Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Jonny Hotnuts on October 20, 2007, 08:55:52 PM
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(http://www.fiatforum.com/gallery/data/500/medium/lowered_with_nose.jpg?292)
http://www.fiatforum.com/gallery/data/500/medium/lowered_with_nose.jpg?292
Any changes I should make???
Is this overkill???
I did not display bars across the top connecting the left and right sides together but I will have something there (I wont know how they will be going in until I see how all the stuff up front will sit).
I will start cutting next weekend.
BTW:
They are 14" tires.
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JNuts,
I thought I read one of Dan W's posts that said there would be a minimum wheel track width, ya might consider knowing what that is before building....
BTW looks stout, nice design, are the tires too wide? or the pic not all to scale...
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Ain't puters grand ?
1. The box section material would be stronger if turned upright.
2. The round tubes that act as a truss are in compression if you hit a bump, and are best if in tension.
3. I would suggest you stay close to the rule changes that might rain on your parade before committing to a design.
The board approved car information will be published here and long before the rulebook is in print.
4. Work on getting ready to be ready, but not to start over.
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Discussions at El Mirage yesterday centered around front tread being no narrower than 6" less than OEM.
Personally, I would turn off the blue tip wrench until the rules are finalized.
DW
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Does anyone know about or when they will be finalized???
I have a ton to do on the car before next year and this is the first step.
front tread being no narrower than 6" less than OEM
I am going to assume that this will apply to ALL modified classes. I would hate to see only mod sports being singled out and other modified classes allowed to run a narrow track.
To me this sounds like a good basis for an arguement.
;)
-JH
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How narrow? What argument?
DW
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we will probably have a good idea of rules that will be changed at the next board meating (couple of weeks) and by the nov meating the correct wording for print in the rule book may be drawn up and i think we will know for sure by dec....dan will have a good idea.... pm him a few days after each board meating...
kent
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we will probably have a good idea of rules that will be changed at the next board meating
kent
Kent, if I knew you better I would accuse you of intentional mis-spelling... Who is the board intending to meat next....
I love this job....
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Jonny:Are you building a full tube chassis,from end to end ?
Or planning on attaching a tube frame front clip to the stock unibody ?
First choice would be a complete tube chassis.In which case,you can start
building everything from the firewall back,while waiting on next years rules.
There have been a few posts here suggesting a minimum tread width rule is coming.
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Or planning on attaching a tube frame front clip to the stock unibody ?
The Fiat has an odd "uni body with frame" design that is a hybrid of both. My intent is to only do a tube nose section from the firewall forward and incorporate the roll cage and the stock “body frame” (in actuality the firewall is behind the seat but I am meaning the wall section forward the driver).
I currently could name off the top of my head a bunch of comp coupes currently running that have less than 38” and more than 6” neg. from OEM.
I wonder how they will take the news that their cars will no longer be legal.
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Where did 38" come from?
DW
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38" is the minimum for mod roadsters.
Doesn’t have anything to do with it now that I think about it but for some reason it was a number I had in my head about minimums when I read through the book a year ago.
One concern that I have is that with only 3" per side a MS car with covered front wheels wells will not have adequate steering clearance unless the front section is budged to compensate to add more clearance or a trend of using very skinny tires to add a few more degrees of steering. Another alternative is to not include covered front wheels with you build.
I am fairly sure that every MS that has covered front wheels (and most that have fabed front ends) along with most CC’s have currently more than 3” on their track width and many records have been broken based on cars that had more than 3” per side.
To me I find that being able to do these sort of changes is the core reasons that you would opt to do a MS or CC instead of a GT or GC-sedan.
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Jonny,
The Alfa built by Rich Manchen, now owned by Mike Cook, has a front tread less than 6" narrower than OEM using covered wheels. Bill Ward's Opel is OEM or wider, the Black Salt Bocar is OEM or wider using covered wheels. Other MS cars are Corvettes with OEM spacing. The ex-Turk Berkley and the Jack White Berkley are very close to OEM, certaintly not 6" narrower.
I agree that MS class is an excellent place to race. Many opportunities to explore different theories. As I mentioned before, to allow the class to change into streamliners again is not the way I would like to see it go.
DW
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Jonny,
The Alfa built by Rich Manchen, now owned by Mike Cook, has a front tread less than 6" narrower than OEM using covered wheels. Bill Ward's Opel is OEM or wider, the Black Salt Bocar is OEM or wider using covered wheels. Other MS cars are Corvettes with OEM spacing. The ex-Turk Berkley and the Jack White Berkley are very close to OEM, certaintly not 6" narrower.
I agree that MS class is an excellent place to race. Many opportunities to explore different theories. As I mentioned before, to allow the class to change into streamliners again is not the way I would like to see it go.
DW
Is the change in width determined by center to center of the stock tires/wheels tread or the hub to hub measurement???
If it is hub to hub you might be able to suck the wheels/tires in enough to help cover the wheel openings with a different wheel offset along with the granted 6 inches,
Sum
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We will be cutting it close on the Berkeley. I guess it is up to us to provide the documentation to prove the legality. The Berkeley workshop manual calls out a "track width" of 42". Depending on how you interpret track width will determine if we have to make any changes. Are they referring to outside to outside, or tread center to tread center, or hub to hub?
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Track width is commonly the distance from center to center if the tire.
There is an aero trick used on modern cars with a feature around the fender well that gets the air by smoothly without skirts and allowed adequate movement for maneuvering.
They spend a lot of time and money on it and you can copy it for free.
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Track width is commonly the distance from center to center if the tire.
There is an aero trick used on modern cars with a feature around the fender well that gets the air by smoothly without skirts and allowed adequate movement for maneuvering.
They spend a lot of time and money on it and you can copy it for free.
(http://purplesagetradingpost.com/sumner/temp-pictures/blowfish-1.jpg)
John talked to one of the guys with Blowfish and that little lip there deflects the air around the opening and it is suppose to reattach behind the wheel opening. But there again they developed it with wind tunnel time. You can make some guesses and hope you are right or use Hooley's Okie wind tunnel and blow air at the area with your air compressor and throw baby powder in the air and see where it goes,
Sum
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1. Wet the surface down and see where it sticks.
2. Film it at El Mirage and see where the dirt goes, doesn't go , and stays.
3. Only use NEW powder. the old stuff sticks to anything.
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I was able to get in contact with J. Miller today and have a WAAAAY better understanding now about what the SCTA's intent is for the MS class and an understanding of how the process works. Funny thing is that he was aware of some of the things I was considering doing to the car…..odd how word gets around!!!
I get it now….and D.W. is in fact not the enemy of creativity after all! (Joking Dan)
The idea and proposed changes were not entirely original on my part but rather a combination of things that had already been allowed to run, currently and in the past on many different cars. In the conversation with Miller I had even mentioned the design aspects of the “Saab Sonnet” without knowing any of its history and eventual outcome. Without getting into details I understand that I should not take design references from a past car and assume that it is ok because it was done before….because there were many things about the Sonnet that were NOT ok….then or now.
I think that setting a minimum track width is fine….but personally would like to see more than 3” per side. 6”per side would allow for enough clearance for a 22-30” tire to have an acceptable turning radius and still have covered wheel wells as allowed in the class without having to take compromises in tire width to gain the ability to effectively turn. This is just my opinion however and while I can agree that there are cars out there with covered wheels that likely have 3” from OEM there are also cars currently running that will not meet this proposed spec..
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As Jack said, rotating a square tube 45° improves its bending resistance considerably (but a PITA to work with, all miter cuts). The off-axis (across the flats) is almost completely immune to bending stress except in a wreck.
IIRC the change is +41.4% to the side length (the stressed axis being the diagonal rather than 1 side).
Where S = length of 1 side, and 1.4142 is 1 ÷ SIN (45°), the new stiffness (assuming equal execution) is:
(S*1.4142)^4 ÷ S^4
Example only; if S = 1":
(1*1.4142)^4 ÷ 1^4
1.4142^4 ÷ 1 = 400% (+300%)
Nice improvement with no weight or material change, just more work!
Note: a smaller change will still occur if the tube is a rectangle, substitute the sine of the diagonal angle in the values.
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Too much information.
Turn it 90 deg, and press on. :wink:
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We will be cutting it close on the Berkeley. I guess it is up to us to provide the documentation to prove the legality. The Berkeley workshop manual calls out a "track width" of 42". Depending on how you interpret track width will determine if we have to make any changes. Are they referring to outside to outside, or tread center to tread center, or hub to hub?
Text books usually define Tread Width as center to center on the tread.
Some racing body rules define Tread Width as outside to outside.
Some rules just specify max or min tread width,
without defining how it will be measured.
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Double post.Sorry.
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We will be cutting it close on the Berkeley. I guess it is up to us to provide the documentation to prove the legality. The Berkeley workshop manual calls out a "track width" of 42". Depending on how you interpret track width will determine if we have to make any changes. Are they referring to outside to outside, or tread center to tread center, or hub to hub?
The spec of the Berkeley track 1.12 meters (44.0 inches) unless you have a narrower one or maybe this was for the rear wheels if they were diffrent from the front.
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"Some rules just specify max or min tread width,
without defining how it will be measured."
Page 19.
DW
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"Some rules just specify max or min tread width,
without defining how it will be measured."
Page 19.
DW
Dan that does define how it will be measured:
"Tread is defined as the measurement from the centerline of one tire to the centerline of the opposite tire of paired wheels".
Is the new rule going to just effect MS or CC and others??
Thanks,
Sum
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MS - the point is to keep the cars looking like cars. The rewritten MS rules, after the demise of the original class, was to keep the cars looking somewhat like streetable cars like Gas Coupe.
DW
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In the days of the real Modified Roadster, Tread was required to be a % of the wheelbase.
The longer you made it, the wider it had to be.
Now with the stretch jobs, we have reinvented Sports Racing.
Hang a replica body on a Streamliner and you can have a Modified Sports, Modified Roadster. or a Comp Coupe.
The flexibility is remarkable and has improved the ability to bend over.
I guess it is OK if that is what you want.
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Is it too late to return Modified Sports to some semblance of what the cars originally were? At least one of the stretched Berkeleys has a Berkeley nose. I can see the necessity for safety of allowing chin spoilers, but why not stop it at a stretch and a spoiler? Does anyone have a car that would need to be scrapped?
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Turk's old car would require a new suspension and a new front clip, Bonner would a new front clip, and believe it or not ours is an original clip but has enough modification that it would be easier to start with a new clip rather than convert it back to original. I wonder if our local Berkeley dealer has one in stock?
Are the changes coming out going to be mandatory for the '08 racing season?
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What is the point in having a MS class if you can only stretch the front to 130” and change the motor manufacture?
Really takes the “Modified” of MS.
Too bad I could not add a back seat and enter in CC or maybe a new class called Comp Sports!!!
(I think that this rule affecting only MS and not CC is BS. To me MS is the CC of the sports car and the rules basically parallel, a rule such as this should affect both.)
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What is the point in having a MS class if you can only stretch the front to 130” and change the motor manufacture?
Really takes the “Modified” of MS.
Too bad I could not add a back seat and enter in CC or maybe a new class called Comp Sports!!!
(I think that this rule affecting only MS and not CC is BS. To me MS is the CC of the sports car and the rules basically parallel, a rule such as this should affect both.)
Personally I don't think you are gaining that much by trying to make the very front so narrow. You still have the frontal area as the widest part of the car. Go back to what Tom and I talked to you about making it similar to the Blowfish. Since you can tuck each side in 3 inches and you can run a narrower tire than stock (remember you are measuring from the tire center to center) you should be able to close the wheel openings if you want. You don't need much of a turn radius there. Go out on the highway with your street car and turn the wheel one inch and see what a drastic change of direction that is.
Don't get discouraged, you will be fine, and remember you set a record where there was no record before, so everyone who tries to go after your record will have to play by the same rules,
Sum
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MS, CC, and MR front ends are all in the same boat.
One little navigation error will really get you off course.
Now after being lost at sea it is tough to get back. :wink:
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What is the point in having a MS class if you can only stretch the front to 130” and change the motor manufacture?
Really takes the “Modified” of MS.
Too bad I could not add a back seat and enter in CC or maybe a new class called Comp Sports!!!
(I think that this rule affecting only MS and not CC is BS. To me MS is the CC of the sports car and the rules basically parallel, a rule such as this should affect both.)
Personally I don't think you are gaining that much by trying to make the very front so narrow. You still have the frontal area as the widest part of the car. Go back to what Tom and I talked to you about making it similar to the Blowfish. Since you can tuck each side in 3 inches and you can run a narrower tire than stock (remember you are measuring from the tire center to center) you should be able to close the wheel openings if you want. You don't need much of a turn radius there. Go out on the highway with your street car and turn the wheel one inch and see what a drastic change of direction that is.
Don't get discouraged, you will be fine, and remember you set a record where there was no record before, so everyone who tries to go after your record will have to play by the same rules,
Sum
I think this is dead on. If you look at an "ideal" nose shape, it's not a pointy triangle :)
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Maybe a "pointy triangle' isn't for landspeed racing, but I'd confirm that with Area 51 folks, 2 B sure!
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Personally I don't think you are gaining that much by trying to make the very front so narrow. You still have the frontal area as the widest part of the car
Smaller front end = reduction of wetted surface resulting in better Cd.
Smaller front end = ability to have smoother transition to the stock body and maintain a linear flow without separation of the boundary layer.
Smaller front end cross sectional area = improvement in CP and better lateral stability.
Only thing a minimum track rule will do is make my car longer.
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How does a narrow front end improve Center of Pressure ?
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Smaller front end cross sectional area = improvement in CP and better lateral stability.
More narrow will not but smaller side surface area will.
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Mr Hotnuts has had to re-explain himself. The key word a couple of posts back was "Wetted Area"- I recommend Prof. Katz book for explanation of terms- it reads pretty easy. In fact Paul Glessner uses it in his aerodynamic seminars as the text.
That comment re: wetted area got me thinkin'...good thing at my age ..but OF COURSE it does and therefore enhances the CP/CG correct relationship. Makes the back half more of a fin because it leaves more body bulk back there..
"It's just a box with five strings and a neck" - Julian Bream
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"It's just a box with five strings and a neck" - Julian Bream
Julian is a bird of a diffrent feather....so old now, doent play anymore.
Still likes to have a few beers at the local pub from what I hear.
Not sure what he was meaning with the quote.....guitars have 6 strings....maybe he also had a banjo laying around we didnt know about.
I learned alot from Bream......
I transcribed his version of the rondo in Am by Dionisio Aguado (considered by some to be his hallmark piece and what I usually finish a concert with).
Here is Bream and my transcription:
http://www.classtab.org/da_r_am.txt
http://youtube.com/watch?v=k_ItONyor04
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havin' fun with you Hotnuts as I hope you know- great that we can all come together and yet have many different "passions"
I'm about to out on the patio and turn on KUSC (LA's ONLY classical station, now and have my evening beer>-Thanks for the references.-They don't play enough of your -type stuff.
got two-three more sign-offs after Bream- hope you'll enjoy!
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P.S to the last- Should have quoted Peabody, not Bream-blew my cover- I'm a listener, NOT a PLAYER! will pass your transcription on, though.