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PostPosted: March 8, 2017, 4:57 pm 
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Lonnie, if you need to go diagonally to include the length of the resonator you could put an X-pipe in after each resonator so the tailpipes exit at the opposite corner. I would admit to it looking odd at best. :?

The CFD pictures were in the 'exterior' sub-forum. I say 'pictures' advisedly, since any CFD predictions within the separated area aft of the tail are likely to be fairy tale quality unless done with a full Navier-Stokes code. CFD isn't sometimes called 'colourful fluid dynamics' without cause.

Edit: link to CFD is viewtopic.php?f=23&t=13379

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PostPosted: March 9, 2017, 12:43 am 
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@Warren Nethercote

Yes, that's it. Now I have to see if there's anything meaningful in it for my exhaust context. :ack:

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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PostPosted: March 9, 2017, 4:39 am 
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Some of the Donkervoorts had exhaust exiting out the back.


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PostPosted: March 9, 2017, 11:54 am 
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TRX wrote:
Some of the Donkervoorts had exhaust exiting out the back.


Thanks. Interesting cars. Some folks hate 'em, some folks like 'em. I like 'em.

I also had another thought last night. That can be very dangerous, especially when I have two thoughts in one day. One of the old 70s-80s SUVs (can't remember for sure, but I think it was a Chevrolet model) had a terrible problem with the rear window getting dirty in rain and/or from dust and debris coming up from the road. It was so bad that it was being raised in the motoring press as a safety issue. The solution was very simple. They put a downward "deflector" on the roof rack that curved the airflow from the roof down over the rear window. That pretty much solved the problem.

So, if I get some exhaust coming back into the cockpit, maybe I can affix a simple aero device to the roll bar or rear deck and change it's flow direction? That thought is bringing me some comfort, anyway. I think I'll need that diagonal run, but don't know for sure yet.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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PostPosted: March 10, 2017, 3:01 pm 
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They've done the same thing with a spoiler on the back of school busses around here now. It seems to work pretty good for keeping windows and tail lights clear.
Kristian

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PostPosted: March 11, 2017, 12:43 am 
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Lonnie-S wrote:
They've done the same thing with a spoiler on the back of school busses around here now.


Yep, wifey had one on her school bus, kept the rear door window clear from sleet, slush, crud, etc.

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PostPosted: March 11, 2017, 1:19 am 
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The trouble is those spoilers need to up in the air flow to work and I don't believe they would be on the back of a 7

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PostPosted: March 11, 2017, 8:31 am 
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This car has a center exhaust and a moderate rear spoiler. No problem with the back being covered with soot. The "jag" turn-downs would also help get the exhaust out of the eddy area.


Attachments:
center exhaust.jpg
center exhaust.jpg [ 905.84 KiB | Viewed 2716 times ]
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PostPosted: March 11, 2017, 8:58 am 
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In the completed builds section is a "My Clubman", two or three spots down from the top. He went with an ls motor, under the car exhaust, center outlet. You might ask him how his is working out. Also, I think the real issue, and I could be wrong, is with vehicles that have an enclosed cockpit and a back window that opens, i.e., Station Wagons, SUV's, etc., where any reversion of the airflow COULD end up with CO getting back into the vehicle and staying in high enough quantities to be a problem. I'm planning on doing exactly what the Clubman is, so if I'm wrong, I may be doing it twice...


Attachments:
ClubmanExhaust.jpg
ClubmanExhaust.jpg [ 85.67 KiB | Viewed 2715 times ]

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PostPosted: March 11, 2017, 9:50 am 
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Yo Lonnie-
From what I remember of those "airflow diagrams" with all the purty colors, there was a fairly large volume of air coming into the cockpit area in the front, coming around the sides of the windshield. That was the actual subject of the discussion, how to limit that buffeting in the cockpit. (IIRC)

Seems to me, like Dismantalus says, the soot/fumes/reversions would be in a low pressure area behind the car's "rear surface" and that unless there's a window and a (relatively) low pressure interior area there for the fumes to go into, it shouldn't be a problem in the cockpit.

Perhaps instead of "turn downs" on the exhaust tips, you could use the same pieces at a 45* angle or even sideways to make "turn outs" and get the exhaust pointed outward into the airflow around/behind the rear tires... Or something... :mrgreen:

Or just drive fast enough to run away from your own exhaust! :mrgreen:

:cheers:
JDK

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PostPosted: March 11, 2017, 11:38 am 
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@turbo_bird
@horchoha
@carguy123
@seven13bt
@Dismantalus
@GonzoRacer

Thanks everyone for the observations and input.

I'm a pretty pragmatic person, and will usually go for practical over pretty. However, the exhaust system, and how it looks and sounds, is kind of an emotional/aesthetic decision for a lot of us, myself included. I really think I'm going to need the diagonal run to the center of the car to fit resonators, which can be really desirable on a V6, especially with a small muffler like I'll have. V6's with out much muffler tend to sound like a Mexican school bus. If you've ever been to Tijuana, you'll know exactly what I mean. They can be loud and raspy and hard to live with. The resonator helps knock the rough edges off a V6 exhaust note. Here's an example, although it's still plenty loud:

Mustang V6 with resonators ==> https://www.youtube.com/watch?v=dJsz7v5nNL0

For the moment, I'm taking my current idea as Plan A. If it proves unnecessary, or impractical, when I get to the decision point, Plan B will be straight back exhaust to the corners of the kick-up.

Although, I kinda like JDs suggestion best, "Or just drive fast enough to run away from your own exhaust! :mrgreen: ." I think I'm passing from "middle-aged crazy" to "old-age crazy" now. :lol:

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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PostPosted: March 14, 2017, 10:16 pm 
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I'm going to do two posts tonight, They deal with different aspects of my build. One (this one) is a request for help. The second one will just be information sharing.

I'm trying to get everything done in the transmission tunnel so that it is finished and done with. Part of what needs to be done is plan for, and route, the 2 fuel lines. In my case, the donor engine has EFI with a fuel input line and a high pressure return line from the EFI system to the fuel tank. Because there is much to be done in the engine compartment and rear kick-up (it carries the future fuel tank), I want to leave those until later.

Here is a horrid, but useful schematic of what I'm after:
Attachment:
File comment: Crude schematic of desired fuel system.
Fuel System Schematic.jpg
Fuel System Schematic.jpg [ 35.56 KiB | Viewed 2644 times ]


The part I need to do now is the red part. However, I need it to eventually interface to the two blue parts: fuel tank; and engine. I know what the engine needs. However, the fuel tank will be up to me and I'd like to do something standard, simple and effective. I have no design for the fuel tank yet.

The blue parts come later as I mentioned. However, I need to terminate the two ends of the red part to some sort of "interface block", which I have no real idea about, but need to identify and purchase now. That's question #1 that I need to solve, "What should I use at each end, and where do I find it?

The second issue is the size of the two fuel lines. The outside diameter of both the fuel and return lines now are 5/16". Those service the stock donor engine of 195HP. Eventually, the engine will have close to 300HP. So, the second question is, "Should I up the size of the fuel and return lines now as the fuel flow required later may require extra volume?"

I'm hoping someone will know the best answer, and I won't have to spend a lot of time trying to figure out and estimate what the EFI system might require at 300HP as this is beyond my knowledge today.

I'd like to run hard lines for the red part in the tunnel for simplicity of routing and attaching. The other two ends, the blue parts, I'd like to do in flexible hose because the routing of hard lines would be difficult.

Here's what the donor fuel line system under the car, and to the engine looked like:
Attachment:
File comment: Fuel lines from engine compartment to the rear axle.
Donor Fuel Lines 1.JPG
Donor Fuel Lines 1.JPG [ 136.16 KiB | Viewed 2644 times ]

Attachment:
File comment: Engine lines in foreground, EVAP system lines in background.
Donor Fuel Lines 2.JPG
Donor Fuel Lines 2.JPG [ 136.57 KiB | Viewed 2644 times ]

Attachment:
File comment: Transition from 5/16" hard lines to braided flex lines to engine EFI system.
Donor Fuel Lines 3.JPG
Donor Fuel Lines 3.JPG [ 134.99 KiB | Viewed 2644 times ]

Attachment:
File comment: End of flex lines to engine. Input line is larger here, but both use 5/16" hard lines.
Donor Fuel Lines 4.JPG
Donor Fuel Lines 4.JPG [ 141.55 KiB | Viewed 2644 times ]


I don't know what those EFI attachment joints are called, but they appear on a number of other vehicles beside my Ford Mustang donor. My front interface block will need to accept hard line fittings in and output to flex line fittings identical to these.

At the rear, I'll probably use A/N fittings as every fuel tank maker seems to deal with those. However, if NPT fittings make more sense, and I can find suitable high pressure flex lines (the Mustang uses 40-45 PSI input) that's fine too. I just need to be smart about the "interface block" at rear and make sure it's something that won't limit my possibilities later, if possible.

Any help on these three things (line size, interface blocks and compatible engine flex line fittings) would be very much appreciated.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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PostPosted: March 14, 2017, 10:50 pm 
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Part 2 (this part) is information sharing. I've been looking at seam sealers and heat/sound barriers. I've decided on 3 of those and here they are:

Interior seam sealer:
Attachment:
File comment: I'll use this on the interior and the transmission tunnel aft of the bell housing where the temperatures are lower.
DSC03665.JPG
DSC03665.JPG [ 120.66 KiB | Viewed 2642 times ]


It has lots of nice qualities like: easy to work; applies with a calking gun; can be brushed on if desired; can go over bare metal or primer/paint; has a service environment of -20°F to 350°F; and other things. It is not fire resistant and not suitable for the firewall. It's also a mild adhesive and works with aluminum too. The cost is about $20 per tube and at many automotive paint dealers.

For the firewall, and the transmission tunnel in high heat areas, I'm using this 3M product:
Attachment:
File comment: 3M Sealant for fire barrier walls. It is designed to stay integral for 4 hours during a house fire. It expands at 500°F rather than melts and will fail at 1,000°F when you would be a crispy critter anyway.
DSC03664.JPG
DSC03664.JPG [ 143.4 KiB | Viewed 2642 times ]


It's available at Home Depot and other improvement stores for about $9, will stick to anything non-oily and is paintable. It will have a heat shield over it (to be identified), so I'm confident it will work well in my Locost.

For the interior heat barrier, and in low heat areas of the interior and the transmission tunnel, I'm going to use Thermozite and Thermozite Plus from Foss manufacturing. They are approved for automotive use and have been tested by the Feds. The company doesn't have a good product page, so I'll post a link to a vendor below. The Plus version has foil on both sides with a synthetic jute in between. The regular product has foil on one side.

Commercial link toThermozite ==> http://www.yourautotrim.com/thercarpad.html

I still have to select a firewall & high area of the transmission tunnel heat/sound barrier material as yet. I do have some candidates, but they're expensive. I won't need that much, so I may just suck it up and buy a known version like Koolmat or Dynamat.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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PostPosted: March 15, 2017, 10:10 am 
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I've used 5/16" OD steel line on many 350 HP cars. The steel lines come in 10" increments up to 50 or 60 inches (O'reilly). The ends are male inverted flare. I've used female inverted flare to 3/8" barb fittings (edelmann) and attach fuel injection hose to connect to tank and engine. At the engine and tank ends of the hose use -6 AN to 3/8 barb and use fuel injection hose clamps (smooth surface, no worm clamps).
For the ford fuel rail connections, Summit has "Fuel Rail Fittings" specifically for Ford such as Fragaola PN 491985 and 491986 for the two different sizes on the SN95 rail. They have a male -6 AN end to which you attach the rubber fuel injection hose.
I don't see the need for a "block" at the ends of the solid lines, just an anchor to the chassis with P-clamps is adequate.


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PostPosted: March 15, 2017, 10:48 am 
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@seven13bt
Thank you very much. You've answered every question. That is much appreciated.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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