Tungsten plates

[SPEEDQUEST]

Any disadvantages of attaching tungsten plate to bottom of car?

[Scrollsawer]

Anything attached to the bottom of the car can scrape the bottom of the Pinewood Derby track. Make sure you read the rules for your race, and ask the race officials what kids of track you have and if they think weights placed underneath the car would create a problem.

Most bottom-mounted weights (usually flat plates of some sort) are recessed into the bottom of the car so that the plate is flush with the wood. If the weight protrudes from the bottom, you're inviting trouble. I'd avoid it if at all possible.

Scrollsawer

[ngyoung]

As long as it still has a 3/8" clearance it should be fine. May want to tape the leading edge to make a slope if you cant in set it flush with the body.

[Topspin.D]

One layer of plate weights is usually ok, but more may be pushing it. Most metal tracks only require 1/4" of clearance. Old school wood tracks may require the full 3/8ths.

[gpraceman]

Most metal tracks only require 1/4" of clearance. Old school wood tracks may require the full 3/8ths.

Most all tracks that I know of, wood and aluminum alike, have guides that are no more than 1/4" tall. Where the 3/8" comes into play is on the curve. If you made a car with a hair over 1/4" clearance, it would bottom out on the ends of the car when it hits the curve. That extra 1/8" clearance helps avoid a belly rub issue on the curve. On the oldest Best Tracks, that clearance was a much bigger issue. They had a 2 ft radius. They changed to a 4 ft radius. Micro Wizard tracks have a gentler curve, so clearance is less of an issue.

When we inspect a car at check-in, if it rubs on the clearance checker, we take it to the track and see if it will actually have a problem on the curve. Most don't, so we let them pass, but those that do, we have the racer make adjustments. Otherwise, the car will drag and likely will not finish.

[Vitamin K]

Most all tracks that I know of, wood and aluminum alike, have guides that are no more than 1/4" tall. Where the 3/8" comes into play is on the curve. If you made a car with a hair over 1/4" clearance, it would bottom out on the ends of the car when it hits the curve. That extra 1/8" clearance helps avoid a belly rub issue on the curve. On the oldest Best Tracks, that clearance was a much bigger issue. They had a 2 ft radius. They changed to a 4 ft radius. Micro Wizard tracks have a gentler curve, so clearance is less of an issue.

When we inspect a car at check-in, if it rubs on the clearance checker, we take it to the track and see if it will actually have a problem on the curve. Most don't, so we let them pass, but those that do, we have the racer make adjustments. Otherwise, the car will drag and likely will not finish.

At our old Pack, we had an old wooden track that had a fairly tight curve section. I remember a lot of cars with low-hanging underside weights getting stuck on the transition. It was pretty sad to see. I felt bad for them. I wish we had the option of testing cars on the track at check-in, but our check-in and race are on different days, and we won't have the track available.

Fortunately, our current track is a Freedom, so the curve is big and gentle as opposed to small and tight.

[Stan Pope]

While I agree to some extent with relaxing the application of a rule if it does not give the car a meaningful advantage, keep in mind that there is evidence that the lowered CM confers some advantage. If that is, indeed, correct and if the builder has otherwise worked at the limit of the rules envelope, then allowing him to run in that manner would be unfair to competitors who abided by that rule.

"Passing" a car that results in it finishing 13th instead of 14th, way down among the pack, is not (in my mind) significant; passing a car with a violation that results in it finishing 1st instead of 2nd is significant!