Pretty cool,,, it's a clean slate,,, it's going to be interesting !!
Dave
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Pretty cool,,, it's a clean slate,,, it's going to be interesting !!
Dave
Jay I have a few questions. What happens to the chain when the one side of the axle goes up or down? Does it just get twisted because I don't see anything to keep the rear sprocket vertical matching the engine sprocket. If it gets twisted how long to the chains last? How much can the chain take? I can't imagine the chain can take the twisting.
Also what size driver would fit. Sorry if I missed the answer to this question. I only saw a picture of purple frog sitting in the car but I'm not sure of his size.
Thanks
Chain drive has been used for many years in F500 to drive the rear axle. What Jay is doing from that standpoint is nothing different. I have done the calcs for a few cars and we generally have three different rear drive ratios so that means three different chains (low speed, medium speed, and high speed track). I would change the chain every 6 weekends which is a full season of the F600 Challenge. The medium and low speed chains don't get used nearly as much so 6 weekends could get you several years. The only tracks I have found need the low speed is Barber and Heartland so far. Jay built a Novakar first with the direct drive and I believe that car has a couple of seasons on it now without any rear chain failures. We use 520 chain which is also used on 1000cc engine engines at almost 50% more power so there is quite a bit of strength reserve.
I'm more concerned about this.Quote:
What happens to the chain when the one side of the axle goes up or down? Does it just get twisted because I don't see anything to keep the rear sprocket vertical matching the engine sprocket.
Yes, the chain does have to take the twist. The twist isn't an issue though. Like I said, F500's have been using chain to the rear axle with the same twist without any issues. I have 4 full seasons on my F600 and I have never had an issue with the rear axle chain failing and I have only changed it at best once a season.
Doesn't the rear sprocket just wear faster than the chain anyway?
The degree of twist can't be too much at all, otherwise you'd get a bunch of drag in on the rear rotor/pads. You can only pull those pads away from the rotor so far before you run into other issues, right?
The rotor and pads move with the axleQuote:
Originally Posted by Daryl DeArman
The chains are not designed to twist I'm surprised none have broken yet. I know there is not much suspension travel in that set up but I know when the chain snaps on a F1000 it makes a big mess.
I'm thinking a proper chain guard is part of the design ? Does this car handle-corner somewhat like a kart chassis ? Jacking the inside tire in a corner ? Or, does the solid rear axle just make the inside-outside tire scrub thru the twisties ? Or, is the typical turn radius such that tire scrubbing-drag is not an issue ? Two more. How much does the rear suspension move ? How much twist is imparted to the chain ? Thx for a very intriguing car !
It seems like a valid point (the chain twist) but looking at it, the chain isn't far from center. With the limited amount of axle travel at the wheel end (maybe 2") the center wouldn't be moving much at all. I know from when I was racing bikes, if the chain sagged more than an inch from end to end when held sideways, then it was time to replace it.
Cheers, Graham.
Quote:
Originally Posted by Earley Motorsports
Exactly this is how we would check the chains on shifter karts. I know if the sprockets were not perfectly aligned and the chain was not straight the chain was junk very quickly.
Quote:
Originally Posted by fvracer27
Modern sealed chains can actually twist quite a bit. Actually they can handle much more than the 1-2 degrees that we see in these cars.
The chain on our first NovaKar f600 has run way over 2 full seasons of racing with zero problems. We have changed the rear sprocket once. Will change the chain and both sprockets this winter just to be safe.
Chains hold up just fine with this setup. They can handle the twist. It has been done for years in f5 and now f6. Never had a chain failure.
As to suspension movement, they are a live axle chassis. Not a kart at all.
Actually, suspension travel is much further than an VanDiemen FE or FC has. It is quite controlled.
Thx ! I'm thinking this would be a great class for my son.
I see that now. Thanks.Quote:
Originally Posted by fvracer27
You are correct.Quote:
Originally Posted by racerdad2
The class philosophy from the beginning in the early 1980's has been to be a low cost
entry level formula car class. And the BOD back in the Fall of 2012 confirmed that they wanted this to be an entry level class. The first step should be the data gathering step hands-on so contact the nearest F5/6 drivers (Aaron Ellis?) and volunteer to crew for them until you have learned all you can about all the cars in this class. We look forward to seeing ya'll
at the track soon.
Jim
Been messing with these cars since 1982
Thx Jim. We'll change gears & check it out after ski season :)
On the way back to Jay's shop - starting body number 2 tomorrow.
Y'all do nice work...
What is all that white stuff...
That is the "turn everyone into idiot drivers fairy dust" that falls from the sky here in the months between October and May http://www.apexspeed.com/forums/imag...es/biggrin.gifQuote:
Originally Posted by BURKY
A question to the people responsible though: What tires are those? 19.5" or 18" OD?
Speaking of tires, doesn't Hoosier warn against subjecting the tires to freezing temps? ;)
Dick
We got the car back in the shop today.
Another.
I already know why Calvin is smiling:checkered:
Did I miss the post where we talk about the price?
I'm more than a little curious.
thx.
In the first post.Quote:
Originally Posted by twofoot65
I think the F600's are way cool cars. I just wish someone would get a little more imaginative with body styles. I don't know the rules, so maybe they cant. Such a fast and kool car deserves a body that matches its performance.
What's wrong with the body? Sleek, aerodynamic and functional.
Nothing. Just something different.Quote:
Originally Posted by quartzracer
Please post a sketch of what you have in mind.Quote:
Originally Posted by tlandon
At the risk of being taken down in flames, I have a few thoughts...Quote:
Originally Posted by Mike Devins
Yes, the car is gorgeous. I genuinely love it. But, and it's a big one, the MSRP is well north of $20k w/o a motor! Is this the direction we want the class to take?
Keep in mind that DSR started out many years ago as a bunch of guys looking to do something different and have fun on a budget. It has now evolved into a cubic-dollars-per-inch class where you will be lapped unmercifully if your car costs less than $60k.
I personally think a car should cost less than $10k to allow "normal people" to race on a reasonably level field. I don't mean we should remain in the dark ages, but this ain't supposed to be F1. "Money changes everything"...
Or maybe it's just me. :rolleyes:
Cheers,
Chris
There is simply no way to build a car at that price as a constructor. I built my own f5 starting with an existing KBS. Not counting the initial car purchase it is more than that just to modify.
Maybe if you access to scrap usable metal and your own CNC/lathe/welding/body molding/leftover resin/Kevlar/glass etc and your own time maybe.
I wish all racing was cheaper. Just In Hubs bearings and wheels you are probably at close to $2000-3000 range.
I am actually a bit surprised at the roller price being so low. I was guessing 26-29000 when I saw the construction.
Quote:
Originally Posted by tlandon
ouch!
Eric (quarts racer) nailed it , you package a race car first to the rules, then as clean aerodynamically as you can given any rules restrictions, and then to it's appearance
as far as the former two will allow, so making it look like an F-I car is counter intuitive.
Tis car embodies practical simplicities in EVERY aspect ,engineering ,design, construction,
you name it, it's not some tuner car.
Dave
Quote:
Originally Posted by twofoot65
I remember DSR way back then. It had very few restrictions thus I said back then that it will be a money class. On the other hand, F500 is a VERY restricted class using relatively inexpensive drivetrains. We will do our best not to allow any rules changes that will unjustifiably raise the costs of the class. BTW, we can always rent you a F600.
Jim
Quote:
Originally Posted by iamuwere
Jay did announce that the price will go up after the first 5 are sold.
Jim
Wait until you see Calvin's graphic!
Dave
We are in the midst of analyzing our costs of the build of the first 5 cars right now. We will know more in a month or so. Our goal is to hold the costs down and to that end all of the next run of cars will be sold as roller kits. Racers or dealers can then assemble the cars.Quote:
Originally Posted by jim murphy
Comparatively these are very economical compared to a FF, way less money and similar lap times.
No shocks and no springs.
10" tires
you can buy about 5 engines for the cost of one Hewland transmission
Chris,Quote:
Originally Posted by twofoot65
The class is already there. $21,000 for an Invader. For an extra $1k over the KBS I'd buy the new Blade every day of the week and twice on Sunday. If you want to race for $10,000 buy a brand new TAG kart and motor, much more competition than the SCCA can offer.
https://lh6.googleusercontent.com/E3...o=w734-h694-no
And no sway bars, BUT there is a rudimentary suspension with the rubber pucks and bell cranks for multiplication (several inches of wheel travel). All part of the restrictions to keep the costs low.Quote:
Originally Posted by Mike Devins
Jim
Been messing with these cars since 1982.
and coming from DSR, no wings or electronic shifters. And no reason to us carbon fiber to get to minimum weight, no carbon fiber brakes, no carbon fiber springs, no $10,000 motors.
I am really looking forward to next season!
If you understand the details and math behind suspension design you will realize there is nothing rudimentary about Jay's suspension design. He has a lot of time and money in material research to come up with the custom material he uses for the pucks. He then made the geometry work with them to provide linear wheel rates. Combine that with other features and you have a great handling car. Pretty ingenious design that works very well.
As far as the cost, Jay is in the ball park of current F5's. I'm curious how many new F5's have been built in the last 5 or even 10 years. I know of at least 7 new builds (all 600's) that should be ready for next year. That is a huge influx of new cars for the class. I think one of the reasons car cost has been going down the last few years in F5 is that they are mostly older chassis that continue to depreciate with very few if any new cars coming in. That is not good for the long term growth of the class. This surge in interest should help the class and bring some new innovation to the class.
As the "stylist" of Jay's new car, I can say that what you see is the result of the tightest fit to the chassis/driver (ok, a real size driver...) and adherence to the laws of aerodynamics to keep the air attached to the surfaces and create minimum lift, and minimum frontal area. All these surfaces were tested in CFD for optimization and Mike did a great job on the physical model to sweeten them up. The result is what you see - simple, clean and functional. - Wait to see how other car's drivers feel as it whistles past them on the straights...:checkered:
Clark.
Clark, I have a question. Why the relatively sharp bump over the front pushrods? Really it leads to a whole other post I should ask about the value of frontal area versus angles to the wind.
Jim, are you referring to the radii where the bump blends into the side of the midsection and the top of the side pod? The bump itself is actually quite gentle and long at over 4" long. This part of the body is, of course, a minor compromise needed for package. The design of the bump was such that it would not create a local separation while generating as little local lift as possible. It does generate a small amount of lift but it also keeps the airflow attached in that area.Quote:
Originally Posted by iamuwere
PS: there is a significant reduction in frontal area from our Runoffs winning F500.
I'm sure in the wind tunnel and CFD that little blister would be pretty much invisible aerodynamically.
I always wonder about blending little blisters like that. Symmetric, asymmetric, etc. length to height three, five, seven times.
Had to imagine less surface area than you already had.
It has about a 50 sq. inch reduction in frontal area.Quote:
Originally Posted by iamuwere
The old man pretending he is a hero driver.