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thestug
2011.04.17, 05:14 PM
I usually race my awd on slick floors. Lately my car likes to spin to the right on throttle. It's possilbe to correct with a bot of countersteer. I think my chassis must be tweaked. I have no other explanation. I have checked my atomic diffs, centered my steering on the remote, checked for binding in the drive train, etc... I was just wondering how to fix it so it will go straight under throttle. I need some one to explain how to fix tweak. I have found a thread that explains, but I don't understand as it has no pictures. Could someone please elaborate?

Scrapper
2011.04.19, 09:49 AM
As i was reading this I thought You could of had been using gear diffs at first which would result in a possible broken outdrive. But you are using atomic ball diffs. Did u check how tight the wheel nuts are? Sometimes an overtightened wheelnut can cause one of the wheels to stop spinning. Maybe it has to do with the tires being to low grip for the surface. I used to have problems like that back in da Xmod days. It would turn the slightest bit then spin out.
Also it could be that if you are using the original clear smoke grey chassis it tends to crack by the battery side on the bottom. Which will leave a 1-2mm gap on the right side of the bottom of the chassis as the batteries stretch it. That could be your culprit. If this is the case You should swap to the Solid Grey sp chassis. Its much stronger and will not result in that area fatiguing. All i run is awd nowadays and every clear grey chassis ive had i always immediately swap it out
If you can post pictures that would be helpful if they are detailed,
FRONT END REAR END AND BOTTOM AND TOP VIEW
Hope this was helpful
Lil Scrap Scrap

thestug
2011.04.19, 11:31 AM
As i was reading this I thought You could of had been using gear diffs at first which would result in a possible broken outdrive. But you are using atomic ball diffs. Did u check how tight the wheel nuts are? Sometimes an overtightened wheelnut can cause one of the wheels to stop spinning. Maybe it has to do with the tires being to low grip for the surface. I used to have problems like that back in da Xmod days. It would turn the slightest bit then spin out.
Also it could be that if you are using the original clear smoke grey chassis it tends to crack by the battery side on the bottom. Which will leave a 1-2mm gap on the right side of the bottom of the chassis as the batteries stretch it. That could be your culprit. If this is the case You should swap to the Solid Grey sp chassis. Its much stronger and will not result in that area fatiguing. All i run is awd nowadays and every clear grey chassis ive had i always immediately swap it out
If you can post pictures that would be helpful if they are detailed,
FRONT END REAR END AND BOTTOM AND TOP VIEW
Hope this was helpful
Lil Scrap Scrap

I use atomic aluminum outdrives, atomic plastic ball diffs, 3racing CF front and rear, blue/grey chassis, and stock knuckles. I run usually on very slick surfaces (linoleum and tile) I have no choice really. It seems like it only needs a small fix to make it right. I can mash the throttle and coutersteer to go straight,but I want it so it will go straight without countersteering.

Scrapper
2011.04.19, 12:42 PM
The tires are the stock i assume

thestug
2011.04.19, 03:17 PM
The tires are the stock i assume

Uhh, nope they are brand new GPM 20degs slicks f/r. It seems to spin on any of my tires though. I'm not exactly sure what tires to buy for slick surfaces. Can X-mod tires by cut to fit mini-z narrow tires? Do you have any recommendations for tires?

Scrapper
2011.04.19, 03:50 PM
Idk but probably pn 6 radial for rear

thestug
2011.04.19, 04:14 PM
Idk but probably pn 6 radial for rear

Do you really think the tires are the problem? I want the car to track straight on throttle ,not necessarily to remove wheel spin. I like my wheelspin. :D

Scrapper
2011.04.19, 06:11 PM
It is probably da tires the wheelspin makes it prob spin out

thestug
2011.04.20, 02:07 PM
I know my X-mod worked well on the same slick floor on hard tires. I wonder why the AWD can't do the same. I still think it is slightly tweaked because it always wants to spin one direction. If it were only wheel spin I would want to spin in either direction depening on steering input. I will re-assemble the car tonight to see if it helps.

KA2AEV
2011.04.20, 07:07 PM
Are you sure that you just do not have one wheel lug tighter that the one on the other side causeing the imbalance?

Scrapper
2011.04.20, 08:22 PM
Awd its not as important. But check that

thestug
2011.04.21, 07:35 AM
Are you sure that you just do not have one wheel lug tighter that the one on the other side causeing the imbalance?

Well I disassembed my entire car, because I'm upgrading to 2.4 this week sometime. I usually use lock nuts, so I dont thread them mor than necessary.

bermbuster
2011.04.21, 08:14 AM
did you try running without the body. If body parts rub or touch it can cause problems. Did you swap wheels from left to right?
With the body off under acceleration do the front wheels stay straight?
The way your diffs are set up can cause this as well. If your rear diff is tight the car will squat and the front end lifts reducing steering control.
Now that you have it apart look for cracked, and broken parts. Stripped and or over tightened screws....Aluminum parts can bend.....check them carefully.
Sometimes another set of eyes helps as well. Get another mini z maniac to help you look at it....

Action B
2011.04.21, 09:50 AM
I know my X-mod worked well on the same slick floor on hard tires. I wonder why the AWD can't do the same. I still think it is slightly tweaked because it always wants to spin one direction. If it were only wheel spin I would want to spin in either direction depening on steering input. I will re-assemble the car tonight to see if it helps.

I think there is a clue here. The Xmods are much more weight balanced, think of the battery and motor configuration. On MA-010, all the batteries are on one side. The additional mass on the battery side is probably giving that side higher grip and the fact that your on a smooth surface really makes the weight difference show as the heavier side of the car makes better tire contact.

Maybe tape some weight on the other side of the chassis from the batteries and see what happens. I think you'll be noticing a difference.

Scrapper
2011.04.21, 09:53 AM
That should work.

thestug
2011.04.21, 02:49 PM
Wow, all good ideas. I have checked the chassis for cracks. There are none. I am cleaning the bearing now in isopropyl alcohol, rihgt now. All my bearings spin free. I will make sure they are seated properly when I Reassemble. I have run without the body to make sure its not rubbing. Does any one know approximately how much weight to add and where to add it? My rear diff is set pretty tight, but how does this affect the steering?:confused: My steering does stay straight while it spins, so its not a steering issue. Thanks for the toughtful replys. :)

Bodom
2011.04.22, 11:54 AM
Hello thestug,
I have MA-010 and I drive it on hard floors too. And I have experienced such on-throttle spinouts too.
I would suggest checking the suspension this way:
Put the chassis on a flat surface;
Lift the rear end carefully and watch the rear tires lifting off. Then put slowly the chassis back on its wheels. The both rear tires should lift off and touch back the gronud simultaneously! If one of the wheels leaves the floor before the other and afterwards touches it early - you have suspension/chassis tweak. Repeat this for the front end. Then you can shim the knuckles/springs to reduce this tweak.
As for chassis weight imbalance - you can check it this way:
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z/P1010484.jpg
http://i447.photobucket.com/albums/qq194/Bodom_photos/Mini-Z/P1010483.jpg
The car rests on a hard stand from the right side and on an electronic scale on the left side.

Action B
2011.04.22, 03:56 PM
Great Body Bodom! I love the Lancia Delta. Such an under-appreciated car. Good suggestion on the chassis check by lifting the back. Many issues have been resolved for me with that method.

Bodom
2011.04.23, 02:47 AM
Thanks Action B. This Delta is my very first mini-z and I love it so much :)
thestug, if you need visualization of what I wrote - let me know and I'll make my best to show you :)

thestug
2011.04.24, 04:51 PM
I like the scale idea, but it seems inaccurate when I try the same. It would be nice to have pictures/video of the car lifting to test tweak. Where do you place shims if one tire does lift before the other? Nice lancia BTW, I have a yellow one:)

Bodom
2011.04.25, 01:12 AM
I like the scale idea, but it seems inaccurate when I try the same. It would be nice to have pictures/video of the car lifting to test tweak. Where do you place shims if one tire does lift before the other? Nice lancia BTW, I have a yellow one:)

Why is it inaccurate? Do you get different measures every time? If you measure the left side weight and add it to the measured right side weight - you should get the whole weight of the car measured on the same scale.:rolleyes:
Also the stand you use in the measure should be relatively the same height as the scale.
Here (http://www.youtube.com/watch?v=Uj3YZ49yU70) is my car having some tweak. In the video I use hook to rise the car as I would mess up with the camera if I used screwdriver as I usually do.
In my case the tweak is caused by binding rear knuckle.
Shimming is usually done by putting some shims under the knuckle or under the spring. Shims under the spring preloads it while not affecting the bottom position of the knuckle. While putting shims under the knuckle affects both bottom position and spring preload (usually).
I cannot give you general advise that will work in every situation.
Hope this helps.

thestug
2011.04.26, 02:11 PM
Why is it inaccurate? Do you get different measures every time? If you measure the left side weight and add it to the measured right side weight - you should get the whole weight of the car measured on the same scale.:rolleyes:
Also the stand you use in the measure should be relatively the same height as the scale.
Here (http://www.youtube.com/watch?v=Uj3YZ49yU70) is my car having some tweak. In the video I use hook to rise the car as I would mess up with the camera if I used screwdriver as I usually do.
In my case the tweak is caused by binding rear knuckle.
Shimming is usually done by putting some shims under the knuckle or under the spring. Shims under the spring preloads it while not affecting the bottom position of the knuckle. While putting shims under the knuckle affects both bottom position and spring preload (usually).
I cannot give you general advise that will work in every situation.
Hope this helps.

When I weigh both sides seperately and add the weight it is less than the total weight of the car by about 5-6 grams. I think I'm going to have to cut a block of wood or something that is the same height as the surface of my scale. Your video says it is private when I click on it. It won't let me view it.

Bodom
2011.04.27, 01:50 AM
When I weigh both sides seperately and add the weight it is less than the total weight of the car by about 5-6 grams. I think I'm going to have to cut a block of wood or something that is the same height as the surface of my scale. Your video says it is private when I click on it. It won't let me view it.

My mistake for the video access rights. Try now (http://www.youtube.com/watch?v=Uj3YZ49yU70).

thestug
2011.04.28, 05:37 PM
My mistake for the video access rights. Try now (http://www.youtube.com/watch?v=Uj3YZ49yU70).

Thanks, I see how the check is done, but if the electronics/motor side of the car lifts first, how do I adjust the preload, ride height, weight, etc... to compensate for the tweak? I have some .2mm shims somewhere. Should I try shims or just adding a bit of weight to the electronics/motor side.

Bodom
2011.04.29, 09:51 AM
Basically everything is explained HERE (http://mini-zracer.com/forums/showpost.php?p=348979&postcount=1).
I saw that you have read it.. But I don't know how to describe it more clearly.
First get rid of any suspension binding. Make sure every knuckle moves freely all the way. Then shim all the knuckles to adjust the desired ride height. After that make the lift-drop test.. and decide where to add shims to preload the springs.
Then test again and repeat the process until you get the desired result.
If it gets worse after adding shim - then you've preloaded the wrong spring.
Move the shim to the opposite knuckle (left/right).
Good luck.

thestug
2011.04.29, 11:10 AM
Basically everything is explained HERE (http://mini-zracer.com/forums/showpost.php?p=348979&postcount=1).
I saw that you have read it.. But I don't know how to describe it more clearly.
First get rid of any suspension binding. Make sure every knuckle moves freely all the way. Then shim all the knuckles to adjust the desired ride height. After that make the lift-drop test.. and decide where to add shims to preload the springs.
Then test again and repeat the process until you get the desired result.
If it gets worse after adding shim - then you've preloaded the wrong spring.
Move the shim to the opposite knuckle (left/right).
Good luck.

Ok, I will try to see what I can do. I have my AWD disassembled right now, because I'm waiting for my new 2.4ghz board. Can't wait. :D