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My Overly Ambitious Idea - Pic Heavy


Dracostan

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As a few of you may have seen, I have had the idea of making a new intake for my 370Z - taking up a chunk of space in @andybp thread ! Thanks :thumbs: - 

 The idea grew out of the result of me buying a set of Stillen Gen2 intakes, to replace the standard airboxes.

20170618_134710.jpg.f135ad454d1bda9cf0cdf75dc26c4687.jpg

I liked the final result and it did add a little underlying gurgle to the engine note that i was looking for.

However, my low-level OCD hasn't taken to the mis-matched side-to-side bent/straight tubes - as well as having the Zeditus itch to make my car just that little bit more different !

 

So, my brain came up with the idea of a full tubular intake behind the throttle bodies to match the shiny short tubes of the Stillen. Jumping on the CAD s/w I have access to through work, I managed to get this to fit together:

5a511569e9ce1_VPlenumIntakeAssembly.thumb.JPG.69b063efa2beacc346749f6aa8401a4a.JPG

 

I figure I can buy in a set of mandrel bent tubes in good quality Aluminium, have the flanges machined up by a local fabricator an tack weld the lot together before sending it to a proper welder to seal up.

The end result should end up looking something like this (excuse the crappy Photoshop skills - I'm an engineer, not a graphic artist!)

5a5116391ce69_VIntakeMock-up.jpg.c808d37e3bef71aeadfe6801a8862492.jpg

 

The Zed is my daily, so to get this going, I need to call on someone with a spare intake plenum to get some measurements of the plenum/lower manifold flange (or, lend me one :p - or best of all, have a CAD model to send me !!) @Adrian@TORQEN  @Mark@Abbey m/s  @Jez @ H-Dev  @Tarmac@TarmacSportz or any spanner wielding good spirit with a Zed in the shed (hint, hint :)  !)

The measurements i need to draw up a flange are shown in the image below

5a5119136ebc9_PlenumFlange.thumb.jpg.5b45503e6f0ba8555e47a898abd85a49.jpg

 

I know this will be a fairly ambitious build, (and I'm under no illusions that this will be a quick one either), but I think will be so worth it, for both the look of it B) and the resulting intake sound resonating through a massive tubular plenum space :teeth:

 

Dracostan

Edited by Dracostan
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On 1/6/2018 at 18:53, Dracostan said:

As a few of you may have seen, I have had the idea of making a new intake for my 370Z - taking up a chunk of space in @andybp thread ! Thanks :thumbs: - 

 The idea grew out of the result of me buying a set of Stillen Gen2 intakes, to replace the standard airboxes.

20170618_134710.jpg.f135ad454d1bda9cf0cdf75dc26c4687.jpg

I liked the final result and it did add a little underlying gurgle to the engine note that i was looking for.

However, my low-level OCD hasn't taken to the mis-matched side-to-side bent/straight tubes - as well as having the Zeditus itch to make my car just that little bit more different !

 

So, my brain came up with the idea of a full tubular intake behind the throttle bodies to match the shiny short tubes of the Stillen. Jumping on the CAD s/w I have access to through work, I managed to get this to fit together:

5a511569e9ce1_VPlenumIntakeAssembly.thumb.JPG.69b063efa2beacc346749f6aa8401a4a.JPG

 

I figure I can buy in a set of mandrel bent tubes in good quality Aluminium, have the flanges machined up by a local fabricator an tack weld the lot together before sending it to a proper welder to seal up.

The end result should end up looking something like this (excuse the crappy Photoshop skills - I'm an engineer, not a graphic artist!)

5a5116391ce69_VIntakeMock-up.jpg.c808d37e3bef71aeadfe6801a8862492.jpg

 

The Zed is my daily, so to get this going, I need to call on someone with a spare intake plenum to get some measurements of the plenum/lower manifold flange (or, lend me one :p - or best of all, have a CAD model to send me !!) @Adrian@TORQEN  @Mark@Abbey m/s  @Jez @ H-Dev  @Tarmac@TarmacSportz or any spanner wielding good spirit with a Zed in the shed (hint, hint :)  !)

The measurements i need to draw up a flange are shown in the image below

5a5119136ebc9_PlenumFlange.thumb.jpg.5b45503e6f0ba8555e47a898abd85a49.jpg

 

I know this will be a fairly ambitious build, (and I'm under no illusions that this will be a quick one either), but I think will be so worth it, for both the look of it B) and the resulting intake sound resonating through a massive tubular plenum space :teeth:

 

Dracostan

As to your title "Overly ambitious idea" , you need to start ignoring the people who say this to you it's perfectly feasible what this generally means is that they lack the imagination or the drive to try it themselves

as for the measurements you need ,I found it easier to buy a second hand inlet which was very inexpensive and also great for mocking up ( I have just had a look and couldn't find any for sale but they do come up honest)

:)

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The simulations side of things is moving on! I have managed to build a model that I can use within the fluid dynamics FEA part of my CAD software :thumbs:  You have no idea how much pain it gave me trying to close the gaps between the main intake tube and the manifold tubes :bang: The model meshing is so accurate it fails on gaps as small as 5 microns ! ffs, but managed to get the joins to match after a considerable amount of copying and pasting between part models.

First runs of the simulation look good, nice and linear round the main tube and smooth transition into the manifold with no tumbling over the corners. I will update this post tomorrow with some screen grabs, when I've done each cylinder.

 

In the mean time, while I'm sure I've done good internet research on the firing pattern of the VQ37VHR, I just want to ask here to confirm the cylinder intake draw sequence - in that each cylinder draws individually, with no overlap or 'shared draw' timing (like cylinders 1 and 4 drawing in at the same time). If those in the know of these things would kindly pass on the arcane knowledge !

 

@andybp Yeah, a used inlet is on the list, just trying to crib a free one first :p 

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Ok, as promised here are the results of the flow analysis:

 

Cylinder 1 (Passenger front)

5a57bc3e0e976_VPlenumFlow-CylDF2s.jpg.5f0ff209685746d21453f8f2763b2733.jpg

 

Cylinder 2 (Drivers front)

5a57bc1992fa8_VPlenumFlow-CylPF1s.jpg.bad4e2cb9c0b008c4e4b8dff342b2948.jpg

 

Cylinder 3 (Passenger Middle)

5a57bf855b473_VPlenumFlow-Cyl3PMs.jpg.0c208b07836d93d3cc2049b5198dccb6.jpg

 

Cylinder 4 (Drivers Middle)

5a57bf95056f2_VPlenumFlow-Cyl4DMs.jpg.c3d1176e1c758be133f5403cada728ff.jpg

 

Cylinder 5 (Passengers rear)

5a57bfb52e8d2_VPlenumFlow-Cyl5PRs.jpg.e3ed1b1d67c122a15db10d2d4dfd9bfc.jpg

 

Cylinder 6 (Drivers rear)

5a57bfc3164c4_VPlenumFlow-Cyl6DRs.jpg.89e5552c487faf868de0b82144178658.jpg

 

As you can see they are all pretty much dead on the same in the flow speeds and the flow paths are nice and smooth. I was surprised at how balanced the draw is side-to-side, I thought the front cylinders would draw much more from their respective throttle bodies.

 

Of course does this mean I have a good flowing design .....  or such a restrictive one that each side is equally choked off! :blink:        Let's go with the first one :thumbs: 

 

Next stop will be the local B&Q to pick up some short pieces of 60mm plastic pipe to check the clearances in the bay - I will also get some 100mm, as I think upping the main plenum tube diameter would help with flow and resident volume. I'll be running the flow sim for the larger diameter over the weekend, so I'll throw the results of that up for a comparison when they're done.

 

:) Draco

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  • 2 weeks later...

So, after a brief respite from having a tooth pulled out of my head :scare:  I made a trip to the local plumbers merchants to get some pipe as a guide:

20180114_141400s.jpg.06f3fa9cbfebb4be23c1cf079b652792.jpg

That's a 68mm coupler, so also gives an idea of clearance too - on putting it place to see, everything suddenly seemed at lot smaller than I remember! The idea of going to 100m diameter didn't make it passed opening the bonnet :shrug:

 

The main issue looks like I will have to move the fuel rail damper (the top hat cylinder on the left between the orange topped bolts). Otherwise there should be enough clearance between the oil filler and the cam cover flange. The wiring loom should be able to be tucked down behind the cam cover flange and the PCV pipes will be relocated with dedicated lines to catch cans.

 

Depending on how much of a pain it is to move the fuel damper, I may have to extend the main plenum tube to locate the TBs in front of the cam cover and pointing the filters and TBs further down into the filter spaces:

5a64c81f2b099_VIntakeMock-up2.jpg.6f0d654132533132adac387c64f6ef7f.jpg

 

In the mean time, anyone got a spare plenum I could have - PM me a price !

 

:) Draco

Edited by Dracostan
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1 hour ago, ZMANALEX said:

I have a plenum from a 350Z HR which may provide you with the measurements that you require.

If suitable, Just drop me a PM with a fair offer.

Thanks for the offer, but preferably I'm after a 370 plenum, just to be sure the measurements will be correct. I don't know what the differences are, so don't want to take any chances :fool:

 

31 minutes ago, 350Butcher said:

Fair play to you for putting the time and work into this!

 

Can I ask why you have linked the 2 inlets (via the horse shoe) and not gone with separate intakes for each bank? 

It's a combination of balancing the draw between the banks and trying to maintain the plenum volume. As you can see in the simulation images, the draw is actually fairly even split each side, no matter which cylinder is drawing. The other reason is - it looks cool ! B)  

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I think it's a great idea to try it I wish you the best and will follow with interest, I've been working on air flow on my modified Radical (only for cooling not intakes) - Not got any software so I go with - "That looks about right" -  However my approach might not be the best and may be why we have just ripped the whole thing apart to start again cause it may look right but it ain't getting cool enough :lol:

 

 

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  • 4 weeks later...

Been a bit, but finally got a decent bit of weather in order to stand under the bonnet with tape measure, notebook & pencil and do my best to put a massive crick in my spine   :wheelchair:

 

Still, my perseverance held  :cold: and I got a good plan of the clearances around the engine bay, took it inside, fired up the laptop and spent another hour translating it into layout I could lay the intake CAD over....

 

 

 

.... only to find the intake won't fit :scare: :angry: :bang: :rant: :blink: :cry:

 

Bugger.

 

The issue is the dirty great VVEL servo motor hanging off the back of the B bank, that sits right in the way of the horseshoe

20180114_141459s.jpg.593ec4929ccf3b86e4e8c10424b43914.jpg

 

Now I could go the route of trying to re-orient the servo and get it to point downward out of the way, but I'm not skilled enough to F around with a system as vital as the VVEL control - and handing it off to a shop that has the skills, would involve far more work and time off the road than I can reasonably accept, just for an intake.

 

While I have had a couple of ideas to reconfigure the main plenum body, it would change the aesthetic far from what I was wanting - basically it would be a rounded off version of the stock plenum in aluminium pipe and plate.

So unfortunately this is going to end before it could get legs.

 

I feel the look of this would be fantastic and would love to see it realised - So I am offering the CAD files I have to anyone who would like to take this on and tweak it for their own use. Drop me a PM and I'll see about getting the files to you.

 

Thanks for all the support and encouragement, especially from @andybp - I look forward to seeing the progress of your ITBs !

In the mean time, I will have to have a sit and think of what Zeditus itch I will scratch next !

 

Cheers all. :thumbs:  Draco

 

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