June 22, 2010 RC Car Action

Project Baja 5B

One dialed racer

(see more photos below)

I have been a fan of the HPI Baja series of vehicles since I saw the fist photos of the prototype buggy and have had a few through the years. I mainly used them for bashing and was lucky enough to race my truck and buggy at the No Limit RC world finals in 2009. It was the most fun I had ever had racing an RC vehicle. The second I heard that HPI was going to be putting on an east coast Baja national at that same track, I started making tweaks to my vehicles so that I would be ready to lay the smack down when the race arrived. I learned a lot while racing last year and ordered some parts and made some tweaks that would make my SS buggy faster and perform better than ever. Here’s what I did to my buggy.

Shed some weight

Anyone knows that a lighter vehicle will go faster no matter what so that was the first thing on my wish list for this project. Basically any aluminum plate components including the chassis are offered in carbon fiber. According to Pro-Line when all their parts are added to the Baja, you can save up to a full pound of weight in the end. That’s a significant amount of weight savings and that will make a big difference on the track. All of the components are well made and fit perfectly on my buggy. The only issue I saw when installed is that one of the support members in the chassis is in line with the on/off switch. This isn’t really a big deal because you can use a small screw driver to operate the switch. I cut the member out of my chassis to make the switch easier to get to when I have my undertray in place. I further decreased weight and added durability at the same time by installing a full set of HPI’s heavy duty gears into the transmission. They are much stronger than stock and are not as wide as the stockers. So that means less weight and a transmission that runs more free because there’s less surface area on the gears which cuts down on friction.

Speed it up

Now that I had shed some weight it was time for a little more speed. I had some decent speed last year for the qualifiers but my slight lack in speed hurt me in the long 20min main. I stared by replacing all my ball bearings with a set of ceramic bearings from Acer Racing. They don’t save you a lot of weight but reduce the rolling resistance of the buggy a lot and that gives you the speed that you need to get up front. Next up was a new engine. The stock SS engine is perfectly fine and produces some great power. Now the S version of the HPI Fuelie 26cc engine has some internal tweaks to make it rev a little higher and produce a little more power so it was the perfect choice for my buggy. Before installing it I attached Outerwears pull-start and flywheel filters to keep debris out of the inner workings of the engine. I further increased the power of my buggy by installing a TGN Track pipe. It’s a rather large pipe but it’s not too heavy and it’s a great addition to my engine. I further increased horsepower by installing a velocity stack from Gabe Brown Engineering. It increases air flow to the engine and raises the air filter slightly at the same time.

Maximum traction

Now you can’t have all that power on tap if you can’t put it down. At the race the year before I found that Pro-Line Bow Ties worked the best on the track and so I left them on for this year’s event. The tires come in Pro-Line’s XTR compound and feature molded foam inserts. Their big lugs are great on fluffy dirt and hold up well from the abuse that the Baja gives them. You can pick them up mounted or unmounted and I went with the mounted fronts and rears for my buggy. Have you ever mounted a set of these tires? The bead locks take a long time to mount up. The included wheels are Pro-Line’s Desperado wheels and they feature a six spoke design, heavy duty bead lock wheels and feature a slight amount of off set for added stability. I also added a set of Gabe Brown Engineering axle extenders and Dark Soul capped wheel nuts to keep the dirt out of the front and rear axles. The extenders make the buggy wider and more stable and the front extenders are kept in place by a screw instead of an e-clip which will keep them in place even after the hardest hit. I had to clearance the front lower suspension arms slightly in order for them to work.

Increased durability

If you’re buggy breaks during the race you’ll never make it to the finish so I decided to install a few items to increase the durability of my Baja. Now these items do add weight and weight kills performance but part of the reason why I tried to reduce so much weight in my buggy was so that I can install some of these items to increase durability without adding too much overall weight to my buggy. The stock clutch bell carrier and top shaft bearing carrier are molded plastic components and can flex when the gears are under loads and that can result in blown spur gears. I replaced the stock clutch bell, pinion gear, clutch bell carrier, gear plate and top shaft bearing carrier with a HD Clutch System from Turtle racing (also distributed by TGN Distributing). The clutch is protected by a fully enclosed clutch bell carrier that features larger bearings for increases durability. Since the bearings are larger than stock, you also get a new clutch bell and pinion gear that fit those new bearings. The new gear plate is a little thicker than stock and has a bearing carrier for the top shaft built into it. With this system installed you will never have to worry about flex in those components ever again. Just to be safe I went with a steel spur gear from Robinson Racing. This sucker will never strip on you. Turtle racing drive cups complete the drivetrain package. They feature rings that are welded around the outside and they keep the drive cups from spreading under loads. I wanted to reduce any flex in the rear of the chassis so I installed a complete set of braces from Gabe Brown Engineering. They stiffen both sides of the chassis and a cross brace completes the package. On the suspension side of things, I installed a complete set of RPM suspension arms and I picked out the white ones so that I could die them orange to match the anodizing on the SS parts. The rear upper links are connected by a threaded rod that allows you to adjust camber. I was worried about that possibly bending on a hard landing and so I made a threaded sleeve after I had my camber set to keep that from happening. Turtle Racing shock towers protect the tops of the shocks and support the mounting screw on both ends to keep them from bending. I also added some aluminum shock tower supports from Golden Horizons to stiffen up the shock towers.

Slowing it down

Well, you can make a car faster and not have a better way to slow it down. I wanted to make sure my buggy was going to be able to slow down consistently and quickly and I didn’t feel that the stock brakes were going to be up to the task. I replaced the stock brakes with a Triple Carbon Brake kit with Aluminum Caliper kit from Vertigo Performance. It features three carbon fiber brake pads and one is mounted on each side of the brake disc assembly and a third replaces the brake disc spacer and sits between the two discs. There’s a lot of surface area with this system and that means better braking and less wear. The aluminum mount ensures a flex free setup and helps dissipate any heat buildup in the system. I ran into a bit of a fit issue with the setup and I found that when using this brake kit with the Turtle racing clutch system you’ll get some binding because of some dimensional differences between the stock setup and the Turtle Racing one. Vertigo Performance is working on that and I solved my issue by grinding a bit of the stock HPI pad away. There’s no time to wait when you have a race coming up!

Electronics

I wanted to make sure I had total control over my buggy during the race and I wanted a radio with some adjustments in it. For this buggy I us
ed an Airtronics M11X. This is one of the fastest radios on the market and it’s packed full of features. It’s also one of the easiest radios to navigate through when making adjustments. The most important feature is the failsafe; which is a very important thing to have when you are running a buggy this big. The stock servos work well when bashing but for racing, I wanted more control so I remove the steering servo and replaced it with an HPI SFL-30MG Digital Servo and it produces 249.96oz-in of torque. For throttle and brake I used an HPI SF-32TT digital servo and that produces an impressive 333 oz-in of torque.

Sweet body

I dressed up my Baja by painted up a new body from Pro-Line and I used Parma Faskolor paints to match the TGN wing wrap that I installed. I made all of the logos on my vinyl cutter and made stencils so I could paint everything onto the body. To keep dirt out of the chassis and my weight as low as possible while racing, I went with a Pro-Line undertray. It does a great job of covering the openings in the chassis and it increases the look of the buggy at the same time.

Performance

I drove my buggy around on some dirt piles near my house to make sure that everything worked like it was supposed to before heading to the race. After a few tweaks, I was ready to hit the track. I didn’t get to the track until just before qualifying so I didn’t have much time to get things figured out on my buggy. I just had to go for it. During practice I was very impressed with what I had built and was confident that my weekend was going to go well. The new engine/pipe combo was producing an impressive amount of power and I’m sure it had more to give. I was going to lean it out a bit but didn’t want to risk blowing up my engine at the nats. The brakes were flawless and easily locked up the tires every time I went for them. My Pro-Line tires were also pretty hooked up. During practice I was running with a few of the fast guys at the race and keeping up with them without a problem so I shut the buggy down and got ready for qualifying. As the day went on the track started to fall apart and my dialed buggy didn’t feel as good as it did during practice. The rear end was stepping out a lot and the traction just wasn’t there like it was before. For rounds two and three of qualifying I was still fighting my buggy as the track got worse and worse. On my way to the track I decided to make some major tweaks to my buggy before the main. I had such a hard time the day before and I figured that I would have to try to bump up into the A-Main and to my surprise I had made the cut. I figured I put my best laps down in that first round. So now, I was determined to win and got to work on my setup. I removed the swaybars, changed back to the stock tires since the track was starting to pack up a bit and I changed the shock fluid in the rear shocks. I was ready! Then, I had some engine issues. It wouldn’t start just before the race and I had to rush to figure out what was wrong and tried to fix it. After changing a bunch of things on the engine, I replaced it with the stock engine. That engine wouldn’t run either so I replaced the tank and solved my problem. In the main my buggy was a lot easier to drive and I was doing well that is until my pipe came loose and the engine started to cut out.

Well….

I had a great time building and racing my Baja 5B. I might have had some issues at the HPI Baja East Coast Nationals but the tweaks I made improved its performance and I’m now more ready for the next big race. I just have to go and tighten some bolts and clean it up and I’ll be ready to dominate. I hope.