Traction Roll

[rfulcher]

I am working on my carpet setup and am running into a bit of traction rolling. I set the right height low, like 15mm. I also moved the shocks out on the mount and the arms. I got a suggestion to blue the side walls on the front tires. Any other suggestions? Outside of those changes, the setup is stock. I am trying to change one thing at a time.

 

[Billl DeLong]

You're not going to be happy with my answer, but I will be as open and honest with you based on my experience with the platform. The EB410 was not designed for carpet/turf and I put a tremendous amount of effort into getting it somewhat stable for turf before I eventually switched to a PR Racing 401R and it was like taking a knife to gunfight after I made the switch, more info here:

• PR Racing 401R

At one time VRP used to make carbon towers that were +3mm taller to help you get lower ride height to deal with the traction roll issue, I never could figure out how to resolve the inside rear wheel from lifting up issue in tight corners as I think that contributed to the traction roll problem, here's my final setup to give you some ideas for carpet but if you want to save yourself the frustration, go get a kit with the similar geometry that everyone else is running (PR, AE, TLR, XRay, Yokomo, etc..)

 

[nub]

I had seen some old VRP carbon towers looking for random items several month ago. You may have to do some digging to find a set if any still exist.

You could also try Pro Star. They have a Kevlar set that says includes the stock shock mounting and a set of higher holes for lower ride height. Their photos don't represent that so I would contact them to clarify if you're interested.



I've never tried carpet myself but I've seen where some will remove the pins or tread from the outside edge of the tire to reduce some of that lateral bite.

 

[rfulcher]

That is a sad, sad answer. I guess I will have to contemplate what to do. I am not a great driver at the moment so I think I will continue to practice with the EB410. I will look for the shock towers. Thanks for your help.

 

[Billl DeLong]

I would keep the car for now, once you start hitting 98% consistency and better on average, then a carpet based platform will help you bump up to the next level.
With the setup you see above, I let Ryan Lutz test drive my car so you can see how it handles. That was when Lutz was still with TEKNO at the time and he had recently ran the EB410 at a big carpet race in Vegas that year... it would be the only time these TEKNO team drivers (Bornhorst and Lutz) would ever run on carpet.

In contrast, it was a TEKNO driver who won Nats with the EB410 on clay which is the track condition the car was specifically designed for:
https://blog.teknorc.com/2018/08/24/tyler-hooks-wins-13-5-4wd-roar-nationals/

 

[rfulcher]

@Billl DeLong, why did you choose to try the PR Racing 401R? It looks interesting enough. Are you still running that care? Have you tried any of the other cars from PR Racing?

 

[Billl DeLong]

@Billl DeLong, why did you choose to try the PR Racing 401R? It looks interesting enough. Are you still running that care? Have you tried any of the other cars from PR Racing?

PR was and still is an emerging brand in the US market, this made it fairly easy for me to get accepted as a team driver through The RC Pro Shop and at that time they offered a bundle deal for me to get sponsorships through Raw Speed (Tires) and Trinity (electronics)... it was a no brainer Trifecta, though not sure if those deals still exist today.

I had regularly raced the following cars up until the COVID shutdown:

• PR Racing 401-LW
• PR Racing 401R
• PR Racing 401R-T

After racing resumed in my area in 2020, the 1/10 program died off and everyone migrated over to the 1/8 track.

I bought an EB48 2.0 and ran that car for about a year along with the SCT:

• BUILD/REVIEW TEKNO SCT410.3
• BUILD/REVIEW TEKNO EB48 2.0

In 2021 I picked up a sponsorship with HB Racing and migrated over to:

• HB Racing E819RS
• HB Racing E8T evo3

At this point I had to drop my sponsorship with PR because HB offers 1/10 classes. Not really a big deal because I wasn't running 1/10 locally anyway. HB is about to release a new 4WD in a few months so I can still race the 401R up until then. I have still kept my sponsorships with RawSpeed and Trinity.

As luck will have it I recently raced my 401R at SDRC a few weeks ago on vacation to SoCal and even though the car has collected dust for the past 18 months, it's still very competitive with all the local fast guys, here's my race results with the 401R:

https://sdrc.liverc.com/results/?p=view_race_result&id=3902059

It's worth noting that I'm running a 2019 release of the kit and they recently updated a 2022 version of the 401R earlier this year.

More info on the new HB Racing D4 EVO3 to be released here which I will switch over soon:
https://hbracing.com/cars/off-road/electric/d4-evo3-1-10-competition-electric-buggy-4wd-en/

I bought an RV last year and plan to travel to many tracks around the US and will take my 1/8 buggy and 1/10 buggy on the road.

 

[Dudlee]

I got a suggestion to blue the side walls on the front tires.

What does blue the sidewalls mean?
I'm running into the same issue on my local track that is Carpet.

 

[Billl DeLong]

Putting CA glue on the front sidewalls will help reduce grip, another option is to insert a stiffer foam insert on the front wheels using medium closed cell foam inserts. You can also clip pins with a toe nail clipper to remove grip:

When I used to race my SCT410 on turf I used a dremel to sand off the outer 2 rows on both sides of the front tires to make a mowhawk and that was the perfect amount of grip without traction rolling:

Normally you don't need to do this with proper 4WD buggy tires.

I ran Schumacher Cactus Fusion on the front, these are very stable and less likely to traction roll without any necessary mods out of the bag, in fact I ran these without inserts:
https://www.amainhobbies.com/schuma...ont-1-10-4wd-tires-2-yellow-schu6895/p1339426

 

[nub]

With the EB410 designed for dirt and clay when going to a high grip surface in general you'll want a lower ride height and stiffer suspension. An easy change from the kit set up without getting crazy is to go one to two steps stiffer on the sway bars.

I don't run on turf or carpet so take this with a grain of salt. I would see how low I could get the ride height on the kit springs. Consider going stiffer a step or two on the springs. See if you can get down to around 15-16 mm. Get both .1 and .2 mm thicker sway bars for the front and rear and go up equally front to rear so you're increasing roll stiffness but maintaining the same F to R balance. With the previous tire suggestions see how that changes how it drives.

Make changes one at a time so you can see how they change how the car drives. If it gets worse go back and try something else. You can add additional changes but document it on set up sheets so if you get lost you can revert to a base set up and start over.

With traction rolling you might need to watch closely what is happening to cause it. On carpet I'm picturing it as the car goes into the turn off throttle the chassis pitching to the outside front wheel and lifting the inside rear. If you're getting good grip in the front, it's going to grip and flip. You can reduce grip in the front as Bill showed above with tires. With sway bars you can also change the balance front to rear for over steer and under steer by changing only the front or only the rear.

If the traction roll is happening as I pictured above there are two possible sway bar options. Go stiffer in the front or softer in the rear. Going stiffer in the front will lessen the chassis pitch to the outside front which if you can picture it is what is lifting the inside rear because it is also stiff. If you go softer in the rear the front can still pitch over to the outside front giving you better low speed steering but the rear will roll onto the outside shock more and with the softer bar won't tend to lift the inside rear tire.

In the end there is no single answer. You'll have to experiment for your track and driving style. Sway bars are cheap and easy to change but don't make big swings. You can tune similarly with shock oils, springs, pistons and roll centers. You know what they say though, KISS.

 

[Billl DeLong]

Most carpet setups are running around 12mm ride height, I also caution not to go too thin on the rear sway bar as the EB410 has a tendency for rear inside wheel to lift up in tight corners... I believe this issue compounds the traction roll problem as the car gets unsettled on 3 wheels, the rear diff will unload and cause gyro forces to make the car very unpredictable. I put a lot of effort trying to fix this issue and was never successful in solving it Just a guess, but willing to bet that's why the factory drivers stopped running the EB410 on carpet as well. The setup on post#2 above was the best I could get my EB410 to handle on turf, it was drivable and rarely traction rolled, but my lap times were drastically faster after I switched to the PR 401R platform. The local turf track we race on isn't as grippy as some carpet places I've been so 14mm works for me, but I often lower my PR 401R down to 12mm at most carpet tracks I've visited.

 

[Matthew_Armeni]

Most carpet setups are running around 12mm ride height, I also caution not to go too thin on the rear sway bar as the EB410 has a tendency for rear inside wheel to lift up in tight corners... I believe this issue compounds the traction roll problem as the car gets unsettled on 3 wheels, the rear diff will unload and cause gyro forces to make the car very unpredictable. I put a lot of effort trying to fix this issue and was never successful in solving it Just a guess, but willing to bet that's why the factory drivers stopped running the EB410 on carpet as well. The setup on post#2 above was the best I could get my EB410 to handle on turf, it was drivable and rarely traction rolled, but my lap times were drastically faster after I switched to the PR 401R platform. The local turf track we race on isn't as grippy as some carpet places I've been so 14mm works for me, but I often lower my PR 401R down to 12mm at most carpet tracks I've visited.

A thinner rear bar (or none at all) will stop the inside rear tire from lifting into turns. Our EB410 is geometrically stiffer than most 10th scale buggies so going to softer rear bars and springs can make the buggy easier to drive.