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Old 03-25-2017, 06:57 PM   #61
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Yes but I never used that tyres, I put them only to take some pictures
The rear tyres used last time are identical to front one, pretty shiny inside, but one of them exploded, so I had to glue it and now are put away.
I have run on a similar track and have found that the stock setup is still the best starting point with a few exceptions.
1) raise the lower rear arm pivot point by 0.5mm over the front. (Higher roll center in rear)
2) 7-10k rear diff oil.
3) Rear shocks: 3rd hole from bottom. (Laying the shock down will make it more progressive and stiffer under load)
4) I understand that it's still a bit cold where you are but Weather permitting, use 34-36 degree tires and treat with Master Gripper "yellow" for at least 15 minutes. These will me more consistent on large sweeping tracks. Tire warmers will be useful too.
Used tires are fine for practice once you have a good baseline setup but until then, get a new set of tires of the same brand as the faster drivers at your track. As you say, "other drivers get around the track quite well". Use the same tires and you can eliminate them as the culprit in your search for a proper setup.
If your suspension is properly set up, the front should feel a little more compliant (softer) than the rear when pressing down on the shock towers with the same springs all around. This is due to the shock mounting points on the rear arms being farther out from the hinge point. That's good as the rear won't roll so easily. (More steering under acceleration)
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Old 03-26-2017, 09:56 AM   #62
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Thanks so much, trying to make these changes I found that shims under rear pivot are only 3mm instead of 4mm suggested by xray setup sheet. I was convinced that they were 4mm, I have a good eye for these things but this time ...
Now it's ok.
About diff oil, I don't like so much 10k because the rear tend to be unstable and the car doesn't get some improvements on power steering. So the real problem is really the roll of the chassis, now I have to work in this way.
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Old 03-26-2017, 10:21 AM   #63
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You mean the shims on the upper part of the rear wheel upright?
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Old 03-26-2017, 11:36 AM   #64
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You mean the shims on the upper part of the rear wheel upright?
The shims on the upper part of rear hub, that of course change roll center and camber gain
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Old 04-16-2017, 04:28 AM   #65
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Hi guys, I probably found an ipotetic origin of the problem. Actual la is only teoric. I though that front springs were 15lb, but no! My used model came with sakura S zero springs, 5.5T about 23lb! So this can explane why I need hard rear tyres, because front ones are also too hard. Could be a reasonable possibility? I have to try normal springs, 2.8 or 3.0 by xray
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Old 04-24-2017, 04:42 AM   #66
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Nothing. It understeers! There is nothing to do, I tried also super super hard rear springs, but in that curve initially understeer than in the middle when I push more with throttle the car spins away.
Just two things I noticed, the wheels wobble at max steering rate, you can see move right and left enough. The steering at very very low speed is inconsistent, the car describes too large circles in my opinion I don't know why, but feels less directe, too "gummy"
The front CVD are not perfectly straight.
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Old 04-24-2017, 06:07 AM   #67
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Try softer springs. 2.8 and 3.0 are probably too hard.
Do you have any 2.6 springs you can try front a back?
I used to run HPI silver springs on my T3 cars
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Old 04-24-2017, 07:30 PM   #68
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Originally Posted by maRRRco View Post
Nothing. It understeers! There is nothing to do, I tried also super super hard rear springs, but in that curve initially understeer than in the middle when I push more with throttle the car spins away.
Just two things I noticed, the wheels wobble at max steering rate, you can see move right and left enough. The steering at very very low speed is inconsistent, the car describes too large circles in my opinion I don't know why, but feels less directe, too "gummy"
The front CVD are not perfectly straight.
When a car is all messed up and wont run right no matter what, you take it apart down to the last screw and then re-assemble according to the kit setup. Xray's steer really hard. Something is amiss that you aren't catching, and a full teardown seems like your current best option.
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Old 04-25-2017, 04:21 AM   #69
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When a car is all messed up and wont run right no matter what, you take it apart down to the last screw and then re-assemble according to the kit setup. Xray's steer really hard. Something is amiss that you aren't catching, and a full teardown seems like your current best option.
I did it until the last screw, and everything is good in my opinion. Only the front CVD are not perfectly straight, and today I'll switch them with rear ones. I didn't find nothing else.
Now the model runs with 2.7 xray springs at the front.
So my conclusion is one: the model itself doesn't have enough steering, or the tyres are not good. I used the same tyres, lrp 32, from the beginning, then, when one tyre exploded, I used sorex 36 only in the rear, and lrp in the front.
It's not an ideal situation, but if the car feels good, don't matter what tyres you are running, I think.
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Old 04-25-2017, 06:22 AM   #70
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I did it until the last screw, and everything is good in my opinion. Only the front CVD are not perfectly straight, and today I'll switch them with rear ones. I didn't find nothing else.
Now the model runs with 2.7 xray springs at the front.
So my conclusion is one: the model itself doesn't have enough steering, or the tyres are not good. I used the same tyres, lrp 32, from the beginning, then, when one tyre exploded, I used sorex 36 only in the rear, and lrp in the front.
It's not an ideal situation, but if the car feels good, don't matter what tyres you are running, I think.
You need to have one matched set of tyres.
If you mix tyres that have done a different number of runs that's not good.
Mixing from different manufactures is even worse.
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