My car worked well today with the smaller rear wing. I have gained some rear traction. Likely suspects are that I moved the motor left. The stiffer rear springs should have reduced traction, but I am able to run that right rear spring almost unloaded. This adds reverse wedge (left down tweak) and tightens the car.
OVAL NATIONALS DEBRIEF (road too)
As you might imagine I peppered the guys that went to the oval nats with questions. As I continue this oval experience I find more things that road guys and oval guys share rather than a big new body of oval knowlege so here goes.
Associated Front Suspension
This suspension has to be hand massaged as pointed out to me early in this thread. The guys that went to nats got a real eye opener. After making these mods one improved about 4 laps. The car traction rolled on the first turn. That is just huge improvement from any modification.
Four Laps!!! How can you not do this!
The main result is the kinkpin (home to all the stiction) drops by its own weight with only the spring removed.
Center Pivot Height (antisquat
Additional gains were made by having the chassis rake (forward low) and rear pod rake(rear low). This is done by extending the ball cup out on the center shock shaft. Use a soft center spring. Now I am just going to call this a high center pivot because I think this is responsible for the improvement. This increases antisquat (pivot height/pivot to axle distance) and improves forward traction. We discussed this a bit on the 1/10 pan thread. Boomer has discussed rake here; I am not remembering whether he ran this way or the opposite.
Now it is my suspicion that whoever had fresh battery packs that tested on the label or better had maybe a 3 lap advantage. We have had trouble getting this type of pack from normal retailers. I have four packs in the mail back to the manufacturer that were short 20-25% of their capacity on testing. More reason to change to LIPO.
EnerG brand charged at 8.25 amps (thats too high for club racing in my opinion, you are on the ragged edge of destruction) seemed to be holding up well and becoming common. Nat just blew an Orion NiMH cell at home, What a loud stinky mess. No injuries. I wonder if it was at 8.25 amps.
Side pivot springs
Were on the soft side. Stiffer on the left of the car, lighter on the right side of the car on rear tripple shock setups. The stiffer spring improves handling quickness. The soft spring keeps the rear roll stiffness low. This soft spring supllies the downtweak. Guys like the neutral position to not have a lot of preload on the springs. Adjusting the legnth of the rod ends shorter would help here by moving the spring seats out. IRS side shocks were favored. David Irrgang, owner of IRS
, was in attendance and racing.
Battery Tray Height
Factory Team Associated racers were running the battery tray with a couple of spacers under it to raise it up. This helps with chassis height problems and helped load the right front wheel. I made similar improvement by adding my longitudinal brace in the picture above. This actually picked up the front of the battery tray 2-3 mm when I put some compression in the brace with the turnbuckle. The chassis (not intended for oval) was sagged that much on the left side. This mod gives the car a little more roll and makes it less twitchy. You may have noticed some pictures of my cars with electronics up high for similar reasons.
Well if there is any place that rear steer (adjusting the pod clockwise from the top) would help, I thought it would be on carpet. None found on any of the top 13.5 class cars. I did a long search through Hobby Talk and found a couple of guys that tried it for stock on flat courses to help the rear rotate. It helped, but helps little when you get a little more power in the car.
So is the carpet setup as advertized by many posters trying to get rid of traction. Well not really. You do turn down your dual rate from 53% to about 20% once you get the car working good, but you reduce scrub if the car has good bite front and back. You reduce motor temps and can run higher gears if your car is not scrubbing as well. That is the way I see it from my interview. Same setups should work good on asphalt.
Rear Pod and T-bar offset. (from Hobby talk)
The LE executioner oval cars offer several mods to move weight on the pod. One is to offset the T-bar to the right. New holes are used in the pod. This is supposed to tighten the car (less oversteer). Next the rear pod can be offset to the left, a longer right hub is used. This further tightens the car. Next motor spacers can be used to move the motor left, this further tightens the car. My experience with one motor spacer suggests that these are significant changes. If your car is too tight maybe you need to ease up on one of these changes. The improvement comes from greater preload on the left rear tire. (Josh does that sound right).