Author Topic: Spectre Streamliner  (Read 24012 times)

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Offline Sumner

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Re: Spectre Streamliner
« Reply #15 on: January 13, 2007, 04:21:15 PM »
Sum
I think in Scott's drawing the rear skin is wider than 6 inches.
I was just suggesting that it change to be about the parachute tube dimension.  In my case that is two 6" tubes for the chutes.


Rick

Thanks, that is what I thought.  Mine is 6 inches also at the moment, but if I have any energy left later I would like to do away with that and taper it back to nothing as I'm not running a large motor and if it even saved me 10-20 hp that would be a lot in my case.

c ya,

Sum

Offline vwong

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Re: Spectre Streamliner
« Reply #16 on: January 13, 2007, 05:45:02 PM »
Hello all, I'm Vincent.  As mentioned in Scott's post, I work for him and designed/modified the body work in this liner.  Let me just say that this is my first ever design on anything aerodynamically related, and I'm liking it a lot.  I welcome any comments, so please fire away.   :-D

Before Scott posted this thread, I had questioned my design especially the body around the engine area.  Like several of you had mentioned, it's tapering the wrong way.  This just confirmed my suspicion about that.  I also like your comments on the nose area, and I'll definately change it.

Again, I welcome any comments......positive and negative.  Thanks.

Offline Dynoroom

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Re: Spectre Streamliner
« Reply #17 on: January 13, 2007, 06:14:30 PM »
Hello -

My main concern here is improved aerodynamics, as our powerplant isn't going to be as powerful as what they ran in the car previously.  We're not looking to set the world (or ourselves) on fire; we want to have fun and learn just like most of you.

Thanks,
-Scott Clark


Hi Scott, as a motorhead I won't comment on the 'liners aero but I would like to hear what type of power unit you'll be using.  :-D
Michael LeFevers
Kugel and LeFevers Pontiac Firebird

Without Data You're Just Another Guy With An Opinion!

Racing is just a series of "Problem Solving" events that allow you to spend money & make noise...

Offline dieselgeek

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Re: Spectre Streamliner
« Reply #18 on: January 13, 2007, 06:53:26 PM »

Hi Scott, as a motorhead I won't comment on the 'liners aero but I would like to hear what type of power unit you'll be using.  :-D

Don't laugh:  we're building up a 529" cadillac.  Hoping to make 1200-1400hp turning a max of 6000rpm, with a pair of PT91B turbos.   

The engine's being built in Albuquerque, but the car is in Ontario if you want to drop by and check it out sometime, we have a mockup block and the Liberty trans should be ready in a few weeks,

-scott

Offline Greyboy

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Re: Spectre Streamliner
« Reply #19 on: January 13, 2007, 07:33:32 PM »
From an interested observer ...

I read with great interest this thread. It confirms to me how much seat-of-the-pants experience it takes to realize such a project.

Also, I assume from the comments on fluid modeling etc. that a cost-effective scale wind tunnel would be quite useful in the development of these cars. So for what it's worth, I pass on something that I found that originates in Belgium:

http://www.vki.ac.be/facilities/pdf/l7.pdf

Thanks, Roger  :wink:

Offline Rick Byrnes

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Re: Spectre Streamliner
« Reply #20 on: January 13, 2007, 08:39:11 PM »
Hello all, I'm Vincent. 
Before Scott posted this thread, I had questioned my design especially the body around the engine area.  Like several of you had mentioned, it's tapering the wrong way.  This just confirmed my suspicion about that.  I also like your comments on the nose area, and I'll definately change it.



Vincent, actually you shouldn't question your design too much.  The front part of your body to enclose the rear wheels is good.  The rear portion needs to be a small angle as well.
Also, rather than wind tunnel, if you can completely surface your computer model, there are a number of companies that can perform CFD without spending a ton of money.  I know of one with a reputed coorelation of almost 1:1 (wind tunnel to real world).  At least in road going type of testing.  They have data from virtually thousands of hours in the tunnel.  Now 300+MPH can make some difference, but there are some valuable lessons to be had in their depth of knowledge.  Particularly they can calculate the changes in aero, (delta effect) of a proposed change. 
You need though a really good fully developed surface.
Your efforts are a nice first cut.
Keep at it, you guys will make a fine, modern peice out of  an already nice liner.

Rick
Rick

Offline Dynoroom

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Re: Spectre Streamliner
« Reply #21 on: January 13, 2007, 10:41:47 PM »

Hi Scott, as a motorhead I won't comment on the 'liners aero but I would like to hear what type of power unit you'll be using.  :-D

Don't laugh:  we're building up a 529" cadillac.  Hoping to make 1200-1400hp turning a max of 6000rpm, with a pair of PT91B turbos.   

The engine's being built in Albuquerque, but the car is in Ontario if you want to drop by and check it out sometime, we have a mockup block and the Liberty trans should be ready in a few weeks,

-scott

I'll PM you for the address so as not to highjack your aero thread any further.
Michael LeFevers
Kugel and LeFevers Pontiac Firebird

Without Data You're Just Another Guy With An Opinion!

Racing is just a series of "Problem Solving" events that allow you to spend money & make noise...

Offline PorkPie

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Re: Spectre Streamliner
« Reply #22 on: January 14, 2007, 07:21:27 AM »
Hey, folks, next time let me know that I wrote "taper" wrong... :wink:

Wind tunnel - first of all, doing a 1:1 scale racer in the wind tunnel cost a lot - also they will get a hard time with the wheel configuration of the streamliner - at last - at that speed - 300+ mph - the most vehicle wind tunnel are out of range.....

Also it's hard to check different aerodynamic configurations of a streamliner in a very short time - to save money - or you be interest to build five different sets of body panels....which you can change in five minutes.

The computer simulation is today to a level which give you the necessary feeling if you be in the right direction or not.
We done here in Germany the computer simulation in the free time of the wind tunnel experts - they was always interest to do something special as the normal street vehicle, may be you got the luck to find someone at your area who like to do it also for fun.

The base concept of this streamliner is alright - there is not too much to change - take care about the main rule of aerodynamic
- the big (taper) angle is in front, the soft one in the rear
- important is, how you go out of the air, means a clear rear end - and not how you go into the air - means front end - but it helps if the front end is also clean :wink:
- steps are not helpful and the Reynolds number had to be focused, too - no problem with the Roy streamliner - he is round :-D enough....

If you got a question in the detail - let me know and I will give you my opinion
« Last Edit: January 16, 2007, 03:13:38 PM by PorkPie »
Pork Pie

Photoartist & Historian & 200 MPH Club Member (I/GL 202.8 mph in the orig. Bockscar #1000)

Offline Rex Schimmer

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Re: Spectre Streamliner
« Reply #23 on: January 15, 2007, 04:48:56 PM »
Interesting to see that Junior has sold his liner, he must be getting closer with his two motor car that is a copy of the Golden Rod.

Anyway, I have hug out with Junior for the last few years a Bonneville and have come up with a list of some of the things that I think would make the 6969 car more aero, they are:
1. Extend the rear end of the car somewhat as you have shown. The discussion as to if it should be 6 degress or 7 degrees is a little mot in my mind as I would make it even longer than either of those angle would make it. The idea, as you have said, is to keep the air attached and this is done by making sure that the trailing surface of the car does not taper at an angle that is so large that it will cause the air to become unattached. So the longer the better. I think that I would take the plan shape of the existing car and then over-lay it with different NACA semetrical airfoil shapes and the one that fit the closest is the shape I would use.

As far as the discussion regarding to cutting the rear of the car off I am with Sum in that if you can have attached air for the full length of the car then why cut of the rear and cause additiona pressure drag when you could reduce it to only the pressure drag that is cause by the thickness of the boundry layer .
2. The front wheel(s) shroud should have a couple of things done to it. The front intersection of the shroud needs to be modified to lessen the sharp angle, the shroud needs to be made so that it goes completely around the front wheels and blend smoothly with the lower part of the body at the rear. The shroud needs to have a "floor" with cut outs for each wheel so that the air going under it does not get trapped.
3. Canopy area: This car could stand a 3-4 inch top chop, there is plenty of room for the driver it you lowered the top, also the transition in this area is pretty sharp and should be modified.
4. Get rid of the NACA ducts for the engine air inlet, NACA ducts work best with attached air and with their close proximity to the canopy and the sides that cover the wheels I doubt that the air is very attached in this area.

I completely agree to the addition of the rear verticle stabilizer as this car is pretty rear weight biased but it has always been a very stable car and runs very straight and true. You should contact Kenny Hoover to discuss how it handles

I am attaching a sketch I made several years ago of some of the changes I would do to this car to make it faster. Junior had about 1000 hp availabe and ran a best of 311 on a 340+ record so with that hp you would need to improve the Cd by about 25-30% to be close to the AFS record which I think is very possible. This car is very well constructed and only needs some real thinking about the aero to become a competitive car.

Rex
Rex

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Offline Greyboy

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Re: Spectre Streamliner
« Reply #24 on: January 15, 2007, 06:10:03 PM »

Wow, this thread is great, what terrific support you all display  :-D

(.. hoping I haven't tanned my nose excessively by the above)

Offline dieselgeek

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Re: Spectre Streamliner
« Reply #25 on: January 15, 2007, 06:37:03 PM »
Rex, thanks for your input and sketch!!  (which looks absolutely awesome)


We are planning on running the AA/BGS category...  we might actually have more power than Junior had available, we are planning dyno cell runs sometime in Feb or March.  If we can't get the Caddy motor to make reliable power, we're going with a backup turbo BBC...

The above contributions are what is so great about this kind of racing...   

thanks again, keep 'em coming,
-scott

Offline Sumner

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Re: Spectre Streamliner
« Reply #26 on: January 15, 2007, 06:58:43 PM »


Great job Rex.  I love it.  I raised the tail a little to the top of the air inlet, but that is just because I can't ever leave things alone :wink:.

I think your suggestions are right on.  Mike has been successful with the NACA duct for an inlet on his liner, but I've seen others fail because of what you mentioned.  I would love to use one on my lakester, but don't feel confident in designing one and placing it so that I am assured that it would work.  I'll chicken out and use an air inlet/tail somewhat like you have depicted.

Anyway I think all of your suggestions and the drawing are right on track and it looks like a record holder to me.

Scott you guys are brave running a Cad to 6000 rpm.  You must be putting a good lower end in it.  I always wanted to put one in my pickup, but will stick with the belly button sbc.   

You guys are going to have a lot of fun with this car.

c ya,

Sum

Offline dieselgeek

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Re: Spectre Streamliner
« Reply #27 on: January 15, 2007, 07:05:23 PM »
our motor guy is spinning them to 6300+rpm and still making power, it takes nice parts and a hefty girdle to hold this engine together.  but it can be a torque monster - turbocharging it will help the smallish intake ports...  Engine will run dry sump oiling, twin turbos and our own engine management (due out in March!)...  Anyways, we're dyno testing the engine in Albuquerque as soon as we have our intake and turbo system mocked up, I'll post pics/vids in this thread once we do that to keep people updated on our progress. 

again, thanks for the input,

-scott

Offline Rex Schimmer

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Re: Spectre Streamliner
« Reply #28 on: January 15, 2007, 07:16:47 PM »
Sott,
When Junior ran 311 it was with a motor from Van Dyne Engineering in Huntington Beach, CA. Stew Van Dyne and I are old friends and he builds great motors and has a lot of turbo big block experience so if you are looking for some one to do your big block, you might contact him. 714-847-4417. Junior's motor was a build with the very best of parts, his Van Dyne engines made a large number of runs without a failure. Junior then went to Shaver engines and never went as fast and did have some reliability problems.

Looking at the AAGS record of the Nish family at 373 I certainly think you could get close, if you doubled the hp and cut the Cd by 30% you could be close.

Rex
Rex

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Offline Rex Schimmer

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Re: Spectre Streamliner
« Reply #29 on: January 15, 2007, 07:21:31 PM »
OOPS!! I missed the AABGS streamliner record is open so you guys will set the standard!!!

Rex
Rex

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