nutsisneat

I had my first outing this weekend at the nationals (Pro-Stock 13.5 blinky)
During practice, on used tires, i could almost go the pace of the fastest guys(+0.2-+.3 sec), but with new handout tires, my car had just not enough traction (about 0.6 sec slower).The race was affected by some rain, track dried up, afterwards i was just off the pace (about 0.6 sec slower than leaders). I had .5 shims under rear lower arms and i'm still using AM26. Is AM06S a must have to get the lowest possible roll center, i see it on almost all setup sheets, most often with 0mm under arms. Any other hints? THX

Oleg Babich

AM06S + 0mm under arms provide the lowest possible roll center and also the possibility of the increased camber gain at the moderate low roll center.

The additional tip for the further lowering of the roll center - removing (grinding) 0,5mm of material from the foot face of the lower AT21 balls. This tip is indicated as AT21S in the setups ( for example in the latest setup from Dominic Vogl ).

nutsisneat

@Oleg

Thanks for your quick reply.
So you think i'm working in the right direction to cure the traction issues?

Just double checking...

THX

hanulec

iTrader: (28)

Lowering the roll center helps.
Other options are trying alternate link lengths and inner/ outer camber link heights

It can depend how the car is (or isnt) rolling..

BlackedOutREVO

iTrader: (67)

Oleg- Does the center driveshaft flex under power or braking? If so, is it a lot? I want to mount my capacitor under it. Doesn't seem like they would touch, but I figured I'd ask.

kyle478

I'm curently running my cap right below the shaft. The capacitor is 1-2 mm away from the shaft and it hasn't rubbed at all.

I have run the car with and without am11 and haven't had any rubbing.

AARON YOUNG

iTrader: (15)

There's a ball bearing guide that keeps it from flexing to the left and down.

Oleg Babich

My current point of view: we should keep the inner lower balls of A700 suspension as low as possible as we can easy transform it either to very low roll center or to the additional camber gain.

MDawson

iTrader: (27)

If you run the center driveshaft guide it should prevent deflection. I have not issues of space or rub issues with a ORCA power cap directly mounted under the driveshaft.

BlackedOutREVO

iTrader: (67)

I figured the guide would keep it from flexing, just wanted to make sure. Thanks guys!

hanulec

iTrader: (28)

And just so everyone is clear -- this requires the "hand making" of the at21s by grinding 0.5mm off the bottom of the at21 balls.

Dawson shared with me his method --
1. Using a long screw, drive the screw through the top of the ball
2. Using a dremel with sanding disk trim the excess metal off the top of the ball from step 1 until appears smooth
3. Measure that balls height using a caliper.
4. With the screw inserted through the new hole at the top of the ball, start grinding the hex bottom of the at21. Continue to measure the ball height to only remove 0.5mm.
5. Always repeat the measurements of step 3 for each ball as their overall heights will be slightly different after breaking through the ball top.

Does anyone have a better method to make a at21s??

Jerry P

iTrader: (44)

No issue here either. I was running my LRP cap directly under the shaft. With the guide in place there is no way it would hit what's below it unless the shaft actually fell out.

hana166

iTrader: (2)

That's brilliant. Didn't think of that. I don't have a better way but as I found AT21S out of stock,

I bought a carbide counterbore, used a 3mm drill blank as a guide and set depth stop to deepen the recesses from 0.5mm to 1mm. So I can just carry on using the standard AT21. Just ripped off the wishbones and bulkheads to do the job. Good if you know anyone with access to a workshop as it takes 5 mins to set up and about a minute to do a plate. If I can find the time I might be able to do a handful for others.

hanulec

iTrader: (28)

Wow - drilling the chassis! Go you! That is an approach, but I rather wreck some at21 balls than a chassis plate.

osorron

Hello, have someone heard about a program called rc crew chief?