I'd like to solicit some ideas on how to best exploit an 8 in. length limit in our rules. Our season is over so this question is for my son and me to ponder and tinker with R&D over the summer. The rules state that the permitted dimensions are not to exceed 8" L x 2 3/4" W x 4" H and 5 oz weight cap. Fortunately, our Outpost and Section don't limit the boys to RR kits and the dreaded dowels. Most everybody uses 7" long BSA blocks. But hey if we can get away with 8", why not take advantage of it IF it can be an advantage. There's no wheelbase limit so we typically run 5 3/4"and a 5/8" to 3/4" COM on a 7" plank at 1/4" thick, with rear fenders. We drill axle holes using the Silver Bullet©. I'll rip cut some 8 " x 2 3/4 "pine banks for starters. We appreciate any thoughts and ideas.
Royal Rangers Wood block dimensions: Can 8 in. length be an advantage?
- Thread starter jator359
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8" all the way, your weight is on the hill longer which means more hp.Never played with an 8" block but i think the rest of the build would be the same as a standard 7" build. I"m sure some of the pros will give you some good input on this.
Not a PRO, but I slept in a Holiday Inn once-
We just concluded an unlimited race with 5oz 8" limits.
Just build your best 7" and add the lightest extension to move the nose out another inch. Make sure the extension will trigger the finish sensor.
Worked on Bearing wheels, Pure Stock, and stock pro type cars where we measured times with and without the extension.
Numbers came out just like the chart, a full 0.01 sec. faster with the 8" car. You are basically moving your COG back another inch.
One of the competitors made a razor wheel / needle axles design where he cut a big slot from the nose to almost the back, so the car nose was almost 5 inches in front of the pin. That moved his COG down the track by 5 inches and the car speed was 0.05 sec slower than if we put a bar on the nose to move the COG back to normal. He was very happy with the new speed, but not so happy when we pulled out our bearing car. Yes it was unfair- but that is what you get when you want to have no rules to "let your creativity run wild"
We just concluded an unlimited race with 5oz 8" limits.
Just build your best 7" and add the lightest extension to move the nose out another inch. Make sure the extension will trigger the finish sensor.
Worked on Bearing wheels, Pure Stock, and stock pro type cars where we measured times with and without the extension.
Numbers came out just like the chart, a full 0.01 sec. faster with the 8" car. You are basically moving your COG back another inch.
One of the competitors made a razor wheel / needle axles design where he cut a big slot from the nose to almost the back, so the car nose was almost 5 inches in front of the pin. That moved his COG down the track by 5 inches and the car speed was 0.05 sec slower than if we put a bar on the nose to move the COG back to normal. He was very happy with the new speed, but not so happy when we pulled out our bearing car. Yes it was unfair- but that is what you get when you want to have no rules to "let your creativity run wild"
txchemist - thanks for sharing your performance metrics. They're always such a huge help in visualizing your insightful explanations. Okay so when you suggest "extension," you're implying an external add-on, sort of like a D. Meade "cheater bar"? Also when you say "moving your COG back another inch," I get that-- it's higher on the hill. I was thinking maybe starting with an actual 8" block though and keeping the same 5-3/4" wheelbase but moving the COG back in the car itself by extending the weight pocket a little more behind the rear axle by moving the entire wheelbase forward VERSUS keeping the rear axle the same distance from the back of the car (as on my original 7" block) and moving the front axle forward thereby extending the wheelbase to say 6-3/4". Does that make sense? Am I just going down a rabbit hole by playing with the wheelbase? Okay I just planned out my summer, lol!
txchemist said:Not a PRO, but I slept in a Holiday Inn once-
We just concluded an unlimited race with 5oz 8" limits.
Just build your best 7" and add the lightest extension to move the nose out another inch. Make sure the extension will trigger the finish sensor.
Worked on Bearing wheels, Pure Stock, and stock pro type cars where we measured times with and without the extension.
Numbers came out just like the chart, a full 0.01 sec. faster with the 8" car. You are basically moving your COG back another inch.
One of the competitors made a razor wheel / needle axles design where he cut a big slot from the nose to almost the back, so the car nose was almost 5 inches in front of the pin. That moved his COG down the track by 5 inches and the car speed was 0.05 sec slower than if we put a bar on the nose to move the COG back to normal. He was very happy with the new speed, but not so happy when we pulled out our bearing car. Yes it was unfair- but that is what you get when you want to have no rules to "let your creativity run wild"
If I had both time AND wood, I would build 8" from start, but we just taped a 1/16" slab of wood to the nose to get the 8". I think if you know the track it will run on you can decide if you need to keep the wheels closer to the nose or not. "D" that is hollow is not good if it fails to trigger finish line.
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