossover to air filter etc. You can also do this without the individual throttle bodies and use a single throttle plate, with a noticeable decrease in throttle response. This whole engine package gets setup on our Superflow engine dyno. A different engine is shown in the dyno room picture.

[jamesjedi]

Thanks for the information and pictures. Very interesting. What would the results be compared to 46 mm PMO's?

[PFM]

James,

The 3.6 manifold is not a bad idea at all, the photos above are very nice but not if $$$$ is a question. Some other things to consider the stock 3.6 induction system, valve to plenum, is tuned for about 6800 RPM. If you are building a high RPM 3.0 it might be a bit long. As for throttle response if a 3.6 is OK for you this should be too. You will need adapters to use the 3.6 injector bases on the 3.0 2 bolt heads they are out there no need to get crazy like I did. The side to side connecting tube does add some low end grunt and can be noticed if you can handle the tires breaking loose when the transition happens in the wrong place. Here is an example of over doing it a little, LARGE throttle door, shortened runners (7700 RPM) and high mount injectors.



You could keep the 3.6 manifold and all stock and the 3.0 will like it just fine.

Stay tuned,

PFM

[PFM]

James,

FYI

Stay tuned,

PFM

[jamesjedi]

That looks amazing. I am trying to understand how it is adapted, a little confusing. So...if the unit is kept stock the results are roughly how much better than CIS? I assume it would need dyno time?

I love the creativity of it. Very tempting to try it with my Euro 3.0.

[PFM]

James,

You have a private message.

PFM

[rsscotty]

This is our adapter that attaches to the cylinder head intake port. On top of this fits the plastic factory piece shown in the second photo that has the rubber sleeve adapter that connects to the plastic intake. This is for the single throttle body applications. The plastic piece holds the injector and fuel rail.

[PFM]

RSScotty,

Nice looking part, please do post the dyno info that would be great. Did you keep the crossover butterfly on your testing?

Stay tuned,

PFM

[rsscotty]

All of our 3.6 intakes use the crossover butterfly or resonance flap. If this is not used the power drops off dramatically.

[jamesjedi]

What is the cross over butterfly?

[jamesjedi]

Interesting to see these adaptations. From a cost effectiveness standpoint, it looks like it could be more practical than IDA's? Obviously the DTA system would be pricey.


The 3.6 intake/injection system looks like it can be purchased at reasonable prices. PFM, what is your engine management system?

[PFM]

James,

MegaSquirt, Staged injectors and 12 LS2 coil near plug.

Not up and running but hope so. If not dust of the old Haltech and a 3.6 distributor.

Stay tuned,

PFM

[Cory M]

Bumping this thread for more info.

I'm thinking about using a 993 plastic 3.6 intake on an engine I'm putting together for my racecar and I have a few questions. I'd be using stock injection components and not ITBs. Engine is a 3.2 block with 3.4 pistons and cylinders.

What kind of gains can I expect to see compared to the original 3.2 manifold?

Besides the adapters what is needed?

Is Rothsport the only adapter source?

What do I need to know about "varioram" vs non varioram? Which is better?

I'm deciding whether it's worth it to go down this route or if I should just stick with stock parts. Not looking for an expensive science project. Any feedback from those who have "been there, done that" is appreciated. Thanks.

[Tareq993]

I have a set of unused adaptors if u need some. Project changed direction.

[PFM]

Tareq993,

You have a PM