View Full Version : Help with MR-03 Traction Roll Problem
Traveler
2009.11.27, 08:05 AM
Hope I can get some help from the experts here.
I was going to hold off on getting an MR-03 a little longer, but the Makers Okabe Jidosha RX-7 looked too good in the pictures. Needless to say I broke down and ordered one, along with some PN MM T-Plates #4 and 5 and the front spring set. The car arrived on Wednesday and the first thing I did was remove the rear stock suspension and pod and replace it with a PN rear setup and #4 T-Plate. I also sanded and polished the kingpins like CT and TJ showed and replaced the front springs with PN grean. Put some RR H.G. bearings in, signficantly reduced the size of the 70 turn motor tabs and threw some worn Kyosho tires on it. By the way, I also switched it to the wide front end and made itss a 94mm WB chassis with a 350z body.
After saying a prayer, putting the batteries in and turning it on I was glad to see no smoke. I was also pretty happy with the handling of this setup and observed what others had reported. Next I decided to put some new rubber on some new PN machined delring rims, 20mm diameter and +1 offsets all around. I went with Kyosho 20d in the rear and 30d in the front like what's on most of my cars. This is where something went wrong :(
I could no longer take a u-turn at any amount of speed without the car rolling off the track. OK, too much front grip. Switched to PN 20d slicks in the front. Same problem. Switched to PN 25d slicks up front. Still rolled like crazy. As I was trying different tires on the front I also incrementally shimmed the front knuckles because with new tires all around the front of the chassis is much higher than the rear. I removed the stock plastic shims from above and below the knuckles and started with 3 0.3mm metal shims below the knuckle for 0.9mm of hight. Still rolled. Added another 0.3 mm shim to bring the total up to 1.2mm below the knuckle. No dice. I'm now at 5 shims for 1.5mm and more initial camber and still rolling. Also tried purple and red front springs. No luck. I finally put some highly worn PN 15d tires mounted on ATM +1 rims on the front and I can make it around the track for several laps before rolling.
Aside from saving my worn front tires from other cars for this one, any suggestions??? I've read everything in the MR-03 forums and don't recall anyone reporting this problem before.
Please help!
hpgod
2009.11.27, 08:16 AM
stiffen the front springs, green is the 2nd softest. yellow is the hardest:)
Traveler
2009.11.27, 08:18 AM
With 1.5mm of shimming under the knuckle, there is increase pre-tension on the springs already. Suspect white or yellow would be too much, but may give it a try.
bermbuster
2009.11.27, 09:14 AM
With 1.5mm of shimming under the knuckle, there is increase pre-tension on the springs already. Suspect white or yellow would be too much, but may give it a try.
that is flawed logic. Your springs may have more pre tension but they still are weak. Stiffer springs will cause the arms to compress less. Your pre tension is only adjusting ride height which is not ideal. Shortening the springs work much better. Now your suspension never unloads so it can be bouncy....
You can also put some CA on the sidewalls of the front tires....
we call it armor alling them...:D
hrdrvr
2009.11.27, 09:24 AM
^ Like berm says, preloading a spring doesnt change its compression strengths. Id try some harder front springs, and maybe try to see if it is hitting anything on compression. I know the 350Z usually has plenty of clearance for tires, but if you are lowering it too much, maybe the front lip is dragging the ground. I have trouble running a 350 on our track, as the elevation changes create small bumps in some of the corners. If I hit those bumps the car either spins out, or flips over. I have to run bodies with higher front clearance to easily solve the issue.
You could drop Chad508 a PM or post a Q in our thread. He had the same trouble with his at first. Hes got it taken care of now, I just dont remember exactly what he did.
Good luck!
Traveler
2009.11.27, 09:33 AM
Thanks guys! I assumed by compressing the spring with shims, it would make for a harder suspension, so I went softer than usual.
Just tried white springs with some 20% worn K30s (sidewalls CA'ed). Still flips. Will try yellow next and the other suggestions.
Traveler
2009.11.27, 09:43 AM
Still flips with yellow. I'm not talking dog rolling over, I'm talking dolphin exploding out of the water and doing twirls mid-air. Very dramatic. Kids think its cool!
H E L P!!!
pedrocamp
2009.11.27, 10:15 AM
I am thinking along the same lines as Landon, body digging in. Try another body or no body...
bermbuster
2009.11.27, 10:19 AM
I am thinking along the same lines as Landon, body digging in. Try another body or no body...
the tires could be hitting a light bucket or the inner fender as well.....
Traveler
2009.11.27, 10:21 AM
The clearance on the front is tons, even with 1.5mm of shims. But I did try 2 other 350z bodies with same results. Maybe I can try your F-430 body at the next race ;)
I'm starting to wish I had waited on the MR-03 :(
MantisMMA
2009.11.27, 10:31 AM
just for kicks switch to 98mm, yellow springs and a stiffer h plate. judging by how you are explaining it it seems like the front tires are hitting something. but i will say that the MR03 has tons of steering and you have to drive it a litttle different as in you cannot crank the steering full lock going into a turn at least until the upgraded knuckles come out. take some steering out of your radio too.
cosmicsoul
2009.11.27, 10:40 AM
Hey Traveler,
The thumbwheel on your radio is your dual rate. Your travel is currently set aT 70. I think your thumb wheel adjustment is at 100% or 70% when I looked last time I drove you car turn it down to 60%. You could try turning you steering curve down as well. Maybe your steering balance I think yours is set 70 left 70 right.
If this doesn't work out I will trade you an F-1 and an am module for this newly aquired pile of doo.
Have a great day!
Traveler
2009.11.27, 10:48 AM
just for kicks switch to 98mm, yellow springs and a stiffer h plate. judging by how you are explaining it it seems like the front tires are hitting something. but i will say that the MR03 has tons of steering and you have to drive it a litttle different as in you cannot crank the steering full lock going into a turn at least until the upgraded knuckles come out. take some steering out of your radio too.
This was going to be the next thing I tried and run it under an ENZO. But I kept tinkering with the front and although it seemed smooth, I put a couple of drops of Kyosho kingpin oil with Fluorine on the tops of the kingpins around the top ball joints and... less flipping... even with "new" tires.:confused:
Will have to review CT and TJ's front end tutorials again to see what then did with these top balls. I'm guessing one of them wasn't rotating smoothly withing the upper arm or wasn't riding smoothly on the kingpin.
Could this be the source of my frustrations???
I envision after market alloy upper arms with delrin balls. Hmmm... Wonder who will make them first?
Traveler
2009.11.27, 10:49 AM
Hey Traveler,
The thumbwheel on your radio is your dual rate. Your travel is currently set aT 70. I think your thumb wheel adjustment is at 100% or 70% when I looked last time I drove you car turn it down to 60%. You could try turning you steering curve down as well. Maybe your steering balance I think yours is set 70 left 70 right.
If this doesn't work out I will trade you an F-1 and an am module for this newly aquired pile of doo.
Have a great day!
Jay, if I thought you knew anything about setting up a car I'd invite you over to help me out :)
yasuji
2009.11.27, 10:52 AM
some of the guys here lower the front of the body to reduce traction roll
i do know that i run my pancar extremely low ,body wise
another thing i have found is that sometimes traction roll is caused by the rear of the car as well
also the mr03 has super quick initial steering,check ur steering punch as well as speed
Traveler
2009.11.27, 11:02 AM
Will play with the radio settings a little. Currently S Speed it off and punch is at 0%. First I think I am going to strip down the front end and sand/polish some more.
Thanks guys! :) Will report if I learn anything for others that may run into the same issue.
CristianTabush
2009.11.27, 11:04 AM
Small tires work for me. I'll send you some trued down 20's w/ your next order...
We already have delrin balls in the works. Prototypes should be here in like 2 weeks.
Traveler
2009.11.27, 11:16 AM
Thanks CT! I just re-reviewed your tutorial and saw what you did with the upper balls. I will have to work on them some more...
CristianTabush
2009.11.27, 12:01 PM
Yeah, there is a lot of stiction at that ball joint. I polished and polished and polished... Some cars are better than others, but mine was REALLY bad... Delrin will make it much smoother. We are also working on some out of different materials.
Traveler
2009.11.27, 12:39 PM
Look forward to those as well as 96mm T-plates.
color01
2009.11.27, 03:18 PM
Still flips with yellow. I'm not talking dog rolling over, I'm talking dolphin exploding out of the water and doing twirls mid-air. Very dramatic. Kids think its cool!
H E L P!!!
The MR03's initial steering response is just too great, that caused my car to traction roll as well. I fixed it by using very worn front tires (K30's, no glued sidewall) and bumping up the damping on all four wheels (stiffer springs on disdk damper, add some grease to the front knuckles).
Also check that you actually still have front suspension travel, what with the amount that you've lowered the car. When I had 1.5mm of shims under the knuckles I could barely move the suspension, that caused a lot of flipping (dramatic mid-air twirls, just like you). Taking out one of the shims did a world of good for me.
So that's two more options for you to play with... ;)
CristianTabush
2009.11.27, 03:24 PM
Those are OTW as well. Allin-all I have like 8-10 projects that I am working on that will be released early next year.
Traveler
2009.11.27, 03:44 PM
The MR03's initial steering response is just too great, that caused my car to traction roll as well. I fixed it by using very worn front tires (K30's, no glued sidewall) and bumping up the damping on all four wheels (stiffer springs on disdk damper, add some grease to the front knuckles).
Also check that you actually still have front suspension travel, what with the amount that you've lowered the car. When I had 1.5mm of shims under the knuckles I could barely move the suspension, that caused a lot of flipping (dramatic mid-air twirls, just like you). Taking out one of the shims did a world of good for me.
So that's two more options for you to play with... ;)
Thanks Brian! The car ran great when I started with very worn K30s on the front. It just happened to be what was on the rims I chose. Problem started when I switched to new front tires :o
I had PN blue springs on the damper until a few minutes ago. I've also tried the PN #5 T-Plate.
After reworking the front moving parts a second time, I now only have the problem in left turns. I can drive the hell out of a right turn no problem.:D I've switched everything that can be switched from right side of car to left, but still have the problem on left turns. May have to work over the right suspension a 3rd time.
In the mean time I'll try your suggestions...:)
color01
2009.11.27, 05:57 PM
I'm on the #6 T-plate with the dual-spring PN top shock -- still have more than enough traction, and the roll resistance probably helps counter traction roll. Could try that too. ;)
Btw, are you braking while turning? That flips the car for me no matter what the setup, and will probably continue to do so until we get cambered front arms (I probably need about 1.5deg on mine).
cosmicsoul
2009.11.27, 06:39 PM
Jay, if I thought you knew anything about setting up a car I'd invite you over to help me out :)
Even if I did know anything about setting up cars and you invited me, I am too busy poolside at Myrtle Beach to oblige.
None the less I hope you get things worked out.;)
cosmicsoul
2009.11.27, 06:41 PM
Have you tried any forward trim on your radio? Just another thought.
Daddy Rabbit
2009.11.27, 07:16 PM
Jay,
Are you in MB?
Traveler
2009.11.27, 07:28 PM
I'm on the #6 T-plate with the dual-spring PN top shock -- still have more than enough traction, and the roll resistance probably helps counter traction roll. Could try that too. ;)
Btw, are you braking while turning? That flips the car for me no matter what the setup, and will probably continue to do so until we get cambered front arms (I probably need about 1.5deg on mine).
No breaking in the turn. Just coasting or light throttle. Will try to stiffen up the rear to see what happens. Bizzare how now it only happens in left turns. Glad we race clockwise at HSH. Fewer left turs :) Thanks!
Traveler
2009.11.27, 07:29 PM
Have you tried any forward trim on your radio? Just another thought.
You bum. Hope you took some cars to run with the MB guys...
Hope to see you before Christmas!
Have fun!
Traction is probably caused by:
1. Bumps on the track
2. dual rate on your radio is full maxed
What you want to do that may help:
1. Super Glue the entire Front tire sidewall on your PN20d slicks
2. Use PN6 Radials (taping it is fine)
3. Must use damper oil and apply on the dds
4. lower down steering dual rate until buzz noise is gone
5. White springs
Good luck and I hope this helps! =)
Traveler
2009.11.29, 12:31 PM
Traction is probably caused by:
1. Bumps on the track
2. dual rate on your radio is full maxed
What you want to do that may help:
1. Super Glue the entire Front tire sidewall on your PN20d slicks
2. Use PN6 Radials (taping it is fine)
3. Must use damper oil and apply on the dds
4. lower down steering dual rate until buzz noise is gone
5. White springs
Good luck and I hope this helps! =)
Thanks for the response TJ
1. My home RCP track is relatively bump free
2. S-Travel on my EX-1UR is set at 70% and my thumbwheel adjustment is also at 70%. No buzzing sounds at these settings.
1. CA on sidewalls seems to have made the flipping worse :o
2. Put some new PN6 Radials on the back just for kicks. No improvement.
3. DPS plate is sanded smooth and lubed well
4. See #2 above. Still too high?
5. Tried every color of PN springs.
Also removed a 0.3mm shim from below knuckles based on Brian's recommendation so I'm down to 1.2mm total. With the factory shims, I was getting major outsite wear on the tires! We really need cambered knuckles!
I'll keep trying... If I don't get anywhere the chassis may go in my clay pigeon thrower :eek:
Thanks again to all for your thoughts.
byebye
2009.11.29, 09:21 PM
What diff are you running? Does the car turn faster to one side more than the other?
Kris
cosmicsoul
2009.11.29, 09:35 PM
Turn your dual rate down some on your thumbwheel in incriments of 2.
Why not go back to the worn out Kyosho 30's you weren't having problems with in your previous posts?
Why not turn you steering to the left down with your steering balance?
It seems to me that most of my cars GT or LM traction roll with new Kyosho 30 rounds or 30 LM fronts until they get some laps on them. You could try truing them yourself with an emory board and dremel.
I know alot of guys run the Kyosho 30 radials in the front they seem to be flatter and lower profile. I could be wrong though.
I admire your persistance, when I break bad and finally buy an MR-03 you will definately be the go to guy!
greenepa76
2009.11.29, 09:47 PM
Hi,
I'm not an expert, but I'll try throw in some input as I have had the same experience with the new 03.
I have a F430 GTC body running the same wheelbase.
We race and putz around on RCP (smooth side) 5 days a week for 25-30 mins during our lunch break and I had really bad traction rolling issues at first with pirouettes all along the track that had a turn. Dolphin dancing and all just as you described. We all run stock cars with stock motors but no limitation on tires or body. Mild suspension upgrades are ok, but no aluminum parts to keep costs down.
Here's what I did to solve my traction rolling issue at work.
I run the PN #4 T-plate with a PN dual spring shock with a dark blue main spring (not very compressed with orange adjustment ring barely touching spring) and 120k diff grease for use as damping inside the shock body.
PN 20 degree slick front tires, PN 6 degree treaded rears on PN wheels with +1 offset all the way around, but I have since added 3 PN 0.2 mm shims per side for more front track. Tires are taped, not glued. I get a little chatter from the front tires sometimes with full throttle turns, but nothing too scary. Tires are not shredding like the 15 degree tires. Also using stock plastic spacer to reduce front ride height. I also use thin steel nuts (from RC helis) with a very small amount of thread lock to hold the front wheels in (watch those bearings) due to the limited thread exposure with the added shims.
Stock springs in the front with the same 120k diff grease on polished kingpins.
Stock Kyosho motor with 8 teeth pinion with Green TRP 900 batts.
I also pretensioned the rear diff with the same 120k diff grease used on the suspension to slow the diff action down some more ( only a little bit of grease). The rear axle is also shimed properly so that there is almost no side to side axle shift. I then added one of the larger diameter PN shims (from MA010 shim kit) to pretension the outer bearing on the wheel to act like a thrust bearing on a ball diff. It only applies pressure on the inner ball race so you'll have to lube frequently and be carefull how much you tighten that wheel nut! I like a lot of on power steering and don't have issues anymore with traction rolling except for coming over one of the crests we have on our bridge that runs over two sections of track. It will roll if I don't let the front wheels settle straight before the tight left hand curve after the "landing".
Hope this helps. Please ask if anything is unclear.
CristianTabush
2009.11.29, 10:26 PM
All you need is smaller front tires. The problem with the camber is also apparent to me, but I have not had a SINGLE traction roll to this day. Our track has REALLY good grip.
Per Traveler:
I could no longer take a u-turn at any amount of speed without the car rolling off the track. OK, too much front grip. Switched to PN 20d slicks in the front. Same problem. Switched to PN 25d slicks up front. Still rolled like crazy.
if the CA sidewall made your car traction roll, then I wont be able to help you on this, Sorry.
Traveler
2009.11.30, 05:13 AM
What diff are you running? Does the car turn faster to one side more than the other?
Kris
Hi Kris,
Currently using a PN 64p diff with 12/52 ratio. Tried another PN diff as well as a QteQ diff, both of which run great. No faster turning on one side. Entire rear end I'm using came off a mod car which was dialed. Only switched the motor out PN 33 turn for 70 turn before using on new 03.
Turn your dual rate down some on your thumbwheel in incriments of 2.
Why not go back to the worn out Kyosho 30's you weren't having problems with in your previous posts?
Why not turn you steering to the left down with your steering balance?
It seems to me that most of my cars GT or LM traction roll with new Kyosho 30 rounds or 30 LM fronts until they get some laps on them. You could try truing them yourself with an emory board and dremel.
I know alot of guys run the Kyosho 30 radials in the front they seem to be flatter and lower profile. I could be wrong though.
I admire your persistance, when I break bad and finally buy an MR-03 you will definately be the go to guy!
Thanks J. Still trying different radio settings. Can't go back to the K30's I was using because there is only 1.15mm of rubber left on them, but I may have some other worn out tires laying around I can use. ;)
Hope this helps. Please ask if anything is unclear.
Thanks for your reply. There is some good stuff you shared and I'll be trying out.
All you need is smaller front tires. The problem with the camber is also apparent to me, but I have not had a SINGLE traction roll to this day. Our track has REALLY good grip.
CT - The PN 20s I've been testing with on the front are starting to get there :)
I'll be out of town most of this week, so I'll be taking a break from my MR-03. The time apart may do us some good. Maybe she'll miss me and starting acting right! :)
Thanks all for your comments. Look forward to resuming my quest this weekend.
Traveler
2009.12.20, 07:53 AM
I promissed an update, so here it is...
My MR-03 will traction roll with ALMOST any new tire on the front (K30, PN20, PN25, etc.) Conversly, it will not traction roll with almost any well worn tire on the front (K30, PN10, PN15, PN20, etc.)
The only exception to this is the new PN Type-X front tires. I got some of these tires in one of my recent orders from PN. Although my car was doing fine with the very worn K30s on the front, I decided to try these new PN tires. Unlike Kyosho and other PN front tires, the Type-X tires are not round, but flat. They also fit the rim very snugly, so I haven't glued them to the rims. With the new PN Type-X 20s on the front, the car handles pretty well.
I'm still at a loss for why Kyosho would design a chassis the requires worn tires on the front to operate normally, unless they only tested this chassis with an LM setup which uses smaller diameter front rims and tires. That would explain why the 03 sits too high in the front with 20mm rims. Hopefully PNs new 03 Arms will be available soon!
lfisminiz
2009.12.20, 12:31 PM
Traveler - wish i could help with the traction roll. Im not getting why your rolls so easy.:confused: I didnt get to run my 2 much yet but both feel good, no hint of traction roll ...yet. I think both have KYO 30 fronts (trued lower). One has white PN springs, the other has purple. The front suspension moves pretty easy/good. The one track is my home basement track which is about 10 tiles long into a sharp turn. The other track i tried it at had a huge streight going into a sharp turn. I guess make sure you have not to much steering dialed in. Make sure front end is smooth/loose. Lower front with a shim under knuckle and true down tires. Make sure rear motor pod is fairly low too. Hope any of this helps. By the way, KYO has some nice lowering shims out for this front.;)
Traveler
2009.12.20, 12:41 PM
Thanks Larry! Its running OK now. Still tuning...
BTW Still waiting for a picture of "the Shelf" :)
lfisminiz
2009.12.20, 12:45 PM
TRAVELER - i have some time off comming up. Im going to try to get pics up of my latest bodies (race painted) and autoscale collection up. New camera should help. Ill probably start a thread in mult-media sub forum and make it on going and updated.........hopefully.;)
Traveler
2009.12.20, 01:06 PM
:cool: Can't wait!
Skv012a
2009.12.20, 02:55 PM
I promissed an update, so here it is...
My MR-03 will traction roll with ALMOST any new tire on the front (K30, PN20, PN25, etc.) Conversly, it will not traction roll with almost any well worn tire on the front (K30, PN10, PN15, PN20, etc.)
I'll second that it sounds like the tire profile is too high and catches on the wheel wells/inside causing it to lock and roll. I personally try to setup the front such that its absolutely free-rolling when suspension is maxed and wheel is turned both ways to avoid any unnecessary rubbing.
MINI-D
2009.12.23, 02:40 AM
Hi Traveler
do you have a part # for: the new PN Type-X front tires?.
Thank you. :)
D
Traveler
2009.12.23, 05:25 AM
Mini-D,
They are RXF15, RXF20 and RXF25. I'm really loving the 20s on my 03!
MINI-D
2009.12.23, 11:23 AM
Thanks Traveler ;)
D
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