Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: dieselgeek on January 12, 2007, 04:13:50 PM
-
Hello -
I figured it would be useful to get suggestions on our propsed streamliner buildup, so I got the OK to post up drawings of our project for Speedweek 07...
A little background info: We (Spectre Performance) brought our Ferrari F40 to the salt last year and became hooked on landracing. Bonneville was great for product testing and marketing for us... so we want to come back next year. Recently, we had a chance to pick up a well-built streamliner (the 6969 car of Jr. Kurtz, usually driven by Kenny Hoover) the "Plastic Express." We brought it home to our shop in Ontario, CA. (California)
After talking to the builder Roy Fjastad, he recommended we close the rear wheels or taper the rear end for better aero. 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. A record would be nice, 200mph club entry would be even nicer...
I have a few design engineers on staff, and in their free time they came up with the below drawing for starters. While we do not have the budget for full-on wind tunnel testing (maybe next year?), we *do* have the ability to print scale models if people think scaled testing is worthwhile? I also have the ability to do some fluid modelling in FloWorks (coming online in the next week or two).
Anyways, here's a preliminary drawing. I welcome any input I can get from you aero guys!
Thanks,
-Scott Clark
(http://www.1320video.com/gallery/STREAMLINER%21/concept_drawing?full=1)
-
Hi Scott. I should be out working on the lakester or doing taxes or maybe figuring out how I'm going to Megasquirt my pickup, so I could be asking you lots of questions, but your new project hooked me :-). First I think you guys are going to really have fun with this one and knowing you I'll bet sooner or later you will have a record.
Ok here are my 'gut' feelings what could maybe help and you had better consult with an expert since I have only stayed at Holiday Inn once in my life :wink:
(http://purplesagetradingpost.com/sumner/temp-pictures/Streamliner-2.jpg)
Hope you have or will have a long trailer, since you would need it for this. I would extend the nose a slight amount and take out that dip by the front tire and extend the nose down into one teardrop shape.
At the back I reversed your angles and made the steeper angle in front of the back tires and then made the rear a more gentle slope to the back and don't chop it off if you can help it. Seems like I have read you can have about a 2 1/2 to 1 slope back there and still keep the air attached.
I'll let someone else jump in now that knows what they are talking about.
c ya,
Sum
-
Scott,
it's not necessary to extend the rear end so as Sum shows - no effect on the aerodynamic, but you guys have to do, the rear end shape has to be turned around - what I mean, from there where you bump the body shape out to get space for the engine and wheels the big tapperd angle had to be - the rear the small angle, you got it exactly opposite around - the most areodynamic shape mistake are done by streamliner builder......so you be are not alone.
Also the nose, you can make it in a round circle like the whole front body is wide - not a circle going over into a angle shape, another curved area into the straight body shape. This increase the airpressure on the front.
See ya
-
Scott, it's not necessary to extend the rear end so as Sum shows - no effect on teh aerodynamic,
The reason I extended the rear was to get the right slope on the rear like you mentioned and leaving the rear open leaves something on the table. Mike is going away from the open back on the Ack Attack and I think he said that will be like gaining 50 hp or so over the drag from the flat rear. Tom seems to think it is important also.
but you guys have to do, the rear end shape has to be turned around - what I mean, from there where you bump the body shape out to get space for the engine and wheels the big tapperd angle had to be - the rear the small angle, you got it exactly opposite around -
PorkPie that is what I did in my drawing. I cut the back angle off and turned it around and cut and pasted it in front of the wheels. Then took the front angle and put it on the back. Since that angle is now less it makes the car longer if you run it out.
If you re-read my post again I think you will see we are saying the same thing, just in a different version of English :wink:, except you think the squared off back isn't hurting the car and I think it will. I also realize compromises have to be made.
I think in the front we are also basically saying the same thing.
c ya,
Sum
-
Sum,
where you add the parachute?
the parachute open back is necessary - and if so, use them to Kamm - if you use the 6 degrees tappered you got not the problem.
the Ack Attack got his problem not on the rear end, he got it on a other spot.
I add the mod sketch that you can see what I meant
-
Sum,
where you add the parachute?
the parachute open back is necessary - and if so, use them to Kamm - if you use the 6 degrees tappered you got not the problem.
the Ack Attack got his problem not on the rear end, he got it on a other spot.
I add the mod sketch that you can see what I meant
Well while you were doing that I re-did the front from the top view and ended up with what you did.
(http://purplesagetradingpost.com/sumner/temp-pictures/Streamliner-3.jpg)
I also think the air will detach at the front the way it is now and needs to either be more rounded in the side and "top" view or the transition into the body needs to be reworked.
The chute would be taken care of like what Tom, Seth, Maning, Wheeler or like what I'm planning on doing and on what Mike is going to do. I still believe the squared off back is giving up something. The rest we agree on. I think what you did in front of and behind is exactly what I had done in my first drawing :-).
To bad these changes aren't as easy to do as it is for us to give advice :wink:.
c ya,
Sum
-
The Tom Burkland/Sam Wheeler solution is fine but shows the problems.
Both are air brakes - Sam got a very small one and can be easy controlled to open exact parallel. Also he needs only a very small chute for his streamline bike.
Tom Burkland got a lot of weight in front (reduce the sideway force effect) of the air brake and also a exteme construction to get it open parallel. Tom's tappered* on the rear end is too much to Kamm, but he got enough power to take not care to this aerodynamic lack.
Using a air brake means
1. parallel open with the same size of brake pattern.
2. solid mechanic behind to hold the force constant
3. just behind the rear wheels (for four wheel vehicle) like Tom Burkland*
By the way, I hope my red lines can be seen on the mod sketch
-
Scott
Welcome to the land of special construction.
I'm in agreement with your sketches and Pork Pie recommendations relative to changes to Roys old liner.
Liners tend to be so complex in many ways, having a small flat rear panel "Kamm effect" I don't think will hurt in a great way. Particularly that the car is designed for "big" v8 power. My aero/design counsel is much more concerned about departure angle (7 degrees included angle) (or Pork Pie 6 degrees)). I think that angle should be used aft of the wheels as well. That means extending the rear a little, but that is one of the easier changes with a rather large return. On my car when done that extension makes the flat rear panel only 6" wide. I think that car enters the air rather nicely as it exists. It should be a very nice ride and provide you with many enjoyable years of racing.
Rick
-
This is great!! exactly the kind of input I was seeking...
The skin on the car, as it sits now, is complete from the nose to the firewall behind the driver's cockput. Fitment of our engine and turbos will require reworking the rear, so we decided it was a good opportunity to improve aero aft of the driver.
I'm getting our designer, Vincent, signed on and will let him elaborate or ask questions. For now, keep it up! We'll make revisions and post them up next week.
Sumner, anytime you're ready to 'squirt that pickup, you let me know!
-scott
-
Scott
Are you going to do the rear skin in aluminum as was originally done by Mel Swain?
He did the skin and basic chassis of my car and the work is just outstanding. As I evolve into a liner, I'm hoping to be able to afford his work, but it is doubtfull. This kind of work "ain't cheap"
Panel fit is just so good.
Rick
-
Scott
Are you going to do the rear skin in aluminum as was originally done by Mel Swain?
He did the skin and basic chassis of my car and the work is just outstanding. As I evolve into a liner, I'm hoping to be able to afford his work, but it is doubtfull. This kind of work "ain't cheap"
Panel fit is just so good.
Rick
The plan is to do the skin in exactly the same fashion as the original car in an effort to maintain what's an absolutely excellent body already. The skin comes off and goes back on easily, everything lines up perfectly, one guy can have it all off or back on in 15 minutes...!
We hired Dean Westmoreland, an australian with much top fuel experience, and he has a resource to do the new tailsection in the same fashion. I wasn't aware who skinned it the first time (thanks!) but it's quite evident they were expert at forming aluminum.
-
I know Roy's streamliner very well.
When he was coming out with the car in 1996 I done a series of picture, was a very clean work with the frame coating...
The nose shape on the sketch is different to the real car...
To the 6 or 7 degrees - there is a discussion under the aerodynamic specialists for the last 60 years, why there is different - 7 degrees for aeorplane and 6 degrees for ground running verhicles.
To Kamm it had to be around 6 degrees for vehicles - it could be up to 6,2 degrees to Kamm.
I discussed this with the specialist in the Vaihingen University Wind Tunnel - the place where Kamm worked as a Professor for Aerodynamic.
Our opinion was that may be the bouncing airflow along the car makes the different. :|
A plane, due to this that the air is complete around the plane body, creates a little bit different airflow.
A vehicle on the ground, like a streamliner, got the effect from the bouncing airflow along the streamliner body - this is also the reason for the different effects of flat or round bottom (depense on the distance from the body to the ground).
Rear end 6 inches wide - this is about 15 cm - this has to be enough for a parachute tube - so where is there a problem :wink:
-
Oh it's not a problem Thomas. To the contrary, it makes the rear very simple and practical. I have considered light aircraft air brake devices, but dismiss due to complexity, and the fact that I do not plan on trying to go 400 MPH.....I think that will never be my ambition.
6 or 7 degrees included angle I think is probably just achedemic as we will see little difference in our application as you say because of ground effect. Our concern will be to make boundry layer stay, or reattach because of the rather large wetted surface.
(long skinny car)
We are in agreement Pork Pie
Rick
-
Rear end 6 inches wide - this is about 15 cm - this has to be enough for a parachute tube - so where is there a problem :wink:
Looks to be about 12-16 inches wide in your drawing and the first drawing.
Sum
-
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
-
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
-
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.
-
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
(http://www.1320video.com/gallery/STREAMLINER%21/concept_drawing?full=1)
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
-
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
-
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:
-
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
-
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.
-
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
-
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
-
Wow, this thread is great, what terrific support you all display :-D
(.. hoping I haven't tanned my nose excessively by the above)
-
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
-
(http://purplesagetradingpost.com/sumner/temp-pictures/Rex-4-sm.jpg)
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
-
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
-
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
-
OOPS!! I missed the AABGS streamliner record is open so you guys will set the standard!!!
Rex
-
Here's the site for a liner from Sweden with details of their wind tunnel experience at Volvo. Jokes about bricks and aerodynamics aside, there's interesting stuff here.
http://www.geocities.com/MotorCity/2078/index.html
Best of luck with the adventure.
Regards,
PJQ
Velocity Science Laboratories
-
Update:
The UPS man brought us a couple presents today!
(http://www.1320video.com/img/STREAMLINER%21/IMG_0154.sized.jpg)
(http://www.1320video.com/img/STREAMLINER%21/IMG_0152.sized.jpg)
-
Alright, mate, and now explain how you get a 16 cylinder Detroit diesel into this streamliner... :wink:
-
Alright, mate, and now explain how you get a 16 cylinder Detroit diesel into this streamliner... :wink:
funny, the boss seriously considered something crazier like an Allison V1710 or one of those soviet tank engines... or maybe a Merlin...
in order to feed 500+ cubes a "low boost diet" and keep the turbos in their efficiency range, we need gigantic turbos. Harry Hruska at Precision Turbo made them especially for our application... we'll come nowhere near the max airflow of these things (this year) but we'll probably do a more typical BB Chevy in two years and take better advantage of the 2800+ hp they should be able to flow...
Now the trick is figuring out how to fit these in the 'liner without doubling the frontal area? PorkPie and others, keep an eye on this post because we may need more aero help!!
thanks again guys,
-scott
-
Scott,
With all the additional "volume" you are going to create by lengthening the car you should be able to move the water tank behind the rear wheels and then hang the turbos in that area. You need to hire Jeff Heywood to do the headers and new tank, he did them for Junior and he is one of the best fab guys around. His headers are true works of art and he has done a number of racing turbo header setups, several for Indy cars and has lots of experience getting every thing tucked in.
Rex
-
Hey Scott, when you get serious:
http://www.landracing.com/forum/index.php/topic,1745.msg20061.html#msg20061
2 is more fun than one!
-
Any thing going on with this these days?
-
Sparky,
Go to the second page of "General Chat" and look at the post from Tom Slick "Another new streamliner". This is the Spectra car.
Rex
-
Thanks Rex,----
SOOO if this thing were going to be front Wheel drive would you just move the wide part to the frt---how would have it changed?