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Post by Rocket R/C on Feb 14, 2007 14:15:46 GMT -5
Since we were talking about car setup, I am curious what most people run for belt sizes and gearing at certain tracks?
Im curious because I wanted to start playing with using a longer belt like a 96, just because it stays tighter to the clutch gear but I am wondering what people have tried and use.
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Post by streetscreamer on Jul 25, 2007 6:52:11 GMT -5
I've tried a lot. Just trying to keep the crankshaft in the centerpoint of the mounting of the rear suspension arms, however, still variations in tension cause jumping of the belt over the teeth of the clutchbell. Especially with 6 teeth type. Those are so sensitive for good function in relation to wear. Therefore I installed my 7 teeth type again. My engine has enough torque to keep the pace. Now I don't need to replace the belt every heat. It is true that longer belts cause longer distance from clutch to rear axle and so the the belt will touch a larger part of the clutch radius (more tooth contact), but italso should fit in your car: it is related to the basic structure / design of your car if it is possible to install such long belt. Be aware that the center point of the rear suspension arms and engine shaft may not be more than 20 mm from each other. (construction rule)
regards, Bart
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Post by Rocket R/C on Jul 26, 2007 9:27:56 GMT -5
That is interesting Bart, thanks for the reminder of the rule. Now if you went back to a 7 tooth clutch bell, did you go to a 34 or 35 tooth rear gear? Im curious about that and weather you have tried longer rear control arms? I saw some really neat arms on Sander Pols car at the Worlds last year, and he thought that they were a little too long for that particular track. He also had a strange pitch belt setup that Trev thought was from an old PB car. My only issue with longer control arms is that the engine must be moved forward. That is ok from a weight and balance point of view, but tough to fit under a body shell. One thing I do want to try is moving the front pivot of the rear swing arms up a little higher, maybe 2 or 3 mm. At some point I would like to make that adjustable, but what it would do is add anti-squat to the rear, giving the car more rear bite. Of course doing that means the engine may have to be raised, and we run into body shell and changing of roll centers, and it could get messy.
Thats just some of the stuff I think about on a regular basis, but getting it onto a car and trying things is a different story. Thanks for writing in and chatting about it. Lets keep it going.
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Post by streetscreamer on Jul 26, 2007 16:41:55 GMT -5
Sounds like I will learn more from you than I can advise you... At least I know that currently Sander doesnt race the special "fine pitch" gears anymore, as the belts were not able to handle the power. True about the longer arms you have troubles with the engine cooling in the shell: Various drivers know how to use an angle grinder / saw in such case.... With 7 tooth on front I just kept the 33 tooth on the rear axle. But the tire is just a little laregr than the gear. That also makes big sense. But okay.... making step to 34~35 would give probably more punch. Honestly I lost already too much chances this season by experiments and troubles to the car to make satisfying results. But: never lost the pleasure!
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Post by Rocket R/C on Jul 27, 2007 5:37:43 GMT -5
Over 20 years of racing experience, and study of both model and full sized racing theory, are more of a curse when your brain wont stop thinking about it..... but I never stop learning. The appeal of the F1 Stock Car to me, is that its been the same almost forever, and never been truly conquered. Its funny to me that Jody continues to win with the oldest design, oldest engine, and has just mastered that setup better than anyone else.... and has put the whole package together. Well the day will come when the right person engineers the right car, and is able to put all the power down, and put the car wherever he wants it, and not even Jody will be able to touch him. It will set a new bar in racing, and we all want to be the guy that figures it out. Thus why we continue to experiment with all sorts of things.... and fail more than we succeed. As long as the pleasure is there when the great idea fails, then we can shovel the pile up and take it home for more revisions.... its a viscous cycle.... but we are having lots of fun doing it! I encourage you to not stop your experimenting.
Thats interesting that Sander does not use the fine pitch any longer. I have done alot of research into industrial belts over here, and the XL pitch that we use is the only pitch that offers the small 2 teeth increments in size. If you go to metric pitch, say 2mm or 3mm, the range of sizes is odd. There are too many gaps but I still havent given up on the project. I think there has to be another pitch with better shaped teeth out there, and slightly smaller, to give a wider range of gear ratios. For right now until I finish figuring it out, we are stuck with XL.
Another thing I had thought of that I havent seen anyone do, is build an engine mount that allows the engine to be tipped back. Keep the crank at the same height, but make it so it leans back say 30 degrees. You cant lay it down completely because you will never cool it enough, and linkage could be a problem, plus the head could possibly hit the axle, but just enough that you could use longer arms, belts, and still fit it inside the shell. If it were at the same angle as the windshield on the body shell, it would be perfect. It would be a challenge to start with a shell on it, unless you had a glow plug igniter that was really long, but I am looking into it.......... another winter project.
Yes the 34 or 35 will give you more punch out of the corners. Remember that to get close to the same gear ratio that a 6/33 gives you (5.5) you would need to be at 7/38 (5.42) to be even close. Now for the track in Fryslan, it may be 6/34 that ends up being right for the size (5.66) but you cant get there with a 7 tooth clutch bell. Whats funny is that in all of my racing I did when I was there at the last worlds, I used the same belt through all my practice days, and all but the last heat.... and I would still use it as a spare in a pinch. I think its a big key to have the tension on the belt stay as close to the same through the whole range, which is only possible keeping the crank directly in line with the front swing arm mounts. As long as the height is correct, it can be a tic in front of those, but not too much. My arrangement has the belt getting tighter as the car squats, or lifts, but right in the center it is the loosest, and where I set the tension. Just something to think about.
Dont stop your experimenting my friend, it will pay off eventually, even if the results are not the best at first. You know a heck of a lot more than the guy that didnt try it!
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Post by hidde35 on Aug 13, 2007 13:54:19 GMT -5
A lot of words with sense Pete, If all things come together, motor, clutch, exhaust, right gear, springs, at the end it works. (comments of a former Dutch, indoor European, and Grand Prix winner). The gearing we used on the Fryslan track was 6-32 or 6-33. A tip: just spray the belt once with some WD-40, It will last a lot longer. I am sponsored now by a Dutch motor builder, actually it is an industrial compagny. It is a special build motor for the stockcar. We are now in our last period of testing on the track! It is a three port engine with rear exhaust with a lot of bottom power. It is a reasonable priced engine and these guys have looked for the best and finest materials. With the on-road version the are going to the worlds in Argentina. Keep going Pete, see you soon.
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Post by Rocket R/C on Aug 16, 2007 9:41:00 GMT -5
Wow Hidde, custom engines! That sounds like something I want to have a look at when I get there. When do you expect they will have some for sale?? Are they planning to go international with sales??
Thanks for the 33 gear tip off, along with the WD-40. I will try that out. My guess on the gear was going to be a 34, but I will give the 33 a try to start.
We will see you in a few weeks!
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Post by hidde35 on Aug 16, 2007 9:52:06 GMT -5
Hi Pete,
The 34 gear will certainly work, be ware of the diameter of the inner back tire! All the marketing work has yet to be started, I will introduce you to the engineers at the Worlds.
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Post by Rocket R/C on Aug 16, 2007 10:44:53 GMT -5
I thought that was the secret to all handling problems..... run on the belt!
I would like to meet them and have a chat, maybe I could help get them started over here if they want to venture out.
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Post by trevortennant on Aug 16, 2007 16:14:19 GMT -5
Hidde is this engine a dutch built device? . The DeRidder was total junk. No power and no piston fit life either in fact the worst engine I ever used. I feel cheap easily obtained engines are better in the long term for stock cars. If the punters feel someone is using special stuff they will go elsewhere. Mr Poels and his sidekick running 600 Euro priced engines are certainly not in the best interest of the hobby. Is there a case for a price limit on engines I think so say £200 max.
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Post by Rocket R/C on Aug 17, 2007 6:23:41 GMT -5
If Sanders is still running his Collari XS400, the equivalent being the Werks B3 can be bought here in the states for under 200 dollars shipped to your door. Thats not excessive to me.
Maybe a production rule could be put in place for larger races, but with stock cars it would be like having a production chassis rule also... what fun would that be?
If anyone wants to build an engine from scratch, or get a new company into the game, how are they supposed to test their engines in competition to see if they stand up without running them? Lots of people in this sport have lots of "one offs" of lots of things. I dont think we can limit it to just chassis design for creativity. Cookie cutter cars are not what this sport is about. No someone running an expensive engine is not a good example for a beginner, but you can buy plenty of power for short money these days. As Japanese engines keep getting better, European engines will have to drop their prices to compete, its always changing all the time. Look at the Picco, you can get a 3 port that is superb for cheap money.... thats great stuff. If a new engine manufacturer wants into the game, lets see what hes got!
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Post by hidde35 on Aug 18, 2007 6:05:12 GMT -5
The engine is at his latest state of testing, a lot of bottom torque without loss of top power. We have tested with different kinds of materials, they are now also in thei final state. The durability is in one work perfect! After two years of testing they filtered all problems out. The go with, if needed an engine mount. there are also 6 and 7 teeth produced and tested. And at the Worlds you can see the results of all this, it looks great and i hope i can drive it into the finals (hi, hi) Hidde
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Post by Rocket R/C on Aug 21, 2007 7:52:20 GMT -5
Well Hidde I think it will be great to check out. Lots of work done there, and lots of worn out engine parts I'm sure!! Keep it going, and I hope it makes the final as well!!
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Post by jeroenj391 on Oct 16, 2007 9:33:33 GMT -5
hello all, i always run a 6-33 gear at all tracks. and a not so long belt 88-90 size. it is right to oil the belt, i also found they stays better. i also rounded of the clutch drum a little bit on the tooths,just a little bit. works fine with me. hope it will help you. cheers jeroen H391
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Post by Rocket R/C on Oct 16, 2007 10:09:16 GMT -5
Thats a great tip Jeroen!
Thanks again for coming by and adding some great knowledge and race experience!
I am going to throw a good question out to you Dutch guys....
I have seen some very impressive longer swing-arm setups on alot of Dutch cars. Also a further forward engine position is needed for that with a longer belt... What advantage to you feel it gives you over a shorter arm car?? Also what size belts are you running with the long arms??
Just something I have been thinking long and hard about.... and something that would generate some good discussion.
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