• Welcome to Tekno RC Forums! Are you a Tekno RC fan? If so you're in luck as you've have arrived to the biggest and best Tekno RC community.

    Come join our community and ask your questions, show off your Tekno RCs and share your experience!

BUILD/REVIEW SCT410.3

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
After 19 logged race days with this chassis, I started running into electrical problems where the wiring to the 5mm bullets on the battery posts would become un-soldered during a race. The excess heat would cause the in-line connects to melt the plastic of the battery case making it unsafe to continue using the same battery:

50068244243_eeb3623283_b.jpg



The cost to replace the battery was going to be around $160+ after shipping so I decided to go a different route and have installed the following electronics for just under $120 shipped total:


Although I probably could've fixed the issue by replacing the worn 5mm bullets with a fresh set, I really didn't like the idea of pushing too much current through on 2S and decided that 3S would be more efficient to help reduce temps and more importantly, extend my run times. I have since ordered the following product which I am told should extend the life of my bullets so they won't tarnish which will prevent the excessive resistance like what was happening to me:


It's worth noting that the 2S pack before weighs only 324g and the 3S pack that I just bought weighs 360g where the extra 36g has made a noticeable improvement in the handling where the truck is more planted and can accelerate faster on corner exit, I was able to drop 0.3 sec off my fast lap time (40 sec hot lap) after swapping out these electronics, and the top speed/acceleration are about the same as before.

Motor Temps:
4300KV@2S = 160°F after 10 min
2500KV@3S = 135°F after 10 min

It really is a no-brainer that I made the right decision to switch over to 3S :)

I've updated my current setup on the OP as well:

50105470506_089af66e65_b.jpg
 
Last edited:
So I just used a Q-tip to wipe the corrosion from the terminal on the top in the following pic, this pack is about a year old in my 401R-T, haven't had any issue with terminals getting un-soldered yet, but definitely needed to be cleaned for sure!


50109854476_0f6c4d0676_b.jpg
 
Hi Bill,
I am about to start building my sct shocks, I was curious if you drilled piston holes bigger? Or are they the stock ones from the bag?
 
Bill,
Thank you so much for this thread. The SCT is my second Tekno build and your assistance is unquantifiable. The tip about the ball ends saved me an hour and a trip for carpal tunnel surgery.

I am building mine to your specs instead of the standard set up.

Thanks again!

Will
 
Hey Bill, just saw your post about going to 3s. Another option is going to 4s with Tekin's 1900kv Pro4 motor. I've run that with Protek's 4s battery, it's the same as their 2s pack, just wired 4s1p instead of 2s2p. So it's exactly the same size and weight.
 
Hi Bill,
I am about to start building my sct shocks, I was curious if you drilled piston holes bigger? Or are they the stock ones from the bag?

I bought these "blanks" here listed on the OP under "Recommended Upgrades":
TKR6163 – Shock Piston Blanks

It's a good idea to have drill bits in the 1.0-3.0mm range with 0.1mm steps between the bits ;)


Hey Bill, just saw your post about going to 3s. Another option is going to 4s with Tekin's 1900kv Pro4 motor. I've run that with Protek's 4s battery, it's the same as their 2s pack, just wired 4s1p instead of 2s2p. So it's exactly the same size and weight.

That's awesome, thanks for sharing!

So far I am VERY happy with the extra weight of the 3S pack, roughly 36g of added weight which would help me break all of my personal records for the current layout (Hot Lap, Hot Main, Hot Qual and Hot Consistency), I would finally start clocking some 99% runs with the truck now and I attribute this to the added weight :)

https://trc.liverc.com/results/?p=view_race_result&id=2529814

99_Club.JPG
 
Last edited:
So I was chatting with a local at the track last night who recently swapped out his 2500KV@3S back to 4000KV@2S and he noticed that the throttle response wasn't nearly as smooth, his consistency was affected and he plans to go back to 3S just because of that aspect alone.

There is also chatter with the 1/8 eBuggy drivers that they are preferring 1500KV@4S instead of 1900KV@4S to get smoother throttle as well, they have to gear up a pinch to compensate for top speed but lower KV makes a big difference to settle things down and improve handling.

When the time comes for me to replace the 3S pack, I may make the switch to 3660-1900KV@4S next!
 
So my son recently got back into RC racing with me on Wed nights, and Thornhill alternates between dirt and turf tracks each week. This past week he ran turf for the first time with a set of (discontinued) Pin Points, and the truck was having major traction roll issues. I know there are tons of setup changes that I can do to optimize performance for turf, but my goal is to make the least amount of work while preserving the dirt setup so here we go.

The ride height for dirt is 25mm which is about the lowest I can get the truck to sit with the stock shocks!

I took a wild guess and decided to try the 1/8 Exceed Mad Drift shocks here:
https://www.nitrorcx.com/mad-cp0154.html

They turned out to be a direct fit and are actually a very high quality shock with almost identical cartridge system that TEKNO uses as well as a threaded piston nut too. They are very smooth and the spring height is perfect for the rear shocks, only thing I added were some shock cushions from Team Thornhill and now the ride height is reduced to 18mm on the rear, I placed the TEKNO shock next to it for reference to see how much shorter the Mad Drift shocks are:

50521646157_7174353959_b.jpg


I used the same shock package on the front, but I had to swap over to the TEKNO TKR6047 (65mm) springs which gave me a ride height of 17mm, so I actually had to add a little pre-load to get the front to match the rear, we will be testing this setup next Wed night and hopefully that's all we need to do to keep the truck from traction rolling on high speed corners... fingers crossed!

50521466831_b7c41efe3e_b.jpg
 
Spent some time on my CNC today milling custom mud guards with 1mm thick carbon for the truck, pretty happy with the results, no tire rub at full droop too :)

50564233122_97530de5a1_b.jpg
 
You should try using the LF SC springs, they're a lot shorter and allow appropriate ride heights and stiffer rates. The fronts are 57mm long, pn's 6103-6107 and the rears are 70mm, pn's 6113-6117.
 
You should try using the LF SC springs, they're a lot shorter and allow appropriate ride heights and stiffer rates. The fronts are 57mm long, pn's 6103-6107 and the rears are 70mm, pn's 6113-6117.

Sounds perfect for turf, I will add these to my next order when the 2.0 truggy becomes available, Thanks!
 
Sounds perfect for turf, I will add these to my next order when the 2.0 truggy becomes available, Thanks!
No problem! I actually use them on all track surfaces. Getting the truck using stiffer spring sbut having a lower ride height is a big improvement.
 
So my son stripped a spur gear last race day and I was going through the truck today trying to set the mesh with the new spur gear but noticed that there was a slight amount of slop on the countersunk washer even though I cranked down as hard as I could on the motor mount screw. I then removed the screw and used a hex wrench to measure the depth of the hole to discover that over time the thread lock that I've been using had pooled up toward the bottom of the threads and when hardened had prevented the screw from driving all the way down into the mount. I tried using a pick to remove the thread lock to no avail, I also considered melting it out with a micro torch, but decided that extending the hole and extending the tapped threads would be the best solution so that in the future I can simply push the old thread lock all the way through the screw hole and not have to worry about this issue ever again. I'm finding it necessary to do this to all the aluminum mounts around the center diff as well, so much easier for long term maintenance:

50763078018_fd32d18ff3_c.jpg



*** I have also added the following upgrade to the OP under the durability section where the newer shock cap bushings will prevent the shock caps from wearing as fast and they will not pop out on you when doing shock rebuilds, highly recommend this upgrade!


 
Last edited:
So my son stripped a spur gear last race day and I was going through the truck today trying to set the mesh with the new spur gear but noticed that there was a slight amount of slop on the countersunk washer even though I cranked down as hard as I could on the motor mount screw. I then removed the screw and used a hex wrench to measure the depth of the hole to discover that over time the thread lock that I've been using had pooled up toward the bottom of the threads and when hardened had prevented the screw from driving all the way down into the mount. I tried using a pick to remove the thread lock to no avail, I also considered melting it out with a micro torch, but decided that extending the hole and extending the tapped threads would be the best solution so that in the future I can simply push the old thread lock all the way through the screw hole and not have to worry about this issue ever again. I'm finding it necessary to do this to all the aluminum mounts around the center diff as well, so much easier for long term maintenance:

50763078018_fd32d18ff3_c.jpg



*** I have also added the following upgrade to the OP under the durability section where the newer shock cap bushings will prevent the shock caps from wearing as fast and they will not pop out on you when doing shock rebuilds, highly recommend this upgrade!


Good catch Bill

i have ran into this same thing on other rigs. Mostly on motor mounts, pinions, spurs. Things that get removed a lot and things that need locktight. I try to use a tap and die on all holes and screws now. Bottoming taps work well for this kind of thing as well.
 
So I finally got around to installing this 3660-1800KV motor in the truck with a 19T pinion:
https://www.rcjuice.com/motor-esc/b...-4-pole-brushless-sensored-4x4-sct-motor.html

I paired it up with this LCG 4S LiPo from SMC, perfect fit with the stock battery straps:
https://www.smc-racing.com/index.php?route=product/product&path=67_96&product_id=549

I ran 1 practice session which lasted nearly 21 minutes before I hit LVC, then I checked the motor temp which read 142°F

Here's a link to the practice session, note that it was listed under my son's name because he's been racing the truck for the past 3 months:

https://trc.liverc.com/practice/?p=view_session&id=8182598

Capture.JPG


Now keep in mind that I had 4 short breaks where I had to make some tuning changes to the radio settings, so if you take my overall average of 40 sec/lap into the 28 laps that I completed that works out to 18.7 min pure run time at 100% hard driving which is still pretty darn impressive!

Unfortunately my son couldn't race last night, so I decided to race the truck myself and got Q2 on the grid and was able to settle down in the main without any wrecks to take the win. Both the 2nd and 3rd place drivers had a faster fast lap than me, but it came down to consistency to take the win, ignore the entry for Connor as he was running 2WD Buggy mixed in with our group:
https://trc.liverc.com/results/?p=view_race_result&id=2794583

Capture.JPG


No doubt I was getting faster every battery pack, but I was also running into some snap over steer issues when going off power from the straights into sharp corners, so I've got some setup changes to make tomorrow to address that issue. Hopefully I can knock a few more tenths off my fast lap before Saturday where I will get to race the truck again and should have an updated setup sheet to include the recent changes I've made.

With the 4S setup, the throttle timing is almost identical to my 4S powered ebuggy, which is really nice so that both classes compliment each other now! I found that running my SCT back to back with ebuggy was making me faster each round with both classes respectively :)

Seriously... everyone should be running these on 4S, it would be awesome to get a 15 min main just like the nitro's get, ha!
 
Yesterday I was the only SCT to show up and instead of getting put into the bucket/beginner class, I asked to be mixed in with the nitro buggy class. I really had no expectations set, but would actually qualify 2nd in the B Main for a 15 min main, and was able to get onto the podium, not bad for a huge disadvantage.... the RD called me into the pits for a stop and go after everyone else had completed their pits to keep things fair.
Anyway, it was so much fun running a longer main with an electric and some other locals were showing some interest of possibly pushing for a single 15 min main instead of double 8 min mains for the SCT class... no more tie breakers in electric, settle everything in just 1 race... oh yeah!

https://trc.liverc.com/results/?p=v..._fLy6bIbyilOcFkHRwQ5DLAE8pvHwwhRDSlf7QaFDB5s0

141097761_4447319978629435_1402579372981771018_n.jpg

SCT410_15_MIN_MAIN.JPG
 
I joined to say thanks for this thread. It's been great to see a more up-to-date build with this truck. My main hesitation was the age of the design but I'm thinking I'll go for it based on what you've shared. It will be my first time on a track. Luckily, 4x4 SCT is the most popular summer class here.

My local hobby shop is recommending a 2s setup. I'll show them the info you posted to see if they think a 3s or 4s might work well for our track.

Edit: I just checked the class rules and 3s is the limit.

It looks pretty rough based on the videos I've seen.
 
Last edited:
Thanks for the feedback @NimblyBimbly!

Glad to hear your track allows 3S, that is quite reasonable with a 2500KV motor which should do nicely.

Good luck with the build, sounds like a lot of fun!
 
Sorry to butt in, but I am looking to find someone to help me complete my build on my et 48.3. Im in delaware. Can anyone point me in a direction please!?
 

Recent Popular Liked

Back
Top