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Old 03-18-2017, 05:10 AM   #31
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hey Marco, shot in the dark here because you said this is your first electric TC.

Check your belt tensions. The front belt should be slightly tighter than the rear. Or the rear slightly looser than the front, depending on how you look at it
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Old 03-18-2017, 01:12 PM   #32
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Yes this is my first EP TC.
Just a question, the xray manual leads me to a doubt.
To get more steering, the steering rods have to be straight (forward hole) or more angled (rearward hole) ?
I know that more angled links correspond to more ackermann so more steering but the manual says the contrary.

Anyway, in the past I found a way to run good with this model, using a Lola Blits body. Lot of steering in every corners, so maybe I only need more weight in the front.
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Old 03-18-2017, 03:03 PM   #33
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I have been comparing your setup with the recommended asphalt setup on PetitRC. You have the car higher and with longer rear upper camber link. Springs are comparable so only thing that stood out was that long rear camber link. That would promote more roll on the rear and would cause the rear outer side to collapse during a corner and raise the inside front tire, massively cutting on power steering. You can try shorter rear link or raise the rear lower arms on the bulkhead side, both lessen roll.
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Old 03-18-2017, 03:21 PM   #34
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Originally Posted by maRRRco View Post
I know that more angled links correspond to more ackermann so more steering but the manual says the contrary.
More Ackerman gives less steering, especially mid to exit, so maybe that's why you're struggling. That and the long rear link.

Read my post a few posts up.
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Old 03-18-2017, 03:23 PM   #35
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I have been comparing your setup with the recommended asphalt setup on PetitRC. You have the car higher and with longer rear upper camber link. Springs are comparable so only thing that stood out was that long rear camber link. That would promote more roll on the rear and would cause the rear outer side to collapse during a corner and raise the inside front tire, massively cutting on power steering. You can try shorter rear link or raise the rear lower arms on the bulkhead side, both lessen roll.
According to xray setup book longer rear camber link provide less roll and more on throttle steering.
Nobody say me to work with roll center, should be the right way? I never usually change them in my nitro cars.
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Old 03-18-2017, 03:45 PM   #36
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Originally Posted by maRRRco View Post
According to xray setup book longer rear camber link provide less roll and more on throttle steering.
Nobody say me to work with roll center, should be the right way? I never usually change them in my nitro cars.
Mr. Dale's suggestions are spot on, I forgot about Ackerman.

About the longer link creating less roll it's one of the many flaws and errors on the Xray guide. The shorter the link the less the car rolls. Try shortening the rear link one step and also try lengthening the front one.
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Old 03-19-2017, 01:34 PM   #37
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Ok, the links now are short.
Probably I found the origin of the problem, it isn't the front of the car like I thought but is the rear, is too planted on the asphalt.
This is due to a combination of springs and tyres. When I switched to a softer rear tyres (28) (because my lrp 32 exploded!) with 15 lb rear springs was a nightmare. I have to put my 25 lb springs, and finally good feeling, the rear was good, I never lost it also with this hard springs, how can be possible?
Then I tried a set of 32 and with this springs the rear was unstable on corner exit. So probably I need the right combination.
Anyway I don't understand why I need this hard rear, I never seen something like that in other cars.

Last edited by maRRRco; 03-20-2017 at 01:49 AM.
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Old 03-20-2017, 02:38 AM   #38
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Originally Posted by maRRRco View Post
Ok, the links now are short.
Probably I found the origin of the problem, it isn't the front of the car like I thought but is the rear, is too planted on the asphalt.
This is due to a combination of springs and tyres. When I switched to a softer rear tyres (28) (because my lrp 32 exploded!) with 15 lb rear springs was a nightmare. I have to put my 25 lb springs, and finally good feeling, the rear was good, I never lost it also with this hard springs, how can be possible?
Then I tried a set of 32 and with this springs the rear was unstable on corner exit. So probably I need the right combination.
Anyway I don't understand why I need this hard rear, I never seen something like that in other cars.
25lbs springs are probably too hard for asphalt racing in modern TC's
Most people use from 14lbs to roughly 18lbs at the highest.
But you are correct that you need to find the correct combination
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Old 03-20-2017, 03:54 AM   #39
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Quote:
Originally Posted by maRRRco View Post
Ok, the links now are short.
Probably I found the origin of the problem, it isn't the front of the car like I thought but is the rear, is too planted on the asphalt.
This is due to a combination of springs and tyres. When I switched to a softer rear tyres (28) (because my lrp 32 exploded!) with 15 lb rear springs was a nightmare. I have to put my 25 lb springs, and finally good feeling, the rear was good, I never lost it also with this hard springs, how can be possible?
Then I tried a set of 32 and with this springs the rear was unstable on corner exit. So probably I need the right combination.
Anyway I don't understand why I need this hard rear, I never seen something like that in other cars.
Your experience corroborates what we've been saying. The rear is too soft in roll because of the long rear links, taking more time to start and stop rolling than the front, therefore weight transfers side to side slower and the grip limits are almost unreachable, high enough that you have to use crazy spring stiffness to have some collaboration from the rear. I could go lower than half that because as you might get from what I said the geometry I run is almost perfect, allowing the use of such soft springs (on tarmac, with all good things that come from them).
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Old 03-20-2017, 05:31 AM   #40
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OK, but now also my geometry is correct!
However I need hard spring.
Ok, tyres (28) are probably too soft for my track with 22 C, so very hard spring were necessary. En fact with a new set of 32 they are too hard, the rear was unstable. So maybe something like 20 lb should be the way to go with this tyres, or better, I'have to use 36 tyres with more standard spring, a bit too hard rear than front.
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Old 03-20-2017, 07:01 AM   #41
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Originally Posted by maRRRco View Post
OK, but now also my geometry is correct!
However I need hard spring.
Ok, tyres (28) are probably too soft for my track with 22 C, so very hard spring were necessary. En fact with a new set of 32 they are too hard, the rear was unstable. So maybe something like 20 lb should be the way to go with this tyres, or better, I'have to use 36 tyres with more standard spring, a bit too hard rear than front.
With rubber tyres we don't run different compounds front to rear, always the same on all 4 wheels.

Different rubber compounds heat up at different rates, and have optimum grip at different temperatures, so for a consistent handling car you need 4 identical tyres.
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Old 03-20-2017, 07:42 AM   #42
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Originally Posted by maRRRco View Post
OK, but now also my geometry is correct!
However I need hard spring.
Ok, tyres (28) are probably too soft for my track with 22 C, so very hard spring were necessary. En fact with a new set of 32 they are too hard, the rear was unstable. So maybe something like 20 lb should be the way to go with this tyres, or better, I'have to use 36 tyres with more standard spring, a bit too hard rear than front.
Do you have to run a control tyre, if not then run a Sorex 32 if you can get hold of them?
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Old 03-20-2017, 08:01 AM   #43
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Quote:
Originally Posted by maRRRco View Post
OK, but now also my geometry is correct!
However I need hard spring.
Ok, tyres (28) are probably too soft for my track with 22 C, so very hard spring were necessary. En fact with a new set of 32 they are too hard, the rear was unstable. So maybe something like 20 lb should be the way to go with this tyres, or better, I'have to use 36 tyres with more standard spring, a bit too hard rear than front.
We will see about that You are thinking contrary to what I run, softer tires have a lower working temperature so soft springs and so on...

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Originally Posted by daleburr View Post
With rubber tyres we don't run different compounds front to rear, always the same on all 4 wheels.

Different rubber compounds heat up at different rates, and have optimum grip at different temperatures, so for a consistent handling car you need 4 identical tyres.
As an aside, most TC trash rear tires, one thing is the ring of death (too much static or dynamic camber) or just wear, indicating the rear tires are overworked. Agree with me?
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Old 03-21-2017, 03:30 AM   #44
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We will see about that You are thinking contrary to what I run, softer tires have a lower working temperature so soft springs and so on...



As an aside, most TC trash rear tires, one thing is the ring of death (too much static or dynamic camber) or just wear, indicating the rear tires are overworked. Agree with me?
Not at all, I have never had a ring of death on the rear tyres, the front tyres do most of the work so they wear the most
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Old 03-21-2017, 07:57 AM   #45
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Not at all, I have never had a ring of death on the rear tyres, the front tyres do most of the work so they wear the most
Great to hear, to be honest the tires I use wear very well but I have a collection of used tires given to me to study that most if not all have some kind of ring of death (various drivers from across the country and different manufacturers).

Waiting to hear feedback from Marco
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