14LikesTamiya F104 Pro!
12-08-2010, 06:25 AM
#3963
if you shim the rear you will go from a negative castor number to a more positive number ie -4 castor to -3 castor which will give you more turn in, less high speed steering. shimming the front will do the opposite. BUT since the arm is in a fixed state you cannot shim too much or the arm will bind (i dont know what the limits are though). the thing is though by using the Tamiya style of camber adjustments when you add more negative camber you also decrease the castor too (see the sketch i posted earlier) so if you want to counter act what the camber adjustment does than you should shim the front to attempt to get the castor back to where it was.
12-08-2010, 06:50 AM
#3964
ok through the wonders of autocad i have drawn out exactly what will happen if you add rear shims to the arms! as the suspension is compressed you will lose static negative camber and i think we all agree with that but what may surprise you is that according to my sketch raising the rear shims by 4mm only gives you .006" of a decrease(with 2mm of arm travel) which is not very much at all (avg human hair is about .007") . now according to Robk doing this will increase mid corning and that is true but now this is got me thinking. my main issue with the 104 frame chassis is just not enough steering in general on asphalt, i just cant seem to get enough high speed steering with the available tire at all. this weekend im going to experiement with this and see what i can come up with on the mantisworx front i can set my static castor to where i get enough turn in and then shim the front so maybe i can get more high speed steering. in theory it should work but i dont know if i can get enough shim under the front to make it effective.
12-08-2010, 07:05 AM
#3965
while we are on the subject of front ends anyone want to explain how the new generation of 1:1 F1 is calculated? you cant apply the normal roll center rules to them because the arms never cross paths! i made a model with "high center" and it is very aggressive as far as what it does when weight transfers. i think that because the chassis is so long you dont get as much "roll" therefore the geometry has to be very aggressive to keep the tires flat. anyone have any insight or links that explain?
12-08-2010, 07:54 AM
#3966
if you shim the rear you will go from a negative castor number to a more positive number ie -4 castor to -3 castor which will give you more turn in, less high speed steering. shimming the front will do the opposite. BUT since the arm is in a fixed state you cannot shim too much or the arm will bind (i dont know what the limits are though). the thing is though by using the Tamiya style of camber adjustments when you add more negative camber you also decrease the castor too (see the sketch i posted earlier) so if you want to counter act what the camber adjustment does than you should shim the front to attempt to get the castor back to where it was.
so in layman terms, shim the rear for technical tracks and shim the front for high speed flowing track?
12-08-2010, 08:06 AM
#3967
ok through the wonders of autocad i have drawn out exactly what will happen if you add rear shims to the arms! as the suspension is compressed you will lose static negative camber and i think we all agree with that but what may surprise you is that according to my sketch raising the rear shims by 4mm only gives you .006" of a decrease(with 2mm of arm travel) which is not very much at all (avg human hair is about .007") . now according to Robk doing this will increase mid corning and that is true but now this is got me thinking. my main issue with the 104 frame chassis is just not enough steering in general on asphalt, i just cant seem to get enough high speed steering with the available tire at all. this weekend im going to experiement with this and see what i can come up with on the mantisworx front i can set my static castor to where i get enough turn in and then shim the front so maybe i can get more high speed steering. in theory it should work but i dont know if i can get enough shim under the front to make it effective.
12-08-2010, 08:36 AM
#3969
i agree with both of you????? i was just clarifying it for those who dont understand(arahawk). i did try it and it does work! there is no argument here at all GEEESH!
12-08-2010, 08:37 AM
#3970
Its always good to back up the feel with the math.
12-08-2010, 08:58 AM
#3972
thank you! it seems like i cant even agree without an argument busting out! i like to verify everything too!
12-08-2010, 12:38 PM
#3974
you have to use ride wheels with ride tires, i made the same mistake!