Traxxas Slash spec class racing at Ryde in 2009 and beyond
#2281

A well timed 13.5 can smoke a 10.5. Well by smoke I mean have it nailed for top end and also have this surge of bottom end grunt. Its not as simple as putting boost up to max and timing to 55 deg, its also about setting start and finish points. having the right pinion and spur for the motor and also being careful with the left finger on the radio.
Besides it all counts for zip if you can't get it down to the ground....
Either way its healthy competition!
Besides it all counts for zip if you can't get it down to the ground....

Either way its healthy competition!

Last edited by reconrc; 05-25-2011 at 06:28 PM.
#2282

A well timed 13.5 can smoke a 10.5. Well by smoke I mean have it nailed for top end and also have this surge of bottom end grunt. Its not as simple as putting boost up to max and timing to 55 deg, its also about setting start and finish points. having the right pinion and spur for the motor and also being careful with the left finger on the radio.
Besides it all counts for zip if you can't get it down to the ground....
Either way its healthy competition!
Besides it all counts for zip if you can't get it down to the ground....

Either way its healthy competition!
Having just done the 6hr Enduro, and talking to Seano & Shane. I can say with confidence that a properly boosted 13.5 can be setup to run just as fast, perhaps a little faster than a 10.5 non boosted, but with much greater efficency. If we go by runtime, then approx 25% more efficient.
If I setup for the same temps, then the 13.5 will be faster down the straight. Whether or not it will be faster around the track will depend on the driver.
Of course driving style will play a big role in runtimes and temps, but the difference between Seano and Shane's runtime was less 2 mins.
For those that are interested, our 13.5 boosted came off at approx 35*C after 6hr of racing, stopping only for battery changes (~30s-40s ea)
I didn't measure, but I was told the 10.5s were hot to touch. I think Peli mentioned 60ish?? But first place were saying theirs was almost too hot to touch. ~75ish??
Having said this... biggest difference between 13.5 and 10.5 will be setup.
#2283
Tech Apprentice
iTrader: (15)


Good chance one of those was mine - I was running a 10.5 last Sunday (Yellow shell) and racing a guy named Tony with a boosted 13.5 (Blue). He was running an almost dead NiMH and was keeping pace with me on the straight - but then beating me around the rest of the track but I think this was mostly better driving on his part.
#2285
Tech Apprentice
iTrader: (15)

+1... sort of...
Having just done the 6hr Enduro, and talking to Seano & Shane. I can say with confidence that a properly boosted 13.5 can be setup to run just as fast, perhaps a little faster than a 10.5 non boosted, but with much greater efficency. If we go by runtime, then approx 25% more efficient.
If I setup for the same temps, then the 13.5 will be faster down the straight. Whether or not it will be faster around the track will depend on the driver.
Of course driving style will play a big role in runtimes and temps, but the difference between Seano and Shane's runtime was less 2 mins.
For those that are interested, our 13.5 boosted came off at approx 35*C after 6hr of racing, stopping only for battery changes (~30s-40s ea)
I didn't measure, but I was told the 10.5s were hot to touch. I think Peli mentioned 60ish?? But first place were saying theirs was almost too hot to touch. ~75ish??
Having said this... biggest difference between 13.5 and 10.5 will be setup.
Having just done the 6hr Enduro, and talking to Seano & Shane. I can say with confidence that a properly boosted 13.5 can be setup to run just as fast, perhaps a little faster than a 10.5 non boosted, but with much greater efficency. If we go by runtime, then approx 25% more efficient.
If I setup for the same temps, then the 13.5 will be faster down the straight. Whether or not it will be faster around the track will depend on the driver.
Of course driving style will play a big role in runtimes and temps, but the difference between Seano and Shane's runtime was less 2 mins.
For those that are interested, our 13.5 boosted came off at approx 35*C after 6hr of racing, stopping only for battery changes (~30s-40s ea)
I didn't measure, but I was told the 10.5s were hot to touch. I think Peli mentioned 60ish?? But first place were saying theirs was almost too hot to touch. ~75ish??
Having said this... biggest difference between 13.5 and 10.5 will be setup.
Also, again taking driver skill out of the equation, if a boosted 13.5 is faster down the straight, being a higher turn motor with a fraction more torque, shouldn't it also be quicker in the twistey parts of the track?
I think these new rules of 10.5 or boosted 13.5 are a great idea and do a good job of giving people the option of going for higher initial cost and more setup time (boosted ESC) vs a low cost ESC, easier to set up 10.5.. I guess its created a situation where its technology vs braun.
#2286

Hmm thats interesting about the temps John. I always thought boosting would (generally) produce more motor heat ? Could this be a case of the boosted motor being more efficient therefore needing less juice to do the same amount of work and so producing less heat as the 10.5?
Also, again taking driver skill out of the equation, if a boosted 13.5 is faster down the straight, being a higher turn motor with a fraction more torque, shouldn't it also be quicker in the twistey parts of the track?
I think these new rules of 10.5 or boosted 13.5 are a great idea and do a good job of giving people the option of going for higher initial cost and more setup time (boosted ESC) vs a low cost ESC, easier to set up 10.5.. I guess its created a situation where its technology vs braun.
Also, again taking driver skill out of the equation, if a boosted 13.5 is faster down the straight, being a higher turn motor with a fraction more torque, shouldn't it also be quicker in the twistey parts of the track?
I think these new rules of 10.5 or boosted 13.5 are a great idea and do a good job of giving people the option of going for higher initial cost and more setup time (boosted ESC) vs a low cost ESC, easier to set up 10.5.. I guess its created a situation where its technology vs braun.
Torque is a function of gearing, so both setups can be geared for bottom end.
Removing boost as an option for a moment. If both setups were geared to run in their optimum powerband (FDR) then the 10.5 will have more punch and be faster because with few turns the motor will be able to draw more current. It will also be faster down the straight because the lower turn allows for a higher kv (all things being equal).
But note that the power difference between a 10.5 vs 13.5 is about 27% (Based on LRP X12), In 1/10 motors, this 27% can easily be made up by adding timing whether it be static or dynamic.
Adding static timing is a little like changing gear ratios. If you make changes to get top end, then you lose some on the bottome end.
Adding Dynamic timing is like being able to change gears in 1:1 cars. Just as you change gears in your family truckster to keep the engine running in it's optimal power band, with dynamic timing you can add X degrees of timing to keep the motor in it's optimal power band. Which gives you more RPM but within the torque limits of the motor.
So in a 10.5, you have more torque and power, but fixed gearing. If you gear for max top speed, you will loose bottom end and the motor with burn out. So you need to balance this.
In a 13.5, careful application of dynamic timing will mean you get the bottom end punch you need to match the 10.5 which is gear taller for more top speed. By the time at 13.5 reaches near it's upper rpm limit, the timing would've ramped up tomore than 50. With that much timing, the 13.5 will have more usable RPM than the 10.5, but still be running within spec.
The long and the short is, with dynamic timing, you can setup a 13.5 to run at max efficiency most of the time and get the max amount of power. Without it, the motor is rarely running within it's optimum spec. The by product is heat.
Just because a motor comes off at 60*C after 5mins and is not burnt out, doesn't mean it's running efficiently. Most of that heat started off a amps in your lipo.
#2287
Tech Apprentice
iTrader: (15)

Thanks for the info John, some good food for thought there.
So I was having a practice with my TC5 at an onroad track today and seeing as there was no one around decided to have a sneaky go of my SC10 on the track. Went through a set of stock rears but had an absolute blast and got some awesome power slide technique sorted. I'm certain my skills have benefited from this experience.
With the cross polenation on on road and offroad in Sydney, does anyone else do this?
So I was having a practice with my TC5 at an onroad track today and seeing as there was no one around decided to have a sneaky go of my SC10 on the track. Went through a set of stock rears but had an absolute blast and got some awesome power slide technique sorted. I'm certain my skills have benefited from this experience.
With the cross polenation on on road and offroad in Sydney, does anyone else do this?
#2288

I have a venom 2.4ghz transmitter and receiver you can have for $30....I mean you said am, but unless it has to be 2.4 would be a better choice Imho....Pm me if interested.
#2290

As for working out setups, it will all be fairly new until there heaps burning around. Take it down and just see how it goes. Grab some fresh proline or j concepts tires, kit setup and then it should be ok methinks.
#2291

Hi all,
Just wondering if people still run SCT at Ryde,
I've been offered a good deal on one
cheers
Just wondering if people still run SCT at Ryde,
I've been offered a good deal on one
cheers
#2292

.
Last edited by old_skoolie; 02-20-2013 at 05:17 AM. Reason: HA HA double post, HONEST!!!!
#2293

Looks like Pro-2 SCT is still a regular class.