January Jam Trophy Race - Hotrod Hobbies - Hamilton

January Jam - Tuning Goals

Before I post my setup I would like to mention two things I set out to do for this race that I think helped tremendously.

1. I rebuilt my shocks after practice and before the last qualifier, but not to change the oil weight. I simply refilled them and built them with as little rebound as possible. After a few runs the shocks tend to suck in some additional air and leak some oil and this increases the rebound. I prefer to run with little rebound as the car is easier to drive fast and doesn't react abruptly or get out of shape. Another racer said my car looked like it was very settled on the track and was almost flopping around. I think that is the point I'm trying to make. The car was settled and had a good amount of steering but it wasn't aggressive or twitchy. I think someone else said it was like a wet noodle.

2. No major setup changes!! Just drive the car and keep it on all fours. After practice i did shorten the rear camber link and checked my camber settings. The only other change I made was to add 1mm spacer to inside ball stud on front camber link and lower the front ride height 1mm after the first and second qualifier. I wanted to keep the car similar in feel each run. The rear camber link change was done to reduce the amount of rotation in the corner to help with stability on 'the ice'. By keeping the car consistent I forced myself to take advantage of where it was working well and adjust my throttle or braking to get through areas where it wasn't ideal. The tight corners on the far right side of the track were slower than I would have liked but I kept things simple by driving nearly the same setup each run. This helped me so much in the main. I could run 39 consecutive laps without having too many surprises and no crashes. The wood section that we love to call 'the 'ice' was very slippery in the final and I had to compensate how I drove the corner (less steering input) so I wouldn't over rotate. I think when people were leaving or bringing their stuff to their cars it cooled the wood and decreased traction. But the goal of driving the same setup gave me a car that I was comfortable with.

I will admit that a decent setup makes the task of driving lap after lap without crashing is crucial. A lot of that setup is useless without good tires but the setup and tires I ran allowed me to stay true to my goals. Setup will be posted tomorrow!

It was very easy to drive and had a good amount of steering, although I do use the brakes in nearly every corner.

Front

30 wt oil, 2 hole 1.6mm pistons, green springs, 3mm limiters

middle on tower, middle on arm

-2 camber, 1/2 toe-in

2-A camber link, 1mm spacer under outside ballstud, 3mm under inside ballstud

aluminum camber block

19mm ride height

25 kickup, 5 degree caster (brass kick up spacer and aluminum pivot)

4 mm trailing spindles (from SCT), spacer behind spindle

1.5mm spacer on top of caster block, 0.5 mm below

no bump steer spacer

Rear

25 wt oil, 2 hole 1.6mm pistons, pink springs, no limiters, shock ends unscrewed 2 turns

middle on tower, outside on arm

-1.0 camber, 3.5 degree toe in (HRC)

2 degree antisquat

1-B camber link, 2mm spacer under inside and outside ballstud

long wheelbase

20.5 mm ride height (measured under transmission)

+1.5 hexes

Aluminum bulkhead/camber block

Misc

Losi gear diff w/ 5000 wt oil

Gearing - 26/78

Team Bluegroove body and Jconcepts wing.

No additional weights on chassis

Electronics

CRC Short Lipo all the way to the rear

Viper VTX10 and Viper 13.5 motor

Spektrum 6040 servo

Spektrum 3100 receiver

MRT PTX Transponder

Tires

Rear: Schumacher mini pin rears (approximately 6 runs)

Front: Schumacher cut stagger low profile (approximately 12 to 15 runs)

No traction additive.

Thanks for the set-up tips much appreciated. I am trying to follow the reasoning behind the changes so I can get better at tuning myself. if you don't mind I have a few questions.

What is your thinking behind the two hole pistons vs just using heavier wt oil? Where can i get 2 hole pistons?

Also, why the 4mm SCT spindles?

The two hole pistons have much bigger holes to compensate for the reduced number of holes. They allow the oil to pass faster initially but then slow down considerably in the later part of the compression. I can drive the car harder into the corners and it also lands jumps with more confidence. You can buy Associated 12mm piston set and it has 1.5, 1.6, and 1.7 sizes. The 4mm trailing spindles calm the steering down and produce a smoother feel through the corner. Stock spindles have 2mm trail

Source: Bob's RC Blog