anyone made a custom intake yet?

[rib256]

I see them for the 4 bangers, anyone done a custom upper manifold? is it needed?

[turbovanman²]

Get ahold of Ondonti, he made an upper but uses the stock lower.

People add spacers to the plenum and remove the divider.

[Ondonti]

I used the wrong size (too small) runner on my upper. My lower is a montero 12v because it fits stock location without cutting/welding the thermostat hosing.

3000gt 12v will be better if you want a longer runner big plenum if you are willing to cut and weld the therm housing.

I couldn't really say anything for "gains" but I wouldnt spray 2100cc's of methanol on a stock 3.0 manifold because it would not distribute evenly. my current manifold seems to get perfect distribution so it at least gives me that benefit, plus it would probably do great with a huge shot of nitrous without using direct port.

stock 3.0 manifold doesn't seem to flow evenly to each cylinder even when well ported.

[Force Fed Mopar]

stock 3.0 manifold doesn't seem to flow evenly to each cylinder even when well ported.

What info are you basing this on?

[Ondonti]

What info are you basing this on?

Personal experience reading plugs, the rear cylinders read leaner (at least they appeared to at the time) in my old boosted Spirit setup...and the rest is just guesstimations of people when talking about nitrous usage. Also one of the reasons why I tried to port the stock intake to promote flow to the first 2 runners.

for a liquid fuel to make the turn into the first 2 cylinders seems pretty torturous. It has to sharply turn left/right, then go up the "hill" (center of plenum).

[mopar3.0]

heres mine

[turbovanman²]

^^^^^^^^^^Nice work,

Is it turbocharged?

[JohnnyIroc]

Nice work!!
but whatsup with the mitsu oil cap?

[Ondonti]

his setup is also nice because he can use 3/S upgraded fuel rails etc. Montero lower seems to be different so I had to make my own fuel rails from scraps which I have gripes about.

[Vigo]

The 3.0 intake manifold is pretty much super awesome compared to an 8v one piece, so thats why there aren't many custom ones being done.. combined with the fact that there are relatively few turbo (k-car) 3.0s.

The stock 3.0 upper intake can support a decent sized throttle body with a little added material and has a good plenum volume when you remove the divider. Really the only issue with the whole 3.0 intake manifold is what brent mentioned for those 2 cylinders, and the sharp turn from the plenum into the runners.

I dont think ill have the distribution problems on my m90 build because my intake charge will be coming down from top-center, roughly

[Ondonti]

Long ago there was a dual TB 3.0 plenum made by cutting 2 in half and joining the 2 TB ends. This would probably do a lot for equalization. Also another reason why I would prefer a LARGE throttlebody over a smaller one.

[Vigo]

Well FWDP sells a jeep 60mm tb flange for like $22 now so thats a nice step forward for 3.0 people willing to do a bit of cutting and aluminum welding. Probably $100 would get you the flange, the junkyard TB (possibly bored to 60 at home), and all the welding done. Some people spend that much on spacers

I had thought in the past of doing away with the plenum entirely and just adding two round plenums directly on top of the runners with an equalization pipe between them like a first gen intrepid 3.5, and then use a modified shaft-driven dual TB setup from that motor (46 or 48mm stock, i had 52s on mine) which accepts the factory style throttle cable and uses factory style sensors.

However with my roots idea that would only complicate things. I think it would be great for high rpm though because that distribution problem would be gone, you'd probably have more plenum volume in total, literally twice the TB bore area, use the stock throttle cable and sensors, and the 90* or worse turn from the stock plenum into the runners would now be completely straight.

[Ondonti]

sounds like what I posted on the internet circa 2004-2005

I think if I was to "fix" the 3.0 intake manifold I would cut the TB flange off, and then weld on a "fan" shaped neck to the end of the manifold (cut off the front of the manifold) so air wouldnt have to make the sharp turn to the first 2 cylinders. Its still not that bad. I think it gets worse when your TB size is small compared to the amount of air its flowing. That creates higher velocities and will help throw air to the back of the plenun (biasing airflow to the rear).

[Ondonti]

sounds like what I posted on the internet circa 2004-2005

I think if I was to "fix" the 3.0 intake manifold I would cut the TB flange off, and then weld on a "fan" shaped neck to the end of the manifold (cut off the front of the manifold) so air wouldnt have to make the sharp turn to the first 2 cylinders. Its still not that bad. I think it gets worse when your TB size is small compared to the amount of air its flowing. That creates higher velocities and will help throw air to the back of the plenun (biasing airflow to the rear).

[Force Fed Mopar]

Sounds like... a double post

You might could make the neck longer, which would allow you to lengthen the curve behind the TB leading to the 1st 2 cyl runners. Which would lessen the angle and facilitate smoother airflow.

[Vigo]

sounds like what I posted on the internet circa 2004-2005

I dont post my ideas the first day i come up with them either

Not too many 3.0 people listening out there... You usually hear my ideas on gmail before they get to the forums anyway

I think it gets worse when your TB size is small compared to the amount of air its flowing. That creates higher velocities and will help throw air to the back of the plenun (biasing airflow to the rear).

I had not thought of that... good thinking.

[Ondonti]

Yeah, gotta make up interesting stuff worth a double post during stupid server backup hour.