SoCal U4RC Summer Series 2018 – Round 4 – Apple Valley Raceway

Tony Phalen April 25, 2018 New RC Cars and Parts 38 Views

Race 4 of the 2018 U4RC Summer Series had us heading back to Apple Valley RC – yes, I actually made it to the correct track the first time (see my Race 3 post where I screwed up my locations). The weather report speculated a bit more heat than past races, so not only was I prepared with some extra bottles of water, I was also expecting a dry, loose track. My Bomber-preparedness plan was looking good (from a workbench standpoint), so I was hoping it would pan out on the track. The Tekno – well, that car pretty much drives itself. Let’s get to the race report…

Axial RR10 Bomber

I’ve been struggling with the Axial Racing RR10 Bomber, having a hard time getting it to where I’m comfortable driving it. The solid axle thing just isn’t my bag, baby, but I’m committed to coming up with a setup. That being said, I made a few changes to hopefully help the performance of this beast on track.

One of the first things I did was remove the spare tire and mount. I’ve been contemplating this for awhile now, thinking the tire might magnify the ‘pivot’ of the Bomber off power – that’s a lot of extra weight out back. I didn’t necessarily want to lose the weight, just relocate it. So, I pulled all the parts off, weighed them and matched that with some lead stick-on weights. As for a place to put it, the Bomber comes with an empty fuel cell just behind cockpit, so that worked perfectly for all the lead. This option also allows you to tune how much weight is used, however I haven’t worked with that just yet.

On the track, this modification did seem to settle the Bomber’s rotation down a bit, making it a easier to drive on the pebbly track. It also seemed to jump a little more flat and land with more of a ‘clunk’ (read: less bouncing), so there’s that. I feel like it’s alot of weight up high, so another relocation might be in order (or removed all-together).

I made a final change to the front shocks. I emptied out the 10wt oil and went to 15wt, however I also drilled out the pistons to a slightly larger hole. I think the oil viscosity/ spring rates were a little off and, since softer springs aren’t available, I figured I’d go with a heavier oil (and drilled pistons). That helped out tremendously with the bouncing front end – now a more ‘squishier’ front end that seemed to soak up rocks and landings better. It was feeling really good at this point.

2.2 Solid Axle – Qualifying
The track had been watered before both qualifiers but, by the time it got to the 2.2 Solid class, most of the wet had gone away. The Bomber felt good in the first qualifier but still didn’t quite have the pace that Jesse Villa’s rig had – he’s the current 2.2 Solid National Champion and a pretty fierce competitor – he’s got that rig figured out! I put down a good Q1 but decided to make a few more changes for Q2. I disconnected the front anti-roll bar (to help through the rocks) and stood the front shock up – never thought I’d use this shock location but let me tell ya, it made a pretty significant difference! I waited a bit at the start to let the group go and was putting in great lap times, ending the heat with a 6/6:00.230 – just missing that 7th lap. Unfortunately that missed final lap relegated me to 2nd overall – had I made it, there’s a good possibility I could have TQ’ed (seeing as laps were in the 45ish second range). I’d be seeing the back of Villa’s Bomber at the start of a race … again.

2.2 Solid Axle Main Event
Before the main started, a call went out to see if drivers wanted the track watered before the start. Some said yes, others said no (including me), but they went ahead and did it anyway. At this point, I KNEW I should have re-connected my front anti-roll bar – watering the track was going to up the grip quite a bit. At the start of the tone, I was able to get past Jesse into the first rock section, but that’s where things sort of fell apart. With a tacky track, the Bomber became difficult to drive and started traction rolling everywhere – and it wasn’t just mine! It took me about a lap to alter my driving style to the track conditions and I could see Jesse right up in front of me – it was on!

Of course, until I crashed. And crashed again. Oh, and the traction roll followed by another crash. Pitiful lap. Started to overdrive the rig on a track that I wasn’t prepared for; simple as that. Oh, and I finished with an 8/6:00.710 – again missing the extra lap by tenths.

Thanks to everyone that has supported Project Bomber. Pay them a visit and see all the cool gear they have.
Car: Axial Racing RR10 Bomber
Servo: Hitec D-951TW High Torque Titanium Gear Servo
ESC: Castle Creations Mamba X Sensored ESC
Motor: Castle Creations 1406 Sensored 4600kV Brushless Motor
Battery: MaxAmps 6500mAh 2S 7.4v LiPo Battery
Wheels: Axial Racing 2.2 Walker Evans Wheels
Tires: Pro-Line Racing Hyrax 2.2″ G8 Rock Terrain Tires
Radio System: Futaba 4PX Computerized Radio System
Paint: Sharkbait Designworks

Still fun and a great day of learning. Here’s the 2.2 Solid A-Main video:

Tekno RC DB48

After Round 3, I did a full inspection of the Tekno RC DB48 and came up with a few options I suggest getting. All of these are long-term fixes and should really help keep the DB48 on-track.

Tekno RC V2 Aluminum Adjustable Hinge Pin Brace “D” Block
The suspension block that takes the most abuse in rock racing is certainly the “A” block – the one at the front of the car. The second, though, would be the “D” block. This part is exposed at the back to rocks and, even though it’s designed as a pretty substantial chuck of plastic, a hard enough hit could cause it to flex and potentially pop a hinge pin – mine was looking pretty beat! To help beef up this area, grab one of Tekno’s Aluminum V2 Hinge Pin Braces. It’s a direct bolt-on, accepts the stock suspension pills and adds some peace-of-mind when flying through the rocks.

Tekno RC Hardened (and Lightened) 44T Spur Gear
In Round 3’s Race Recap, I suggested picking up 3 or 4 of the Tekno plastic 44T spur gears. While I still think that’s a viable option, I installed one of their 44T Hardened Steel Spur Gears to test it out. My thought process is this; any small pebbles that get caught in the plastic gear might get spit out simply because the plastic will flex (but get deformed in the process). With a hardened (and lightened) steel gear, there ain’t gonna be any flex. If a rock gets caught up in there, it’s lock-up city. I’m going to keep using the steel one for now, but am also going to look at modifying the chassis to allow rocks to fall through the bottom, similar to most 1:8 scale vehicles.

Tekno Aluminum Servo Horn
This is actually an upgrade you should do right away. Like, right now. As you’re reading this, flip over to Tekno’s site and pick one up. Seriously. I guess I’ve been pretty lucky, but not this race. Q1 saw me strip this out after the first lap – the rocks can really pay a toll to a 9lb rig with a plastic servo horn. Thankfully my buddy Shawn Rusin was on hand with a spare to get me through the race day. Aluminum servo horn ordered and on the way. Just make sure you get the one for your servo (ie, 25T for Futaba servo, etc).

2.2 Unlimited – Qualifying
I’ve been looking to get a little more rotation out of the DB48 without having to mess with the diffs – that’s a messy tuning chore. I removed the steering stop shims and shortened the wheelbase a bit – that was a good choice through practice and going into the Quals. Q1, however, ended after the first lap when I stripped out the plastic servo horn. No bueno. A quick dig through a Shawn’s parts box had another one in my hand, but now I was a little freaked that it might happen again! Q2 came and it was all about putting in consistent laps – not shooting for anything super fast and certainly trying to protect that servo horn! I was able to put in a time good enough for 3rd qualifier – 1 second behind 2nd and a full 7 seconds off the TQ (ShumzzR himself). That’s fine – a clean run was all I was looking for.

2.2 Unlimited Main Event
At the start tone, I thought I might be able to squeeze past 2nd qualifier Chris Pickering, but after a slight touch I thought it safer to hang back and wait to see how the first couple of corners panned out. That worked great as Shawn and Chris touched going through the first snake section, allowing me drop into 2nd heading to the left part of the track. That, however, only lasted for a short time. That back tabletop is very deceiving; while it may appear that you’re lined up for it, it has a slight curve to it and, if you’re not really lined up, will send you off and into the only tree around – watch the video and you’ll see. Another unforced error (decision to double jump or not) on the following lap had me upside down again, but then it was head down time. At the 6-minute mark, I was able to put in a fast 11 lap run to take the win! This car is simply amazing!