who holds the speed record?
08-10-2004, 09:45 PM
#151
Someone already has in a flame thread that ajg created a month or so ago. Besides, he'll probably give you what the sticker says on the motor.
08-10-2004, 09:45 PM
#152
Originally posted by CraigH
So what kind of RPM does your motor turn?
So what kind of RPM does your motor turn?
08-10-2004, 09:48 PM
#153
Originally posted by rtypec
Besides, he'll probably give you what the sticker says on the motor.
Besides, he'll probably give you what the sticker says on the motor.
08-10-2004, 09:55 PM
#154
Tech Master
Naw...Thats not a # strait from the sticker. Trinity rates their motors at 5v..That'd be my guess for his motor anyway (10t Epic B2 Quad Mag)
Then again...he coulda just used a calculator
I think its possible....but I don't know the varibles (tire chunking, controlability or anything)
Then again...he coulda just used a calculator
I think its possible....but I don't know the varibles (tire chunking, controlability or anything)
08-10-2004, 10:05 PM
#155
alright guys you need to calm down, how bout this, until the video comes out no one can fully prove anything. if the video doesnt come out then that means his car didnt do what he said it can and he's wrong and we drop the subject. if the video does come out and proves everyone wrong then ajg is right and we drop the subject anyway.
08-10-2004, 10:25 PM
#156
Ok I did the math:
gear ratio:58/31=1.87
gear ratio divided by tire circumference
4.316/1.87=2.30 times top rpm 48003=110407
Ok divide by 12 to convert inches into feet
9200 divide this by 5280 (mile)=1.74 times 60 (for minutes) per hour =104.55mph
Now there is alot of varibles like tire friction, aero drag, and it the motor could pull the weight up to the top speed.
So yes a micro could go 70mph in theory.
gear ratio:58/31=1.87
gear ratio divided by tire circumference
4.316/1.87=2.30 times top rpm 48003=110407
Ok divide by 12 to convert inches into feet
9200 divide this by 5280 (mile)=1.74 times 60 (for minutes) per hour =104.55mph
Now there is alot of varibles like tire friction, aero drag, and it the motor could pull the weight up to the top speed.
So yes a micro could go 70mph in theory.
Last edited by CraigH; 08-10-2004 at 11:14 PM.
08-10-2004, 10:29 PM
#157
Trinity uses the fantom dyno, which is 5 volts last I checked, unless they got it upgraded to 7, but its still only 7 flat, not 7.2
Later EddieO
Later EddieO
08-10-2004, 10:52 PM
#159
The only thing that I cant see is that a short wheel base moving at 104mph is covering 152 feet per second. It must have one hell of a body to keep it stable.
08-10-2004, 11:16 PM
#161
If Cliff Lett would have used a straight mile run and then radar his car it would have been over 120ish or so. But they were going after a closed course record I believe.
08-11-2004, 12:37 AM
#162
ajg - weight has an effect on acceleration, not top speed.
Transmission efficiency does affect top speed because of the drag it puts on the motor to wheel transfer.
Tire size has a LOT to do with top speed - that was what all those calculations were trying to show.
Just a few notes about pan cars - as long as you keep the front wheels on the ground (as in - don't HIT anything) the faster you go, the more downforce will be produced, thus the HARDER it is to make it fly. This is unless you hit something that will LIFT the front end - barring that, you won't get a pan car to lift.
Good proof - look at the speed run of over 110 mph done at Irwindale Speedway with an L3 (modified) - it didn't lift off. It DID touch the barrier and disintegrate. . .but it didn't lift.
btw - the fastest cars won't be 1/10th scale, they'll be 1/8th scale nitro. I need to find it, but I've seen several clocked by police radar at well over 100mph, geared for track and acceleration, not top speed. Gear them for speed. . .and with the GTP style bodies for downforce. . .makes the brushless micros (which would be cool, don't get me wrong) or the 1/10th pan car (which is my favorite) completely irrelevant. . .
Transmission efficiency does affect top speed because of the drag it puts on the motor to wheel transfer.
Tire size has a LOT to do with top speed - that was what all those calculations were trying to show.
Just a few notes about pan cars - as long as you keep the front wheels on the ground (as in - don't HIT anything) the faster you go, the more downforce will be produced, thus the HARDER it is to make it fly. This is unless you hit something that will LIFT the front end - barring that, you won't get a pan car to lift.
Good proof - look at the speed run of over 110 mph done at Irwindale Speedway with an L3 (modified) - it didn't lift off. It DID touch the barrier and disintegrate. . .but it didn't lift.
btw - the fastest cars won't be 1/10th scale, they'll be 1/8th scale nitro. I need to find it, but I've seen several clocked by police radar at well over 100mph, geared for track and acceleration, not top speed. Gear them for speed. . .and with the GTP style bodies for downforce. . .makes the brushless micros (which would be cool, don't get me wrong) or the 1/10th pan car (which is my favorite) completely irrelevant. . .
08-11-2004, 01:01 AM
#163
ajg: what boomer said is exactly true. The laws of physics work.
At top speed, the mass of the car is not the limiting factor. Rather, wind and transmission resistance are keeping the car from accelerating further. An f-1 car would probably reach the same top speed with a full tank versus an empty tank, but will take a longer time to accelerate. In fact, it could be the case that an f-1 car has a higher top speed with a full tank, if the straight-line aerodynamics are somehow improved with full fuel.
That being said, even if your speed meter is theoretically "correct", where the rollout is calculated perfectly, the error is probably very significant at top speed. Even on a smooth surface, your tires will occasionally leave the ground, or be spinning at a rate which exceeds the true velocity of the car. This effect is magnified with very small wheel diameters, since essentially the tires are constantly slipping under maximum load. This can be seen even in full-size cars, where the speedometer is a lot more accurate than the speed gauge that is currently in your mini. When a stock porsche 911 turbo's speedometer reads 60 mph, it's moving close to 60 mph. But, when the speedometer reads 180 mph, the car is really moving several mph slower. That's why the velocity of the car needs to be verified by an outside speed gun.
Regardless, can't we stop turning these threads into complete flame joints? Give the kid a chance, since we really can't prove or disprove all the claims. If he can get the car rollin, then awesome! I'm sure there will be a lot of impressed people. But, if it doesn't happen, then the threads will die and he'll quiet down. Bottom line, I optimistic about the planned attempt, but I can't really buy the current claims without validation.
At top speed, the mass of the car is not the limiting factor. Rather, wind and transmission resistance are keeping the car from accelerating further. An f-1 car would probably reach the same top speed with a full tank versus an empty tank, but will take a longer time to accelerate. In fact, it could be the case that an f-1 car has a higher top speed with a full tank, if the straight-line aerodynamics are somehow improved with full fuel.
That being said, even if your speed meter is theoretically "correct", where the rollout is calculated perfectly, the error is probably very significant at top speed. Even on a smooth surface, your tires will occasionally leave the ground, or be spinning at a rate which exceeds the true velocity of the car. This effect is magnified with very small wheel diameters, since essentially the tires are constantly slipping under maximum load. This can be seen even in full-size cars, where the speedometer is a lot more accurate than the speed gauge that is currently in your mini. When a stock porsche 911 turbo's speedometer reads 60 mph, it's moving close to 60 mph. But, when the speedometer reads 180 mph, the car is really moving several mph slower. That's why the velocity of the car needs to be verified by an outside speed gun.
Regardless, can't we stop turning these threads into complete flame joints? Give the kid a chance, since we really can't prove or disprove all the claims. If he can get the car rollin, then awesome! I'm sure there will be a lot of impressed people. But, if it doesn't happen, then the threads will die and he'll quiet down. Bottom line, I optimistic about the planned attempt, but I can't really buy the current claims without validation.
08-11-2004, 01:05 AM
#164
The only problem with a gas car for speed is the rpm limit vs gear ratio vs hp. The gas can be geared for 200mph but if there isnt enough horsepower to pull it then its no good.
* Comparsion- My roommates car weighs 2700pounds and has 190hp with a 3.54 rear axle ratio. The tranny is .50. My car weighs 3300 pounds with 195hp and a 3.73 axle ratio. The tranny top gear is .74. His car tops out at 125-130. Mine has hit 150-153. The difference is his is a four cylinder and mines a V8. Does this help any?
* Comparsion- My roommates car weighs 2700pounds and has 190hp with a 3.54 rear axle ratio. The tranny is .50. My car weighs 3300 pounds with 195hp and a 3.73 axle ratio. The tranny top gear is .74. His car tops out at 125-130. Mine has hit 150-153. The difference is his is a four cylinder and mines a V8. Does this help any?
