Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: oj on November 30, 2016, 05:30:41 PM
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Is there a better wheelbase and track width? Should front and rear wheels be in same track? Any advantage in asymetrical wheel base, like one side ahead of the other or just one tire staggered? Should the front tires be leading the sheetmetal (like the nose of a lakester), be equal to it or be behind it? Any other tire placement questions or issues I should be asking?
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Why would you want to place one side ahead of the other? We are not bracket racing here.
DW
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If the tread with is the same front and back then you only have to make one hole in the wind. You talk about staggering the wheels. I hope your not trying to go around corners with a lakester. As for wheelbase my feelings is longer is better after watching short wheelbase dragsters run 50 years ago.
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if you are going to fair the axles then it helps to have the inside of the frt and rear tires be the same!!
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Our lakester is 45.25 front, 31 rear, 140 wheelbase. Could not tell you if that is good, bad or indifferent but it is the configuration that a friend of ours, Lynn Yakel, suggested. Since he was the designer for the original streamliner when we converted to lakester, Ben Jordan called him to get his best guess for aero.
Seems to work for us :cheers:
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Our lakester is 45.25 front, 31 rear, 140 wheelbase. Could not tell you if that is good, bad or indifferent but it is the configuration that a friend of ours, Lynn Yakel, suggested. Since he was the designer for the original streamliner when we converted to lakester, Ben Jordan called him to get his best guess for aero.
Seems to work for us :cheers:
Didn't Lynn Yakel design or consult or something on the Larsen&Cummins #115 Liner? What a beautiful and successful car!
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If the tread with is the same front and back then you only have to make one hole in the wind.
I think that might have some merit on a very short wheelbase car but with the length of the wheelbase of most lakesters I feel the air fills back in behind the front tire and the rear then has to pass through it.
On the spreadsheet I have that helps to calculate the HP needed to run a certain speed with a lakester ....
http://purplesagetradingpost.com/sumner/bvillecar/bville-spreadsheet-index.html#HP needed for A Lakester (http://purplesagetradingpost.com/sumner/bvillecar/bville-spreadsheet-index.html#HP needed for A Lakester)
... I have inputs for front and rear tire heights and widths and Cd's,
Sumner
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Yeah, I agree with Sumner plus the path of the air flow is relevant to the shape of the body.
Sid.
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How about the forward placement of the front tires, I see some cars with an extended front and some tanks the tires are ahead of the body. Any thoughts on this?
It looks like my tires will be ahead of the nose, the front axle about 12" behind the tank nose.
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Regarding the track width of a lakester, I am of the line of thinking that the farther away from the body the better. With the tire mounted close to the body the interaction of the air going over the body and the disturbed air around the spinning wheel/tire completely disrupts any potential for attached air flow after the tire. If you happen to look at a lakester that has its' rear wheels close to the body, and there are several that have run damn fast, you can many times see a streak of salt on the body just ahead of the tire. I believe that this is the result of the air turbulence caused by the tire preventing attached air flow from going past the tire and along the body behind the tire. You have effectively made the back of the car into a non aero surface. The data that was provided by Woody regarding lakester aero shows that the tires are the single largest aero load, next are the axles. Stream lining the axles is pretty straight forward and easy and effective so I like a wide wheel base, streamlined axles and close attention to wheel size and aero attachments. (Check out Sparky's front wheels for some great thinking about improved wheel aero!)
Rex
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Regarding the track width of a lakester, I am of the line of thinking that the farther away from the body the better. With the tire mounted close to the body the interaction of the air going over the body and the disturbed air around the spinning wheel/tire completely disrupts any potential for attached air flow after the tire. .....Rex
(http://purplesagetradingpost.com/sumner/bvillecar/Body-Sum-1.jpg)
I agree and the rendering that you did above of what my car, if ever finished, might look like illustrates one possible view of what you are talking about. The side pods will be shaped like an inverted foil at the leading edge and trailing edge.
(http://purplesagetradingpost.com/sumner/bvillecar-2/12-30-07-t12.jpg)
The pods are 6 inches tall and contain the axles and room for a small amount of suspension travel and storage for cooling water tanks between the axles on both sides,
There is more on my design thoughts here (take them with a grain of salt 8-) )...
http://purplesagetradingpost.com/sumner/bvillecar/construction%20page-1.html
and body here....
http://purplesagetradingpost.com/sumner/bvillecar-2/construction%20page-88.html
Sumner
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Regarding the track width of a lakester, I am of the line of thinking that the farther away from the body the better. With the tire mounted close to the body the interaction of the air going over the body and the disturbed air around the spinning wheel/tire completely disrupts any potential for attached air flow after the tire. .....Rex
(http://purplesagetradingpost.com/sumner/bvillecar/Body-Sum-1.jpg)
I agree and the rendering that you did above of what my car, if ever finished, might look like illustrates one possible view of what you are talking about. The side pods will be shaped like an inverted foil at the leading edge and trailing edge.
(http://purplesagetradingpost.com/sumner/bvillecar-2/12-30-07-t12.jpg)
The pods are 6 inches tall and contain the axles and room for a small amount of suspension travel and storage for cooling water tanks between the axles on both sides,
There is more on my design thoughts here (take them with a grain of salt 8-) )...
http://purplesagetradingpost.com/sumner/bvillecar/construction%20page-1.html
and body here....
http://purplesagetradingpost.com/sumner/bvillecar-2/construction%20page-88.html
Sumner
Thanks, I'll read thru the links with great interest. I have no idea what an 'inverted foil' is at the moment but I suspect its' one of the things I'll have to earn about.
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Rex are you talking of belly tank bodies, rear engine dragster type bodies or something like Sumner drew?
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Rex are you talking of belly tank bodies, rear engine dragster type bodies or something like Sumner drew?
The drawing above was done by Rex....
Sumner
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bearingburner,
I would mainly consider "tank" style bodies as they are inherently aerodynamic, flat sided dragster style bodies, many of which have either no body work behind the rear wheels or have a tail section that is to short and the transition from the main body to the tail section is an abrupt transition will typically have the rear wheels close to the body and it probably does not make much difference as the wheel/tire completely disrupt the air flow anyway. Yes there are some flat sided cars that have gone very fast, that is usually because they have really strong engines and I also know that the very successful J,I,and K class lakester, the Bockscar ,is flat sided and the rear wheels are fairly close to the body but the success of this car probably shows what the minimum wheel/tire clearance should be to have good air flow over their very aero rear body shape. It also shows that Stainless builds some really killer motors!
rex
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Rex
Thanks for the clarification.
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We were very fortunate that Ben Jordan, Lynn Yakel and Roberta Nichols were good friends. Lynn and Roberta were long time Bonnevillers and Aero Engineers. Lynn was involved with multiple streamliner designs, and in the mid 70's Ben asked him to design a body to go 200 in the K class. While we were not successful in that endeavor, after the liner debuted at the salt in 76, a lot of small flat sided liners started showing up and going very fast. One of the first was Don DeBring, a Lockheed engineer that apologized for stealing the basic idea and went very fast with a junkyard Fiat motor. It was OK, because we stole his rear motor design when we turned the Bockscar into a lakester. Lynn gave us the axle positions for the car and their track widths. While our configuration may not work with a tank or with large motor classes it has worked for us and as of this writing it holds 9 200 MPH+ records in G, H, I and J classes. (I always clarify time, because every record is temporarily held)
Rex, I wish I could take credit for our motors, but a lot of our motors were group efforts with my partners Marty and Kevin Sutton. Our first Kawasaki was originally a Bob Wirth motor, till we pushed it a little too hard. :-o We ran Honda, then Kawasaki, and since 2002 Suzuki motors... We've run most of them to their failure point... Our current G motor is the first 1630 Steve Knecum built.... I got it with an old Larry Forstall race bike... we hope to run it at WoS next year when John Goodman has his G/F lakester ready to race with us.
We are HP loyal not brand loyal. :cheers:
my little ramble through history is over, go look at successful cars, then build it any way you decide, race it, be safe, have fun and go fast
:cheers:
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The JCB streamliner was flat-sided too.
Regards, Neil Tucson, AZ
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Lynn Goodfellow's Mormon Missile Duramax-powered liner was flat, too, as I remember. Got a great video of it when Curt looped it leaving the pits on the return run for the FIA record - shows many sides of the car... :roll: The vid is on the other 'puter, sorry.
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1980... Don DeBring's Longshot. H/FS... return record runs... he went 224+ to get in the club
but we digress... this is a Lakester WB and Track thread
(and yes, that is a previous I/GT record holder @ 120.872 also on return runs that morning)
so back to subject :cheers:
How long is the tank you are thinking of using
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And some young Vesco people in the background, and wouldja lookit that surface -- it looks like it's all salty or somethin'.
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1980... Don DeBring's Longshot. H/FS... return record runs... he went 224+ to get in the club
but we digress... this is a Lakester WB and Track thread
(and yes, that is a previous I/GT record holder @ 120.872 also on return runs that morning)
so back to subject :cheers:
How long is the tank you are thinking of using
Digress all you want, there is no end of the pleasure I am getting from it.
I dunno how long it'll be, I got some basic dimensions for a stretched +20" P-38 tank off the internet, it shows 173". I am designing from the nose rearward and am currently about 72" back from the nose. The chassis actually starts about 12" behind the nose and I've gotten as far back as the seat rear braces/shoulder hoop/rear cage intersection. I would venture a guess and say the WB about 150ish", sound reasonable?
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Yep that's the way, start at the front & keep stacking $hit up until you get to the back! Don't skimp too much with the spacing, it get's a lot more crowded in there than you think. :oops: Don't make the mistake of sitting upright so you need to park an oil rig on the top of the thing.
Sid.
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Yep that's the way, start at the front & keep stacking $hit up until you get to the back! Don't skimp too much with the spacing, it get's a lot more crowded in there than you think. :oops: Don't make the mistake of sitting upright so you need to park an oil rig on the top of the thing.
Sid.
And when you are measuring stuff (you) for the drivers compartment and cage (especially height) be in full fire suit and helmet. They add a lot. Not only when you are lying back but also when you enter sitting up and slide back to the seat. The front bar of the over-helmet cage may interfere getting in and out, even if there is apparent adequate clearance when you are fully seated.
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Sid is right, packaging can be a bitch... the better you can see, the more sitting up your are, the slower you are going to go.
Jack is also right... you have to get in and out with all your gear... including Hans and helmet
Remember you are not driving in traffic :roll:
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it will blow your mind how far forward you will have to but the hoop over your legs to be able to get in and out---also the helmets are changing from cert to cert---we are having to make changes to see well over the lower part of the helmet face plate junction---do not forget the head sock--- it makes a difference what position the helmet wants to ride on your head. Also I suggest using the 9 point safety harness---it is harder to make the cockpit work but you are in there much more "locked down"
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The JCB streamliner was flat-sided too.
Regards, Neil Tucson, AZ
Flat sided makes more sense for a streamliner than a lakester. Wheels are flat sided.
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If you look at them sideways the wheels are round. :-D
Regards, Neil Tucson, AZ
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Are ya keepin up with all this OJ? :-D What's OJ short for, ya last name isn't Simpson is it? :evil:
If you plan on getting yourself down in there or even looking through the nose, you will need to come up with a helmet with enough front opening depth to see over the chin area plus the mandatory head n neck crap. Put the helmet on, standing straight put your chin on your chest, if you can see your feet that'll work. If ya belly's in the way......build a door car. :|
Sid.
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Are ya keepin up with all this OJ? :-D What's OJ short for, ya last name isn't Simpson is it? :evil:
If you plan on getting yourself down in there or even looking through the nose, you will need to come up with a helmet with enough front opening depth to see over the chin area plus the mandatory head n neck crap. Put the helmet on, standing straight put your chin on your chest, if you can see your feet that'll work. If ya belly's in the way......build a door car. :|
Sid.
Nope, not Simpson & the glove don't fit me either!
I haven't missed anything, my pea brain is processing and absorbing at full speed. If I ask the same questions next week its' because I temporarily confused myself.
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just keep pondering the car will finally get around to telling you what to do---but it can and will change its mind if THINGS C?HANGE :-D
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Are ya keepin up with all this OJ? :-D What's OJ short for, ya last name isn't Simpson is it? :evil:
If you plan on getting yourself down in there or even looking through the nose, you will need to come up with a helmet with enough front opening depth to see over the chin area plus the mandatory head n neck crap. Put the helmet on, standing straight put your chin on your chest, if you can see your feet that'll work. If ya belly's in the way......build a door car. :|
Sid.
Nope, not Simpson & the glove don't fit me either!
I haven't missed anything, my pea brain is processing and absorbing at full speed. If I ask the same questions next week its' because I temporarily confused myself.
As you can see there are a lot of people here willing to share there knowledge, unlike most other motor sports. Tanks are a different animal & salt racing is a whole different animal even to straight line airport stuff. Weight & balance & front end geometry are hugely important on the salt, you'll get basically the same advice from tank/lakester guys & then a theoretical variation from others. You are about to embark on building an oversize ship in a bottle where everything is a compromise & the rewards are huge.
Sid.
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Are ya keepin up with all this OJ? :-D What's OJ short for, ya last name isn't Simpson is it? :evil:
If you plan on getting yourself down in there or even looking through the nose, you will need to come up with a helmet with enough front opening depth to see over the chin area plus the mandatory head n neck crap. Put the helmet on, standing straight put your chin on your chest, if you can see your feet that'll work. If ya belly's in the way......build a door car. :|
Sid.
Nope, not Simpson & the glove don't fit me either!
I haven't missed anything, my pea brain is processing and absorbing at full speed. If I ask the same questions next week its' because I temporarily confused myself.
As you can see there are a lot of people here willing to share there knowledge, unlike most other motor sports. Tanks are a different animal & salt racing is a whole different animal even to straight line airport stuff. Weight & balance & front end geometry are hugely important on the salt, you'll get basically the same advice from tank/lakester guys & then a theoretical variation from others. You are about to embark on building an oversize ship in a bottle where everything is a compromise & the rewards are huge.
Sid.
A friend that raced competitive NHRA 'Stock' class went to visit Bonneville and was shocked at the attitude. He said that his fellow racers at an NHRA event were a secretive, backstabbing vindictive bunch that celebrated whenever a fellow racer got 'tore down' by tech but everybody he talked to in Bonneville would drag him over to their car, enthieustically tear the car half apart to show him what they'd done to run so fast. Quite a difference.