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Post by bsadad on May 3, 2009 19:54:32 GMT -6
 So pros tell me what i can do different to gain more speed. Can not rail ride due to center rail is to rough and the track is wood. Let me give you the car specs and you evaluate the cars for me and give me some ways to gain speed. Car one Rear weight is 112.4 Front weight 31.4 com is 1 inch length of car is 6 13/16 long rear axle is 1 29/32 from rear front axle is 5 17/32 from rear. Running 3.3 gram wheel with grooved axles. I sand axles from 1500 to 4000 grit and then used mothers aluminum wheel polish.Wheels i sanded from 1500 to 3000 grit and used micro gloss on hub bores. And polished wheels with graphite. Average time was 2.47225 on four runs best time was 2.466 Car two rear weight 106.0 front weight 38.0 Length 7 inch Axle 1 was 1 9/32 from rear axle two was 5 29/32 from rear polished wheel and axles same as first car. Average time on this car was 2.47555 on four runs best time on this car was 2.471 .Com on car two was 1 3/16 in front rear axle. |
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Post by Ricerocket on May 3, 2009 20:06:51 GMT -6
Nice looking cars! One thing you can do if your pack requires you use the stock axle slots (our Pack does) is to cut as much as you can get away with off the back and glue it to the front. This is what we did with this car a couple of years back:  What this does is effectively makes the ramp a little longer for your car by pushing the weight that much farther up the ramp. |
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Post by roosclan on May 3, 2009 22:33:48 GMT -6
Nice looking cars! One thing you can do if your pack requires you use the stock axle slots (our Pack does) is to cut as much as you can get away with off the back and glue it to the front. This is what we did with this car a couple of years back: What this does is effectively makes the ramp a little longer for your car by pushing the weight that much farther up the ramp. We do the same thing since we are required to use the axle slots. You will only be cutting about .3" off the back end and gluing it to the front, but every fraction of an inch helps. |
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khouse
Head in the Pine
Posts: 199
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Post by khouse on May 3, 2009 22:45:41 GMT -6
I would still cant the rear wheels. Move your weight back. Get your COM less than 3/4 inch. Polish your axles to 50,000 grit or more. I would still rail ride. Round the inner part of your dominant wheel. Then adjust your non dominant wheel to where it barely touches. I would make the inside front wheels 1.75 inches between them. Use hob-e-lube. If your rule will let do what Ricerocket did then do that also. Is the total weight of your cars 5 oz?
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Post by bsadad on May 3, 2009 23:36:21 GMT -6
We do not have to run the stock axle slots. We can move the wheels any where as long as we don't exceed the max wheel base of 4 5/8. Or council race is May 30 will try to bulid another two car befor then and try to move the com to 3/4 inch.and cant. The rear axles. Have to change wheels to more stock type they were not happy with wheel mods. They are infact changing the rules befor council. To make our wheels illegal to run.
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khouse
Head in the Pine
Posts: 199
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Post by khouse on May 4, 2009 6:02:38 GMT -6
Put the rear axle from the back around 5/8 inch then measure 4-5/8 to the front axle holes.
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derbydominator
Head in the Pine
"Zero Gravity" PWDR Pro Modified
Posts: 146
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Post by derbydominator on May 4, 2009 11:27:09 GMT -6
I did not see it in your description but can you raise one of the front wheels off the track? If so, then that is a must. Just drill that axle hole about 1/8" high. Also, as Khouse pointed out, you can still rail ride. Regardless of the track conditions, you are going to make contact with the center guide rail. Might as well minimize the damage by rail riding. Cant the rear wheels until the outer edge is just off the ground with a full revolution of the wheel (negative camber). Then adjust the forward dominant wheel (one wheel that is touching) with positive camber where the wheel is riding on its outer edge. Then adjust such that the wheel is steering the car about 2-3" into the rail over a 4' stretch of track. We do this on a plexiglass sheet purchased and cut at Home Depot. That way, the FDW will actually ride along the center guide rail as opposed to rubbing on the top. This should diminish the effect of any track roughness. This will increase stability with the car especially if you go more aggressive with the COM (3/4"). You will also need to notch the car body in about 1/16" at the FDW. This will force contact between the FDW and the guide rail while the rear trailing wheel stays off the rail. Also, I assume you coned the wheel hubs? We finish with "0000" steel wool and polish on the inner wheel tread. It becomes more important to get that edge as smooth as possible with a rougher track.
Biggest question is how did the cars do relative to the competition? I assume your times were from your pack race? Making it to the council race is a great achievement though so congratulations getting that far. You have plenty of time before that race so you should be able to improve your times with the suggestions on this thread. Best of luck!
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Post by bsadad on May 5, 2009 4:21:06 GMT -6
Our rules requrie all wheels be touching the track. The competition was at best one car length behind us. The only car close to us was a father and son in our pack that we helped. The five boys out of our pack that went to district finished in the top eight out of fifty two boys. We have three boys from our pack going to council race.
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khouse
Head in the Pine
Posts: 199
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Post by khouse on May 5, 2009 19:56:05 GMT -6
Just because 4 wheels need to touch - doesn't mean they all have to bear equal weight. I would make your non dominate wheel just barely touch.
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