- Serpent S411 - Ed Clark - Practice - Logan - 20.10.2012 -


PDF File


Best car has been on that track, car turning around rear, rather than washing the front.
Very stable! Needed a bit more mid rotation, but this was possibly down to tyre's (newer rears than front's after a cracked rim)
Steering - V2 (#401465), Ackerman spacer 1.5mm
Diff - Xray T3 (Xray#304900), 50mm rear shafts (Xray#305328), Xceed Oil.
Shocks - RCM, Delrin pistons (#160120), Tamiya black bladders (TAM53576), Blue Xrings (TAM42214) +0.7mm shim to seal, 1mm hole in top cap, minimum rebound, RIDE Springs (Ride#28026)
Motor Mount - V2 one-piece (#401451), with V1 centre piece (#401367). Top deck raised 0.5mm, and mount screwed into top deck in forward middle screw only
Suspension - All Hard plastics (Arms F #401452, R #401453, R hub #401454, C-hub #401455), DCJ's(#401445) in front, -1mm rear hex (#804195).
Top deck - Cut standard 2mm (#401374) to flexie shape, but with brace above steering posts.
Note about diff - Xray Driveshafts a direct fit into Serpent Axles, can use Serpent cross joint as well. Also VBC Wildfire diff and axles will fit (appear to be a direct copy of Xray) for half the price.... :P


Had a succesful night at logan last night, feel like I'm making good progress with the car now. Was stable, but with plenty of steering.
I know I've mentioned it before, and for fear of sounding like a stuck record, but the modded top-deck on the car really has made a big improvement. On the long drive home, I've come up with a description for how...
Before, the car would turn in, then washout, the front loosing grip (and I believe this is because it over-flexed), so all the settings were done to get the car to turn mid-corner to avoid this washing... and that then started to make the car unstable elsewhere (particularly in quick direction changes).

Anyway, tried a host of things again. From the previous week, went back to 3.0 block in first run that seriously helped to settle the car down a lot over the previous week. Car did feel quite lazy though, so for the first qualifing run, dropped 1mm out of the inner camber links to get back some corner speed, and this worked a treat. More corner speed in the high speed, and better reaction in the slow speed stuff
For the second qualifier, I just changed the top deck, back to the BD7 style mounting, and this did seem to help with getting the rear of the car to rotate more, had none of the weird nervous feeling that it had had before with the old top-deck. Still a bit of a lack of rotation mid-corner, but I had other things to try out, and due to cracking a rim, was running slightly newer tyres on the rear than the front.

For the first final, I wanted to test out something that a lot of guys in the UK are running, which is a Xray T3 diff in the back of the car. It's interestingly a direct drop in (amusing given Gary's post above!), although you need to use the 50mm rear driveshafts to stop them binding on the cup joint. Thankfully, they are all a direct fit into the serpent axles, can even use the snake cross joint. The diff itself is 10g lighter than a 2gear snake, and feels a lot smoother too boot.
Unfortuantly, following the practise laps (in which it did feel smoother to drive), the start didn't go to plan, as starting on the back of the grid off the racing line and covered in dirt, gave it some power and promptly 360'd into the rope, pulling the rear camber link out of the hub... doh!

So third final, left it as is, and the car again felt better, having a smoother feel (despite heavier oil in the diff), and seemingly better throttle response... I like it! Times I'm not sure on, but I was a lot closer and on pace with guys who I've been far behind in recent weeks, so a definite improvement, and feels like I've now found that base setup for me that I can just put down and it'll work without having to do lots of crazy stuff...

Never did get rid of the mid-rotation issue, but laying the shocks in one hole on the rear should help that.

Best news of the night though, was finding out that a VBC Wildfire diff is basically a copy of the Xray, and the standard CVD dogbones fit snuggly in the serpent axles... so rather than forking out $100 bucks for the xray stuff (I borrowed the diff and axles to test!), can get the same stuff for a fair bit cheaper... on the list for next time

Source: