Xray T4 LCG conversion and more...
#33
Not so fast my good friend. You changed the angle of the shock relative to it's lower mounting point once it is in motion. Picture this please, with the shock lowered it will rotate with the arm more than converting that motion to shock travel. That's why the nitro sedans and Proto have the shocks mounted that way, to still retain the shock travel to wheel travel part right.
#34
Tech Adept
Joined: Jul 2014
Posts: 227
Thanks!
Going by your setup:
1. narrower front end using bushings but increase width back to maximum by using wider wheel hexes, middle height bushings(try centred dot and inmost, see which one you like more);
2. now use the same rear bushing configuration as you have in the setup but raise them to top position.
Both changes increase roll stiffness (not bad by itself) but most importantly keep the roll centres a bit higher (they are bellow ground stock, that is a crutch).
3. now that you've increase roll stiffness you have two options, 1 if the car is too stiff and the wheels get off ground at every tiny bump them the springs are too stiff and you need softer ones. 2 the car is too responsive during cornering, increase camber link inner shims by 1mm front and rear and use thinner roll bars.
4. I think your front bushing configuration is the culprit together with the flex. See the Ford GT arm sweep configuration.

Going by your setup:
1. narrower front end using bushings but increase width back to maximum by using wider wheel hexes, middle height bushings(try centred dot and inmost, see which one you like more);
2. now use the same rear bushing configuration as you have in the setup but raise them to top position.
Both changes increase roll stiffness (not bad by itself) but most importantly keep the roll centres a bit higher (they are bellow ground stock, that is a crutch).
3. now that you've increase roll stiffness you have two options, 1 if the car is too stiff and the wheels get off ground at every tiny bump them the springs are too stiff and you need softer ones. 2 the car is too responsive during cornering, increase camber link inner shims by 1mm front and rear and use thinner roll bars.
4. I think your front bushing configuration is the culprit together with the flex. See the Ford GT arm sweep configuration.

#35
Joined: Sep 2010
Posts: 3,569
From: My house.
Now that you mention ic TC yes, their suspension is similar to that one I shared and has less roll than normal electric TC. The main points are the upper arm angle and upper arm length compared to the lower arms. If that generates more grip depends on many tire parameters like sensitivity to load, construction and chemical composition.
#36
Tech Adept
Joined: Jul 2014
Posts: 227
Now that you mention ic TC yes, their suspension is similar to that one I shared and has less roll than normal electric TC. The main points are the upper arm angle and upper arm length compared to the lower arms. If that generates more grip depends on many tire parameters like sensitivity to load, construction and chemical composition.
#37
Joined: Sep 2010
Posts: 3,569
From: My house.
Cant compare both cars, the ic ones have the centre of gravity far higher than electric TC. If you've made extensions then you positioned the lower shock point closer to the wheel, therefore increased wheel rate (stiffer spring at the wheel).
I'm testing today some changes to a standard TC suspension to address the high amount of roll these cars have, will update here soon.
I'm testing today some changes to a standard TC suspension to address the high amount of roll these cars have, will update here soon.
#38
Tech Adept
Joined: Jul 2014
Posts: 227
Cant compare both cars, the ic ones have the centre of gravity far higher than electric TC. If you've made extensions then you positioned the lower shock point closer to the wheel, therefore increased wheel rate (stiffer spring at the wheel).
I'm testing today some changes to a standard TC suspension to address the high amount of roll these cars have, will update here soon.
I'm testing today some changes to a standard TC suspension to address the high amount of roll these cars have, will update here soon.
#39
Joined: Sep 2010
Posts: 3,569
From: My house.
Lower arms level and compensate the upper arm angle so the roll centre remains at ground level or slightly above, that cut roll tremendously. The way you are doing it's softening the spring at the wheel, it will roll and bottom out more. To lower the CG and lessen roll you have to do like xray ulp shocks, shorten them and mount them lower.
#40
Tech Adept
Joined: Jul 2014
Posts: 227
Lower arms level and compensate the upper arm angle so the roll centre remains at ground level or slightly above, that cut roll tremendously. The way you are doing it's softening the spring at the wheel, it will roll and bottom out more. To lower the CG and lessen roll you have to do like xray ulp shocks, shorten them and mount them lower.
#41
Joined: Sep 2010
Posts: 3,569
From: My house.

The thing I'm trying is the lower arms parallel with ground, the middle figure in the pic.
About the shock being softer or stiffer depending the angle and distance away is simple Mathematics. The farther away and/or lay down the shock is the softer it is and vice versa.
Test went half well, the car lacks bite and grip but roll seems too little.
#42
Tech Adept
Joined: Jul 2014
Posts: 227

The thing I'm trying is the lower arms parallel with ground, the middle figure in the pic.
About the shock being softer or stiffer depending the angle and distance away is simple Mathematics. The farther away and/or lay down the shock is the softer it is and vice versa.
Test went half well, the car lacks bite and grip but roll seems too little.
#43
Joined: Sep 2010
Posts: 3,569
From: My house.
I think you are misunderstanding how a suspension works. Doesn't matter where the force goes, for that the suspension only has to manage camber, toe and track width. Where you put the other stuff isn't important, the huayra puts the shock above the suspension because it can't be packaged anywhere else.
#44
Tech Adept
Joined: Jul 2014
Posts: 227
I think you are misunderstanding how a suspension works. Doesn't matter where the force goes, for that the suspension only has to manage camber, toe and track width. Where you put the other stuff isn't important, the huayra puts the shock above the suspension because it can't be packaged anywhere else.
Red arrows: how the force is being apply and where.
Blue arrow: that’s where in conventional cars the shocks would be and where the force would be apply on
#45
The only part of the car touching the track is the tyre. You can't magically create (or reduce) weight transfer with some trick suspension geometry.
The geometry affects RC, damping, stiffness, camber gain etc. But the tyre can't tell where you've mounted your links and shocks. It's just a tyre. That car pictured will be made like that for mechanical/layout reasons.



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But is crazy enough to try it 