HPI 2-speed gearings
Life without a bread
I'd like to know how I can tinker with my gearings... I would like to
have quicker acceleration and higher top-end speed...
My gearings right now are 13/16T and 44/41T It would be best if I get
to keep my 13/16T clutchbell coz I can't remove just one (the 13t or
the 16t) coz they are fixed... and the next one available would be
13/18T... so what combination would give me quicker acceleration from
standstill and give me higher top end speed against my current gears?
Hmmm with the 13/18T would I be able to use my 44/41T spurs and what
would I expect to have with this 13/18 over 44/41T combination??
Tom Markert, N3WTF
Well since both of your choices here seem to be first gear 13 -> 44
your acceleration would be the same...
Seems that I haven't ever seen a gear set that would offer both top
end AND accel. I would say go for the acceleration gear set and try
different pipes and tunning to get the top end out of her....
Increasing top end without changing the gearing.. A few ideas...
Slam that body! make it so the body is as LOW as possible.... Not just
to the ground but overall profile... Less wind resistance is the key.
Bearings... Get that thick grease out of them and use a light oil
(synthetic is best here).. Problem with this is increased maintence..
You'll need to clean and relube more often.. Less rolling resistance
here is the key...
Better breathing... More air in and better flow out will let your
motor rev quicker and higher! (hmmm theres a good "Both worlds" thing
to try)....
Loose some weight! (Not you, the car!) Get rid of that Carry handle on
HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
around the car for excess weight but be carefull not to upset the
balance or integrity of the chassis....
Just a few ideas off the top of my coffee starved brain....
Life without a bread
wrote:
TOM! Where have you been!!? :))) Nice to see you again replying to my
post... :)
>Well since both of your choices here seem to be first gear 13 -> 44
>your acceleration would be the same...
Ok, but can I use my 44/41T with a 13/18T clutch bell? What can I
expect if ever this can be done?
>Seems that I haven't ever seen a gear set that would offer both top
>end AND accel. I would say go for the acceleration gear set and try
>different pipes and tunning to get the top end out of her....
But Tom, you see different pipes means spending... And pipes here in
my country would cost me a lot. I am not rich... :))
Anyways, I can, if ever, mess with this pipe I have right now... what
or how much performance gain percentage wise, if I can tweak it
correctly? I presume that it would be directly opposite if I do it
wrong, right?
>Increasing top end without changing the gearing.. A few ideas...
>
>Slam that body! make it so the body is as LOW as possible.... Not just
>to the ground but overall profile... Less wind resistance is the key.
does this aerodynamics thing really affect 1/10th R/C?
>Bearings... Get that thick grease out of them and use a light oil
>(synthetic is best here).. Problem with this is increased maintence..
>You'll need to clean and relube more often.. Less rolling resistance
>here is the key...
Ok, I can probably tore out the cover in order to do this... or pluck
it out... synthetic oil is rather expensive here too, and hard to
comeby... if ever I can grab one, it would be coming in gallons, no
quarts pints or whatever.
Can I use WD-40 or silicone shock oil?
>Better breathing... More air in and better flow out will let your
>motor rev quicker and higher! (hmmm theres a good "Both worlds" thing
>to try)....
We're talking about tuned pipes here? I have rebored my slide carb to
be 6mm... (geez, broken two of them)
>Loose some weight! (Not you, the car!) Get rid of that Carry handle on
>HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
>around the car for excess weight but be carefull not to upset the
>balance or integrity of the chassis....
>
carry handle?? the one near the engine?? It's just 5 grams I think...
>Just a few ideas off the top of my coffee starved brain....
Did you know that with each cup of coffee, you deny your brain 25% of
it's vitamin B supply for I think 4 hours or 8 hours? Resulting to
grey hairs?? And it can complicate gall bladder problems... :))
Tom Younger
>On 7 Oct 2000 01:13:59 GMT, n3...@magpage.com (Tom Markert, N3WTF)
>wrote:
>
>TOM! Where have you been!!? :))) Nice to see you again replying to my
>post... :)
>
I've been around. And thanks for noticing me before I answered. (I take it
this is referring to one of the other Toms though)
>>Well since both of your choices here seem to be first gear 13 -> 44
>>your acceleration would be the same...
>
>Ok, but can I use my 44/41T with a 13/18T clutch bell? What can I
>expect if ever this can be done?
>
No, you can't, because this means you'll be changing the size of one of the
pinions without changing the size of the spur it meshes with, which will screw
up the gear mesh of one of the pairs of gears.
The sum of the radii of each pair of gears (where a pairing of gears mesh
together, for example 13/44 and 16/41) must be equal, or else the pair of
pinions or pair of spurs cannot be coaxial (run on the same shaft). Since the
radius is proportional to the circumference, this makes figuring out which sets
of gears will work together quite easy; the sum of the number of teeth in each
gear pair must be equal. Your 13/16 clutchbell will work with your 44/41 spur
combo, because 13 + 44 = 16 + 41. However, 13 + 44 <> 18 + 41, therefore this
set of gears will not work. In order to use the 13/18 clutchbell, your spur
gears need to have a difference of 5 teeth.
>
>>Seems that I haven't ever seen a gear set that would offer both top
>>end AND accel. I would say go for the acceleration gear set and try
>>different pipes and tunning to get the top end out of her....
>
That's the whole point of a 2-speed; you can get the best of both worlds when
you shift (if you can find the right gears that is).
>But Tom, you see different pipes means spending... And pipes here in
>my country would cost me a lot. I am not rich... :))
>
>Anyways, I can, if ever, mess with this pipe I have right now... what
>or how much performance gain percentage wise, if I can tweak it
>correctly? I presume that it would be directly opposite if I do it
>wrong, right?
>
You can tune the powerband of your engine a little bit by changing the overall
length of your exhaust; a longer exhaust will give the engine more bottom end,
and a shorter exhaust more top end. The effects of this are noticed more with
a tuned pipe; I'm not sure what pipe you have on your car at this point.
>
>>Increasing top end without changing the gearing.. A few ideas...
>>
>>Slam that body! make it so the body is as LOW as possible.... Not just
>>to the ground but overall profile... Less wind resistance is the key.
>
>does this aerodynamics thing really affect 1/10th R/C?
>
Yes, but more in the handling department than top speed, unless you start going
extremely fast. What limits top speed is friction, which comes primarialy from
air resistance, followed by drivetrain drag (bearings) and tire rolling
resistance.
>>Bearings... Get that thick grease out of them and use a light oil
>>(synthetic is best here).. Problem with this is increased maintence..
>>You'll need to clean and relube more often.. Less rolling resistance
>>here is the key...
>
>Ok, I can probably tore out the cover in order to do this... or pluck
>it out... synthetic oil is rather expensive here too, and hard to
>comeby... if ever I can grab one, it would be coming in gallons, no
>quarts pints or whatever.
>
>Can I use WD-40 or silicone shock oil?
>
WD-40 is primarialy a cleaner. Check out
http://draco.acs.uci.edu/rbfaq/FAQ/62.html -- I pity anyone who expects it to
work as a good lubricant. Sillicone shock oil tends to be quite thick, and
I've never been convinced the lubricating qualities of sillicone (by itself) is
very good. Use standard everyday motor oil (the stuff people put in real
cars); it's a very good lubricant for a very low price; people seem to forget
about it far too often.
>>Better breathing... More air in and better flow out will let your
>>motor rev quicker and higher! (hmmm theres a good "Both worlds" thing
>>to try)....
>
>We're talking about tuned pipes here? I have rebored my slide carb to
>be 6mm... (geez, broken two of them)
Better flow in refers to your air filter.
>
>>Loose some weight! (Not you, the car!) Get rid of that Carry handle on
>>HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
>>around the car for excess weight but be carefull not to upset the
>>balance or integrity of the chassis....
>>
>
>carry handle?? the one near the engine?? It's just 5 grams I think...
>
The mass of the car has a negligable effect on top speed (it is limited to the
increased rolling resistance a heavier car has). It has a much more
significant effect on the acceleration rate of the car (how quickly it can
change direction and get to top speed), but has no real effect on top speed.
>>Just a few ideas off the top of my coffee starved brain....
>
>Did you know that with each cup of coffee, you deny your brain 25% of
>it's vitamin B supply for I think 4 hours or 8 hours? Resulting to
>grey hairs?? And it can complicate gall bladder problems... :))
Good thing I can't stand the swill.
___
TTTTT OO M M The sixth sick shiek's sixth sheep's sick. |~~~|
T O O MM MM @o o@
T O O M M M So if it is in it or if it is on it, it is *
T OO M M as it is, be it in it or on it. `-'
Mike F
Its been 7 months now that my wife has been pregnant. Any hair that I might
have possibly
been able to keep is now doomed to be gray anyway.
I had a nice freak flag too, at one point.
Drink on!
Mike F
Tom Younger wrote:
> No, you can't, because this means you'll be changing the size of one of the
> pinions without changing the size of the spur it meshes with, which will screw
> up the gear mesh of one of the pairs of gears.
>
correct.
> The sum of the radii of each pair of gears (where a pairing of gears mesh
> together, for example 13/44 and 16/41) must be equal, or else the pair of
> pinions or pair of spurs cannot be coaxial (run on the same shaft).
correct.
> Since the
> radius is proportional to the circumference, this makes figuring out which sets
> of gears will work together quite easy; the sum of the number of teeth in each
> gear pair must be equal. Your 13/16 clutchbell will work with your 44/41 spur
> combo, because 13 + 44 = 16 + 41. However, 13 + 44 <> 18 + 41, therefore this
> set of gears will not work. In order to use the 13/18 clutchbell, your spur
> gears need to have a difference of 5 teeth.
>
This doesnt sound right.
Your best bet is to see what HPI offers. You WILL need to replace the clutchbell
AND both spurs.
..I tried to write out the calculation for pitch radius's but its too early. I'm
not even close to the right formula.
I just know that 'keeping the sum of the teeth constant' is incorrect.
If your interested, i'll dig out my Machinery's Handbook for some boring formulas.
...As I have my fourth cup of coffee....;o)
Tom Markert, N3WTF
without a bread) wrote:
>On 7 Oct 2000 01:13:59 GMT, n3...@magpage.com (Tom Markert, N3WTF)
>wrote:
>
>TOM! Where have you been!!? :))) Nice to see you again replying to my
>post... :)
My father died and I have been tying up loose ends, and now Joanne and
I are moving next week so we've been packing.
>
>>Well since both of your choices here seem to be first gear 13 -> 44
>>your acceleration would be the same...
>
>Ok, but can I use my 44/41T with a 13/18T clutch bell? What can I
>expect if ever this can be done?
>
>
Ummmm Not thinking str8 yet.... Maybe stronger punch at mid range
>>Seems that I haven't ever seen a gear set that would offer both top
>>end AND accel. I would say go for the acceleration gear set and try
>>different pipes and tunning to get the top end out of her....
>
>But Tom, you see different pipes means spending... And pipes here in
>my country would cost me a lot. I am not rich... :))
>
>Anyways, I can, if ever, mess with this pipe I have right now... what
>or how much performance gain percentage wise, if I can tweak it
>correctly? I presume that it would be directly opposite if I do it
>wrong, right?
You still running the stock muffler? Theres a trick you can do if you
are!
>
>
>>Increasing top end without changing the gearing.. A few ideas...
>>
>>Slam that body! make it so the body is as LOW as possible.... Not just
>>to the ground but overall profile... Less wind resistance is the key.
>
>does this aerodynamics thing really affect 1/10th R/C?
EXTREMLY! Once you get your suspension tuned in somewhat, put on a
different body style! You'll be amased at the difference!
>
>>Bearings... Get that thick grease out of them and use a light oil
>>(synthetic is best here).. Problem with this is increased maintence..
>>You'll need to clean and relube more often.. Less rolling resistance
>>here is the key...
>
>Ok, I can probably tore out the cover in order to do this... or pluck
>it out... synthetic oil is rather expensive here too, and hard to
>comeby... if ever I can grab one, it would be coming in gallons, no
>quarts pints or whatever.
>
>Can I use WD-40 or silicone shock oil?
DO NOT EVER use silicone oils / grease for stuff like this... Silicone
is derived from silica (sand) and is "gritty"...
>
>>Better breathing... More air in and better flow out will let your
>>motor rev quicker and higher! (hmmm theres a good "Both worlds" thing
>>to try)....
>
>We're talking about tuned pipes here? I have rebored my slide carb to
>be 6mm... (geez, broken two of them)
>
>>Loose some weight! (Not you, the car!) Get rid of that Carry handle on
>>HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
>>around the car for excess weight but be carefull not to upset the
>>balance or integrity of the chassis....
>>
>
>carry handle?? the one near the engine?? It's just 5 grams I think...
Racers worry about RX choices. Thier argument is this one is better
BUT weighs 1 gram more then the other! Your dealing with very low
horse power, EVERY gram can make a difference
>
>>Just a few ideas off the top of my coffee starved brain....
>
>Did you know that with each cup of coffee, you deny your brain 25% of
>it's vitamin B supply for I think 4 hours or 8 hours? Resulting to
>grey hairs?? And it can complicate gall bladder problems... :))
Well I drink 3 pots a day and twice that on the weekend.. Gave up
alcohol and being diabetic, diet soda is my only soft drink choice and
it SUCKS! Iced tea with no sugar SUCKS... I do drink water.. About 1
glass every 3 to 4 cups of coffee to keep hydrated....
>
Tom Markert, N3WTF
wrote:
>>>
>>>Slam that body! make it so the body is as LOW as possible.... Not just
>>>to the ground but overall profile... Less wind resistance is the key.
>>
>>does this aerodynamics thing really affect 1/10th R/C?
>>
>
>Yes, but more in the handling department than top speed, unless you start going
>extremely fast. What limits top speed is friction, which comes primarialy from
>air resistance, followed by drivetrain drag (bearings) and tire rolling
>resistance.
>
WHAT! Lets race. once with my Acura NSX body then with my Grave Digger
body (yes it's mounted on a nitro touring car!).. MAJOR top end
difference.. Even with my F-150 I can VISUALLY see a top end
difference.
>>>Loose some weight! (Not you, the car!) Get rid of that Carry handle on
>>>HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
>>>around the car for excess weight but be carefull not to upset the
>>>balance or integrity of the chassis....
>>>
>>
>>carry handle?? the one near the engine?? It's just 5 grams I think...
>>
>
>The mass of the car has a negligable effect on top speed (it is limited to the
>increased rolling resistance a heavier car has). It has a much more
>significant effect on the acceleration rate of the car (how quickly it can
>change direction and get to top speed), but has no real effect on top speed.
>
WRONG AGAIN. In a perfect world the track is level. BUT as we all seem
to understand this is not a perfect world... The track may be slightly
uphill, or a number of other factors.... These motors are severly
limited in HP and incase you never realized Torque is for take off, HP
is for mid to top end pulling power.....
This is why my 1:1 pick up truck is quick once I get over 2,000 RPM
but untill I get there some 6 cyl imports leave me standing at the
line... I have no torque compared to my HP (not to mention my
gearing).. And dont bother trying to help! I built it this way cause I
cant keep traction with any more launching power..
Tom
> On Sat, 7 Oct 2000 04:16:04 -0700, Tom Younger <tyou...@csc.uvic.ca>
> wrote:
>
>
> >>>
> >>>Slam that body! make it so the body is as LOW as possible.... Not just
> >>>to the ground but overall profile... Less wind resistance is the key.
> >>
> >>does this aerodynamics thing really affect 1/10th R/C?
> >>
> >
> >Yes, but more in the handling department than top speed, unless you start going
> >extremely fast. What limits top speed is friction, which comes primarialy from
> >air resistance, followed by drivetrain drag (bearings) and tire rolling
> >resistance.
> >
> WHAT! Lets race. once with my Acura NSX body then with my Grave Digger
> body (yes it's mounted on a nitro touring car!).. MAJOR top end
> difference.. Even with my F-150 I can VISUALLY see a top end
> difference.
>
With the type of racing I do, top end isn't very important, but handling
is. I mentioned that the body makes a bigger difference in handling than
it does in top speed, not that it doesn't make a difference in top speed.
If you read what I said agaon, I list aerodynamic drag as the primary
limiter on top speed, which would be caused by the body.
> >>>Loose some weight! (Not you, the car!) Get rid of that Carry handle on
> >>>HPI's. Loose that 5 cell RX pack for a lighter 4 cell unit... Look
> >>>around the car for excess weight but be carefull not to upset the
> >>>balance or integrity of the chassis....
> >>>
> >>
> >>carry handle?? the one near the engine?? It's just 5 grams I think...
> >>
> >
> >The mass of the car has a negligable effect on top speed (it is limited to the
> >increased rolling resistance a heavier car has). It has a much more
> >significant effect on the acceleration rate of the car (how quickly it can
> >change direction and get to top speed), but has no real effect on top speed.
> >
> WRONG AGAIN. In a perfect world the track is level. BUT as we all seem
> to understand this is not a perfect world... The track may be slightly
> uphill, or a number of other factors.... These motors are severly
> limited in HP and incase you never realized Torque is for take off, HP
> is for mid to top end pulling power.....
Severely limited in HP? Yah, right. Look at the power to weight ratio of
any R/C car out there, and compare with any full sized car. I'm not going
to put down any absolute numbers because I don't know any off hand, but
I'd wager R/C cars have about twice the power to weight ratio many exotic
cars have.
Although it is true that the weight makes a difference going up and down
hill (I did forget about that), cars go downhill as well as uphill if the
track has hills, and a heavier car will have an advantage over a light car
on a downhill to a lesser degree than a light car will have an advantage
over a heavier car uphill. But, the two will come close to cancling out,
the major difference being air resistance (proportional to the square of
the speed).
Saying that, the on-road tracks I run on are close enough to level where
this does not make a difference.
Again, a heavier car will be slower to accelerate than a light car (on
level ground; it will accelerate faster after reaching a certain speed on
a steep downhill), and unless you run in an area with substantial hills,
the mass of the car will not make a noticeable difference (provided you're
within reason, of course). I feel I have to make these qualifications to
some people; of course if you strap 20 extra pounds to your car, of course
you're going to screw it up majorly.
Life without a bread
wrote:
>I've been around. And thanks for noticing me before I answered. (I take it
>this is referring to one of the other Toms though)
Hey! :))
>No, you can't, because this means you'll be changing the size of one of the
>pinions without changing the size of the spur it meshes with, which will screw
>up the gear mesh of one of the pairs of gears.
>
>The sum of the radii of each pair of gears (where a pairing of gears mesh
>together, for example 13/44 and 16/41) must be equal, or else the pair of
>pinions or pair of spurs cannot be coaxial (run on the same shaft). Since the
>radius is proportional to the circumference, this makes figuring out which sets
>of gears will work together quite easy; the sum of the number of teeth in each
>gear pair must be equal. Your 13/16 clutchbell will work with your 44/41 spur
>combo, because 13 + 44 = 16 + 41. However, 13 + 44 <> 18 + 41, therefore this
>set of gears will not work. In order to use the 13/18 clutchbell, your spur
>gears need to have a difference of 5 teeth.
Yep... Tried it, and it wouldn't mesh.
>That's the whole point of a 2-speed; you can get the best of both worlds when
>you shift (if you can find the right gears that is).
>You can tune the powerband of your engine a little bit by changing the overall
>length of your exhaust; a longer exhaust will give the engine more bottom end,
>and a shorter exhaust more top end. The effects of this are noticed more with
>a tuned pipe; I'm not sure what pipe you have on your car at this point.
What are the right gears? I have an HPI Super Nitro Kit with a .15FE
engine, and an HPI Tuned Pipe and Exhaust Header Set and 2 speed
tranny.
>Better flow in refers to your air filter.
Ok, I am using a K&N Air Filter, is this good?
>The mass of the car has a negligable effect on top speed (it is limited to the
>increased rolling resistance a heavier car has). It has a much more
>significant effect on the acceleration rate of the car (how quickly it can
>change direction and get to top speed), but has no real effect on top speed.
It doesn't have any effect on top speed? Let's say for a quarter mile,
your 1:1 car hits 80mph... that is without any load except you.
Now let's say you have 5 add'l passengers, surely, you won't hit your
80mph at the end of the quarter mile right? so it does affect your top
speed right? And if ever the track is endless, I am sure you can't
reach your top speed with 5 passengers on board, compared with if
you're just driving alone, coz the engine's flywheel will be working
double time right?
These things confuse me.
>Good thing I can't stand the swill.
Hehe
>
>___
>TTTTT OO M M The sixth sick shiek's sixth sheep's sick. |~~~|
> T O O MM MM @o o@
> T O O M M M So if it is in it or if it is on it, it is *
> T OO M M as it is, be it in it or on it. `-'
>
Nice sig... Twisted my tongue already...
Life without a bread
wrote:
>My father died and I have been tying up loose ends, and now Joanne and
>I are moving next week so we've been packing.
Oh... I don't know what to say Tom, I didn't know. I am sorry. My
symphaties...
>You still running the stock muffler? Theres a trick you can do if you
>are!
With this kit, I am using the HPI Tuned pipe & exhaust header. But
please tell me what the trick is coz I am planning to tinker and bore
some holes on my son's Nitro Z10...
>EXTREMLY! Once you get your suspension tuned in somewhat, put on a
>different body style! You'll be amased at the difference!
So I need to buy a setup board... is this that necessary??
>DO NOT EVER use silicone oils / grease for stuff like this... Silicone
>is derived from silica (sand) and is "gritty"...
Shit! Silly me... I used silicone shock oil and mixed it with an off
the shelf grease and slammed some mudpie size bunch into my diffs!
>Racers worry about RX choices. Thier argument is this one is better
>BUT weighs 1 gram more then the other! Your dealing with very low
>horse power, EVERY gram can make a difference
Hmmm... so out goes that 9v square batteries, and those wirings and
leds and lights I installed to make the dang thing visible at night
when I try to hit it full around 2am in the morning just to piss my
neighbor who's been dumping trash in front of my house... (I think
I'll just have those lights and leds light-up the gutters.. LOL!)
I even bought my son a nitro kit so that we can race at 2am... coz
this neighbor complained against me and now he closes his windows just
to muffle the sounds I think... now we're two... I guess closing it
wouldn't make that much difference! LOL!
>Well I drink 3 pots a day and twice that on the weekend.. Gave up
>alcohol and being diabetic, diet soda is my only soft drink choice and
>it SUCKS! Iced tea with no sugar SUCKS... I do drink water.. About 1
>glass every 3 to 4 cups of coffee to keep hydrated....
3 POTS!!!??? Whoa!!
Tom Younger
(*SNIP!*)
>
>>The mass of the car has a negligable effect on top speed (it is limited to the
>>increased rolling resistance a heavier car has). It has a much more
>>significant effect on the acceleration rate of the car (how quickly it can
>>change direction and get to top speed), but has no real effect on top speed.
>
>It doesn't have any effect on top speed? Let's say for a quarter mile,
>your 1:1 car hits 80mph... that is without any load except you.
>
>Now let's say you have 5 add'l passengers, surely, you won't hit your
>80mph at the end of the quarter mile right? so it does affect your top
>speed right? And if ever the track is endless, I am sure you can't
>reach your top speed with 5 passengers on board, compared with if
>you're just driving alone, coz the engine's flywheel will be working
>double time right?
>
Well, if you go over a measured distance and take acceleration rates into
account, a heavier car will be slower (unless possibly on a downhill).
So, if you're drag racing, you definately want as light a car as you can get
away with. However, if you're running on a dry lake bed and you can take as
long to get up to terminal velocity as you want, there will be no significant
difference in the terminal velocity of a heavy car vs. the terminal velocity of
a light car, provided functionally they're the same car otherwise. Terminal
velocity is determined by the drag of the car (predominantly air resistance)
and the horsepower of the car, neither of which have anything to do with the
mass of the car.
Theoretically, it takes no effort to turn a flywheel at a constant speed (what
you'd be doing at terminal velocity); mass only matters when you're
accelerating it.
Tom Younger
>Tom Younger wrote:
>
(*SNIP!*)
>> radius is proportional to the circumference, this makes figuring out which sets
>> of gears will work together quite easy; the sum of the number of teeth in each
>> gear pair must be equal. Your 13/16 clutchbell will work with your 44/41 spur
>> combo, because 13 + 44 = 16 + 41. However, 13 + 44 <> 18 + 41, therefore this
>> set of gears will not work. In order to use the 13/18 clutchbell, your spur
>> gears need to have a difference of 5 teeth.
>>
>
>This doesnt sound right.
Well, it is. Here's why.
We want the distance between the centers of two pairs of gears to be the same.
This means we want the sums of the radii of both pairs of gears to be the same.
Let's give some gears some names. The clutch bell has on it P1 and P2 (pinion
1 and pinion 2, corresponding to 1st and 2nd gears respectively). The layshaft
has on it S1 and S2 (corresponding to spur gear 1 and 2 respectively). We want
the sum of the radii of P1 and S1 to be the same as P2 and S2, otherwise both
gears will not simultaniously be meshing. This is all stuff we agreed upon
which I (*SNIP!*)ped out of this reply.
Let's now figure out some gear radii. Let's first establish a convenient unit
of measure. Let's measure in units of tooth spacing. This means that our
unit of measure will be the distance between two teeth on a gear. This unit
will be the same for all the gears in question, since they mesh. (Technically,
S1 and S2 could have different pitches, as long as they corresponded to P1 and
P2, but I don't think anyone ever does this). Therefore, the circumfrence of,
say, a 42 tooth gear would be 42, and the circumfrence of, say, a 24 tooth gear
would be 24.
The radius of a gear is: radius = circumfrence / (2 * PI)
Therefore, the distance between the pinion shaft and the layshaft of our setup
would be:
P1 / (2 * PI) + S1 / (2 * PI)
If you know how to add fractions, you know this is the same as:
(P1 + S1) / (2 * PI)
Now, we just do the same thing for the other gear. We have:
P2 / (2 * PI) + S2 / (2 * PI) is the distance between 2nd gear. This
simplifies to:
(P2 + S2) / (2 * PI)
Now, we want the distance between the centers of 1st gear to be the same as the
distance between 2nd gear. This gives us:
(P1 + S1) / (2 * PI) = (P2 + S2) / (2 * PI)
Using simple algebra, we can multiply both sides by (2 * PI) [which is just a
scalar], and we are left with:
(P1 + S1) = (P2 + S2)
Back to our original definitions, and this means that the sum of the teeth in
1st gear (the sum of the teeth on both the pinion and spur) must equal the sum
of the teeth in 2nd gear if you want both sets of gears to mesh simultaniously.
>Your best bet is to see what HPI offers. You WILL need to replace the
clutchbell >AND both spurs.
HPI should offer many combinations; you may very well be able to find some that
they don't list (for bizarre applications) if you keep in mind what you
actually need to do to make it work.
>..I tried to write out the calculation for pitch radius's but its too early.
I'm >nnot even close to the right formula.
We don't really need to go into that much detail; that's trying to figure out a
seperate problem. Besides, just remember that:
The diametric pitch of a gear = the number of teeth you put in the circumfrence
of a 1" diameter gear. Therefore, a 64 pitch spur gear that has 64 teeth would
be 1 inch in diameter, and a 128 tooth 64 pitch spur would be 2 inches in
diameter, etc.
>I just know that 'keeping the sum of the teeth constant' is incorrect.
Please review the math above.
>If your interested, i'll dig out my Machinery's Handbook for some boring
formulas.
Not necessary.
>...As I have my fourth cup of coffee....;o)
Maybe you had 3 too many. . .
Tom Markert, N3WTF
without a bread) wrote:
>On 7 Oct 2000 13:56:42 GMT, n3...@magpage.com (Tom Markert, N3WTF)
>wrote:
>
>
>>My father died and I have been tying up loose ends, and now Joanne and
>>I are moving next week so we've been packing.
>
>Oh... I don't know what to say Tom, I didn't know. I am sorry. My
>symphaties...
Thanks.... He's in a much better way now though. Alcohol and diabeties
pretty much took it's toll on him.
>>You still running the stock muffler? Theres a trick you can do if you
>>are!
>
>With this kit, I am using the HPI Tuned pipe & exhaust header. But
>please tell me what the trick is coz I am planning to tinker and bore
>some holes on my son's Nitro Z10...
I forgot that you had the HPI tuned pipe. I was talking about that
goofy square looking boxy muffler that the HPI NRS4 comes with.
>> Once you get your suspension tuned in somewhat, put on a
>>different body style! You'll be amased at the difference!
>
>So I need to buy a setup board... is this that necessary??
Well they do help some but you dont need a setup board.. Go look at
RPM gauges.. A toe gauge, Camber gauge, and ride height gauge is what
I use.. Neither of which was over $20.00 US.... Then get a nice FLAT
piece of plexiglass and place the car on that so that your sure the
car is sitting level... (trust me here! I tried doing it on my work
bench and had things worse then when it came outta the box!).
But the original post here was about the body.. I slam mine so far
down, that if the suspension is FULLY compressed, the tires are
approximatley 1mm from hitting the inside top of the wheel wells! Then
I also trim the rest of the body so when suspension is compressed that
I have about 1/8 inch ground clearence. This larger gap is incase
there are some cracks or divits in the lot where I'm running.....
>
>>DO NOT EVER use silicone oils / grease for stuff like this... Silicone
>>is derived from silica (sand) and is "gritty"...
>
>Shit! Silly me... I used silicone shock oil and mixed it with an off
>the shelf grease and slammed some mudpie size bunch into my diffs!
Another point is that I NEVER pack my diffs FULL of anything unless
it's one of my off road toys... It can hamper handaling (you loose
some of the differential action!) and it's alot more friction in the
drive train making the motor work harder and possibly giving slower
top end speed..... In my diffs I normally use automotive wheel bearing
grease. I buy the synthetic stuff that the local circle track racers
use.. Just a medium coating here will do....
>
>>Racers worry about RX choices. Thier argument is this one is better
>>BUT weighs 1 gram more then the other! Your dealing with very low
>>horse power, EVERY gram can make a difference
>
>Hmmm... so out goes that 9v square batteries, and those wirings and
>leds and lights I installed to make the dang thing visible at night
>when I try to hit it full around 2am in the morning just to piss my
>neighbor who's been dumping trash in front of my house... (I think
>I'll just have those lights and leds light-up the gutters.. LOL!)
YEA! Pitch the lights! That'll ruin your handeling BIG time as well!
>
>I even bought my son a nitro kit so that we can race at 2am... coz
>this neighbor complained against me and now he closes his windows just
>to muffle the sounds I think... now we're two... I guess closing it
>wouldn't make that much difference! LOL!
>
Hopefully he dont have a gun. Redwolf, Joanne (my wife), and I were
all running outfront of my house one AFTERNOON and the neighbor
started yelling at us.. He called the cops. The cop started asking us
where he could buy one, how fast are they, and said ignore the old
bastard and left. 10 minutes later he came outside and got in his car
and said he was gonna run them over... Took him 15 minutes to realize
how fast and agile these things are! HAHAHA.. 2 days later he was
outside with a .22 handgun and took a shot at my wifes 4-tech. Spent
30 days in the lock-up! pleaded insanity!!!!!
>>Well I drink 3 pots a day and twice that on the weekend.. Gave up
>>alcohol and being diabetic, diet soda is my only soft drink choice and
>>it SUCKS! Iced tea with no sugar SUCKS... I do drink water.. About 1
>>glass every 3 to 4 cups of coffee to keep hydrated....
>
>3 POTS!!!??? Whoa!!
Well it's 8:12 AM here and I'm just about done the first pot. been up
since 7:05 AM...... Check the NG through the day and I'll post each
time I make a new pot.. BTW Joannes working today so it's only me here
drinking it!!!!!!!
Ya know, this is turning into one helluva long post!
Chris Gagnon
Chris
"Death Before Unconsciousness!"
Life without a bread
wrote:
>Well, if you go over a measured distance and take acceleration rates into
>account, a heavier car will be slower (unless possibly on a downhill).
>
>So, if you're drag racing, you definately want as light a car as you can get
>away with. However, if you're running on a dry lake bed and you can take as
>long to get up to terminal velocity as you want, there will be no significant
>difference in the terminal velocity of a heavy car vs. the terminal velocity of
>a light car, provided functionally they're the same car otherwise. Terminal
>velocity is determined by the drag of the car (predominantly air resistance)
>and the horsepower of the car, neither of which have anything to do with the
>mass of the car.
>
>Theoretically, it takes no effort to turn a flywheel at a constant speed (what
>you'd be doing at terminal velocity); mass only matters when you're
>accelerating it.
Hmmm... I don't know what to say... You've explained them very well...
Maybe an A+ would be appropriate... Hehe Seriously thank you very much
for explaining them very well...
Mike F
are children in India who are sleeping right now?"
as we get further off topic.....
Mike F
passengers is still very correct.
See, rc cars are VERY light.
1:1 cars are not.
If you add few grams here & there to a rc car, you will have about the same
top speed, but you will lose the acceleration battle with a similarly
equipped-but-lighter car.
A 1:1 car is different - they are friggin heavy. The tires are soft and usually only
inflated to support a couple occupants.
5 passengers, especially if they are as heavy as my fat ass, would add almost
exactly 1000 lbs (american) !
That works out to be a hell of a lot of rolling resistance. Roughly like your super
nitro carrying around a concrete block.
Forget about the added friction in the bearings - thats nuthin compared to the power
loss you get from the squished tires.
Life without a bread wrote:
> On Sun, 8 Oct 2000 03:23:25 -0700, Tom Younger <tyou...@csc.uvic.ca>
> wrote:
>
> >Well, if you go over a measured distance and take acceleration rates into
> >account, a heavier car will be slower (unless possibly on a downhill).
> >
> >So, if you're drag racing, you definately want as light a car as you can get
> >away with. However, if you're running on a dry lake bed and you can take as
> >long to get up to terminal velocity as you want, there will be no significant
> >difference in the terminal velocity of a heavy car vs. the terminal velocity of
> >a light car, provided functionally they're the same car otherwise. Terminal
> >velocity is determined by the drag of the car (predominantly air resistance)
> >and the horsepower of the car, neither of which have anything to do with the
> >mass of the car.
> >
> >Theoretically, it takes no effort to turn a flywheel at a constant speed (what
> >you'd be doing at terminal velocity); mass only matters when you're
> >accelerating it.
>
> Hmmm... I don't know what to say... You've explained them very well...
> Maybe an A+ would be appropriate... Hehe Seriously thank you very much
> for explaining them very well...
>
> >
> >
Paul D
"Mike F" <van...@home.com> wrote in message
news:39DF114D...@home.com...
> Its been 7 months now that my wife has been pregnant. Any hair that I
might
> have possibly
> been able to keep is now doomed to be gray anyway.
> I had a nice freak flag too, at one point.
> Drink on!
Wait until after she's been
pregnant.................................................
Then the grey and white hairs come with vigour to smite the dark away
quickly.
--
..................Paul D.
If it ain't broke, it don't need fixing, it needs upgrading. ;-D
PS, hope it's a good pregnancy and all's well. Been there twice only,
but it's hell every time. :-P
jericsm
Life without a bread <theb...@nospamallowed.com> wrote in message
news:39ded5b5...@63.211.125.92...
<*snip*>
>
> Did you know that with each cup of coffee, you deny your brain 25% of
> it's vitamin B supply for I think 4 hours or 8 hours? Resulting to
> grey hairs?? And it can complicate gall bladder problems... :))
LOL. hate to think the few grays that i have come from coffee, thought they
came when i picked up a wife. then again, i did start to gulp down coffee
more after getting hitched.... :)
Life without a bread
wrote:
>Thanks.... He's in a much better way now though. Alcohol and diabeties
>pretty much took it's toll on him.
Diabetic hmmm... If u don't mind, what caused his death? I mean
diabetic people tend to develop lots of complications. How old was he?
The reason I ask is that my father is also diabetic, and he's kinda
'hard headed'... And lately we're starting to notice some things...
>I forgot that you had the HPI tuned pipe. I was talking about that
>goofy square looking boxy muffler that the HPI NRS4 comes with.
My kit is Super nitro and it comes with a rounded CAN-like muffler.
the stock muffler of the NRS4 is better looking...
You said something about some trick with these stock mufflers... care
to tell me about it??
>Well they do help some but you dont need a setup board.. Go look at
>RPM gauges.. A toe gauge, Camber gauge, and ride height gauge is what
>I use.. Neither of which was over $20.00 US.... Then get a nice FLAT
>piece of plexiglass and place the car on that so that your sure the
>car is sitting level... (trust me here! I tried doing it on my work
>bench and had things worse then when it came outta the box!).
The only problem with adjustments is that I always hit the gutters and
all... so each time I crash it, I need to readjust... but I will get
those RPM gauges... my LHS reserved an RPM Camber Gauge for me... coz
here in my country, their inventory goes very fast since there's only
3 hobby shops I think...
>But the original post here was about the body.. I slam mine so far
>down, that if the suspension is FULLY compressed, the tires are
>approximatley 1mm from hitting the inside top of the wheel wells! Then
>I also trim the rest of the body so when suspension is compressed that
>I have about 1/8 inch ground clearence. This larger gap is incase
>there are some cracks or divits in the lot where I'm running.....
That low???! How often do you buy new bodyshells?
>and said he was gonna run them over... Took him 15 minutes to realize
>how fast and agile these things are! HAHAHA.. 2 days later he was
>outside with a .22 handgun and took a shot at my wifes 4-tech. Spent
>30 days in the lock-up! pleaded insanity!!!!!
LOL!
>
>Ya know, this is turning into one helluva long post!
Yep... I enjoy exchanging posts with guys around this newsgroup... :))
Tom Markert, N3WTF
without a bread) wrote:
>On 8 Oct 2000 12:13:50 GMT, n3...@magpage.com (Tom Markert, N3WTF)
>wrote:
>
>
>>Thanks.... He's in a much better way now though. Alcohol and diabeties
>>pretty much took it's toll on him.
>
>Diabetic hmmm... If u don't mind, what caused his death? I mean
>diabetic people tend to develop lots of complications. How old was he?
>
>The reason I ask is that my father is also diabetic, and he's kinda
>'hard headed'... And lately we're starting to notice some things...
>
The death cert says Massive coranary (heart exploded) but for the last
couple of weeks he was "here now gone later" He would be watching TV
and mom would bring him diner and he'd ask whats this for, I just ate,
and "does my mom know that your in here". That kinda stuff.. But then
again he had been a painter for close to 30 years so the fumes (and
the pot he still smoked) probably caused most of that.
Is you dad type 1 (needles) or type 2 (pills) ? There are different
complications... E-mail me at n3...@yahoo.com and explain some of your
worries and I'll try to help.. That way we can keep it personal.. I've
read and studied everything that I could find on the subject and also
volunteer at the hospitial with new on-set adult diabetics....
>>I forgot that you had the HPI tuned pipe. I was talking about that
>>goofy square looking boxy muffler that the HPI NRS4 comes with.
>
>My kit is Super nitro and it comes with a rounded CAN-like muffler.
>the stock muffler of the NRS4 is better looking...
>
>You said something about some trick with these stock mufflers... care
>to tell me about it??
I was talking about the square muffler.. I found a small but usefull
trick on it.
>
>>Well they do help some but you dont need a setup board.. Go look at
>>RPM gauges.. A toe gauge, Camber gauge, and ride height gauge is what
>>I use.. Neither of which was over $20.00 US.... Then get a nice FLAT
>>piece of plexiglass and place the car on that so that your sure the
>>car is sitting level... (trust me here! I tried doing it on my work
>>bench and had things worse then when it came outta the box!).
>
>The only problem with adjustments is that I always hit the gutters and
>all... so each time I crash it, I need to readjust... but I will get
>those RPM gauges... my LHS reserved an RPM Camber Gauge for me... coz
>here in my country, their inventory goes very fast since there's only
>3 hobby shops I think...
>
Well I rip mine apart every week anyhow just to fix "race damage" and
when doing this I re check all my settings anyway.. After you find a
set up that you like, then resetting it after a run is only a couple
of seconds.
>>But the original post here was about the body.. I slam mine so far
>>down, that if the suspension is FULLY compressed, the tires are
>>approximatley 1mm from hitting the inside top of the wheel wells! Then
>>I also trim the rest of the body so when suspension is compressed that
>>I have about 1/8 inch ground clearence. This larger gap is incase
>>there are some cracks or divits in the lot where I'm running.....
>
>That low???! How often do you buy new bodyshells?
Ummmm I'm a bit ruff.... I usually jump over the fire hose perimeter
at least once per race (the hose is inflated BTW).. That normaly leads
to some wild flips and crashes that beat the hell out of the body...
Figure I get a month at least out of a body without repairing it.. But
then again I enjoy doing the bodies so I probably give up easy on
them! LOL
AirCoryale
insignificant when trying to achieve maximum terminal velocity. Weight (mass) does
affect an object especially a race vehicle. It dosen't matter whether you're in a
car, plane, bike, swimming or running, LITE is BETTER!
The lighter the car the faster and better it will perform. Comapring two vehicles
with the same engines, gearing, and body shape but differences in weight, the
lighter vehicle will accelerate faster, have a higher top speed, and corner better.
I could give all the physics formulas but it would be simpler for you to test this
yourself by running a simple track.
1) Time your speed to cover a certain straight line distance.
2) Time your speed over a curved distance.
3) Now put on a pair of 5 pound ankle weights and repeat the tests.
In all physics calculation regarding objects in motion weight (mass) must be taken
into consideration. As far as a heavier vehicle accelerating downhill faster being
better than a lighter vehicle, just don't have a curve at the end of the hill. The
heavier car will brake sooner or take out the fence. The lighter cars can carry a
higher speed through the radius of the curve, therefore it's overall performance
going downhill would be better.
Air Coryale
"More is good. Alot is better. Too much is just right!"
Life without a bread wrote:
Tom
> I have to disagree with the statements regarding the mass of an object being
> insignificant when trying to achieve maximum terminal velocity. Weight (mass) does
> affect an object especially a race vehicle. It dosen't matter whether you're in a
> car, plane, bike, swimming or running, LITE is BETTER!
>
Airplanes and boats are very different than cars. With airplanes, part of
the thrust is used to support the weight of the plane, therefore a heavier
plane will be slower than a light plane, all else equal. With boats, the
drag on the hull is greater with the more water it displaces, so the same
holds true with that (heavier is slower). With bicycles, they have an
extremely small power to weight ratio, therefore they are very sensitive
to extremely small changes in friction (rolling resistance from the
tires), so a heavier bicycle will be slightly slower than a light bicycle,
but it is not extremely significant.
With R/C cars, the rolling resistance does not change significantly when
doubling the weight of a car. Therefore, saving a couple grams of weight
off your car will not affect the terminal velocity in a repeatable,
measureable way.
> The lighter the car the faster and better it will perform. Comapring two vehicles
> with the same engines, gearing, and body shape but differences in weight, the
> lighter vehicle will accelerate faster, have a higher top speed, and corner better.
> I could give all the physics formulas but it would be simpler for you to test this
> yourself by running a simple track.
Please give me the physics formulas. This will tell us the theretical
difference, and you will see that the mass has a negligable effect on top
speed in a straight line.
> 1) Time your speed to cover a certain straight line distance.
> 2) Time your speed over a curved distance.
> 3) Now put on a pair of 5 pound ankle weights and repeat the tests.
>
I thought I made it clear from the beginning that I was talking about
straight line terminal velocity.
> In all physics calculation regarding objects in motion weight (mass)
> must be taken into consideration.
This is true. However, sometimes the result is vanishingly small. This
is the point I am still trying to make.
As far as a heavier vehicle
> accelerating downhill faster being better than a lighter vehicle, just
> don't have a curve at the end of the hill. The heavier car will brake
> sooner or take out the fence. The lighter cars can carry a higher
> speed through the radius of the curve, therefore it's overall
> performance going downhill would be better.
>
This still has nothing to do with terminal velocity in a straight line.
>
> Air Coryale "More is good. Alot is better. Too much is just right!"
>
That would be "A lot", not "Alot".
Life without a bread
wrote:
>Is you dad type 1 (needles) or type 2 (pills) ? There are different
>complications... E-mail me at n3...@yahoo.com and explain some of your
>worries and I'll try to help.. That way we can keep it personal.. I've
>read and studied everything that I could find on the subject and also
>volunteer at the hospitial with new on-set adult diabetics....
He's type 2... And thanks... I will email you...
>I was talking about the square muffler.. I found a small but usefull
>trick on it.
In anycase, I'd like to know what that trick is... who knows, it might
work with this mouse-can... :))
>Well I rip mine apart every week anyhow just to fix "race damage" and
>when doing this I re check all my settings anyway.. After you find a
>set up that you like, then resetting it after a run is only a couple
>of seconds.
I do these every now and then... Ok, ok. After every run. And before I
even begin, I tell myself, "Ok, let's make this one swift checkup and
cleaning... try and control yourself and try not to get carried away
and do some heavy 3-hour minimum tinkering.."
I always end up breaking something whenever I clean it. Aww...
>Ummmm I'm a bit ruff.... I usually jump over the fire hose perimeter
>at least once per race (the hose is inflated BTW).. That normaly leads
>to some wild flips and crashes that beat the hell out of the body...
>Figure I get a month at least out of a body without repairing it.. But
>then again I enjoy doing the bodies so I probably give up easy on
>them! LOL
Wild flips... hmm... Just this morning, my car took 3-360degree
roll... it always happens when I am at near top end speed, and then I
brake and steer at the same time...
Hurts my tyres that much... oh well it's cement now asphalt...
Tom Markert, N3WTF
without a bread) wrote:
>On 10 Oct 2000 01:26:41 GMT, n3...@magpage.com (Tom Markert, N3WTF)
>wrote:
>
>>Is you dad type 1 (needles) or type 2 (pills) ? There are different
>>complications... E-mail me at n3...@yahoo.com and explain some of your
>>worries and I'll try to help.. That way we can keep it personal.. I've
>>read and studied everything that I could find on the subject and also
>>volunteer at the hospitial with new on-set adult diabetics....
>
>He's type 2... And thanks... I will email you...
>
>
>>I was talking about the square muffler.. I found a small but usefull
>>trick on it.
>
>In anycase, I'd like to know what that trick is... who knows, it might
>work with this mouse-can... :))
>
>>Well I rip mine apart every week anyhow just to fix "race damage" and
>>when doing this I re check all my settings anyway.. After you find a
>>set up that you like, then resetting it after a run is only a couple
>>of seconds.
>
>I do these every now and then... Ok, ok. After every run. And before I
>even begin, I tell myself, "Ok, let's make this one swift checkup and
>cleaning... try and control yourself and try not to get carried away
>and do some heavy 3-hour minimum tinkering.."
>
>I always end up breaking something whenever I clean it. Aww...
>
>>Ummmm I'm a bit ruff.... I usually jump over the fire hose perimeter
>>at least once per race (the hose is inflated BTW).. That normaly leads
>>to some wild flips and crashes that beat the hell out of the body...
>>Figure I get a month at least out of a body without repairing it.. But
>>then again I enjoy doing the bodies so I probably give up easy on
>>them! LOL
>
>Wild flips... hmm... Just this morning, my car took 3-360degree
>roll... it always happens when I am at near top end speed, and then I
>brake and steer at the same time...
>
>Hurts my tyres that much... oh well it's cement now asphalt...
hehehehe Try launching it about 6 1/2 feet into the air at full
throttle and bouncing it about 5 times off the concrete and have it
then (still airborne) slam into a full size van! This was just one
event!
I also had it ,full throttle again, do cartwheels (nose over tail)
about 12 times and hit a light pole..
This was all because the Hobby Shops parking lot where we were "speed
tuning" was a bit choppy and the body bottomed out and caused a wierd
bounce...
99% of the time a weird bounce at full throttle ='s indy car type
crash!
StuntsKid
AirCoryale <airco...@loudoun.com> wrote in message
news:39E2C69D...@loudoun.com...
> I have to disagree with the statements regarding the mass of an object
being
> insignificant when trying to achieve maximum terminal velocity. Weight
(mass) does
> affect an object especially a race vehicle.
>
> 3) Now put on a pair of 5 pound ankle weights and repeat the tests.
>
Doh! That is a pure schoolboy error!
This affects purely acceleration, as with every footfall, the velocity of
your foot falls to zero. While your body carries on at a constant velocity,
your feet are accelerating and decelerating constantly. A more efficient
way to test this is to attatch the weight to your torso!
As for practical demonstrations I have had numerous runs down the Flying K
in Les Arcs. This is a 60 degree groomed ski piste specially designed for
speed skiing. My heavier friend (about 2 stone or 28lbs more - that would
be 15.4% more) was convinced that he would eclipse my speed due to my
lighter weight. As it was, we were neck and neck with a speed difference of
around 2kph and a final measured speed of 148kph - a mere difference of
1.35%. This is probably due to my superior style and reduced air
resistance!!! :-)
As for real life, lightening your car without affecting strength is great -
go for it!
Drive ON
Phil
Matt V
On Sat, 07 Oct 2000 12:05:31 GMT, Mike F <van...@home.com> wrote:
>(snipped)
>
>Life without a bread wrote:
>
Jonny Hodgson
> Severely limited in HP? Yah, right. Look at the power to weight ratio of
> any R/C car out there, and compare with any full sized car. I'm not going
> to put down any absolute numbers because I don't know any off hand, but
> I'd wager R/C cars have about twice the power to weight ratio many exotic
> cars have.
Last time I looked my electric 4WD buggy had about the same (certainly
the same order of magnitude) as my 1:1 car, or possibly my dad's (rather
newer but comparable class) 1:1 car. Which is odd, 'cos it feels more like
a Group A rally car at about 3 times the PWR...
Jonny