Landracing Forum
Tech Information => Technical Discussion => Topic started by: Roadster943 on March 03, 2004, 01:52:00 AM
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I am in the later stages of building a D/G roadster. I have most of the mechcanicals in. Now I need to start thinking about ballast.What am I looking for as far as total car weight? Do I want it even front to backside to side, or??? I do understand I need to keep the weight LOW!! Thanks Roadster943
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Whoops Sorry Joe I got this in the wrong spot. I sorry, I am new to this and Obviously not too good at it . I have no idea how to get it to the right spot now that I started this. I hope to do better next time. Roadster943
<small>[ March 03, 2004, 01:02 AM: Message edited by: Roadster943 ]</small>
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Roadster923, you are right about keeping any ballast low. You also should make sure it is well secured. One of the tricks of keeping these cars pointed the direction you want to go is the "dart concept". The dart concept means you keep the center of gravity (the weighted point of the dart) ahead of the center of drag (the feathers).
We used to think we had to run a bunch of balast in a roadster - we ran ours at about 3800# (220 MPH, C/GR). Many of the faster roadsters today seem to be 2500# to 3000#. We'll be looking forward to seeing your new toy on the salt.
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Try Lead shot in the Frame Rails. Weight is low, and distributed. You just have to stand the Car on it's end!
Mike M.
847 F/P/MP
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I got to tell you lead shot in the frame rails is a great idea. I would have never thought of that in a million years. Dude, you should have worked with nasa.
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old stock car trick make tech. let the lead during the race.
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My suggestions are close to the others. I don't know the configuration of you frame but the center of the car ahead of the rear axle is best. Try not to put too much in the rear unless thats all you got...As Bob said don't forget the arrow doesn't go straight without front weight. Mine ran 215 at 3500# wet with driver. Spun at 185 at 2800# My split was 42% front 58% rear. Good Luck....J.D.
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I mentioned the lead shot in the frame rails to a kart buddy years ago. He put the lead shot in, and had the plug come out during the race. It sure was interesting to see everybody behind him sail off the track!
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A D/G engine at about 600-700 hp could run at about 3200-3600 lbs.
Beg, borrow or steal a set of scales and start off at around 40% in the
fronte and 60% in the rear. Left to right should be even.
Set up your car so that you can add or subtract weight as needed.
You might want less weight at El Mirage and more at B-ville
The rear tires will allways try to pass the frontes if you get out of shape,
even if your off the throttle. The best way to keep a roadster going
straight is the keep rotating the earth, when she noses over or runs
out of power or gets pedaled to much she just won`t go straight.
Remember that its the rear tires pushing the car foreward that will
keep the car going where you point it....
Thats what works for me and I am sure the opinions will vary, but
everybody will agree that the weight needs to be low in the car, and
don`t take any shortcuts on safety items.
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do not tech your car and add or change stuff. Tech your car as you plan to run.
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do not tech your car and add or change stuff. Tech your car as you plan to run.
We don't need another El Mirage problem :x :twisted: Tech and rules are there for a reason.......
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Roadster943 -- Did you get my Private Message (I'm new at this!)?
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Hey Stan, What the tonnage on your roadster? Or even just the frame?
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Our C and D Street Roadster weighs 3000 pounds wet with driver with absolutely no ballast. It's about 55% rear and 45% front. It's a steel-bodied Model A with a 1/4-inch boxed frame, mounted very low. The rear end is over the frame. It has an 18-gallon water tank in the rear. It's run 209+ on the salt and the tach is just as good as a speedometer. If it's slipping, we can't tell. We don't know the weight of the bare frame, but we sure can't pick it up. It gets deeper, and wider, towards the back to a maximum of about 5" width and 12" depth. The frame is segmented inside to allow us to add shot, but so far the air inside is sufficient. Al Simon built it. Last year we ran El Mirage for the first time with the C motor and went 189, just what the tach said. Later in the year we put the D motor in and only went 173 (with the wrong, C motor, gear). We hope to re-gear it for El Mirage later this year and do a little better, but that D record of the Barbees' is real stout! The car has had the same owner for over 40 years and is still licensed for the street and could someday return.
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And as a further thought, now we find it would probably be good to lighten it up a little, especially for the D motor at El Mirage. But we're stuck except for draining off some of the water (or a major rebuild, which is not going to happen).
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Hey Stan, Al builds a great car, sounds like he got yours right on.
See ya on the dirt (5 more weeks).
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roadster943, Our roadster runs El mirage at about 3200# and is straight as a arrow. took awhile for that to happen. Right to left with fluids and driver ,you want an even balance,front to back , 55%on the rear and 45% on the front,with all of the weight between the axles ,and below the axle center line.The car was originally completed at 2600#, no lead bebbes,(nice thought)just lead.With a B motor on nitrous we went 217.000 at El Mirage and received the DIRTY 2 CLUB rookie of the year. Have fun and make sure the little wheels get to the timing traps first. V/R Eric Eyres #832
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spdracr, if you ran a B engine on nitrous, you are certainly not in the
street roadster class and the B/FR record is quite a bit higher than
217. I am not sure how that got you in the club. Forgive me if I am
overlooking somthing.
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Sorry John you've been here for a while but this is one you apparently missed you. Being the Dirty 2 Club "rookie of the year" is well known but not what anyone really wants.....It's the guy who consistanty drives over 200 but doesn't quite make it into the club by setting a record.
Knowing the Eyres bunch as I do, as much as Eric liked the accolades, a few more miles an hour and a Dirty 2 hat would have brought a much bigger smile. Go Eric and Russ...J.D.
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Now I get it, went threw the same thing myself trying to get in the club.
On the D/BGR record I made several runs in the 196-199 range.
Finally in Nov. with good conditions made a 203 run.
Two years latter Cook jr. took it to 211.
Good luck spdracr and crew, all these C & B records are pretty stout.
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That would have made you a member of the dirty 199 club along with the Barbees.....:)....J.D.
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Yea, we used to hand towels to each other every Sun. afternoon. :oops:
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Thanks PROMACHINE and JD, Hey 4.5 mph to go and I hope to erase one of those W&W records. NOW I'M thinking of that fastest normally aspirated roadster record,Heck whats another 10-11 mph.
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We tryed to hit that 227 all year last year. That is why I am interested
in the weight of the cars.
Once again, Nov. looked to be the best conditions. I poured in 100%
and the car went pretty straight. The rear tires were going 235, but the
fronte tires were only going 221.
It won`t be easy, but I don`t plan on giving up.
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We tryed to hit that 227 all year last year. That is why I am interested
in the weight of the cars.
Once again, Nov. looked to be the best conditions. I poured in 100%
and the car went pretty straight. The rear tires were going 235, but the
fronte tires were only going 221.
It won`t be easy, but I don`t plan on giving up.
Hey John if the rear tires go through the lights first do ya think that 'el do?
:lol:
Given a good course you guys will "get 'er done"
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Thanks Mike, Well at the dirt drags I don`t know how good the coarse will get.
But I can tell you that when Cook Jr. took my D/BGR record, he spun
threw the lights, It seems that high boy roadsters are much more
aerodynamic backwards. Maybe we will give it a shot....NOT. :shock:
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I like all this roadster talk, maybe we should have our own forum on
this sight. I can hear the crickets now. Chirp chirp chirp. :roll:
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How many of you run a spool in the rear end of your Roadster? :)
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not me...J.D
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Thanks all good info. Yes Stan Back I did get the measage. I made it out to S W 04. I ended up with 550 # of shot in the frame rails, 30 # in the front crossmember, 100 # behind the seat and 18 # LR to even it out side to side. Ended up with 3000 # wet with diver, 1800 rear 1200 front even side to side and all but 100 between the f & r axels. I can get more on the front and some off the rear if that ends up being what it wants.The results you ask. First get it through tech. The car was under the tent with the panels off when Billy tells us to go to the drivers meeting and rookie meeting! Oh great. That was a long 1 1/2 + hours thinking my car is being picked apart without me being able to say Ya but ! First thing out of Billys mouth on our return was "who did the tin work on this car? " Gulp, ah I did. Well he compliments us, says it looks great, hands me my log book and tells us to have fun. First pass, 131 mph , most fun I have ever had in a car. D license O yea, man this is fun! Second pass, 2 mile marker, 150 mph, # 7 rod takes out the side of the block, ah crap, pull the chute, go left, (short course) stop, get out (quickly) assure saftey personel I'm ok. Well now what did I learn? Check oil filter after every pass, if somthing does not feel right get out of it and go right before there are a bunch of expencive parts on the course and you have to go left and let everyone know you screwed up. Well what did that 5 miles cost me in broken parts? $1500 per mile. Still fun? Oh yea! I dont know how much of this kind of fun I can afford but I will keep at it. Second year you ask? Well I tell people I had too much horsepower, yea I know, there is no such thing but with the rear axel mounted solid it is more or less true. I am not complaining about the course and I would like to say Thank You to everyone that did all they could to give us a course to run on.
Yes I have a spool in the rear. No problem yet, just that pesky rod.
Well I hope I provided a little entertainment. I will see you all on the salt in August.
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Roadster943, if you are running a wet sump oil system, you might
want to add 2 or 3 quarts of oil so you don`t run out at the 2 mi.
Thats the first thing lots of people learn at B-ville. :wink:
No spool for me-no spins in 11 years-247 @ B-ville-225 on the dirt :o
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We're one-wheel drive with only one wake-up problem at the 4-mile a few years back with a side wind. Noticed we were looking at the pits! Always been able to get out of the throttle, then pull the chute. Lots of (early) times the chute never came out, but backing out of the throttle or putting in the clutch slows the brick down so much we never knew it wasn't out. We easily get off by the 5 3/4 without a chute. Some times the 5 1/2.
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Roadster943,I'm with PROMACHINE all of the wet sumps we run at b-ville or el mirage a min 12 quarts of oil(I use mobile 1 syn.),my dry sump use 5 gallons of mobile 1(cheapest thin that will ever go in that motor). We do not use a spool either 217elmirage ,and wheel tach 241.at the salt. Aren't Roadsters cool. Have fun Eric
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Even tho I started with a coupe, vintage thank goodness, IMO there should only 3 classes: 'liners, lakesters & roadsters. Damn is good to have one....:)...JD.... oh yeah I forgot....... fuel only
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Well J.D., its obvious your parents didn't drive a Studebaker, maybe a Kaiser, or God forbid, a bathtub Nash........... :wink:
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...although I must admit, I would love to run a slammed 50 nash on the salt. Think about it, you could be spinning thru the lights, and set the record both ways....lol :roll:
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'29 Ford Roadster, Craeger overhead, Winfield cam, Duel down drafts, Bobbed fenders & no running boards, Chrysler grille shell, Solid hood, Chopped windshield & top, Dual exhaust down the right side. I've got pictures of the car at Muroc in 1938. Dad worked at the Western Auto in Glendale before becoming a wind tunnel model maker during the war. I was and still am one of the "lucky ones"... J.D.
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WOW!!! I wish it was in my living room. It would have been nice to pick your dads brain..............
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I've been digging in the archives and found this post. Very interesting.
I am confused by the discussion. I understand the 'dart concept', which is a great simplification, however, everyone goes on to state that they are biased with weight to the rear: -Followed by reports of going through the traps backwards :D
If I want to go through the traps with the front tires first, should I put more weight in the front? Of course I'm being facetious. I'm reading up as much as I can, but the real world results are throwing off my physics as usual.
From what I'm seeing, a front weighed car will lose traction when hitting the 'wall', but you still need enough weight on the front to keep the backside from coming around. Am I right? And at least in roadster dynamics this means more weight on the rear.
So let me have it. Am I on the right track? How do the production class cars keep the car going forward? Maybe that should be a different topic?
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I've been digging in the archives and found this post. Very interesting.
I am confused by the discussion. I understand the 'dart concept', which is a great simplification, however, everyone goes on to state that they are biased with weight to the rear: -Followed by reports of going through the traps backwards :D
If I want to go through the traps with the front tires first, should I put more weight in the front? Of course I'm being facetious. I'm reading up as much as I can, but the real world results are throwing off my physics as usual.
From what I'm seeing, a front weighed car will lose traction when hitting the 'wall', but you still need enough weight on the front to keep the backside from coming around. Am I right? And at least in roadster dynamics this means more weight on the rear.
So let me have it. Am I on the right track? How do the production class cars keep the car going forward? Maybe that should be a different topic?
I TOO HAVE BEEN DIGGING, WE HAVE A FRONT WHEEL DRIVE D GAS ROADSTER WHAT NOW....DO ALL THE RULES CHANGE??
OBVIOUSLY ANY THOUGHTS WILL BE APPRECIATED
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What year rule book do you have?
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What year rule book do you have?
2010
got to 165 before we broke the drive
we got that conquered (we think), however dont know whats instore at higher speeds..