Exotek B6 / B6D battery strap review

I spent the evening doing some touch up work on my B6D, and installed the Exotek battery strap.  I'm a big fan of Exotek stuff, but I'm really not a fan of this strap.  The fit is super tight on my shorty battery and pretty much impossible to get the battery in or out of the chassis.  You'd have to shave the parts down a bit to loosen the death grip they hold on the battery.  Also, the brace presses down tightly on the motor wires, so you would probably want to reroute them from their normal location.

Exotek makes really great parts, but for me, this battery strap is a miss.  I will be taking it out and selling it.

No replacement for displacement

That's a well known phrase in motorsports, which basically means horsepower is going to help you more than anything else you can do to your racecar.

Even in the RC world, I find that to be true.  I spend a lot of time tuning the handling, traction, and responsiveness of my cars, which definitely improves the consistency of my lap times.  But honestly, every single time I stick in a faster motor, or use a fresher battery, or drop some weight off the drivetrain, it drops more tenths off my lap times than any sort of new shock package or roll center change.

The last time I went out with my 17.5t B6D, I was doing lap times consistently in the 16.3/16.4 second range with some old, worn out Lipos.  I removed the car, put in one of my newer batteries, and the first lap out I did 16.0 seconds.  Literally no other changes, just put in a better battery with more punch and dropped 0.3 seconds.

So to that end, I finally decided to get some MIP pucks and a lightened/cut topshaft, along with the Exotek battery strap for more rear traction and some bling.  I was already running MIP bi-metal outdrives, but the Pucks have dropped another 9 grams of rotating mass on the driveshafts and aluminum outdrives, so the buggy should be faster.

The current layout at my local track has a tight right-hander directly into a monstrous jump.  With a slow 17.5 buggy, you need to take a wide entry line and a long run-up to make the jump  With a fast 17.5, you can apex the corner and immediately go up the jump, so horsepower definitely helps a ton in your lap times.

Hobao Hyper TT tuning

I spent the afternoon at my local, indoor clay track tuning the Hyper TT.  It's now driving WAY better than the stock setup.  Note that that these changes are for indoor clay on slicks, it's probable that a looser surface would require a different setup.

I got rid of the front swaybar the second day out, and this time I ditched the rear swaybar which made the truck come alive.  It does roll a bit, but I'm now running pretty stiff springs, and you need that roll to generate traction.  With the rear swaybar, the only way you can get the car to drive is to huck it into a corner and slide the rear around, but that's really not the best way to go about driving.

The stock setup has really soft rear springs, and overly firm front springs.  The front damping is actually pretty close, but the rear damping is too firm.

What I'm currently running is Black Losi 2" front springs, and Blue Losi 2.5" rear springs.  Front shock oil at Associated 30wt and rear oil at 27.5wt.  Guys in the past apparently were running 25wt in the rear, but I found too much movement and it was pretty unbalanced running 30/25.  30/27.5 is much better.  This shock package makes for a more composed, balanced, and stable vehicle.

Shock package:

• Front:  Losi Black (LOSA5135), Associated 30wt oil
• Rear:  Losi Blue (LOSA5160), Associated 27.5wt oil

The other main issue with the truck is that it pitches forward and back way too much.  The stiffer springs and shock oil help, but I ended up moving the rear arms back 1 spacer (1mm) which lengthens the wheelbase a little bit and keeps the truck more stable.  I also added 1mm less droop in the rear from full extension which keeps the truck from pitching forward so much under braking.  So I'm at full droop front (no limiters) and 1mm less droop in the rear.

The other area I spent some time developing was my electronics package.  Normally I run cheap $50 Hobbywing Justock ESC's, but this Hobbywing SCT Pro I'm running has a lot more adjustments than I'm used to.

Changes I made to the ESC:

• Coast is at 10% (up from 0)
• Braking at 75% (down from 100)
• Punch at 6

The Hyper TT tends to nosedive when you let off the throttle, but the Coast % smooths the off-throttle setting which keeps the truck more flat through the air.  This is the first ESC I've had with this setting, and it definitely helps smooth out the truck and the way it flies.  Highly recommended if you have the adjustment.

The last thing I did was replace all of the steering bushings with bearings and add a 1mm TLR ballstud washer on top of the posts.  For some reason, the top screws like to back out, I'm hoping this alleviates it a bit.

Overall I found the truck has a fair amount of slop and movement, but you just have to trust it and muscle it around and ignore the fact arms, hubs, and wheels are moving around all over the place.  It will stick.  It always drives better on power -- even in the air, a tiny bit of throttle keeps it stabilized and flying flat.

I still broke a rear arm and that ended my day, and I also forgot to get the dogbone, so I'll be upgrading to rear CVA's this week.

Futaba 3PV / T3PV transmitter bag

I found this lunchbag at Target that makes a perfect radio bag for the Futaba 3PV.  It zippers closed, has a little bit of padding and only cost $5!

http://www.target.com/p/embark-insulated-cooler-lunch-bag/-/A-51359801

No titanium needed

I threw my B6D on the scale.  The only lightweight parts it has is the slipper eliminator and AE lightweight body.  Everything else adds weight (brass C-block, aluminum D-block).  It's amazing how light the latest buggies are!

Hobao Hyper TT / Ofna Hyper 10TT review

After enjoying the TLR 22-4 2.0, and its quirks, I decided to try another unusual vehicle.  Ofna was a company that was around a few years back, and they sold the Hobao Hyper TT under their brand and called it the Hyper 10TT.

Well, Ofna is no longer around, but Hobao has decided to sell their vehicles directly in the U.S., so they brought back the Hyper TT.  It originally came out in 2010 and is now currently sold by Tower Hobbies again.

Overview:
The Hyper TT is a 1/10 scale Truggy, which is basically a 4WD stadium track.  It's a close cousin to the Hyper 10SC and the mini-ST that used to be sold.  They are essentially the same vehicles, with different length chassis and different bodies, but use the same arms, drivetrain, shocks, steering, etc.  So about 90% of the parts are interchangeable.

Now, this truck is really the only vehicle in its class.  Nobody makes 1/0 scale truggies.  The Traxxas Stampede can be converted into something similar, but has nowhere near the performance of the Hyper TT.  Trust me, I've had a Stampede truggy, and the high-center gravity chassis makes it fairly unsuitable for racing/track applications.

Build: N/A
The Hyper TT comes as either an RTR or 80% almost ready-to-run (ARR), which means the rolling chassis is pre-built.  I chose the latter and added my own electronics and glued up my own tires (it comes with wheels and tires unmounted) and painted the body.  The kit was reasonably well built by the factory, the only thing I would suggest is to make sure you thread-lock all of the screws threaded into metal.  They don't use loctite on most of them, and I found my steering post screws backed out.

Design: 5
The Hyper TT is essentially a 1/8 scale buggy scaled down.  It's got a 1/8 style drivetrain utilizing 3 diffs (front, center, rear), steel Mod 1 gears, dogbones down the center of the aluminum chassis, and a centralized motor on one side and the battery on the other.  It also uses pillowball suspension, which is the only 1/10 scale vehicle I know of that features this.

The drivetrain is extremely durable and loud and is probably the highlight of this truck.  It's got steel dogbones in the rear and CVA's in the front.  I ran a 4500kv 4-pole SMC Racing motor on 2S and it could definitely take more power.  I think there are guys out there running 3S with no problem.  The drivetrain is very beefy.

The pillowball suspension up front is a first for me, and honestly I'm not really a fan of it.  There's no camber link adjustment to modify roll centers, so you have to rely on springs and ride height.  The pillowballs are beefy steel units, but the arms and steering knuckles are pretty fragile.  More on that later.

The steering is a little archaic, and there's not enough Ackermann built into the steering at full lock.  This makes the truck not able to carve around sharp 180's very well, and I think it's more suitable to a medium sized track.  Unfortunately, the Ackermann is not adjustable.

Overall, I like the general idea of scaling down a 1/8 scale platform to make a beefy little truck, but some of the design choices could have been better, namely the pillowball suspension.

Performance: 5
The out of the box setup is rather poor, and there are definitely some changes you need to make to the factory setup.

The shocks are actually reasonably good units -- they're full aluminum small bore shocks with bladders.  Not my favorite design, but they're smooth and don't leak and work fine.  The front silver springs are too stiff, and there is too much damping, so definitely get yourself some Losi black or blue springs and lower the shock oil wt.  In the rear, the springs are actually way too soft -- Losi blue is the firmest I could find that fit, and are a lot better, but maybe still a little too soft.  Rear shock damping is ridiculously stiff, go with 25wt or 27.5wt Associated oil.

In the front, you need to ditch the front swaybar and add a little toe-out, and then you'll have a decent amount of steering and can move onto more tuning.

The truck jumps OK -- it tends to jump nose-high to me, I'm not sure why, and landing is adequate.  While the drivetrain is beefy, throttle control is a little iffy because there is a fair amount of slack in the drivetrain.  So it's hard to be precise with the throttle and braking application.

I have to say that the performance feels a little bit dated to me.  The truck originally came out in 2010 and it doesn't quite have the super taut, connected feeling that today's vehicles have.

There's also a fair amount of pitch front/back due to the short wheelbase and vast amount of power most guys run.  This isn't really the truck's fault, but it would be nice if the design allowed you to dial in more anti-dive or anti-squat.

So overall, I have to give the truck a mediocre score.  It's not great, it's not terrible, it's OK once you do some tuning.

Durability: 1
Honestly, this is my main issue with the truck.  It is extremely fragile.  It was fragile back in 2010, but fast-forward 6 years, and today's vehicles are super durable, and this truck feels like it's made of glass by comparison.  I pretty much break something every time I run the truck, which is a shame, because it's pretty fun to drive.

On the first battery pack, I broke the steering knuckles.  The second time I drove it I broke an upper arm.  The same day I was there, another kid broke the front top plate/hinge pin brace.  The third time I drove the truck, I broke a rear arm.

Fortunately, there are some upgrades you can make to the truck to make it more durable, but no matter what, the arms will still periodically break, so just expect that.

Durability upgrades that are pretty much mandatory:

1. Aluminum steering knuckles.  Integy still makes them, and STRC used to.
2. Aluminum top plate.  Made by Hobao, Integy, STRC.  The top plate also functions as the top hingepin mount, and that's the part that will crack.
3. T-bone Racing front bumper.  If you lawn dart this truck, this bumper will go miles towards preventing breakages.
4. Boil all of the arms and the rear hub carriers.  I did find that this helps quite a bit and softens the plastics so they are more resilient.

Rear CVA's are also a good idea.  When (not if) you break a rear arm, the rear dogbone will pop out and be a pain to find.

On the plus side. the body and molded plastic wing are quite thick and durable and I suspect will hold up very well in the long run.

Value: 5
At $219, the Hyper TT seems like an amazingly good deal.  I mean, where else can you get these kind of specs for $200?  Aluminum chassis and shock towers, fully aluminum shocks, pillowball suspension, front and rear gear diffs with a center diff.  Wheels, tires, body, wing all included!

But once you start going through the truck, you notice where Hobao cut some corners.  The steering rack uses bushings.  The rear driveshafts are dogbones.  They use self-tapping screws to mount the servo.  The turnbuckles have holes in them instead of square/hex shaped so you can't use a standard turnbuckle wrench.  It uses battery straps.  The shock towers are cast pieces.  The plastics are brittle.  The body clips are a joke.  The wheel nuts should be tossed directly into the trash.

At the end of the day, you're going to have to spend $20 on new turnbuckles, $30 for aluminum durability parts, $15 for a bumper, and about $30 in spare parts for when things break.  Throw in some miscellaneous wheel nuts and clips, and you're in for over $300.

This is about what it would cost to get a Stampede roller off eBay and build a similar truck.  The Hyper TT will have better performance, but the Stampede will be way more durable.  So kind of a wash.

Support: 3
There aren't a lot of places to get Hobao parts.  Your local hobby store isn't going to carry parts, so you'll have to get stuff from the Internet.  Hobao carries all the spare parts online, but the stuff ships from Taiwan and takes about 8 days to get to my house in California.

Dislikes:
Really the fundamental flaw with the Hyper TT is that it's not very durable.  With upgrades, it's at least adequate and won't break every time you hit something, but I would still consider it not very durable.  The steering has some geometry issues as well.

Conclusion:
If you want a 1/10 scale 4WD race-style stadium truck, this is pretty much the only game in town.  The Stampede is the closest competitor, but can't touch the Hobao performance-wise.  I can't really recommend the truck for most people because it just isn't very durable.  But if you want something unique, and you're OK will being your own parts warehouse, the Hobao is fun to drive and pretty cool.

I always get people asking me about the truck whenever I bring it out to the track, because there really is nothing else like it.

Which do you choose, a hard or soft option?

I was working on my B6D and Hyper TT, and thought it was rather funny.  On the B6D, I'm trying hard arms front and rear on the new build.  And on the Hyper TT, I was trying to soften the plastics by boiling them in water for 20 minutes on the stove.

B6D parts transfer

I'm partway through my build, and have pretty much all the parts transferred over from my B6 to my B6D.  You can see them in the pics.  I don't have any bling parts -- all of these are performance-related and have helped my buggy tremendously at my local, small, indoor clay track.  A quick review of the hop-ups and the situations I found them to be useful:

• Aluminum steering rack (less slop):   The stock plastic steering rack has a lot of slop that this eliminates.  Be sure to get an aluminum servo horn also to go with it.
• Schelle Type 1 steering arms (small, tight tracks):  They add more Ackermann at full lock, allowing you to rotate around tight 180 degree turns more quickly without pushing mid-corner.
• Laydown transmission (mid-high traction tracks):  The laydown helps  by allowing you to carry more corner speed into and through the corner.  It also allows you to mount your shocks on the front of the arms which lets you carry even more speed by centralizing the weight.
• Slipper eliminator (17.5 buggy):  Drops a bunch of weight from the drivetrain for quicker acceleration and top speed.
• MIP bi-metal outdrives (17.5 buggy): Drops a bunch of weight from the drivetrain for quicker acceleration and top speed.
• 12g brass C-block (used with Laydown):  The laydown transmission gives up a bit of forward traction.  This adds it back.  If you have a heavy motor (like my Reedy M3), the 12g block is good.  If you have a light motor, go with the 25g block.
• Aluminum D-block (more adjustments):  This D-block allows you to use the insert pills to give more adjustment for track width, toe-in, and anti-squat in the rear.

B6D

Time for a new kit!

My B6 was getting rather worn, and rather than buy all the parts and replace everything, it was cheaper to buy a new kit and sell my old one.  My B6 had basically been converted into a dirt version, so I got a B6D to replace it.

Hobao Hyper TT parts

One thing I'm getting to learn quickly is where to get parts for the Hyper TT.  My local hobby stores don't carry Hobao parts, so I'm reliant on the internet to get stuff.

Current sources for Hobao Hyper TT parts:

• Hobao eShop - this is Hobao's online store where you can get parts.  They have everything in stock, but the downside is that the stuff ships from Taiwan.  Shipping is crazy cheap though, I think I ordered 10 parts and shipping was fixed at $6.  In California, parts take about 8 days to get here, which is the main downside.
• Tower Hobbies - they are starting to carry the basics, like A-arms, shock towers, and steering knuckles.  Selection is very limited though.
• Nitrohouse - they are/were Ofna themselves, and they still carry a good amount of parts.  They're located in Southern California, and are probably the quickest source for stuff Tower doesn't carry.
• STRC - they used to make a bunch of Hyper TT hop-up parts, but most of them are discontinued.  As of the time of this writing, they still had some good stuff like hardened driveshafts and some aluminum parts.
• Integy - this is the place to get aluminum steering knuckles, rear hub carriers, basically anything you want to upgrade to aluminum.  I think they are still producing their full line of Hyper TT parts.  Make sure you stick with the billet aluminum stuff;  the cast aluminum parts are very weak.

Note that most Hyper 10SC and mini-ST parts also fit the Hyper TT, so oftentimes the same parts is listed as being for those vehicles.

Setting up a car for the first time

The last couple of kits I've bought have had remarkably good kit setups, so there wasn't a lot I had to do to get the car working pretty good in very short order.

But the Hyper TT out of the box is not quite at that finished level of setup, and requires a fair bit more work.  I'm not done with tuning, but I thought I'd share my thoughts on what I'm focusing on initially to get a base setup.

1. Setting up the steering.  Your goal here is for the car to track straight, have equal steering links front and right, and equal throw left and right.  Steering should be maxed out on each side so that you are getting full steering.  Your servo should be centered, and EPAs set with nothing hitting at max steering lock.
2. Tires.  The proper tires mounted for your surface need to be on the car, else the rest of the tuning process is not going to go well.  For me at my local track, this means Pro-line Primes in the winter, and Pro-line Electrons in the summer.
3. Gearing.  You want to have the right gearing (and motor timing) so that your motor is running at the right RPM for the track you're on and not overheating.

Ok, now you have a car that at least works and is not going to break on its own.  Next up is some basic tuning to get the car in the ballpark.

1. Ride height.  You're going to have just start with some number, and refine it over time.  For buggies on dirt, something in the 21-24mm range is typical.  For trucks, somewhere in the 28-30mm range.  Just pick something off a setup sheet or start with one of the above numbers and do your tuning with that.
2. Shocks.  The goal here is just to get some reasonable springs and shock oil wt in the car.  The springs need to suspend the car decently and have some forward/backward pitch under acceleration/braking, but not too much.  It should also not slap when landing jumps.  The shock oil will need to match the springs -- the stiffer the springs, the thicker the oil you will need and vice-versa.  The oil needs to be thick enough to land jumps and not slap too much, yet light enough so the car is still supple on the bumps and ripples of the straightaways.
3. Swaybars.  With the shocks working decently for the surface, you need to consider the swaybars, if they came with the car.  The only time you should need swaybars are generally either on super-high grip (carpet/astroturf), or if you're running a short course truck or bigger vehicle.  I pretty much never use front swaybars on my local, small, indoor clay track, and only sometimes use rear swaybars.  Buggies and stadium trucks on dirt shouldn't generally need them unless something is really unusual.

These things may take a couple of tries to get it close; it doesn't have to be perfect, you just want stuff in the ballpark so that you aren't trying to do the setup with something completely out of whack.

After that, you'll be messing with roll centers, and shock positions and Ackermann and such.  But in my opinion, this is the stuff you need to do first before you worry about more advanced tuning.

Hyper TT initial thoughts

Got to run a couple of packs through the Hyper TT today.  My session was cut short by the break of the day, in this case I hit the pipe and sheared off the pillowball on the upper arm.

Initial impressions of the Hyper TT:

• Cheap
• Mini 1/8 scale truggy
• Fragile

Beefed up 22-4 2.0 steering link

The stock steering linkage between the rack and servo horn is a little wimpy.  Some people have reported that it strips out.  I'm not sure that's the case, but I was having issues with my trim getting knocked out of alignment after a hard crash.  So I looked into beefing up the drag link, (as it's called)...

You just need a couple of Losi/TLR parts:

• LOSA6025 - old school Losi HD ballcups for 3/16" ball studs
• TLR234038 - a 3.5x75mm TLR HD turnbuckle

You can re-use the stock ballstuds, here's what it looks like installed:

 

Also check that the ballstud clears the belt tunnel.  Add a 1mm ballstud washer if necessary, mine was gouging the plastic a bit.

Hyper TT electronics weights

Still waiting on some parts to put my Hyper TT back together, but I'm getting ready for suspension tuning.  The proper springs and shock fluids are going to depend on the weight of the car, and my Hyper TT is (I think) on the heavier side.

On the left side, I have the battery at 306g.

On the right side, I have the motor (201g), ESC (86g), and servo (52g) = 339g.  So the right side is a little heavier than the left side, just from the electronics alone.  When you add in the aluminum motor mount, servo mount, and wiring it's probably a fair bit heavier.

VRP pistons and Yokomo springs

I spent the afternoon testing some parts in my B6.  First up was a set of VRP EU pistons, 3x1.4 front and 2x1.7 rears.  That's the normal size I use in my B6, so I did a direct swap and replace, leaving everything else the same.

These are the EU pistons intended for high-bite/carpet.  They basically separate compression and rebound damping.  Compression damping is normal, but they have additional valves that open for rebound, giving you quicker rebound.  From what I understand, the EU pistons differ from the original VRP pistons in having a smoother, smaller sidewall, resulting in less drag.

Unfortunately, they didn't work very well in my B6.  They were pretty good on landing jumps, but on any sort of straight away I felt there wasn't enough rebound damping and the energy from the rear end was not getting damped enough and the rear end was bouncy.  I couldn't tell much of a difference in the front, but the rears were definitely not right.  I tried softer and harder springs, and heavier oil, and it got a little better, but still not right.

In the end, I put my original machined AE pistons back in and it was back to being really good.  It's possible I need the older original-style VRP pistons which are more intended for loose dirt conditions.  But we run slicks on damp clay, so I thought the high-bite pistons would work.

The other part I tested was Yokomo rear springs.  A friend let me borrow a few sets to try -- the Yokomo Green rear spring is really popular among B6D drivers, and I can see why.  They basically feel like the low frequency TLR springs I sometimes use in my TLR cars.  They're a little smoother and give a little more traction and feel more linear with less bounce.  Green felt pretty good and I also tried a slightly stiffer spring (Orange), but that was too stiff.

If you're still running Associated rear springs on dirt, I recommend you give the Yokomo Green spring a try.  Part number:  YOKYS-A1200