Zerodefect

Pan cars are still more addictive than TC.

Touring cars are the WWE of carpet on road.

bgymr

iTrader: (2)

I'm a big fan of simple, anything 4wd doesn't meet requirement. More than twice the bearings and drivetrain parts.

Zerodefect

And weight. TC's are 1380 grams. More weight equals more broken parts whenever you hit a turn marshall.

JeffofSpace

Thanks, All. Here in Seattle this class started with 2-3 cars at the beginning of the season, now a dozen.

I’m coming from 1/12 stock and mod, so some of the tuning advice is a bit different. Why such medium center shock springs? In both mod and stock 1/12 we run a stiff center spring. Does the forward battery position play into this?

old_dude

iTrader: (1)

Just a refresher guys. The front hinge pin mounting blocks do not establish caster on their own (0, 5 & 10). Those a reactive blocks, not caster blocks. They determine the rate caster is removed upon spring compression. Caster is established by locating the upper arm forward or back on the chassis with respect to the lower kingpin pivot ball. This is a very common mistake made even by veteran racers.
Note on my caster numbers. I run as much much as possible. Typically right up to the point that the car wants to over rotate on corner exit. Then I back it down until the car flows out of the corner smoothly. On my CRC car the front of the reactive blocks and clamps are actually machined away to allow for more caster than available out of the box.

liljohn1064

iTrader: (17)

How much static caster as measured at the king pins? How are you modifying the caster mount/ lower arm to increase caster?.

JeffofSpace

The 0, 5, and 10 degree blocks...the hinge pins rest on top of them.

old_dude

iTrader: (1)

And those numbers are the angle of the hinge pin with respect to
the chassis, not the amount of caster.
I grind away the front of the reactive blosk and the hinge pin clamp. This allows for the upper arm to be positioned further reward and increase the static caster.

JeffofSpace

Ah right, read fast and thought he was asking about reactive. Thanks.

liljohn1064

iTrader: (17)

Gotcha, I never thought about trying something like that. I usually run very little caster to begin with. I might have to play around with a set of caps and caster blocks and a lot more shims. It makes sense that the further back you tilt the king pin, the more direct the action of the front suspension will be as it compresses and then decompresses.

Zerodefect

I've always found that more reactive caster smooths out mid corner and exit. And reduces traction rolling a little in the same spots. Kinda over rated. I use the medium reactive caster in 12, and none in wgtr.

And that static caster may increase turning in, and mid corner. More caster always seems best, until the car gets tippy or too intense.

Opposite of every tuning manual. Go figure.

old_dude

iTrader: (1)

If you put the car on the scales and turn the front wheels you will see what caster does. It transfers weight from the outside to the inside front wheel and to the opposite rear wheel. That is wedging the car which helps it rotate. The reactive reduces caster on compression. ) has no reduction, 5 is medium and the 10 is max caster reduction on compression. The opposite happens on the side that lifts. To see it, take a wheel off and cycle the kingpin up and down with each reactive block.
Now we can approach another subject. Roll center. The CRC front end has available roll center shims. Lets hear some of you run that one around.

Zerodefect

I run the thinner carbon fiber shim in 12 stock to calm the car down. Thick shim sure felt like understeer to me. No shim on the WGTR.

redmonster27

iTrader: (34)

Hey old dude. I run. Both the 2mm and 2.5mm. Shim in my car at the same time. That's right 4.5mm of roll center shim added. I ran it at the champs that way. Seems to make the car very reactive

JeffofSpace

Where do you adjust roll center on the car?