On The Fence

[Tninl]

Like a few others threads i have seen recently i just picked up a limitless roller, i couldn't pass it up with the sale going on. Hopefully you guys aren't getting too tired of these threads just yet.

My goals with this build is speed running. I am new to speed running but not RC's in general. I have ran RC's off and on for the last 20 years, however they were mostly off road bashers. So i plan to work my way up gradually but at the same time I like the thought of having a lot of headroom.

I was planning on completing a build soon so i had already started doing some research but i am on the fence between the XLX2 with a 1717 - 1650 KV and the XLX2 with the 2028 - 1100KV. My original plans had me going with the 1717 but when i was pricing everything out i noticed the difference in price is only about $20. This has me second guessing my initial thoughts.

I have done a bit of research regarding the 2028 and realize some aftermarket parts are needed to complete it. Also with the motor orientation being changed and the batteries moved as well it will be a bit more difficult to dial in the suspension/ balance of the car.

My concerns are the drivability between the two. On some of the videos i have watched running the 2028 set up it appears to be more difficult to keep down. For example when Raz was testing it he said if he he ramped the throttle up too fast even over 100 it would power wheelie. Given i will be new to speed running i would hate to get in over my head and become discouraged.

Let me know your thoughts between the two. Am i over thinking this and making it sound more difficult than it is running the 2028 or do you recommend sticking with the 1717 and potentially change the build down the road? Does anyone have experience driving the two set ups? Can you give some insight on the difference in drivability and handling between the two?

Thank you for your time.

 

[gotnitro]

51 looks, no responses.

Have a look through here.

https://www.arrmaforum.com/threads/speed-runners-how-fast-did-you-go-today.24467/

 

[Tninl]

Thanks, i have browsed through there and come across some great info/set ups. People don't always post a ton of details on that thread though.

 

[LicketySplit]

I personally went with the 1717 for a couple reasons. Mainly my OCD. Lol. I wanted the batteries on each side for symmetry. That being said the 1717 gives you plenty of head room. I wasn’t planning on setting records with my first speed run car. I will, however, be building a GT chassis at some point with a larger, flipped motor.

 

[SrC]

Out the gate, I always knew I wanted to keep my Lim and Infr. with the Saddle packs. Keeping my Motor in Stock orientation. I believe an 80mm length motor will fit in the stock position. Don't quote me. I only run 6s with a 4274 HW sensored motor. Sometimes running even 2 6s bricks wired in Parallel. So weight distribution is even more important for me.
I use a Cross Weight Scale for all my builds. Especially my On road fast rigs. I use weight ballast to get it perfect. As little weight as needed. I have 1/4 oz just ahead of the fr. shock tower. There is a cutout for ballast weight placement under the front bumper support for this reason. Keeps the nose planted under load. But only a scale can dictate where and how much you will need, if at all.
Much depends on what your target speed goals are. And Radio range is part and parcel to successful attempts.
I wrecked my Lim. a few times. Bad passes. Some due to tire blow outs even. It was cheaper for me to buy 2 more Lim rollers in the past for parts from carnage that resulted.
I feel chassis weight balance is most important for successful consistent runs.
I rather stay with a Saddle config, motor in its stock position, and design my rig around this. Whatever motor and ESC will work around this.
My spin.

BTW, the Lim body has some speed limitations at some point, being an open wheel body design. Removing the front Canards and trimming the rear wing down Flat, is important once you break 100mph. Droop is also important. Chassis needs to be raked.

Edited.

 

[Tninl]

Thanks for the replies. I was already leaning towards the 1717 and keeping the motor in the stock position. You made some good points about the balance and the distance as well. I am not even sure i have a good location with adequate distance to utilize the 1717 to its max potential.
My intentions aren't to break any speed records either and if i do happen to reach the limits of this set up i can always change it down the road. With that being said i think the 1717 is the winner here.
Thanks again.

 

[LicketySplit]

For what it’s worth I’ve only been doing speed runs for about a month. Still tuning the suspension and tweaking things. PB is 132 with the 1717 running 8s and 34/34, and I still have a lot of head room.