John Stranahan

iTrader: (27)

Oval Meet
Jimmy's Battle Axe Test and Tune

Jimmy has a brand new original model Battle Axe at the track. At first he was not sure to run it or not. Today it was at the track built up. Having some experience with the car things went fast and well.

Firstly the front suspension was tight. We took off both kingpins and polished them until they dropped through the lower bushing without friction. We loctited the little brass set screws by previous experience. We ran the kit red front progressive springs pointy side up with no upper spring bucket. They may be a little soft. I notice in my previous setup I have written purple springs which are 1# stiffer. Next session we should try the purples as we had a tad too much steering traction at days end.

We set the left down tweak with scales to 12 ounces. This means the left rear weights 12 ounces more than the right rear. This proved to be about right again but was difficult to obtain with kit springs. We changed to a Wind Tunnel right rear copper 15#, and left rear orange 6#. I reversed the nut on the right rear shock and added an RC18T spring collar to the inboard end of the nut. All this was required to get 12 ounces. Note there is a stiffer set of Windtunnel springs now available that would make this task a little easier. Also, readjusting the length of the plastic rod ends on the right side shock may have helped.

We offset the left rear outboard about 8-9 mm. This makes the car go to the right out of the corner instead of looping in toward the inner board on corner exit.

We used 35 weight oil all arround. The center spring was medium about 15 lbs by touch and was silver in color. Don't know the brand, so I cannot be precise here.

We set ride height to 5.5 mm in the front by adding a 3 mm CRC shim to the 5 mm shim on the car. We set the rear at 7 mm for now. This will drop to a good height with some tire wear. He had all new uncut tires on the car.

Unfortunately the car came with a new radio. 1/4th of your oval setup is in the radio. I removed huge amounts of exponetial (nearing 100). I think this was put in backwards as the car was very sensitive near the middle and would tend to huge weaves with slight movement of the wheel. Anyway go easy on this and usually you want to go negative to remove sensitivity near the middle. I removed half of the travel. I tightened the servo saver screw one full turn. Finally the radio was almost right. The dual rate adjustment on the DX3 radio was unknown to me or I would have cut steering some more. We had too much. I also felt a small size servo saver was not returning to center well. Use the Kimbrough Medium Servo saver instead.
Kimbrough 131 Medium servo gear saver Hitec$3.89
Kimbrough 201 Medium Servo Saver, black, Includes adaptors for Futaba, Hitec, Airtronics$4.95

We set chassis level. We will set rear droop to about 2 mm. Right now its about 5-6 mm.

Jimmy was running the typical oval wing. I increased angle of attack to match the winshield which I have heard is good for flat asphalt. I believe this is in the Hypedrive tips Barry posted earlier in this thread. This helped pin the rear down better in the turns.

We finished the session on xxPink left front, Purple right front, Pink left rear, XXPink/purple right rear. The car drove well. We still had too much steering traction. A little stiffer front spring should cure that. As we finalize this setup I will make changes to my original setup on this car. We have learned a good bit about tires since I posted a battle axe setup before.

pics, some cars from todays meet.
John.