Matt’s Schumacher CAT SX – February/March 2010 Update

My latest outing with the CAT SX saw me competing at the new-look Indoor Finals race that’s now called the BRCA British Winter Open Championship. In 2010 the BWOC would be hosted by the Worksop club at the Bassetlaw sports centre venue that also hosts the popular Schumacher Winter Series.

After chatting to Toni Rheinard of Speed Passion Europe at the recent Petit RC event, my CAT SX was now equipped with a Speed Passion speed controller and motor, replacing my ultra-reliable but dated LRP stuff. The LRP products have been so very reliable with the motor only ever once being removed in the CAT SX chassis since it was installed around 15 months previously.

The install of the new Speed Passion was relatively easy although its dimensions and design meant a little dry fitting before finally deciding upon a suitable layout. The greatest problem came from the MRT personal transponder that in some places can have a serious affect on the range and level of glitching. After some fiddling and adjusting, the Speed Passion package was installed and checked, before packing up and heading to Nottinghamshire.

The surface at Worksop is an indoor sports floor that is rubberised and is of low to medium grip. The tyres are the same as what we used at Maritime last month for the Petit RC event but the grip is much lower. My starting et-up saw me make a number of changes including removing the front ant-roll bar and moving the front lower shock position back to the middle.

First practice was OK, but I knew I wanted to try the chassis without the 130g lead weight under the chassis. The second practice and the car was event better by being more agile without affecting the balance. This was how I would start the racing. Its now I have to confess that I am a RC driver who has only competed at National and Regional events using the staggered start system. As a result, my race craft is not as good as some others who have honed their skills to a much higher level. All I can say is that I didn’t enjoy the racing. The BWOC adopted the Reedy Race format where you have five races against different people. In most of my five races I found my inadequacies highlighted, ending up in the middle of the pack. My other short coming is that I can drive better in practice without the pressure, but my lines go to pot and I tighten up as soon as the serious stuff begins! As a result, I was not at the sharp end of the field come the end but the car worked well. It wasn’t helped though when the front belt snapped before one race and the fact that I was collected a couple of times by drivers behind me. Hindsight is wonderful and looking back, I probably should have softened the oils as it was a little too stiff in damping, especially with the large lead plate removed, but I can’t change it now!

That said, the Speed Passion items worked well and I left the gearing the same as my previous stuff. I did play around with the settings on the speed controller as I tried different levels of drag brake and punch, but once again, I confess that it was my ability that meant I finished where I did and nothing to do with car or equipment.

As I write this though, I like many are eagerly awaiting delivery of the new version of the CAT SX called the SX2. With big bore shocks, tweaked suspension parts, new transmission pieces and a revised chassis, there is little point in me running the CAT SX so my focus has been on the 2WD. Hopefully my next update will be all about the new Schumacher 4WD buggy and how that goes!

Matt’s Schumacher CAT SX Specification

• Car: Schumacher CAT SX
• Radio: KO Propo Vantage III Universe
• Receiver: KO Propo KR-302F
• Servo: Spektrum H6040
• Speed Controller: Speed Passion Pro GT2.0
• Motor: Speed Passion Competition 3.0 5.5R
• Batteries: LRP 5300 40C LiPo
• Charger: Much More ACDC Silent Charger Platinum LCD
• Gearing: 21/83

Set-Up

• Front Suspension
• Oil: 
40wt
• Piston: Three-hole drilled to #55
• Spring: Schumacher Grey (old)
• Track Washers: 1mm front and back
• Anti-Roll Bar: None
• Shock Position Mount: Middle
• Shock Position Wishbone: Middle
• Front Rake: 10-degrees
• Caster Block: 10-degrees
• Washers: 0mm
• Front Link Bracket: 38mm
• Washers on Hub: 0 (hub carrier trimmed down level)
• Rear Suspension
• Oil: 35wt
• Piston: Three-hole drilled to #54
• Spring: Schumacher Red (old)
• Wheelbase: Short
• Toe In: 3.25mm
• Anti-Squat: 1.3-degrees
• Rear Link Bracket: 37.5mm
• Washers: 3mm
• Shock Position Mount: Middle
• Shock Position Wishbone: Inside
• Hub Position: Middle
• Anti-Roll Bar: None
• Transmission
• Rear Diff Height: Low
• Front Diff Height: Low
• Layshaft Pulley: One-way
• Front Drive: Diff
• Gearing: 83/21
• Internal Ratio: 23/33

Notes

• Schumacher Yellow Minipins
• Front firm insert
• Rear soft insert
• Front tyres with a row off inside and outside
• Diaphragm centre cut out and removed

Thanks to everyone who assists me with my racing including:

• CML Distribution
• Horizon Hobby UK
• JConcepts
• LRP
• Much More UK
• RudeBits
• Schumacher
• Speed Passion
• Trishbits
• Upgrade