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Old 02-27-2014, 01:02 PM   #13906
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Actually he said inline gives more initial turn in. Trailing gives more on exit.

Touring car guys who convert to off-road probably would favour less trailing. But it really depends on your driving style. And trailing is easier to drive in the rough, as the steering is less aggressive when the car is being tossed around over the bumps.
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Old 02-27-2014, 01:30 PM   #13907
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I guess I interpreted his story wrong about his personal experience. I had to go back to re-read it. Nevertheless you can see the front end movement between the two setups pretty clearly.

I personally run a pretty aggressive setup. Right now I have it set for 20 degrees caster with inline steering.
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Old 02-27-2014, 01:54 PM   #13908
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I guess I interpreted his story wrong about his personal experience. I had to go back to re-read it. Nevertheless you can see the front end movement between the two setups pretty clearly.

I personally run a pretty aggressive setup. Right now I have it set for 20 degrees caster with inline steering.
Mid motor? with Inline less caster. Yup! cause it pushes like a dump truck with 30 and trailing. I think most of your setup comments refers to Mid Motor setups, and my comments and experiences were more about tailored to RM setups.
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Old 02-27-2014, 02:32 PM   #13909
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Yup MM3.
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Old 02-27-2014, 06:00 PM   #13910
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Mid motor? with Inline less caster. Yup! cause it pushes like a dump truck with 30 and trailing. I think most of your setup comments refers to Mid Motor setups, and my comments and experiences were more about tailored to RM setups.
Mid motor isn't any more prone to pushing than rear motor.
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Old 02-28-2014, 03:27 AM   #13911
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Mid motor was a fail for me , after battling with the car and struggling to be competitive, I converted back to rear motor 3 and BAM! Car and driver are happy. So MM is not for everyone, and not the only competitive car on a high bite track.��
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Old 02-28-2014, 04:34 AM   #13912
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@fredswain: Why are you running MM3 as opposed to MM4?

@Dan-O : How long did you run mid motor? Was this your first time? I agree it's totally different than rear motor, takes a completely different setup and driving style.
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Old 02-28-2014, 04:38 AM   #13913
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+1 on the inline/trailing conversation as well as where to position the caster blocks in relation to the axles. I remember reading this somewhere along the lines that this adjustment was intended just how fred explained it.

Fred have you tired moving the rear hubs around to change the weight over the axles? I've found with mid motor you seem to get a bit more forward bite when you move the hubs forward so they are closer to the motor.

Finally getting some track time in this weekend! Can't wait!
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Old 02-28-2014, 07:06 AM   #13914
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I run MM3 because I hate the way MM4 drives. If MM3 doesn't work, I run RM3. There is too much artificial weight transfer with mid motor. When you artificially shift weight rearwards, you do so by taking that weight off of the front. Have fun steering under power! The real problem is that there is less static weight on the rear wheels which is why MM typically has less forward bite than RM. RM has so much rear bite as a result of the motor placement that we run it's rotation counter and then try to limit rear weight transfer with antisquat. I run MM3 with saddlepacks and no antisquat. Now I've got the weight I need on the drive wheels and still keep the front end down under power. I can get on the throttle sooner in a corner as a result. If I find a scenario where I would need to add too much rear weight, I'd just revert back to RM3. I will never run RM4.

I run the rear hubs all the way back. I make sure the cvd's are as inline as possible. I don't want them sweeping forwards. Basically I setup a mid car every way that other people don't and it works just fine because I understand what is happening and why. I know people are going to tell me that MM4 is the standard and that's fine but I disagree. I had 2 MM cars before the 210. I had an Atomic Carbon Cr2 which was a mid motor Losi XXX and I had an X Factory X-6. The X-6 was better than the Cr2 but the 4 gear made it tough to drive aggressively. Yes you could turn under people but you have to coast around the corner and get back on the throttle later than I'd prefer. Yes you can tune that out but at the expense of handling in other places. MM3 has it's disadvantages too so I'm not saying it is the solution. I just like it better than MM4. The best layout for MM is what the Team C TM2 uses with a few tweaks.
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Old 02-28-2014, 08:14 AM   #13915
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I hear you on the MM3 vs MM4. There is less weight shift on acceleration. But that really depends on the level of grip at your track. We hardly have enough grip at our local clay or dirt tracks to even consider mid motor. Let alone trying to run MM3. They don't sugar or put stuff in the tracks here. Everyone who tries MM here (locally) is too busy trying to keep the back from spinning out so they all revert back to RM. And the times I have ran on carpet using MM is limited, so I am sure Fred is far more knowledge on MM setups.

As for RM setups. RM3 is good on most dirt/clay tracks. But as for the RM4, it does provide more traction than the RM3. When the traction is low, the RM4 will shine more. You can out accelerate your competitors while they gingerly apply the throttle. Not to say that you can't run the RM4 on med grip, it works too but you have to understand that there is a lot of weight transfer happening on the RM4. Under acceleration, the front goes light or wheelies, which is what a lot of people complain about using RM4. You need to move the battery full forward and add anywhere from 30-45g of weight up front to keep the nose down, and you probably want to run 3 anti squat to give you as much off power steering as possible. We also use 10-15 drag brake to assist with steering. Remember our tracks are technical more point and shoot tracks.

Last weekend we had a trophy race and our team placed 3 cars in the A. When they watered the track our advantage was minimal compared to the RM3 cars, perhaps 0.1 or 0.2s per lap, but I think that more of less has to do with our suspension setups and not transmissions. But we were noticeably about 0.5s faster per lap when the track started to dry. When the track was fully blown out, our advantage was closer to a full 1s.

The key is to find a setup that is balanced and keeps the car consistent whether its wet or dry. What I mean about consistent, is that the car won't push or over-steer regardless the condition of the track. If it pushes in wet, and over-steers in the dry, then the setup isn't balanced. You can get any setup to work RM3 or RM4, you just have to understand the benefits and drawback of each and work around it to find that happy harmony of setup that the car likes.

If you have a track the is consistent at med grip, then perhaps RM3 is better as there is less work to do to get that setup. But on tracks where the conditions change round to round, and especially outdoor tracks - having a car that can provide max grip is better. So when they water I don't have an advantage and we are at par, but as the track dries, I slow get quicker and am able to push harder and charge and force others to drive aggressively and hope they spin out on exit.
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Old 02-28-2014, 09:49 AM   #13916
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Quote:
Originally Posted by Dino_D View Post
I hear you on the MM3 vs MM4. There is less weight shift on acceleration. But that really depends on the level of grip at your track. We hardly have enough grip at our local clay or dirt tracks to even consider mid motor. Let alone trying to run MM3. They don't sugar or put stuff in the tracks here. Everyone who tries MM here (locally) is too busy trying to keep the back from spinning out so they all revert back to RM. And the times I have ran on carpet using MM is limited, so I am sure Fred is far more knowledge on MM setups.
mid motor can and does work on surfaces other than sugared dirt and carpet. in fact, it's just as good, if not better, than rm on most surfaces. the problem is there is only one car on the market that builds mm cars that work well on dirt and they never have any kits in stock (x factory).

weight distribution is key, and nobody on the market, in my opinion, has it right yet (xf is pretty darn close).

If I put a black garbage bag around my car and asked you to determine if it was mm or rm based on its weight distribution, you would tell me it's rm. In truth, it is mm. That is the key to grip, static weight distribution. Doesn't matter if it's rear or mid motor. If it has the weight in the right place, it will grip. Doesn't matter if it's high bite clay or loosey goosey dirt. Doesn't matter if it's mid motor or rear motor. With the weight in the right place, it will grip. Period. End of Discussion.

Remember, the goal of mid motor isn't to put more weight on the front wheels. It's simply to put all the weight within the wheelbase. You can still load the crap out of the rear wheels and you still get the awesome handling characteristics of mid motor. You just don't have to worry about the back end snapping out.

With that said, I race my custom dex210 mm3 chassis on a med bite clay track and have no problems putting down power. None. I can even lift the front wheels. It drives beautifully.

Not a good example of my driving, but a good example of my car's grip. I'm the only one, mid motor or rear motor, that was clearing the entire table top in the middle of the track. Everyone else was jumping to the top and driving off it. If you look close enough on the first lap, you can even see me lift my front on the approach to the jump from putting down so much power. Again, it was in mm3.
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Old 02-28-2014, 11:12 AM   #13917
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Quote:
Originally Posted by Dino_D View Post
As for RM setups. RM3 is good on most dirt/clay tracks. But as for the RM4, it does provide more traction than the RM3. When the traction is low, the RM4 will shine more. You can out accelerate your competitors while they gingerly apply the throttle. Not to say that you can't run the RM4 on med grip, it works too but you have to understand that there is a lot of weight transfer happening on the RM4. Under acceleration, the front goes light or wheelies, which is what a lot of people complain about using RM4. You need to move the battery full forward and add anywhere from 30-45g of weight up front to keep the nose down, and you probably want to run 3 anti squat to give you as much off power steering as possible. We also use 10-15 drag brake to assist with steering. Remember our tracks are technical more point and shoot tracks.
This confuses me. What you are saying is that in order to get more grip on tracks with less traction, you are changing to RM4 from RM3. However then you are not only moving battery weight forwards but also adding weight up front. Why would you do this? It's counterproductive. You want to shift more weight rearwards but then add that weight back up front to counter it. If rear grip gets low, all you need to do in RM3 is to reduce rear antisquat and add a little weight to the rear as necessary. The end goal is to get more rear grip and this accomplishes that. It also does it without the negative problem of losing on power steering.

I don't tune any differently for RM or MM. The technique is all the same and so are the results. The actual tune itself varies though.
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Old 02-28-2014, 11:33 AM   #13918
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Here is a video of my teammate's car (white and blue) running RM4. Towards the end you can see his car seems faster, but actually, as the track dries, the other cars just got slower above 19s. His times were all within mid 18s all race. He never got a 19s lap. Its a point a shoot track which favors RM more.

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Old 02-28-2014, 11:50 AM   #13919
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What I'm asking is if you are searching for rear grip, why are you changing to RM4 to shift weight rearwards artificially only to then move weight static forwards and add more weight up front to get weight off of the rear wheels to counter it? It would make far more sense to keep RM3 and to just reduce antisquat and potentially add a little weight to the rear.

That looks like a fun track. It doesn't look like point and shoot driving to me though.
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Old 02-28-2014, 11:58 AM   #13920
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so for my local wet clay track my mm4 car has great traction and turn in.......but when the track is too wet (slimy mud) or dry (slightly dusty) the car pushes like crazy in the "rear motor" turns like 180's....from what you guys have been saying I think i will try less caster or less trailing? Am i correct?

Another thing i noticed is that the TLR's have the shock on the back of the rear arm in midmotor and in the front for rearmotor....i know this is a possible mod for the durango but i cant find a solid explination of what the benefits/drawbacks are.
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