An easy solution is to go with Black HDPE, or some sort of color. Then it won't yellow. Plastics are not invulnerable. But the location of this tank should insure that they last longer than the owner.

 

Black would seem to be a logical color that's less likely to show from any gaps in interior trim etc.
Off topic but I'm struck by how many on the list are interested in TWO tanks. Didn't realize so many had two FDs. Most days one is PLENTY for me.

 

Black isn't a bad idea. But I wanted something translucent. My thought was "it's good to be able to see how much fluid is in there" - but admittedly - we won't be able to see it behind the interior panel.

That said - the manufacturer doesn't believe we should experience ANY yellowing - regardless of if it's behind a panel or exposed to sunlight.

 

White reflects. So even through a small opening that is exposed to light, the fluid level will be much easier to spot than on a dark container per say.

 

* per se...

 

Might make it trickier filling her up though. You don't want to spill methanol in your trunk...

My comment about the yellowing is not purely aesthetic. If plastic is yellowing it's often times becoming brittle or weakening in general. I stand to be corrected on that though as I'm most familiar with plastics in the engine bay which obviously is exposed to heat as well as chemicals.

Someone with more understanding than I have, please feel free to correct me on this.

Nick

 

1. Spalato - 2 tanks
2. ZoomZoom - I'm in for at least 1. Maybe 2.
3. Slideways FD - 1
4. Silvertrd - 1 tank
5. jza80 - 1 tank
6. the spyder-
7. Izanami - 1 tank
8. SpeedCrazie - 1 Tank
9. photoresistor - 1 Tank
10. jsemerica - 1 Tank, maybe 2
11. Myocardial Infarction - 1 Tank
12. Rocketeerbandit - 1
13. Brekyrself - 2
14. 20005.3 - 1
15. Knotsonice - 1
16. Kensin - 1
17.Gio612
18.7krayziboi
19.#slevin
20. Fourtyounce - 2 maybe 3. Matt Gold for PreZident!
21. One for me please, Charlie
22. Redgti (James, uk) -1
23. Khan Racing - 1
24. Sigma
25. Alex Newman - 1 (UK)
26. thatdon
27. MattUK (UK - Can post to a mate state side if required)
28. Ptrhahn. 1
29. Iantboyd - 1
30. Fendamonky - 1
31. Sc0rp7 - 1
32. ColdFeet - 1
33. jkstill
34. Montego -1
35. Zepticon - 1 tank
36. Matthew Ng - 1
37. p51hellfire - 1
38. thanson90
39. s8nana - 1 (AU)
40. Runrex -
41. Garethb -1 (New Zealand)
42. Dhanson31
43. Ondabirdhouse - 1 (possibly 2)
44. Tictakman - 1
45. BaconHunter - 1
46. Trout2 - 1
47. spirit rx-7 - 1
48. Saham -1
49. Cvzg77r-1
50. pingu81 - 1
51. moshaka - 2 tanks maybe 3
52. Ryans93rx7 - 1
53. Rarotary - 1
54. TWIZTIDRX -1
55. XPT700 - 1 tank and shipping to Scotland
56. Sukisuki - 1
57. Daleclark - 1
58. Smokey The Talon - 1
59. Ghoujoumian - 1
60. Talkwrench (UK) - 1
61. red_dragon - 1
62. Street-heat7 - 1 maybe 2
63. Jonnybravo408- 1
64. THE TECH
65. KompressorLOgic - 1
66. TurbosaurusRX
67. Nashman69g - 1
68. Selonari - 1
69. Neutron - 1
70. Stivat - 1
71. Sgtblue -1
72. mcon (Ireland) - 1
73. BlackPEP - 1
74. RoboticsRacer
75. Hai-tek7 - 1
76. Monkman33
77. DnlCappy
78. Orbitalmovment
79. Helloninja - 1
80. Sideo - 1
81. yehreally - 2
82. $lacker - 1
83. Macer - 1
84. SimonFD3S - 1 (FRANCE)
85. j_man1100 - 1
86. ncx94 - 1 (France, and could dispatch here if you want to make only one shippment)
87. wazway 1
88. 1987 T2
89. REAmFC3S 1
90. M104-AMG (1)
91. Kissama (France)
92. TomU
93. Boriboost 1
94. MaczPayne 1
95. NetSeven 1
96. B-TAG - 1
97. RCCAZ 1, possibly 2
98. rotaryfdtt - 1
99. BeREv - 1 (France - Rotorhead on RX-7 France forum)
100. touki - 2
101. - dhahlen 1, possibly 2
102. cloud9 - 1
103. Moe Greene - 1
104. seipherzero - 1
105. m4drx - 1
106. Rawbz08 - 1
107. David Hayes - 1
108. Harry SB - 1 tank.​​​​ California.
109. Net Seven - 1
110. primerGrey - 1, possibly 2
111. MDP - 1
112. elfking - 1 tank. California.

 

Hey guys! Sorry for the delay, had some ups, had some downs. But we're moving forward.

So the second 3D printed prototype made it to me late last week. The quality is unreal, very, very impressed with the acralite. Only downside? It broke in shipping. Doh!



HOWEVER, before it shipped, the guy that printed it for me managed to snap some pics:





The good news is: none of the mounting points broke - so I can still test fit with the new mounting hardware. The bad news is: I can't do a bunch of planned "slosh testing". However, the printer ALSO managed to do some testing himself:

I'm really impressed with how stable the bottom sump stays. I think this should relieve any concerns about potential starvation. Remember, the primary nozzle is all the way to the bottom, below the fill level sensor. You can also run additional sensors if you so choose.




So the next step is to test fit this one as-is, I'm predicting it will be 100%. From there, we green light the mold production and then hurry up and wait!

I plan getting an official Group Buy setup, pricing announced and start taking deposits within two weeks.

 

Epic update, looks great!

 

Very exciting! prototype looks great!

 

Matt - Kudos to you for the speed of development and execution. You are doing a great service to the community with this product.

 

Second that!!

Might want to try a slosh test with less than half-full, e.g. one quarter, one eighth. Can you 3-D print some small horizontal baffles just around the top of the sump area? It might help with lateral g's, should you find an issue.

--- ---
| |
| |
--------

 

Oops, there are supposed to be spaces between the vertical bars... It is supposed to be a cross-section of the sump area, showing a smaller entry at top.

 

Sadly - the prototype broke en route - so I can't guarantee additional slosh tests unless I can really mend the damage (which, I might be able to end up doing). However, I want to test fit first in case the additional weight does more damage.

I could 3D print anything - but the ultimate production method (blow molding) won't allow for baffles. We already went down that route and thus why we settled on additional nozzle bosses.

 

You could create an easy baffle where the two tanks are bolted together. Just need to put a piece of plastic between the two halves and cut some holes in it.

 

If memory serves, final production will be all one piece

I think that the best way to reduce slosh might end up being to just jam a few small pieces of fuel cell foam through the opening and towards the center of the tank (using a curved metal rod or something). It doesn't really matter if they go all the way to their intended destination, as long as they compartmentalize the tank while still allowing fluid passage through at an appropriate rate

 

Apologies, I should have made this clear. The "bolted together" design of this tank was ONLY due to the limitations of the 3D printer size. We had to print in two pieces and assemble afterwards. The final design will all be one piece.


Exactly. Final production will be all one piece.

Good idea on the fuel cell foam. That or secondary nozzles if you're concerned. But I have to imagine 99% of people will be fine with the one nozzle / one level sensor as-is.

 

Again, thanks for doing this, and I apologize for not recalling that from prior posts.

I certainly will be happy with whatever you decide, and I think everyone understands it is your call. So take the following as suggestions only, to be accepted or rejected:

The ability to experiment with baffles after installation might be a strong argument for a two piece design, and worth the extra cost. Reviewing the difficulty and many different approaches to gas tank baffling for the FD may show it is a far from easy problem to fully anticipate the worst case a priori, with vibrations, splash, wave interference, and heavy draw out of the sump, all at the same time.

Obviously, lateral g's are the most significant concern, and the tank is long in exactly that direction.

A two piece design does introduce the need for a good seal, but given the excellent liquid gasket materials available today, that seems like a solvable problem.

 

Honestly, we're way too far down the path to consider revising the design - and as I mentioned the manufacturing process just doesn't support it. That said, Harbor Freight sells a $30 sawzall!

In all seriousness, for those that really, really have issues with slosh after initial use, I think the first step will be multiple nozzles with pick ups placed throughout the tank. That's going to solve 99% of any issues and those issues are going to but in the 1% of extreme use.

A second solution could be adding a baffle after the fact - but wouldn't require cutting the tank in two.



Simply slitting the side of the tank and inserting a baffle would be your best solution.

After these make it out into the wild - I'd be more then happy to share the CAD files and/or exact dimensions of what a baffle would be.

How's that sound?

 

Totally understand, and that sounds great. If there is a good spot for it, a reasonably sized flat on top of a single piece design would provide an easy way to cut a larger access point that could then be easily covered and sealed.

 

To or side - wouldn't really matter - but you're right. From above would keep leak potential to a minimum.

 

Not sure I understand the idea of having 2 draw points for the injection pump. Are you saying run a Y fitting of some sort to 2 different tank locations and then back to the single injection pump? I've never seen that done, so would it cause issues with the pump losing prime if one became uncovered during slosh? I'd think the uncovered location would beco,s the path of least resistance and the pump would suck air.

Or are you suggesting a full second pump and feed as a double redundant system?

Any idea how much fluid was in the tank during the test sloshes? My thought was that I'd run one single pickup point and make sure the tank was topped up before every track session. I currently use about 1/2-3/4 gallon during a 30 min session so if the capacity is 2 gallons that should give me enough remaining to not get air hopefully.

 

Let me start out by saying - the idea of the tank is to be "agnostic" to any meth injection kit on the market. That was really the one high level qualification for doing this. We didn't want to pigeon hole people into running either the AEM or Aquamist or Brand X.

I've seen some setups that run dual nozzles, so I wanted to be sure we accounted for that in the design - thus the additional nozzle bosses. That said, I think 99% of the people out there will run a single nozzle on the side/bottom below the level sensor. One, it's the lowest point in the tank and two, multiple nozzles are only needed for the most extreme driving situations.

As for how people would run multiple nozzles - that's really dependent on what meth injection kit you were running... and how you were running it. In a perfect, over engineered world, you'd probably run some sort of swirl pot. Two nozzles feed into one central tank, then out from there. However, I'm sure there are simpler ways to run this with Y connectors and check valves.

All that said, I think the multiple nozzles will be for the .01% of people that are in extremely extreme situations.

The tank itself is looking to hold 2+ Gallons (7.5 liters). It's a TON of juice. Running to below 1/2 a tank is going to take a LONG time. If you're drinking 1/2-3/4 gallon every 30min session, that's 3-4 sessions without topping it off, which I can't imagine happening. For a street car that's not a WOT nearly as much as a car in session, this should be more than adequate.

 

1. Spalato - 2 tanks
2. ZoomZoom - I'm in for at least 1. Maybe 2.
3. Slideways FD - 1
4. Silvertrd - 1 tank
5. jza80 - 1 tank
6. the spyder-
7. Izanami - 1 tank
8. SpeedCrazie - 1 Tank
9. photoresistor - 1 Tank
10. jsemerica - 1 Tank, maybe 2
11. Myocardial Infarction - 1 Tank
12. Rocketeerbandit - 1
13. Brekyrself - 2
14. 20005.3 - 1
15. Knotsonice - 1
16. Kensin - 1
17.Gio612
18.7krayziboi
19.#slevin
20. Fourtyounce - 2 maybe 3. Matt Gold for PreZident!
21. One for me please, Charlie
22. Redgti (James, uk) -1
23. Khan Racing - 1
24. Sigma
25. Alex Newman - 1 (UK)
26. thatdon
27. MattUK (UK - Can post to a mate state side if required)
28. Ptrhahn. 1
29. Iantboyd - 1
30. Fendamonky - 1
31. Sc0rp7 - 1
32. ColdFeet - 1
33. jkstill
34. Montego -1
35. Zepticon - 1 tank
36. Matthew Ng - 1
37. p51hellfire - 1
38. thanson90
39. s8nana - 1 (AU)
40. Runrex -
41. Garethb -1 (New Zealand)
42. Dhanson31
43. Ondabirdhouse - 1 (possibly 2)
44. Tictakman - 1
45. BaconHunter - 1
46. Trout2 - 1
47. spirit rx-7 - 1
48. Saham -1
49. Cvzg77r-1
50. pingu81 - 1
51. moshaka - 2 tanks maybe 3
52. Ryans93rx7 - 1
53. Rarotary - 1
54. TWIZTIDRX -1
55. XPT700 - 1 tank and shipping to Scotland
56. Sukisuki - 1
57. Daleclark - 1
58. Smokey The Talon - 1
59. Ghoujoumian - 1
60. Talkwrench (UK) - 1
61. red_dragon - 1
62. Street-heat7 - 1 maybe 2
63. Jonnybravo408- 1
64. THE TECH
65. KompressorLOgic - 1
66. TurbosaurusRX
67. Nashman69g - 1
68. Selonari - 1
69. Neutron - 1
70. Stivat - 1
71. Sgtblue -1
72. mcon (Ireland) - 1
73. BlackPEP - 1
74. RoboticsRacer
75. Hai-tek7 - 1
76. Monkman33
77. DnlCappy
78. Orbitalmovment
79. Helloninja - 1
80. Sideo - 1
81. yehreally - 2
82. $lacker - 1
83. Macer - 1
84. SimonFD3S - 1 (FRANCE)
85. j_man1100 - 1
86. ncx94 - 1 (France, and could dispatch here if you want to make only one shippment)
87. wazway 1
88. 1987 T2
89. REAmFC3S 1
90. M104-AMG (1)
91. Kissama (France)
92. TomU
93. Boriboost 1
94. MaczPayne 1
95. NetSeven 1
96. B-TAG - 1
97. RCCAZ 1, possibly 2
98. rotaryfdtt - 1
99. BeREv - 1 (France - Rotorhead on RX-7 France forum)
100. touki - 2
101. - dhahlen 1, possibly 2
102. cloud9 - 1
103. Moe Greene - 1
104. seipherzero - 1
105. m4drx - 1
106. Rawbz08 - 1
107. David Hayes - 1
108. Harry SB - 1 tank.​​​​ California.
109. Net Seven - 1
110. primerGrey - 1, possibly 2
111. MDP - 1
112. elfking - 1 tank. California.
113. technomentor - 1, possibly 2

 

Wonder if there is room To run a semi large hose from the washer tank downhill via gravity feed to a small surge tank that houses the actual feed nozzle, that would eliminate the risk of slosh effecting the wide narrow tank.