Landracing Forum
Tech Information => Technical Discussion => Topic started by: jdincau on December 12, 2006, 06:29:27 PM
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This is an essay question;
Compare and contrast the drag reduction techneques displayed by the Goldenrod and JCB under body shape versus the Costella and Flatfire underbody shape.
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Both types worked for records for cars metioned. Bottom is only a part of, and needs to work with, the total package needed for success in any given class 2, 3, or 4 wheeled.
When all options are considered, there are no decisions to be made. FWIW we haven't decided for sure yet on the bottom or total body design on our Lakester, still working on the chassis and parts to be enclosed. Product will probabley be a result of our talent/tooling/$$$ factors [all three "challenged" in today's speak].
Reality usually prevails over theory. Exceptions to everything is what keeps it all interesting.............
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Flat bottoms, skirts , and stuff really suck good for a lot of things, until you get a little sideways and then they really suck up and you get to learn to fly.
All of those things working together are called an "AIR DAMN" and you are likely to get some air time.
Flying is easier than landing as most flat bottom racers willl tell you if they speak of it at all.
A correctly balanced round bottom will try to go straight if you just leave it alone.
Put enough weight in a flat bottom and you can mask some otherwise real problems.
When you are in it over your head, it is a little late to go back to fix it and you have to deal with what is left.
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Professor Dolan, I love it
Professor Dolan, I love it! With all the postings on here about c.d., drag coefficients, aero this and slipstream that, you have summed it up perfectly. If you don't have a round belly, it better be low, heavy, and minimumly sprung, if at all........Here's to you, Professor..........................
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How the hell did I do that? :mrgreen: :roll:
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"Theoretical records are set by theoretical projects."
Round, low , heavy, with very little spring ?
Are you talking about My "Dunlap"?
Dunlap: The part of your round belly that DUNLAPPED over yer belt.
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If you look in my favorite Aero reference books, "Race Car Aerodynamics" by Katz and "The Leading Edge" by Tamai they both have charts that show the Cd of a shape decreasing as it is ran closer to the ground and then at a height, usually given as a percentage of the total length of the body the Cd starts to go up. They also give a pretty good explanation of what happens if you take something like a tank and run it very close to the ground. But then you have Rick Yacouchi's car (Rick if I butchered your last name I'm sorry!) lower than a snakes belly and it holds more records than anyother car at B'ville or El Mirage. And when he brakes the records it is not by a couple of MPH, he destroys them. Yes flat bottom cars probably "need" to not have suspension and they certainly "need" smooth salt or dirt to go fast. I think that the really dangerous flat bottom cars are like the Mercedes sports cars that did some "test" flying at LeMans a few years ago. They had huge flat areas, located infront of the front wheels, that were ran at a very low height and as soon as they did a little lift on the "hump" on the straight they did fly! Cars like Rick's have pretty small "plan view" area and also not much over hang in the front so although they may exibit some of the problems that the Mercedes cars had I would think that it would be much less.
Rex
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:?I keep looking @ pictures of crowers T and it appears to be a flat bottom with a nose that shoves the air off to the sides, is this aproach prone to flying?? not knowing any better this looked like the front I was going to use on my oakland, good idea or bad??????
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I guess you didn't see Bruce's liner do the spin.
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Flat bottoms, skirts , and stuff really suck good for a lot of things, until you get a little sideways and then they really suck up and you get to learn to fly.
All of those things working together are called an "AIR DAMN" and you are likely to get some air time.
Flying is easier than landing as most flat bottom racers willl tell you if they speak of it at all.
A correctly balanced round bottom will try to go straight if you just leave it alone.
Put enough weight in a flat bottom and you can mask some otherwise real problems.
When you are in it over your head, it is a little late to go back to fix it and you have to deal with what is left.
Flat bottom solution like the Nebelous Theorem II, the Jack Costella car which is used by Rick Yacoucci, got the advantage that they reduce the effect of the bouncing airflow along the car which is important to go really fast.
But you can do this only if you got no suspension like the NT II or extreme short spring movement - 2/10 of an inch. If you run the car like the NT II, more springload will let the car flip...
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:roll:Jack please enlighten me - no I didn;t see spin all I have is pics that crower sent, and it appears to be in good shape, was told was one of the sweetest sounding engs on salt-- but did it fly or did it just spin and stay down??? another question that should be under rules,:: are alerons: rudder & stabilizere legal on modified roadster, would be a saftey pluss to make the landing easier & safer..
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Roadster, Coupe/Sedan and other classes where belly pans or step pans are permitted have a flat bottom by necessity. Are some of the things we?ve heard hear, like limited or no suspension, weight carried low, also to be used for these cars as well?
To focus just on roadsters they have no flat areas ahead of the front wheels, but what about other things like:
Should ride height be as low as possible?
Should bottom rise at an angle front to rear to allow trapped air to exit easier?
If so, what angle should this be?
John
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I guess you didn't see Bruce's liner do the spin.
you have my curisoity way up now Jack, are the pics of bruces T pre spin as it appears to be in perfict shape< or did it flat spin with no damage?? is it one of these { if they will talk about it rides}thinking about round:a long nose like bruce used could be round bottom and blended to flat by the time the firewall is reachedwould this try to stay straight if left alone or with a flat rear section would it agrivate things????I ain't into trying to design airplanes on wheels, I like motors, unfortunatly they need to be in something on wheels to enjoy the sound.
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The liner did a flat spin because the weight and balance depended on the side thrust from the wheels to keep it straight.
That is not a good place to start.
He used Gilmer Metric belts like you might use on a blower on aluminum wheels with the tooth turned in.
While they seemed like good idea on paper they did not offer the grip required to keep it under way.
You might compare it to a dart or an arrow that needed wheels and grip on the ground to stay straight.
Would you suspect there was something wrong with the shape, and balance or would you spend more time to improve the side grip.
The motor and drive train in both cars were a master work and did very well.
The split billet 4 valve push rod heads and the quick change gear feature were totally unique.
"Flat bottoms work until they don't and then they fly up until they don't.
Landing is where it all ends."
My kid said "They really suck until they blow."
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:cry:Hey jack were talking about 2 different rigs here, was interested in the 23 T withe the nash eng {the modified roadster} not the liner. please - your thoughts on what he did with the T, aero wise that is..
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The Modified was built for his son Danny to drive and featured many things not common to the Modified of the day.
I think it was the first one built to take advantage of the new SCTA rule that no longer required the wheel base be a % of the track width.
It was a pioneer with respect to a lot of things for example the 4 OHV billet, twin head, push rod 37 Nash motor, and the belt driven conversion from a turbo charger that was not allowed in Vintage engines, to the Mercedes mechanical fuel injection with the rack.
The quick change feature on the rear drive was made by him on the input shaft.
He also had the ability to put a Dyno pump in the car in the place of the transmission and could load all the motor systems on board without spinning the wheels.
All of this and some real thought to aero features that were never really proven against a similar classed car because there were none in it's short life.
It was interesting but under utilized.
As Bruce is prone to do he quickly went on to other things including his Reno Air Racer and the Exhaust heat recovery engine.
They say his imagination is never ending and most of his projects are waiting for an end.
This is not to avoid the subject but to give him suitable credit for the project as far as it went.
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8-)Thanks to you Jack, as usual helpful info - that T looked real good to me @ time & still does- I know Bruce thinks up a lot of neat stuff , and probably hasn't the time to thrash out one good idea before another looks more interseting. isn't anybody else following up with the aero ideas on that car??????
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8-)Thanks to you Jack, as usual helpful info - that T looked real good to me @ time & still does- I know Bruce thinks up a lot of neat stuff , and probably hasn't the time to thrash out one good idea before another looks more interseting. isn't anybody else following up with the aero ideas on that car??????
Are there pictures somewhere of the car (Internet?? or a program??)?? I don't know if I've seen it or not.
c ya,
Sum
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This is a tough essay question. All things engine related can be tested on the dyno. All things aero related can be tested in the wind tunnel. Except underbody aerodynamics. In the wind tunnel you sit on a non-moving plate, nothing like the ground whistling under you at 200 mph.
The flat bottom concept also lends itself to the possiblity of ground effects down force.
Because we always see the static car sitting in the wind tunnel with the smoke streaming over it, we always seem to think of the air moving over the car, instead of the real world where the air is static and the vehicle punches through it. It is easier sometimes to picture the world filled with water so that you can think of the flow over things. Much easier to visualize.
So the answer is all about drag and how to reduce it. We can all picture the super slick shape of the streamliner and picture the smooooooth air flow. When it comes to the underside, it's anything but smooth.
The flat bottom concept leans toward keeping the air out from underneath, but there is still air under there, and it's subject to a shear layer between the stationary ground and the moving vehicle. You still have a 200 mph difference in speeds. Picture what a small pebble would do. Picture it bouncing between the ground and the underside, and then picture the air doing the same thing.
The round bottom concept treats the underside the same as the top side. Pick the bottom up out of the ground effects, let the air bleed out.
(http://www.iit.edu/~iit100/bf2.jpg)
The Blue Flame is the ultimate in round bottom, least possible ground effects design. JCB and Goldenrod are not even close.
(http://www.channel4.com/4car/media/features/2006/andy-green-interview/03-large/dieselmax-launch.jpg)(http://www.motoringpicturelibrary.com/docs/hi-mpl340001188c.jpg)
Ecofire
(http://www.landracing.net/emAlbum/albums/Other and Misc/FIA Meet 2006/Sept 29, 2006//IMG_4574.jpg)
Which one is better? Have you looked at the speeds these guys are going? :-o :-o Whichever one you think is better, look at the speed the other design is going.
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getting the car 'off the ground' has it's limits as well. consider the handling dynamics of a car that is long has a narrow track and a high CG.. Close your eyes and see the thing starting to get just a little sideways then do the lateral load transfer calcs.. It won't be pretty. :-o a 4 inch change in CG is a big deal when the track is only 28 inches. There is no way to change this with suspension or anything else the load transfer does not car how it is suspended or if it is at all. See 'Race Car vehicle Dynamic' W. Milliken and D. Milliken........
As far as wind tunnels and rolling roads it can be done just not cheap. It is not completley idendical but very close. See 'Race car Aerodynamics' by Joseph Katz.. An interesting read. mostly sporty car stuff but as a result lots on underbody flows as well.
dave
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Bruce's liner is the only one that I've seen or ever heard of that actually spun without rolling and crashing. That in and of itself was and is quite interesting. His body shape was based on that of a trout. On another note, Roger Lessman's liner, had a flat bottom and a down force suction tunnel. When boost really came on, he spun the wheels and as soon as it started to get sideways, it flew big time. His new car has a different set-up on the bottom but will still use aero downforce. We have a semi-flat bottom but rounded edges and sides that hopefully lets air spill out from underneath. According to our computer analyisis, at 300 mph in free air we generate 300 #s of lift but next to a plane surface it's 700 #s of downforce. So far it has worked pretty well.
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When you start getting really close to the ground like Yacoucci's and Main's cars you have both the bottom of the car and the ground plane that have a boundry layer and they start to mix and this is the area and that is difficult to define. If you look at pictures of Yacoucci's car at El Mirage there is very little apparent turbulance along the sides of the car which would indicate that the air going down the side of the car is still attached, which is the least drag and most desirable situation. On cars like the JCB and the Golden Rod I would think that the air going under the car is at a higher velocity than the air going along the sides and therefore it is at lower pressure and is drawing air from the edge of the car to the bottom area. This is how ground affects works, you accelerate the air under the car to make it lower pressure than the air going over the car and the differential pressure times the plan area of the car is down force. Aero down force using ground affects is probably not a good idea for a Bonneville car. As Dave Dahlgren said, you get a little side ways and the down force goes away and now the "pencil" rolls follow.
On round bottom cars if you run them to low then the air that is trying to go under the low spot is interferred by the boundry layer of the car and the ground and it becomes turbulent and un-attached. This can make the lower rear half of the body act as a "bluff" body which means that this part of the body is now subject to "pressure drag" as it is no longer a "streamlined" body, i.e. the air stream is attached to the body completely from the front to the back. This can increase the total drag of the body by 100% in some cases.
At the speed that are ran at Bonneville very little of the air flow around any of the streamliners or lakesters is laminar, most is turbulent but to be an efficient stream lined shape the air needs to remain attached. It is when the air becomes turbulent and then becomes un-attached that drag is signifigantly increased.
Rex
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This is a tough essay question. All things engine related can be tested on the dyno. All things aero related can be tested in the wind tunnel. Except underbody aerodynamics. In the wind tunnel you sit on a non-moving plate, nothing like the ground whistling under you at 200 mph.
This is the kind of wind tunnel 20 years ago - today the wind tunnel are rolling wind tunnels and the scales are so sensitive that the react when you forgot a small nut on the floor...
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Aerodynamic, shape, flat or round bottom, all is a question of the overall package - and by the way, the Golden Rod nearly starts to flip when he was at 425 mph. The Blue Flame design has nothing to with car design - a rocket powered vehicle needs a totally other shape as a racer which brings the power to the ground. The JCB - at last they found out that theorie and reality is sometimes different.
What is really important - how you go thru the air and how you got out of the air....
Some years ago a streamliner went up in the air when his chute opens during the acceleration in the 2nd mile - the chute lift the car for a short time on the front and the rest was historie...
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Are there pictures somewhere of the car (Internet?? or a program??)?? I don't know if I've seen it or not.
c ya,
Sum
[/quote]I have a couple of blak&white pics that have been looked to death, I will try to take a pic of & send to you, if it works you could post so people know what we are talking about{ I don't know how to post pics} apparently not that many people have seen this car, I paid particular attn as it fit program I was interested in, Okland is a bit bigger than T but a rare roadster these days, specialy an origional tin one,: that still has the "true blue " paint still on it. Off to see if I can get a usuable pic.Sent pics- not good qty- does't pork have some? he seems to have pics of about everything- pics were 1988- car no=118 agmr qualified@230.4 & cracked a head on 1931 nash eng.
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I have a couple of blak&white pics that have been looked to death, I will try to take a pic of & send to you, if it works you could post so people know what we are talking about........................
That sounds good. Are you e-mailing them or snail mailing them??? If you e-mailed them before this post I didn't get them,
Sum
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:evil:sent to email drs on your h, pg,{sumner1@purpletradingpost.com}. but am on slowwwww ll and some pics have been known to take 12 hr to get there.
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:evil:sent to email drs on your h, pg,{sumner1@purpletradingpost.com}. but am on slowwwww ll and some pics have been known to take 12 hr to get there.
Old Indian way - one cloud....yes....two clouds......yes yes.......three clouds....stop......four clouds....no......five clouds.....no PayPal.......... :wink:
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:evil:sent to email drs on your h, pg,{sumner1@purpletradingpost.com}. but am on slowwwww ll and some pics have been known to take 12 hr to get there.
Old Indian way - one cloud....yes....two clouds......yes yes.......three clouds....stop......four clouds....no......five clouds.....no PayPal.......... :wink:
Russ I got the pictures after they got thru the smoke. Here they are.
(http://purplesagetradingpost.com/sumner/temp-pictures/Russ-1.jpg)
(http://purplesagetradingpost.com/sumner/temp-pictures/Russ-2.jpg)
(http://purplesagetradingpost.com/sumner/temp-pictures/Russ-3.jpg)
Here is what you also put in the e-mail. It might help someone:
Paper is shiny & worn so this is best I can seem to get front is like soapbax derby shoving air off to sides and as near as I can tell from pics there appears to be lexan slide plates on sides that are on slots that let it ride on salt keeping air out. maybe I can get a photo shop to do better??
c ya,
Sum
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:evil:sent to email drs on your h, pg,{sumner1@purpletradingpost.com}. but am on slowwwww ll and some pics have been known to take 12 hr to get there.
Old Indian way - one cloud....yes....two clouds......yes yes.......three clouds....stop......four clouds....no......five clouds.....no PayPal.......... :wink:
Now I know where Pork Pie learned his Aero. From the Indians :wink: Enter the forest quietly, make no large disturbances while passing through, and leave as few traces as possible after having done so..................
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Pork Pie;
Where did you get the information that the goldenrod was unstable over 425?
Jim
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Pork Pie;
Where did you get the information that the goldenrod was unstable over 425?
Jim
Witness, team member, film material and computer simulation in a (computer) wind tunnel.
Friends of mine checked this in his free time for me, after I watched the film material and asked a bunch of people about this what I saw.
At full speed the car was with the frontend up the ground, on some views of the film sequenzes I got, you can see this very clear - if you got the right film material to watch.
By the way, unstable is the wrong word - it went very well straight for this speed - but he was lifting on the front.........
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Are you sure that was not with the pollywog? I know from talking to both Bob and Bill, that the front wheel drive car was lifting and heading in any and all directions, but never heard a word about the big car being unstable. I'll give Bill a call and see what he says. Anyone else have input to this?
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Polywog had 3" or more scrub radius . I'm pretty shure that was the cause of it's handling problems . The drive line was a copy of Jim Colberts front wheel drive roadster . Does anybody remember how that handled ?
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Wow! I know from persomal experience how that works, or should I say doesn't work
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Are you sure that was not with the pollywog? I know from talking to both Bob and Bill, that the front wheel drive car was lifting and heading in any and all directions, but never heard a word about the big car being unstable. I'll give Bill a call and see what he says. Anyone else have input to this?
No, I mean not the Pollywog.
Also, I didn't wrote that the car was unstable, he went very good straight.
What the car done, he lift the nose by highspeed, they faster he went he lift more.
Some of the lift was coming from the bigger diameter of the tires, but the front lift more than the rear.
You can't see this not right on the official movie film, but on a other tape which I got a chance to watch.
When I talked with Bill about it, he said that could be possible, Bob was very busy to keep the car going due to the very bad salt condition and he was never sure what cause this problem really.
A good friend of mine, who was with the Summers Brothers at the salt, was a very expierenced witness.
he confirmed that what I saw on the movie, also that from the view on the official tape this lifting was not so visible.
More interested is, that the computer simulation shows the same reaction as it was in reality.
If you ask now, where I got the measurements. This friend has a complete set of blue prints with the measurements.
The Golden Rod is may be very similar as the Thrust II from Richard Noble - the 1983 car. Data's taken during the run and later computer simulation showed, that if the car went on his last run 5 km/h (3 mph) faster, he has flipped.
But the car was absolute stable in the straight direction.
Walking on the borderline.............. :wink:
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Bob told me that the polywog was speed limited by the fact that it was front wheel drive and the front was lifting and the tires would spin. The tach showed him that. So both cars had severe lift under the nose?
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Gentlemen,
Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.
Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.
I could say more, but will relax for a while and enjoy the high country snow.
My regards to all,
HB2
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Harold, I think you've got it right. Goldenrod was good, Polywog was a definate problem. Bob was a consumate driver on the salt.
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Gentlemen,
Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.
Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.
I could say more, but will relax for a while and enjoy the high country snow.
My regards to all,
HB2
The 3 mph was for the Thrust II
...............and computer simulation today is something different to the stoneage 40 years ago.....may be you talk to Ron Ayers..............
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Gentlemen,
Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.
Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.
I could say more, but will relax for a while and enjoy the high country snow.
My regards to all,
HB2
Very strange.......was it not Walter Korff who tooks care for the aerodynamic and testing programm???
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Gentlemen,
I did not initmate that my kindred did any design work on the Goldenrod, just aero work in the tunnel (also some suggestions on how to apply the tunnel data). That work was done in the GALCIT 10ft tunnel that was in use at Caltech for 68yrs.
There is a photo of the two brothers in the CALTECH wind tunnel with the scale model of the Goldenrod that is at the site for HRM http://www.hotrod.com/featuredvehicles/113_0505_summers_brothers_goldenrod/engine.html
I have a lot more information than the old b&w taken there on Nov 18, 1964.
There is a great story about the air intake scoops and some politics and pouts associated, but that will keep til another day.
Regards,
HB2
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:-P Great Stuff Guys---Good lord, I feel like such a uninformed newbee!!!
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"Theoretical records are set by theoretical projects."
Round, low , heavy, with very little spring ?
Are you talking about My "Dunlap"?
Dunlap: The part of your round belly that DUNLAPPED over yer belt.
I heard of that Thing,but is it Real :|?
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When the Golden Rod was in the backyard from Don Green, the car was not so dirty.
Also not when it was on show display, during the time when he was on tour with Bill.
The windtunnel model shows not the later shape as used at Bonneville - a copy of this windtunnel model was for a long time in Richard Dixon's museum in Wendover - painted in white/blue/red - the color of a sponsor who was interest to use this car for another attempt - but at last it was not released on lack of the necessary money.
We used for the simulation the shape of the 425 mph run. The record version with his airbrakes - means air intake scoops which the Chrysler engineers liked to be used - would be different - and may be more worst.
When they checked the 425 mph version with the computerprogram it showed the effect of lifting. To find out how the lifting can be reduced, they modified the shape of the computer datas. When the nose - means the front line of the nose - was 2 inches closer to the ground, the effect was nearly gone.
May be some people can remember the picture after the first high speed runs when the nose body work collapsed - by the way, Tom Burkland got in the 411 nose also a dent from the high speed pressure.
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Here's a picture of the Goldenrods bottom, the record setting air scoops, & the finished car before it was sent to the Ford Museum. Note the scoops used in on the finished car are the ones used in most photos.
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Nice job, Michael.
The scoop on the finished liner was original for the record designed, but not used. Another run after the record showed the real potential of the original scoop.
The other scoop, from the Chrysler engineering was real airbrakes.
By the way, when they used this Chrysler scoop during the record run, the scoop was white painted.
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Here's a picture of the Goldenrods bottom, the record setting air scoops, & the finished car before it was sent to the Ford Museum. Note the scoops used in on the finished car are the ones used in most photos.
Thanks for the pictures Mike. I was just reading Hot Rod this morning and saw the picture of the liner in the museum finished. Very nice. I see were they are also going to have a more in depth article in the future.
In the middle picture the scoop that is shown has a horizontal splitter in the middle of it. Was that to divert air to two separate engines (2 scoops/4 engines)???
Guys I'm a little confused as to which scoops were actually used for the record at this point. I assume they are the ones in.....
(http://purplesagetradingpost.com/sumner/temp-pictures/summers-2a.jpg)
....... Mike's middle picture (above) and......
(http://purplesagetradingpost.com/sumner/temp-pictures/summers-3a.jpg)
......... not the bottom picture (shown above)?? I messed with this picture a little trying to look inside the scoop and there appears to me to maybe be a vertical splitter used on this scoop configuration??
(http://purplesagetradingpost.com/sumner/temp-pictures/summers-1a.jpg)
Were the cutouts in the body for the scoops in this picture meant to work with either of the ones above or did they just materialize??? They don't seem to fit the base of the scoop with the horizontal splitter in the first picture above.
How long was this car anyway???
c ya,
Sum
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Here's a picture of the Goldenrods bottom, the record setting air scoops, & the finished car before it was sent to the Ford Museum. Note the scoops used in on the finished car are the ones used in most photos.
(http://purplesagetradingpost.com/sumner/temp-pictures/summers-1a.jpg)
Were the cutouts in the body for the scoops in this picture meant to work with either of the ones above or did they just materialize??? They don't seem to fit the base of the scoop with the horizontal splitter in the first picture above.
c ya,
Sum
Sum,
I believe this picture is the bottom of the cars body.
Tom G.
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Sum,
the big scoop, which was original white, not gold painted, was the one which was on the streamliner when he set the record. The middle wall was to make the scoop stronger and also to get the air more controlled to the engine. Had nothing to do with two engines.
The original scoop you can see on the complete car, aerodynamicly right, was use by the 425 mph run.
The other picture shows one of the under panel with the wheel cut outs. so it looks it was the rear wheels.
What surprised me, is the big Chrysler scoop - in gold, also the original Chrysler scoops was sold some years ago at ebay :|
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Sum, your looking at the bottom as Tom says, the tires stick through the holes.
I'll try to post some more shots of it's construction.
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A few more...
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Some shot before restoration... or salvation...
Everyone Have A Merry Christmas!!
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Really a nice work you done with restauration.
What I can't believe to today, how easy Bob went into this car. I always got a hard time when I climbed in and I'm 4 inch smaller than Bob - after the fifth time I thought now I know it how to go in and the next time again it was hard to get my head under the rollbar, Bob done it with the helmet on :|
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more....
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Comming to the end...
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Enjoy...
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This is a shot of the one transfer case before being reworked. The car is a true treasure and a testament to the LSR racer who can not be told "it can't be done".
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Mike,
Thanks for the pictures. :-) That was a real treat.
Tom G.
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Wow!
Sure makes my V4F dreams look really small. :-D
Mike
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This car was just a little bit complex :wink:
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Incredible! Absolutely Incredible! Just Great to see. Thanks.
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Mike,
Thanks for the fantastics pictures of the Golden Rod! I really did not get a true feeling for the amount of work and engineering that went into this car. So typical of the kind of work that the Sumers did. I think that an old friend of mine, Don Borth, did alot of the aluminum work. He did most of Mickey's Challenger and I also think he did work on the Golden Rod body which would explain why it was so smooth. Don was a real artisan with aluminum.
Thanks again.
Rex
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Mike,
Thanks for the fantastics pictures of the Golden Rod! I really did not get a true feeling for the amount of work and engineering that went into this car. So typical of the kind of work that the Sumers did. I think that an old friend of mine, Don Borth, did alot of the aluminum work. He did most of Mickey's Challenger and I also think he did work on the Golden Rod body which would explain why it was so smooth. Don was a real artisan with aluminum.
Thanks again.
Rex
It was Mickey Thompson's father who done the bodywork on the Challenger - see Mickey Thompson's book.
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Since there seemed to be much interest in the Goldenrod and many comments concerning the aerodynamic design and application, many might find the SAE paper 660390 equally entertaining. The paper was written all about the Goldenrod and covers the aerodynamic testing in the Caltech 10ft tunnel as well.
SAE papers are generally available in the SAE transactions for any given year. A good research librarian will help find what you want.
Another good article on the Goldenrod is from the Feb 1966 Sports Car Graphic.
Enjoy and Regards to All,
HB2
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The complete story is in Walter Korff's "Designing Tomorrow's cars" - the first publish of this book was 1980.
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Walter Korff was also the author of the two 1966 publications that I listed. He did some very insightful work. Korff also wrote the SAE paper, "The Body Engineer's Role in Automobile Aerodynamics", presented in 1963. I understood that it was that paper that made the Summers work possible.
Although I have not read his book, I am sure that he must cite his SAE works as well.
Throughout history in the US, there have been many gearheads that have done things in aerospace and automobile technology at the same time. Korff was certainly one of those.
Regards,
HB2
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PorkPie
I have pictures somewhere of Don Borth making both the nose and the rear portion of the Challenger at Mickey's shop in Long Beach. Mick's dad certainly may have helped but Don was the craftsman that did the difficult parts.
Rex
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I agree with Rex as I was at his shop many times during the build of the whole car. Don was a master craftsman with alum.
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I agree with Rex as I was at his shop many times during the build of the whole car. Don was a master craftsman with alum.
So you are saying, Mickey Thompson is not correct what he tells in his book????
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In my copy of Challenger by Thompson-Borgeson on pg. 115 it says "Don Borth of El Monte, a master craftsman with sheet aluminum, was still ironing out the body panels at his shop.
Yes Mickey's dad helped but Don was involved, a reread might be in order. :lol:
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Nolan did it with 1 BBC and as far as wind tunnel results, he would just shut the door.
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In my copy of Challenger by Thompson-Borgeson on pg. 115 it says "Don Borth of El Monte, a master craftsman with sheet aluminum, was still ironing out the body panels at his shop.
Yes Mickey's dad helped but Don was involved, a reread might be in order. :lol:
Alright, I done this book out again - so as have to understand them now, Mickey's dad done the wooden mock up which was used to get the aluminium in shape - if you read the comment to one of the picture, it sounds first, that he done the base work and Don done the finish.
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Certainly nothing against Mickey's dad, I never knew the man, but there is a lot of difference between making the body buck and actually making the aluminum fit to it, both take some skill but I know that Don could do both not sure if Mickey's dad could do the aluminum part. Maybe DT could comment on this, he was just a young squirt at the time but I am sure that he would know. Danny if you are reading any of this please comment.
Rex
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both take some skill
Rex
I know, I done both :wink:
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My son Jeff quizzed me about the round bottom versus flat bottom comments. I am glad he did! I had not been on that site yet. It is a very interesting read. I also enjoyed the pictures and downloaded them for future reference.
I am not an engineer, aerodynamics expert, or even a good student sometimes, but I do have some experience in this arena. Our car was first designed with rounded lower sides from the belly pan to the side panels. I ran over 230 mph with it at the World Finals in 1992, the first year it ran. It seemed to handle well, but when Jeff started driving in '97 (on worse salt I would add) there was a big problem. It would spin the wheels @ about 215 mph and immediately spin. I personally believe that the spins were induced by over correction, but I was not in the seat so that is just my analysis. Never the less it tried to fly when side ways. I have video of the second spin which I slowed down and watched frame by frame. when the car was broadside to the course, the front wheels were two to three feet off the ground. (The first two spins were snap spins, once around and on down the course)
For the World Finals, we added 500 lbs of weight just behind the front axle to move the center of gravity forward and stabilize the car. I made the first run at the World Finals on a very bad course. The car moved around on the course when spinning the tires, but stayed straight . After a couple of runs, we broke a front suspension arm when it hit a hole in the turn out area. We repaired the arm and removed half the weight. That was a mistake...this time when it spun, it was a lazy spin and the second time around it went over twice.
On the rebuild, after it crashed in '97 on it's third spin, I got rid of the rounded lower panels and put skirting on the sides. This created enough down force under the car I had to reinforce the belly pan because it was being sucked down forward of the engine. At the same time I added a spoiler to the rear. The car now sticks to the course like glue, does not spin the wheels and goes straight, even on the 2005 course. Things may change, but at present I vote for the flat bottom with skirts.
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You discount the effect of the spoiler ?
Get the suck down a little sideways to break the seal and see how it reacts.
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I think that it is a foregone conclusion that a rounded bottom vehicle probably has a higher roll rate, once that it is clear of the friction of the tire/salt interface. However, it is a better path to achieve lower wetted Cd in some circumstances. The nasty influences of the undervehicle air is easiest to trap/keep from occuring with skirts. The skirts or body parts that function like them are easier to apply.
Having said all that drivel, I still prefer round bottoms and skirts! LOL
Regards to ALL,
HB2
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I like round bottoms in skirts also. Sorry, just had to be said. :evil:
Doug Odom being bad in big ditch
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I think that we may have two different methods of generating down force with low and flat bottoms that we are talking about here and we need to clarify. One method is the type used in todays F1 and sports car design in that they are required to have a "flat" bottom but are also allowed to have a rear difuser area. On this type of "flat" bottom design the air is allowed to come in from the front of the car and is accelerated which increases the velocity of the air and therefore drops the pressure and generates down force. With this type of arrangement if the car gets side ways the air entering the front of the car is reduced or cut off entirely and the down force is reduced or goes away completely so this design is very dependent on the car going straight. Also with this design if the front of the car is raised, by a large bump say or it is shielded, say by following another car to closely, then the down force can go away and if you remember the Mercedes coupes at Le Mans a few years ago, they will do back flips.
The second type of method, and I think the one that Tom may be using on his car but is also used on Mann's Ecotech liner, is where you run a skirt around the complete perimiter of the car, except the back end, and the idea here is that if you prevent any air from entering the area under the car and it will become a low pressure area and generated down force. This method was very popular with Can Am cars back when they were single seaters and usually made from a converted Lola T330 Foumula 5000 car. With this method when the car gets a little sideways down force is still being generated because the system is not dependent on the air coming under the car from the front. Of course if the car hits a bump of something that causes it to allow air under the car then the results are the same as above. Sky-ground, sky-ground, sky-ground, etc.
Rex
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That is just part of the secret to make the bottom of a door slammer faster is to let out more air than you let in.
Do it without add on DO DADS and keep the car small.
Ground clearance and body angle in relation to the wind is as important as anything else.
How you route the exhaust can be a free air spill / dam nobody thinks about.
Zero gapping the body panels is another freeby that just takes a lot of cheap labor.
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Jack,
You make some excellent points. Normal stuff that has to fit on the car can be used in your favor to "cheat" the air. The attention to the details is often much more labor than just buying parts. There have been some great examples of very successful vehicles that didn't "look trick", but were very trick with details like the zero gaps that you mentioned. The underhood stuff and undercar stuff must work together. Afterall, the components stack into a system that must work together.
Sure hope that I don't forget all that stuff on my own junk! LOL
Regards to All,
HB2
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in 1962 Norm Thatcher told 3 green kids running a brand new dodge 413 Ramcharger "just because you have a radiator dosent mean you have to let air go through it" I still treasure that lesson
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in 1962 Norm Thatcher told 3 green kids running a brand new dodge 413 Ramcharger "just because you have a radiator dosent mean you have to let air go through it" I still treasure that lesson
That would have been Mr. Norm to you kid. LOL
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Years ago we got a super speedway cup from Petty. 72 Dodge Charger they had run the year before. Boy, you would not believe how much Bondo they had put on the bottom of that body. LOL :lol:
Doug Odom in big ditch
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Rex is correct. We don't intentionally let air under the car. This is not a "ground effects" car. If you inspect the nose of our car, you will see that the lower edge of the rubber shirting is formed by the salt. I still won't change what works until it doesn't! :roll:
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Sorry Rex,
"Mann's Ecotech liner..."
Actually, I think you are referring to Ron Main's car. Ian Mann is one of the computer geeks that is a part of Ron's crew.
I was the guy that did the original mounting of the mentioned skirts on Ron's car. This car was rebuilt in Rich Manchen's shop after the blowover (who can recall that year?)
Rich and Jim Miller turned that car into what it has become.
I am proud to say that I sweep the floor in the shop while that project was going on,
DW
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Dan
I remember the blow over as it was right in front of us in the timing stand, I also remember all of the bags of lead shot that was held down in the nise with MC ties downs and they came loose in the drivers compartment
. Driver was lucky. However there are lots of stories and lessons learned in these incidents.
Glen
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That is sorta like the guy that got beat up by his own fire bottle.
The medics said "You are gonna get some bruses and hurt for awhile but otherwise you seem OK."
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Jack as I remember that became a instant rule as well, hose clamps and nylon ties won't hold the mass after the first hit. The one I was on was a Studibaker and the bottle was still attached to the hose and it hit everything inside the car including the driver. Another lesson learned the hard way.
:-D
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Flying is not the problem, it is the multiplr landings.
Remember when a roll bar was a towel rod bolted to the floor so you could crab it and hold on ?