Arrma Kraton 6s speed run 94.5mph (stock electronics)

[LibertyMKiii]

Finally got a clean 6s speed run
Stock Arrma BLX 185 system(esc and motor)
94.5mph!!! very satisfied with the results!

 

[Peeeenuuutt]

Telling you man, that blx 185 ain’t too bad of an esc. Throw some caps on her if you havent already, that Kraton will break 100.

 

[LibertyMKiii]

Telling you man, that blx 185 ain’t too bad of an esc. Throw some caps on her if you havent already, that Kraton will break 100.

I want to give it another shot as is. My goal is to break 100 on stock electronics. (no additions like cap packs)
It may have a few more mph in it. I think pulling the TBR wheelie bar off might help a little also.

 

[Lazy Bushman]

Looking forward to seeing how this goes

 

[LibertyMKiii]

Pulled the wing and wheelie bar to see what improvements to air drag might net in speed. Sadly only about 2 mph according to the GPS although it appeared faster. I would recommend keeping the wing to anyone running the Kraton body at high speeds. Under braking it began fish tailing pretty badly.

96.1 mph is the new PB with this Kraton and probably where I will stop with it. Saving all my good electronics for the Arrma Limitless build.

 

[Brett33]

Have you tried going one size up on the tires. I know you don't want to go too big the bigger the tire the more roll out you have until weight and aerodynamics are a factor.

 

[Greywolf74]

Have you tried going one size up on the tires. I know you don't want to go too big the bigger the tire the more roll out you have until weight and aerodynamics are a factor.

I was going to mention that about wheels size and rollout but then I saw this thread is 2 years old.

 

[LibertyMKiii]

Have you tried going one size up on the tires. I know you don't want to go too big the bigger the tire the more roll out you have until weight and aerodynamics are a factor.

I was going to mention that about wheels size and rollout but then I saw this thread is 2 years old.

The problem is that we only have 3 options for tires on RC cars that can handle high speeds.
1. GRP Belted 1/8
2. Arrma Hoons 1/8 size
3. GRP Belted 1/5 (requires different wheel hex) and has significantly more rotating mass, tire width (reduced aero), and potential for the tire to come un-glued from the rim.
4. Foams - (BSR, Contact, Gone Bananas, SP Racing, and others) These are the best option for high speeds over 140mph, but have 50% or less of the grip provided by the GRP tires. Foams require significant downforce to be usable on high power 8s cars.

Any RC car running under 140mph should be on GRP 1/8 tires in my humble opinion.

 

[Greywolf74]

Are Ipanema tires not a thing anymore? A decade ago when I was running a 100+MPH Rustler Ipanemas were my go to and GRPs my second.

 

[pl9171]

Pretty impressive.
I like the suspension amrs/tires set up.
Thanks for sharing

 

[LibertyMKiii]

Are Ipanema tires not a thing anymore? A decade ago when I was running a 100+MPH Rustler Ipanemas were my go to and GRPs my second.

I don't believe so.
Got into the hobby about 3 years ago and have not heard of those tires.

 

[Papabear_1972]

I know that this has already been mentioned (kind of . . . ), but those tires are not the stock tires that come with the kit? If they are not what other changes did you make to the car that are not stock?

 

[Greywolf74]

The problem is that we only have 3 options for tires on RC cars that can handle high speeds.
1. GRP Belted 1/8
2. Arrma Hoons 1/8 size
3. GRP Belted 1/5 (requires different wheel hex) and has significantly more rotating mass, tire width (reduced aero), and potential for the tire to come un-glued from the rim.
4. Foams - (BSR, Contact, Gone Bananas, SP Racing, and others) These are the best option for high speeds over 140mph, but have 50% or less of the grip provided by the GRP tires. Foams require significant downforce to be usable on high power 8s cars.

Any RC car running under 140mph should be on GRP 1/8 tires in my humble opinion.

I would try the 1/5 scale grps if it were me and you can find a hex conversion. More rotating mass just means the motors gonna pull a few more amps and get a little hotter. As for them coming apart I wouldnt think (unless they have some known issue) that they would be any more likely to come apart than the 1/8 scale GRPs.

 

[LibertyMKiii]

I know that this has already been mentioned (kind of . . . ), but those tires are not the stock tires that come with the kit? If they are not what other changes did you make to the car that are not stock?

Correct those are GRP 1/8 scale tires. I like to run the S1 compound for the highest level of traction.
I used the Limitless spool assembly with a 34t spur gear and a 37t pinion.
It also has nero BLX springs to stiffen up the suspension significantly. I used longer screws for the droop screws to get it low and swapped the battery connector to IC8 which has 8mm bullets inside of it.

Other than that everything is original.

I would try the 1/5 scale grps if it were me and you can find a hex conversion. More rotating mass just means the motors gonna pull a few more amps and get a little hotter. As for them coming apart I wouldnt think (unless they have some known issue) that they would be any more likely to come apart than the 1/8 scale GRPs.

If you were using an aftermarket ESC a few more amps would be ok. The BLX185 esc always stops at 94-98 mph due to amperage limiting.
I have zero doubt that GRP 1/5 tires will net a slower speed. You can make up for tire/wheel diameter with gearing.

 

[Greywolf74]

If you were using an aftermarket ESC a few more amps would be ok. The BLX185 esc always stops at 94-98 mph due to amperage limiting.
I have zero doubt that GRP 1/5 tires will net a slower speed. You can make up for tire/wheel diameter with gearing.

I was unaware you were hitting a current ceiling already. So if you're unable to push it any harder how to you propose to break 100MPH? Using a bigger pinion or smaller spur is also going to increase amp draw too.

 

[LibertyMKiii]

I was unaware you were hitting a current ceiling already. So if you're unable to push it any harder how to you propose to break 100MPH? Using a bigger pinion or smaller spur is also going to increase amp draw too.

With that RC the only ways would not leave it looking like a stock Kraton any more...

3 options:

1. Upgrade the ESC to a Castle
2. Improve aerodynamics
3. Remove weight (likely not enough benefit possible here)

 

[tntpoof]

whats going to be the most visible?. Id say #2.. esc not really.weight ok let me weigh that puppy..

 

[LibertyMKiii]

whats going to be the most visible?. Id say #2.. esc not really.weight ok let me weigh that puppy..

#1 thing you can improve when dealing with speed is using a Castle ESC with good batteries. You will have to tune the car's setup of course with stiff suspension and rake (rear higher than the front)

With a castle ESC James McCoy took the Kraton to 142+ speeds

It was an aftermarket body but not a very aerodynamic one...

People are pushing the Infraction and other truck bodies into the 120-150mph range all the time, which they are shaped like a brick. James McCoy has taken the Delta Plastiks thunder truck body to 168 mph.

Kenny has taken a Slash 4x4 with GT body to 146 mph with the Arrma 6s line BLX 2050kv motor.

It goes to show you don't have to go out and buy a giant motor and tons of carbon fiber parts. Factory Arrma motors that sell for around $40-60 on eBay work pretty darn good. You do need a very well setup diffs and suspension, strong/capable ESC, good batteries and connectors. For ESCs the XLX2 being the best and MMX8s being second best.

 

[Quip]

Very cool