Official Speed Runs

[ajlovering12345]

Hi

When do you think we should officially recognise a speed run? I know Nic has done faster runs and I wont be happy until I have done over 100 but when do we recognise the runs we do as an official time??

If we wait for the once a year comp I think thats too long a gap but we cant recognise every run we do unless we can back it up somehow. We could have an official record at the comp and post unofficail ones. Only the ones done at the comp count as official.

I was thinking of getting a few guys interested and running a speed test say every couple of months and post the times on the net.

Any suggestions?

Cheers

[Mod Man]

Hmm, interesting. That is a good idea. I know, for me, I am in this for the fun of it, not so much to compete. But, knowing a run is really as fast as people say, is important. I like video taping each run with the radar gun showing the top speed. A GPS reading may be the hardest to fake if a run is merely posted on-line without "Official" recognition.

I know how fast my car has gone and how much accelleration was still occurring at the point the speed reading was taken. That is enough for me (for the most part). :)

Matt

[Hard Case]

AJ

In my own mind, my team & I -- have already broken last years record during testing.
http://www.flickr.com/photos/9608643@N03/864065605/
http://www.flickr.com/photos/9608643@N03/864065593/

What everyone else will accept---I'm not sure, but witnesses video & a reliable measuring method, would be a step in the right direction.


However
With the "planned" event in the UK & a possible East coast speed-run. It's way more fun to get together with a bunch of great people & have fun doing it at the same time. :)


Records were made to be broken.........
Nic

[ajlovering12345]

So 141 is the "unofficial" record to break then.

I have an idea I'm mulling over. There are a few guys around here that are interested in doing speed runs and we can use the drag strip end to run as long as they are not holding an event. I will start a club and run every a small club event every 2 month. As long as I have 2 different methods of measuring the speed of the car I'll post results on a web site somewhere, possibly our own

Any practice runs can be posted as unofficial but we will only recognise the speeds measured at the club events and also the world events once a year.

[fuzzymuff]

So 141 is the "unofficial" record to break then.

I have an idea I'm mulling over. There are a few guys around here that are interested in doing speed runs and we can use the drag strip end to run as long as they are not holding an event. I will start a club and run every a small club event every 2 month. As long as I have 2 different methods of measuring the speed of the car I'll post results on a web site somewhere, possibly our own

Any practice runs can be posted as unofficial but we will only recognise the speeds measured at the club events and also the world events once a year.

Hi Tony.
Where would you be holding the speed runs in England as I would be very interested in having a go at this..congrats. on your 88mph run.
Graham

[ajlovering12345]

It will be at the Long Marston Drag Strip near Stratford Upon Avon. What was you thinking of running? Have you got a car ready now? I will be at the strip this weekend testing the car if you want to come along.

Rossendale is about 2 hrs drive from Stratford

[fuzzymuff]

Hi.
This weekend is out.Work .
I would like to build a nitro car.1/8 scale
I was the person at the 2005 euros in Halifax with the collection of vintage model cars.
Will you be forming an association for the British side in the speed runs.
Graham

[ajlovering12345]

Hi.
This weekend is out.Work .
I would like to build a nitro car.1/8 scale
I was the person at the 2005 euros in Halifax with the collection of vintage model cars.
Will you be forming an association for the British side in the speed runs.
Graham

Yes defiantly! I have had a lot of interest and the best way to handle this is to form a club where we can run every 2 months or so. We should be able to organise a world champs in association with the guys in the USA. Although we are a small number we all feel the more doing this the better!

1/8th would be great! With one engine and very high gearing they have a lot of potential. I just ordered a Murnan Modified OS 18 TZP for the Kyosho 1/10th car. It slots straight in and this will be my scale car. It will be 4wd geared for 120 mph :D:D

[TPhalen]

From our Guiness run of 111mph, I know, without a shadow of a doubt, that they will NOT accept any runs in which the radar gun is moved (a little thing called cosign error)...ie, follow the car as it passed by the gun. It must be videotaped from behind the gun (which can be hand-held as long as it doesn't move), and show the vehicle pass by the gun in the video.

If you can get that, you're golden!

[HarryCallahan]

Hmmm

200 mph is possible but I would suggest not with your first speed car. I have found there is a long and steep learning curve before you can hit really fast speeds and you need to aim for lower speeds so you learn a few things to more onto the next level. If you aim for the top speeds straight off you will never get there as there is too much to take in and your car will keep failing and this will put you off.
My suggestion is design a car, if its electric, that will do 120 mph. This can be achieved pretty easily and then take the lessons learned into the next design.
For an electric car traction and handeling are the biggest problems but not the only ones. It takes a while to be able to trust sending the car away to 400m so you can barely see it so you think that a shorter run up will do.
For a 2kg car to accelerate from 0-100 mph takes a minimium of 600 ft. The car accelerates at 0.6G and the wheels are on the limit of adheasion at every point on the run.
Now if you take 150 mph. The min run required is 1210ft and your pulling 0.6G for 11 seconds. You need to feed the power in and keep the wheels from spinning for the complete run. The calcs show that the traction force available is 11.56N and the force needed to accelerate is 11.2N so you see the problem. Not unless you had perfect control for 11 seconds will you get to 150 mph.
To get above 150 mph here are the problems. (200 mph)
Run up with no downforce = 2200ft. This is too far so you need the car to have downforce to improve traction. This will increase the drag coeficient and you need more HP. You then need to ensure you accelerate at 0.6G and increase acceleration when the downforce comes into effect and the faster you go the faster you need to accellerate, up to 1.5G. This control can only be achived with electronic traction control. You also need around 7-10Hp available at the wheels
The conclusion is that to get to 100 mph is pretty easy. To get to 125 is also pretty easy but takes a few failed attempts. To get 150 Mph is really hard and will be the perfect run. To get to 200 mph you need a very special car with electronic traction control, Electronic stability control and 10 hp available.
http://www.racing-cars.com/forum/smileys/smiley2.gif

[porra]

How accurate are the GPS systems out in the market? I heard they are really accurate and if so, wouldn't a GPS reading be better then radar and/or speed traps?

[Mod Man]

GPS requires 3 seconds at a given speed to record accurately. I have only seen full throttle for 1.5 seconds max and that was still accellerating. The car would need to see 3 seconds at full speed to get a decent reading.

It is a bummer. I bought the GPS for my Eagle tree and still have not used it because I found out it wasn't going to work right. :(

Matt

[wqqdster]

Just as with full scale cars, I believe that the only records that should be recognized are those set at a sanctioned meet. Sanctioned by whom? I dunno. What's the criteria for timing? Dunno that either. However, that won't stop anyone from claiming they hold a record. Individual accomplishments are just that and may show the potential for a record breaking run.

Gary O

[Hard Case]

Gary
I respect your beliefs.
It's just unfortunate that speed events do not happen more often. In full size speed runs, @ El Mirage ,CA. run about 6 times a year---at Bonneville I think they twice a year. Yet the fastest car ever ( Thrust SSC ) set THE record in the Black Rock Desert. It was not a "sanctioned" event. The special conditions it takes to do such a feat, warrants such a venue.
Even Cliff Lett's , Guinness World Record run, was not sanctioned.
http://www.flickr.com/photos/9608643@N03/1573101144/


Hopefully, in future, more sanctioned speed events will happen more often,
with better & better conditions --- to show how fast an R/C car can go.

Records were made to broken....
Nic Case

[Mod Man]

Hey Nic!

I agree. Records should be at a sanctioned event. However, there should be more sanctioned events throughout the country and the world. That way everyone can have a shot at setting a record at a sanctioned event.

Matt

[wqqdster]

Nick & Matt,

Y'all are the Big Dogs here.....you know way more about the ins and outs of the subject. I just found out about this stuff three weeks ago but am collecting parts for my own car. This thing has possessed me and I will be at the SoCal meet next July(?).

I agree that there should be more meets and drag strips are probably the best place for them....smooth, straight, level and long. Is there some reason why the drag strip timing speed trap isn't being utilized? If its an NHRA or IHRA track those clocks are dead on. I live 45 minutes from Sears Point (it'll NEVER be Inferion!) and plan on doing my serious testing there.

Gary O

[ajlovering12345]

Hi

Drag strips are good for comps but your better off going to the airstrip to practice as the surface is better. I find drag strips very slippery.

Glad to see another convert to the speed scene. Its a lot more fun than people think

Cheers

[catchin air]

sorry guys stupid question
how do yuo keep radio contact?
i am working on a speed car and looking for 100 and i will be happy but i am afraid i will loose contact and that would not be good
looking to do on a closed road and have a cop friend use a radar on it for speed

[Mod Man]

Radio range is a big discussion. I run a DX3 with 9db gain antenna for 1400 to 1500 foot range (cannot even see it and am still in range).

I have not done much with my car for about 3 months now (lots of family stuff happening). Also, I am in the process of upgrading my Taig CNC mill with a 4th axis rotary table. That is taking up alot of my time. :)

Nic, I gotta call you and catch up. Its been a long time.

Matt

[ajlovering12345]

sorry guys stupid question
how do yuo keep radio contact?
i am working on a speed car and looking for 100 and i will be happy but i am afraid i will loose contact and that would not be good
looking to do on a closed road and have a cop friend use a radar on it for speed

I use the spektrum system modified with an external 9dB antenna located on a 15ft pole and an in line 1 watt amplifier. I tested the system on 2 hills and we still had signal aver 3 miles. Like Modman say 1500ft is ample and you can get that from 40 mhz systems

[catchin air]

do you just run a wire from the controller ant to the pole ant for that kind of range

[ajlovering12345]

No. Connect this bit to the motherboard on the spektrum

http://cgi.ebay.com/Pigtail-cable-RP-SMA-H-FL-WIRELESS-WiFi-mini-PCI-CARD_W0QQitemZ290096282140QQihZ019QQcategoryZ45000 QQtcZphotoQQcmdZViewItem

Then this bit to the cable

http://www.solwise.co.uk/wireless-export-outdoor-1w-booster.htm

Then this bit on the end

http://www.solwise.co.uk/wireless-indoorantenna-omni-9osc.htm

Check the connections as you might need a Female-Female connector. Here

http://www.solwise.co.uk/wireless_adaptersundries.htm

[catchin air]

thanks for the info

maybe i can talk the drag strip into runnig my car to see where i need to go from here

i will cut my rs4 apart to use the parts and two speed

would like a two speed setup for a electric car any ideas

[B4Maz]

I would have to say a sanctioned speed run would be the official run. Any individual could go out and do a speed run, but would speed measuring equipment be calibrated properly? Also, Billy bob would have different equipment than Joe bob and would have different results from each other. At least if it was sanctioned, the timing equipment would be the same.

Also, even if there were errors in the timing equipment during an event, everyones run would have the same error. The speeds would be relative to each other in the event. The difficulty will be if there are multiple events around the world and making sure the equipment is calibrated as accurately as possible.

-Nick Maslowski
www.fastrc.blogspot.com (http://www.fastrc.blogspot.com)

[ajlovering12345]

thanks for the info

maybe i can talk the drag strip into runnig my car to see where i need to go from here

i will cut my rs4 apart to use the parts and two speed

would like a two speed setup for a electric car any ideas

No need for a 2 speed in an electric car. IC engines need them as there is no power at the bottom end but with electric motors there is power all the way to top revs. Torque is a function of the batteries to supply amps so all you need is a motor with a low internal resistance and your OK. Just gear it up for the best top speed and you will save weight by not using a 2 speed

[ajlovering12345]

I would have to say a sanctioned speed run would be the official run. Any individual could go out and do a speed run, but would speed measuring equipment be calibrated properly? Also, Billy bob would have different equipment than Joe bob and would have different results from each other. At least if it was sanctioned, the timing equipment would be the same.

Also, even if there were errors in the timing equipment during an event, everyones run would have the same error. The speeds would be relative to each other in the event. The difficulty will be if there are multiple events around the world and making sure the equipment is calibrated as accurately as possible.

-Nick Maslowski
www.fastrc.blogspot.com (http://www.fastrc.blogspot.com)

Even if you have a one off event the timing gear can have errors to the last event so you will still get errors. We have agreed in principle at least that the speed records can only be accepted if they are achieved in open competition and there is at least 2 reliable and working methods of measureing the speed.

We could come up with a host of other criteria but for now thats it. At our last event there was a decent wind following the cars and we found it made a difference of around 4mph as the speed with the wind was 8mph faster than against it. This means in reality we should run in both directions and take the average but practically we dont have the track length to do that

[catchin air]

thanks

[porra]

Is there a device that can accuratly measure speed? For a event like this I think a trasnponder like device should be made and whoever is having the event should mount on competitors cars.

[ajlovering12345]

Thats exactly what we used. The AMB system with a split timing loop and a set of hand out transponders or PTs if you have one. The loop was 30m apart and the time take to trip the 2 loops taken.

There was a feature in the software called Speed Trap and the software recorded the speed and logged it against all the entered drivers. We could split the drivers into classes and run heats for each class. It then printed out the speeds against the names.

We checked this speed against the radar gun. The radar gun would read 3% less than the loops due to Cosine error

For the next event we will either use a beam trip or cut a groove in the surface and lay the cable in ground and leave them there.

[wqqdster]

What sort of timing increment do you get with a transponder? Our local timer just goes to a tenth of a second. Is that a function of the timing device? It seems that at those speed a hundredth of a second could be a big difference in time. I'll have to do the math and figure it out.

[ajlovering12345]

Not sure but the guy who rigged it up said he got 1/10th of Mph and now he can get 1/100 of mph. I know the lap times we get at club races are down to 1/1000 but for a 30m gap at 103 mph thats 0.2mph for every 1/1000 of a second and 0.35mph at 150 mph.

This is the reason we said to break a record you need to be at least one full mph above the record or it doesnt count.

[porra]

Sounds very good. I will try to make the next event.