Dracostan Posted January 6, 2018 Share Posted January 6, 2018 (edited) 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 - The idea grew out of the result of me buying a set of Stillen Gen2 intakes, to replace the standard airboxes. 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: 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!) 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 - 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 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 and the resulting intake sound resonating through a massive tubular plenum space Dracostan Edited January 11, 2018 by Dracostan 3 Quote Link to comment Share on other sites More sharing options...
andybp Posted January 7, 2018 Share Posted January 7, 2018 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 - The idea grew out of the result of me buying a set of Stillen Gen2 intakes, to replace the standard airboxes. 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: 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!) 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 - 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 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 and the resulting intake sound resonating through a massive tubular plenum space 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) 1 Quote Link to comment Share on other sites More sharing options...
Dracostan Posted January 10, 2018 Author Share Posted January 10, 2018 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 You have no idea how much pain it gave me trying to close the gaps between the main intake tube and the manifold tubes 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 Quote Link to comment Share on other sites More sharing options...
Dracostan Posted January 11, 2018 Author Share Posted January 11, 2018 Ok, as promised here are the results of the flow analysis: Cylinder 1 (Passenger front) Cylinder 2 (Drivers front) Cylinder 3 (Passenger Middle) Cylinder 4 (Drivers Middle) Cylinder 5 (Passengers rear) Cylinder 6 (Drivers rear) 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! Let's go with the first one 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 2 Quote Link to comment Share on other sites More sharing options...
Dracostan Posted January 21, 2018 Author Share Posted January 21, 2018 (edited) So, after a brief respite from having a tooth pulled out of my head I made a trip to the local plumbers merchants to get some pipe as a guide: 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 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: In the mean time, anyone got a spare plenum I could have - PM me a price ! Draco Edited January 21, 2018 by Dracostan 2 Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted January 21, 2018 Share Posted January 21, 2018 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. Quote Link to comment Share on other sites More sharing options...
350Butcher Posted January 21, 2018 Share Posted January 21, 2018 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? Quote Link to comment Share on other sites More sharing options...
Dracostan Posted January 21, 2018 Author Share Posted January 21, 2018 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 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 ! Quote Link to comment Share on other sites More sharing options...
350Butcher Posted January 21, 2018 Share Posted January 21, 2018 I would've said it'd be better to increase plenum volume on each side but feed each bank separately. Also the air flow meters are reading values going to each bank that way I guess looks are individual..............form follows function though Quote Link to comment Share on other sites More sharing options...
nissanjuke Posted January 21, 2018 Share Posted January 21, 2018 this is thinking out the box, and I love this as this engine has potential, how much would the power gain be after a retune. Quote Link to comment Share on other sites More sharing options...
Keyser Posted January 22, 2018 Share Posted January 22, 2018 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 Quote Link to comment Share on other sites More sharing options...
Dracostan Posted February 19, 2018 Author Share Posted February 19, 2018 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 Still, my perseverance held 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 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 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. Draco 1 Quote Link to comment Share on other sites More sharing options...
andybp Posted February 19, 2018 Share Posted February 19, 2018 It's a damn shame I wanted to see this it was going to look really cool' so over to plan B I expect to see a proposal on my desk by monday. Quote Link to comment Share on other sites More sharing options...
Cimanu Posted April 10, 2018 Share Posted April 10, 2018 If nothing else, those flow diagrams are really impressive. Well done sir 1 Quote Link to comment Share on other sites More sharing options...
whywontthisletmeregister Posted April 10, 2018 Share Posted April 10, 2018 awesome little read !! 1 Quote Link to comment Share on other sites More sharing options...
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