Building a new car

[woodman]

OK, I just got some parts to build a car for the 75 foot flat track I built.....The motor is Pro Slot 4000 Euro MK1 26,100 rpms....What ratio would be good to start with?


The track....
viewtopic.php?f=22&t=6290&start=30

[jcis4me]

Use 48 pitch gears 9 tooth pinion and either a 29 or 30 tooth spur gear. I run the same on my Parma Flexi 5 on a lazy 8 track approx 85 ft and it fly's.
Marty

[TuscoTodd]

Woodman -
I think you are going to have a lot of fun with that 1/32 JK Cheetah II chassis! We use those and the Parma International chassis for our "EuroSport" sport class at the local commercial track. We utilize PlaFit Fox II motors which are very close to the motor you are using, except according to http://slotcarnews.blogspot.com/2007/02 ... -list.html the PlaFit motor has more torque.
The ratings there are:
Plafit Fox II (FK-130) 27,000 RPM/12v, tested 26,866 RPM/12v
.7A, tested 208 gcm/12v, tested 14.0W/12v

Pro Slot Euro Mk1 (FC-130) 26,100+ RPM/12v tested 27, 616 RPM/12v CW
155 gcm/12v, 10.1W/12v tested 184 gcm/12v CW, tested

We run the cars on both both a flat road course and a big' banked King track (can be seen here: http://slotblog.net/topic/8629-marks-mo ... ld-canton/ ). For those tracks, I run a pretty tall ratio of 16:35 (64 pitch) - but I would think with the shorter straights and tighter corners on your layout - you would want to go with a much steeper ratio as it will accelerate harder and have better brakes allowing you to run deeper into the corners. I would think that you would want to go somewhere in the 3.6 to 4.0 to one ratio to get the most out of the car?
You can probably use a stock scalextric car (or any car with a known motor rpm and gear ratio) as a bit of an indicator - if what you are currently running can't ever hit max speed/rpm on the end of your straight sections, you will want a steeper effective ratio than what your "example" car has.

If you want to get fairly technical, you can use this site: http://www.advanced-ev.com/Calculators/TireSize/ to plug in your motor rpm 18,000rpm), the tire diameter (.830 for a Scaley Cougar) and the gearing ration (3.27 for 11:36) and calculate for speed - gives: 13.6mph top speed.
Similarly, using the details from the car you are building - motor rpm (26,100), tire diameter (.790 for new JK 8712's) if you want to keep the same top speed of 13.6, you can calculate for gearing - which equates to 4.512 which would fall between a 9:37 and a 9:38.

Now the Pro Slot motor you are using has notably more torque than a stock Scalextric motor, so it will accelerate faster to the cars top speed. So if you are already topping out at the end of your long straights using your "known" example car, you will definitely want to look at exploring shallower gearing to allow for more speed.
But conversely if aren't able to get up to full speed with your Scalextric type cars - you may want to try something in the 9:37 area to start and see if the added torque allows you to achieve top speed before the end of your straights - if so, then you can look at dropping back the ratio a bit to get more speed out of the car. :)

That may be more than what you were looking for - but hope that helps!
:D

[waaytoomuchintothis]

And get some spotters because you can't see those things go by that fast.

[Florida_Slotter]

[waaytoomuchintothis]

In-sane. They don't even look like cars. But at least a spotter can yell "Turn! For God's sake Turn! Turn! Before it shoots through the wall and kills the guy next door, Turn!" Get it?

[TuscoTodd]

Marty - that has to be a ROCKET with a Falcon 7 in there - WOW! :banana-dance:

In regard to seeing them - that is part of the idea behind the paint scheme I used on mine - makes it easy to pick out...
viewtopic.php?f=19&t=6383&p=72952&hilit=feeling#p72952
:)

[waaytoomuchintothis]

That will get your attention, which from my unhappy experience at commercial raceways of today, is the very best you can do. Normally, I don't like to see the Red, White & Blue used for something that isn't directly connected to the US, but that is a very creative use that doesn't take away from the national symbols at all. Excellent work, as far as I'm concerned, and yeah, it definitely would be easier to follow! Being 63 this year, the objection to crazy fast is admittedly getting a edge to it, but you did a great job of bridging the gap. I would still need someone to tell me when something that fast went by, but then I guess cars that look like scale model racers on a home track might be boring to some folks under 30, and we need them in the hobby, by whatever description, ya know?

[Florida_Slotter]

[TuscoTodd]

waaytoomuchintothis -
Thank you for the kind words on the paint scheme - I am pretty happy with how it turned out, and it definitely does make it easier to follow around the track, particularly when you are at the opposite end of the King track. :)
The Plafit motors that are specified for the class we run are 60% of the power of a 16d type motor, so while they have some pretty decent speed, they aren't the "brutal quick" cars I have seen some guys running during practice times. :)
On the more "scale" front - we run box stock Scalextric classes every Wednesday on the road course (it has magnetic braid) and everyone has a good time with it! (There has also been talk about possibly starting a non-magnetic class, which I think will be pretty interesting as well - haven't tried that yet, but I am dipping a toe into the "plastic chassis - but no magnet" arena in building a car for the Carrera Proxy here on the forum) :D

Marty -
I haven't participated in any of the really "fast" racing classes at our local commercial track - the 1/32 EuroSport and F2 (uses JK inline chassis) are the quickest classes we run on Wednesdays - which is typically the only day I go to the track. Both classes are a lot of fun as they are set up similar to a box stock class -which keeps the racing REALLY close and a lot of fun!
Appreciate the heads up on the Pro-Slot "Euro" motor - didn't realize that those were a potential direct snap in replacement - I may have to see about picking up one of those to "play" with! :)

[woodman]

Thanks a lot for the replies....the body is a Parma P70541B 1/32 Ultimate Intrepid

[oldtimer]

Although I haven't stepped into the arena of JK chassis set-ups, I do race the plastic chassis Scalextric, Slot.it type cars. I read comments indicating the the Pro-Slot "Euro" motor(s) snap right into the plastic chassis.....
Can anyone elaborate on which specific motor or motor(s) are being referred to as well as which plastic chassis? I am always looking for various engine/gearing/chassis combinations and am curious to know how a snap in Pro-Slot "Euro motored car would fare up against some of the other modified plastic chassis cars such as some of the higher RPM Scalextric Sport motors or the higher RPM Slot.it or NSR Shark motor series in their respective chassis.
Thanks

[woodman]

Building a fleet of three Indy cars, I'll put on a race of equal cars when done, 3 cars for the 3 lane track!.....One down 2 to go and man was this a fun car to run las night....The parts finally came in except the rear Pro-tracks..

3 3/4'' wheel base whith these JK 1/32 cheetah 11 chassis....Same motor as the car above



Also running 8-30 gears on this...