Sideways Daytona Prototype

[War Eagle River]

Sideways Daytona Prototype
Piranha 21.5k
Sideways Motorpod
11/28 AW Gears
CG Motor Adaptor, CGMA001

[HomeRacingWorld]

I have not done this conversion on any of the inlines.

I want to. From what you say, this is the hot setup. I like seeing the standard can motor.

[War Eagle River]

[Pappy]

The Racer/Sideways Daytona Prototype is a great running car. Mine are all set up with sidewinder pods. I want to try one set up like this one. As far as motor pod float, I tighten down the screws on my motor pods and still use a piece of tape on the bottom to limit or dampen movement. All my movement is in the body and I like to use a little rubber washer between the body and chassis both front and rear. I like to use roll-out ratio for gearing. For those that don't know, roll out ratio takes into account the rear tire diameter. You must also take into account total weight of the car and weight distribution. I like a 65% rear and 35% front distribution.

The formula I use to figure out roll out ratio is "Tire diameter x Pi (3.14159) divided by teeth in spur x teeth in pinion.

The best running Group 5 car I have on my track has a roll out ratio of 1.06185742 . It has .806 diameter rear tires with a 13/31 gear ratio. So if I went to a .770 diameter tire I'd want to drop to a 13/30 gear ratio which would give me a roll out ratio of 1.0482433 which is close. A .770 tire with a 13/31 gear ratio is a 1.014429 .

[mether05]

Never heard of this "Roll Out" formula, what magic number are you looking to arrive at? 1.00???? Or is it end result related, in other words you're trying to get close to a known good ratio on your track, the 1.06...? ("The best running Group 5 car I have on my track has a roll out ratio of 1.06185742")

Just curious! Thanks, BobM <><

[Brumos RSR]

I'm also interested in this rollout. My question is what are the 4 screws for just forward of the pod and behind the front axle? I've never built or seen a prototype opened up before.

[GTOking]

[mikeinclover]

[Pappy]

[War Eagle River]

Pappy, not sure how the rollout formula would pertain to slot cars. Still too many variables to consider, even if you think the you have the optimum gear ratio. Weight, voltage, controllers, track surfaces, etc, and the biggie...the driver. It might translate in real race cars, but then they also have to consider many variables as well.

[Pappy]

I agree, to many variables to say roll out ratio is the secret to speed. It's like people who say a car doesn't handle well unless it's at least a 110 grams. Where that 110 grams is, is as important as being 110 grams. It's just another thing to look at when comparing cars and making gear ratio changes.

[Pappy]

War Eagle,

Here's where roll out ratio could be of use. Let's say I want to go to a different offset motor pod than the one I'm currently using. If I lower the chassis to much and it's illegal and I have to use a larger diameter tire I could figure out the gear ratio to get the same roll out ratio that I had. Same goes if I raise the chassis because I want to use a smaller diameter tire, I can figure out the gear ratio to compensate for the smaller diameter tires. It does come in handy at times.

[MacMoose]

The large number of variables present is not a reason to discount any one of them. A large number of very small gains can amount to a substantial improvement. The "rollout" is the only true means of comparing gear ratios. If you alter rear tire size you alter the distance traveled per axle revolution and, by obvious connection, motor shaft revolution. On extremely short tracks the difference can be quite small, but it is there and measurable. On the tracks I race on (between 70 and 150 feet in length, non-magnet) the differences are marked. The rollout is a necessary calculation.

[Pappy]

1/10 of a second a lap doesn't sound like much but in a race where everything else is equal it's a lot. In a Retro race on a 155' King track they are turning laps in the 4.6, 4.7 seconds a lap range. If someone has a car that is capable of turning a 4.7 second lap and they did that for 24 minutes (3 minutes per lane x 8 lanes) they'd turn 306.38 laps. If I had a car that could only turn a 4.8 second lap and I did it for 24 minutes I only have 300 laps. So a 1/10 of a second with everything else being equal I would be spotting the other guy 6.38 laps on a 155' track before the race even begins. That's hard to make up.

In a 6 hour endurance race it's really a lot and in a 24 hour race, forget it. Any little thing you can do to pick up a 1/100 of a second helps.

[War Eagle River]

Roll out....Way to technical for the average home circuit racer. Still comes down to the racer having to tune the car to his own driving abilities, and then being able to drive it.