2WD indoor set up soft vs stiff

[lee.romang]

I am racing a TM2v2 on a high grip, flat and fast indoor track and struggling to get a good set up.

I have tried stiffening the car and lowering it to get rid of grip roll and lose some front end but the car is still hard to drive.

Having spoken to a well respected F1 driver he suggested going the other way, softening and raising the car to make it more docile and easier to drive.

This is a completely alien way for me to set up a car on this kind of track but you have to listen to someone of his level.

Does anyone have any more thoughts on this soft vs stiff set up?

[sosidge]

There are lots of important things in a setup apart from ride height and springs. Tyres are 90% of any setup.

As far as the suspension settings go, buggy geometry is designed around bumps and jumps. The geometry "works" when the front wishbones are around level and when the rear driveshafts are around level. If you slam the car low, you get the CG down low (which is good) but you also make the roll centre a lot lower (which will increase the tendency to roll). Stiffer springs will compensate for that lower CG a little.

But slamming the car low also means that the shocks have even more droop. This is good for bumps and jumps but unnecessary for a completely flat track. More droop also encourages grip roll.

First way to approach the grip roll problem is tyre choice. If you have too much front end, use a tyre with less grip.

With suspension settings, either run the car on a conventional off-road setup, or if you want to slam it low and run stiff springs, decrease the shock length as well to get rid of the droop you don't need. It might require a lot of shock rebuilds to get the right settings but a car with a lower CG is going to be quicker once you get it sorted.

[lee.romang]

Originally Posted by sosidge

There are lots of important things in a setup apart from ride height and springs. Tyres are 90% of any setup.

As far as the suspension settings go, buggy geometry is designed around bumps and jumps. The geometry "works" when the front wishbones are around level and when the rear driveshafts are around level. If you slam the car low, you get the CG down low (which is good) but you also make the roll centre a lot lower (which will increase the tendency to roll). Stiffer springs will compensate for that lower CG a little.

But slamming the car low also means that the shocks have even more droop. This is good for bumps and jumps but unnecessary for a completely flat track. More droop also encourages grip roll.

First way to approach the grip roll problem is tyre choice. If you have too much front end, use a tyre with less grip.

With suspension settings, either run the car on a conventional off-road setup, or if you want to slam it low and run stiff springs, decrease the shock length as well to get rid of the droop you don't need. It might require a lot of shock rebuilds to get the right settings but a car with a lower CG is going to be quicker once you get it sorted.

Thanks for this are you saying spacers in the shocks to restrict the ride height could ultimately get a better performing car on this type of track?

[sosidge]

Yes, but it might take a few experiments to get the right setup - each mm difference in a shock makes a surprsingly big difference to the handling.

By the way you don't want to restrict the ride height, you want to restrict the droop. Artificially lowering the ride height with spacers will make the car handle like a complete dog.

[lee.romang]

Originally Posted by sosidge

Yes, but it might take a few experiments to get the right setup - each mm difference in a shock makes a surprsingly big difference to the handling.

By the way you don't want to restrict the ride height, you want to restrict the droop. Artificially lowering the ride height with spacers will make the car handle like a complete dog.

Ok thats interesting. Does less drop mean less grip or just less roll which will make the car less likely to roll over?

When should drop be added?

[sosidge]

Take a look at elvo's setup guide, it can answer your question and many more http://home.scarlet.be/~be067749/58/

[MHeadling]

http://www.petitrc.com/setup/teamc/S...sTeamCTM2.html

[lee.romang]

Originally Posted by sosidge

Take a look at elvo's setup guide, it can answer your question and many more http://home.scarlet.be/~be067749/58/

Thanks for the advice.