210 rm3 or rm4 for dirt?
 

Can anyone who has tried it tell me if you can feel a difference between rm3 and rm4 mode? I failed at the search button on this subject. Thanks.

i have yet to test my RM4 on dirt, i gave up on my RM3 coz somehow the rear tends to want to go first, dont know if its my setup or my slipper is tad tight, but seem i cant get enough rear traction when i hit the throtle.:woot:, so i decided to try Rm4.

Think someone on here might chime in for us.

thanks. I actually tried mm4 first on dirt and found I needed a lot more traction. That's why I then changed to the rm4 config., since it was easier to do that than rm3 :D No track time on rm4 yet so if rm3 gave more grip then I can convert before next outing.

Not to take away from this forum but rctech has an ok forum as well. Thats nearly all they drive on there and a lot of RM talk

I drive RM3 on dirt.
when I drive RM4 and I go full throttle on the straight away, the nose of the car feels to light. I cant correct the line that im driving with steering.
And you have to feather ( be verry smooth ) going on the throttle

For me RM3 is the way to go on dirt. I have a pretty good setup and can push the car really hard.

I don't drive a 210 (yet), but a member at my club does. He uses MM4 on clay! :eh?: He has worked on a decent base setup for a while, but he's got the mid running sweet for both dirt and astro. He had two cars, one RM, one MM. He stopped trying to get the RM to run well as he was having problems to get it balanced and found himself only driving the MM4.

And if it means anything to you, he's one of the quickest guys around the track :p So what I'm saying is, perhaps you could try out the mid motor on dirt?

Oops just realised the title might not give all the info. It should read dest210r and not probably what everyone thought - dex210. Sorry for the confusion. :blush:

Fernandez: Thanks. I am hoping that the heavier weight of the st's front end might reduce the lightheadness of rm4

Origineelreclamebord: Thanks. That shows I haven't really worked on the chassis enough. Now on the fence of reconverting back. OK, maybe after trying rm4 first.

I tested it at the austrian nats last sunday, in training the clay track was really wet so the grip was there and the Rm4 gave more steering because the torque of the motor goes to the front. My laptimes were faster about one tenth of a second than hupo and only a little bit slower than Trauner.

When all dried up the track was really slippery and very difficult to drive, I made it in the A-main, but i noticed to late that i should switch to RM3 for this slippery conditions.

SO FOR YOU ALL:

RM4 when grip is there.
RM3 when slippery.



BRGDS

Andi

You actually have it backwards buddy.

I drove the RM4 and should have switched to RM3

sorry to post on this very old thread but this is exactly the question I try to answer for a DESC210R on a dusty, bumpy and overall rough track

what would be your choice?

in the theory it would be RM4 but based on what has been said here middle motor or RM3 can also be an option? :eh?:

RM4 will give you the most traction on low bite. It has to do with the motor direction spinning the same as the tire. This allows the car to squat more under acceleration thus giving you more grip. The downside is that it will perform wheelies easier under acceleration when grip is a medium. A little bit of added weight to the front 30g-42g , near the steering servo will keep the front down. But you can out accelerate others out of corners.
Another thing is when jumping, throttle control has less of an effect in the air so hitting the brakes in the air will slowly bring the nose down or vice versa. Remember you can take advantage of coming out of the corner faster and getting on the throttle harder than most. Use it to your advantage.

I have also tested RM4 in med-high bite. It works pretty good too, but you might find that you will start to understeer a bit, thus you need to compensate by using harder rear springs to get the car to turn, and as the track starts to dry, then the car becomes more neutral.

RM3 will have slightly less traction as the motor spins opposite from the tires, hence there is less squatting effect. There is less chance of wheelies as well since the grip is reduced. Most 2WD use RM3. Normally this setting is better on medium grip tracks, but it can also work well in low grip if you use more toe in and play with antisquat. It is easier to control the attitude of the car in the air (Nose up or down with throttle).


When in doubt and you know its loose. Try RM4 first, then you can always change it back to RM3 compare.

If the track is truly bumpy, try mid-motor - even with low-bite.

The thing is that the weight behind the axle causes a lot of inertia on the rear end. It's completely true the inertia results in added stability. However, if you hit the threshold that the car gets out of balance - which inevitably the car will on a low bite bumpy track. It could be either because the rear end loses grip or that the car hits a bump very hard, but the end result is the same: the inertia that helped you before will make it very hard to correct the car because it's been corrected by a force big enough to unsettle it in the first place.

Every MM car I tried seems to suit me better than RM. It loses traction earlier and is more easily unsettled, but in a smooth, forgiving manner. It's as if the MM car announces the necessity to correct the car to keep it going in the right general direction, which gives you a zone to control how settled your car is. In contrast, the RM car pretends everything is in check, then suddenly points it's nose in the wrong direction like a stubborn mule and reports to you that you've exceeded the physical limits of the car's stability.

In the end it's all a matter of preference though - the story above is what I think of it, but best to try it is just to remove/add a gear and flip that gearbox around - it's what it was designed for after all! Of course, try an appropriate shock setup too, but it's worth spending some time on finding out your preferences on this. Once you feel comfortable with a car you'll get in the zone that results in consistency and pace :)

Thanks for being so detailed, this makes sense. I don't have much time before the first race of the championship that's why I wanted a feedback first but changing motor position takes a few minutes so this is no excuse.

I'm used to MM as I generally drive 2wd on astro and I'm a smooth driver aswell so it suits my driving style better. The car is here, I can't wait to get this thing running

https://lh5.googleusercontent.com/-d...89-no/2014+-+1

Nice :) Have fun with the build! If you're used to MM, I think that might again be a reason to try MM on the SC first.

Also, it's good to keep in mind the SC is a lot longer than the buggy, so an MM SC with the same battery/electronics positions may have a weight balance that's further to the rear than your MM buggy...

It really doesn't matter which version you have on a bumpy track. Its a matter of your suspension tuning and weight balance.

I agree that a RM car will have more weight in the back which makes it easier to swing around, but its about balancing the car. With RM we tend to move the battery full forward on low/med bite which stops the car from rotating too much. As for hitting the threshold, it really depends on your roll center and shocks. Having too much roll can make the car hook in corners, so if it starts to hook, maybe you need to stiffen the rear a bit more with a heavier spring and go up a weight in oil. The MM has most of the weight in the middle so it can run a slightly lighter rear end shock package. You just can't change the motor from MM to RM and expect it to work perfectly.

But the advantage of RM is being able to get on the power faster and hard than others and using that to your advantage. Don't get me wrong, MM is good. It carries way more corner speed, sure has slightly less grip, but it is more consistent with the grip it has. MM is also better thru chicanes and high speed sections. If I ran MM, I would try to carry more corner speed, take a out in out approach on corners while the RM I can just hug the corner and punch it out.

It really depends on the tracks you race on. European tracks tend to be more fast and flowing thus favoring MM, while US track are more 90 and 180 turns which favor RM.

I see what you mean Dino D, but that's exactly why I stated it's a matter of preference and the way I wrote it down is how I experience it.

And yes, indeed I have driven balanced RM cars, I'm not saying it's impossible - I shouldn't, because the particular car+setup I refer to was on a flowing astroturf track :lol:

However, I do feel MM's 'feel ok' to drive quite easily whereas the RM's 'happy handling zone' is smaller.

Again, like I stated in earlier, that's how I feel...