Review: HPI E-Firestorm Flux Stadium Truck

I’ve always been a pretty big fan of HPI vehicles, continually looking forward to what they have to offer and what I can add to my RC collection. Their decision to boost power and stuff everything with the ferocious FLUX system has elevated their vehicles to a completely different realm than ever before. My first experience with this power system was in the HPI Savage XS, a mini-monster that seemed almost supersonic on a 3S LiPo battery. While it was brutally quick, it was also incredibly durable and continued my belief that HPI knows how to build some very fast cars. Now it’s time to test the FLUX in something a little bit bigger, a little bit heavier and, thankfully, something that comes equipped with a wheelie bar!

AT A GLANCE
WHO MAKES IT: HPI Racing
WHO IT’S FOR: Everyone
PART NUMBER: 112878
HOW MUCH: $320
BUILD TYPE: RTR

FEATURE BREAKDOWN
• The E-Firestorm comes with a molded composite chassis that features a separate front and rear clip. Both can be removed with just a few screws for maintenance or repair, but tied together create a pretty solid platform. The servo is inline and held in place by a molded top deck. Just behind that is the battery tray; out of the box this tray can accept a 2S LiPo pack. A separate 3S LiPo battery strap is also in the box, part of the Bonus Speed Pack that HPI has included with this kit. On the right side of the chassis is the waterproof receiver box that is screwed to the chassis. No chance on this thing falling out! On the left side is the EMH-3S FLUX ESC. It looks quite big compared to most ESCs, but it can easily handle a 3S LiPo and comes equipped with its own cooling fan on top.

• In typical fashion with Stadium Trucks, the E-Firestorm features front and rear independent suspension. The long, molded arms are nice and thick and have a touch of flex to help with durability. Threaded shocks are standard as are adjustable turnbuckles throughout. I like the fact that HPI didn’t lowball the E-Firestorm by removing a bunch of tuning features after they stuffed it full of FLUX. You still have access to wheelbase, roll centers, camber, toe, and Ackermann and shock locations. Heck, they even threw in a few extra arm mounts. If you ever get tired of just going fast in a straight line, this truck is very capable of putting in some laps at the track!

• Steering duties are handled by HPI’s SF-10W waterproof servo. This servo has plastic gears and is rated at 36oz/in at 6V with a speed of .18sec. While not as savage as the FLUX system, it is able enough to keep the E-Firestorm pointed in the right direction. The bellcrank system features a built-in servo saver, something you’ll be happy is included! We ‘tested’ out this feature many times as we tried to see how long we could keep the front end up in the air. We’re happy to note that we didn’t encounter any stripped gears during the initial test session.

• To make sure the E-Firestorm continues constant forward progress, the low-profile transmission has been loaded up with a full set of metal gears. We did replace the stock pinion and spur with a set of 35T/77T gears; both were included and required to reach the posted 77+mph this truck is capable of doing. Driving the rear wheels are a pair of 3.5mm dogbones, spinning the rear tires through a set of quality bearings. Powering this whole system is the 4000Kv FLUX brushless motor. While it is coated in a matching black color and does mount in the typical location, its chunkiness is there to let you know this truck has some major junk-in-the-truck.

• HPI didn’t just want to send another Stadium Truck to the market; they wanted to do so while making a statement; that statement being that this truck could do 77+ mph right out of the box! To quench your thirst in the speed department, HPI added what they call the Bonus Speed Pack. This Pack includes speed items like a wheelie bar, high-speed pinion and spur and 3S LiPo battery strap. Since most people would be bolting these parts on prior to the truck’s first run, I figured it was my duty to do the same, you know, for the sake of the article!

PROS
+ Sharp-looking package
+ Incredibly fast FLUX power system
+ Accepts 2S or 3S LiPos
+ Waterproof electronics
+ Built for speed, but has plenty of tuning options for track use
+ Blitz Short Course slipper clutch
+ All-metal transmission
+ Bonus speed-pack included
+ Capable of 77+MPH…

CONS
– Stock tires weren’t the greatest at high speeds

ON THE TRACK
We’re just getting past the winter months here in Connecticut and extremely happy to be able to get back outside and drive. In our parking lot we have a pretty substantial, multi-level parking structure with an open top level. This place is nice and flat, perfect for any high-speed runs. The E-Firestorm definitely fits in this category.

We charged up one of HPI’s Plazma 3S LiPos and secured the pack in place with the included 3S battery strap setup. During the initial test run, I noticed the E-Firestorm’s clutch was slipping on acceleration. After a quick few turns using the included four-way wrench, it only took quarter-throttle to get the truck’s nose up in the air (I guess I tightened it a bit too much). I made a few controlled passes to test the speed and came to the conclusion that we definitely didn’t have enough room on top of the parking structure! This truck is fast and, even with controlled throttle passes, would get a little wobbly when reaching maximum velocity. I think the problem was it continued to want to lift the front end up in the air, resulting in only the rear tires touching the ground. This caused a little instability, so my suggestion is to be careful if you need to tighten the clutch.

I backed the slipper off a bit and that made it a lot easier to drive. The fun came when I found that a hearty blip of the throttle would get the E-Firestorm up on the wheelie bar … JUST the wheelie bar. Yes, this truck would whip the front end up so hard that it would lift it right off all four tires and up on the wheelie bar for a second or two. It became a game; how long could I get it to ride on just the wheelie bar. Sometimes it would work, other times it would get out of control and tumble and yet other times it would flip over on its lid and slide for a long way.

After I had completely drained the battery, I brought the E-Firestorm back in for a quick once over. Tires still glued – check. Protruding parts like suspension arms, shocks, axles and wheelie bar all in good shape – check. Body scratched and gouged beyond repair – double check. When it comes to vehicles that tout some super speeds, I usually don’t hold back. That can sometimes result in a pretty major repair bill, but I’m happy to report that over the multiple packs I’ve put through this truck, the only thing that needs replacing is the body.

SPECS & TUNING OPTIONS
DIMENSIONS
LENGTH: 16.7 in. (425mm)
WIDTH: 12.8 in. (325mm)
HEIGHT: 5.8 in. (147mm)
WHEELBASE: 11.4 in. (289mm)

BODY, WHEELS AND TIRES
BODY: Pre-painted stadium truck
WHEELS: Nylon multi-spoke
WHEEL ADAPTER TYPE: 12mm hex
TIRES: Ribbed front, mini-block pin rear

SUSPENSION
TYPE: 4-wheel independent
SHOCK POSITIONS: (F) 3-tower, 2-arm, (R) 3-tower, 2-arm
CAMBER: Adjustable turnbuckles
ROLL: Ball stud heights
WHEELBASE: Adjustable with shims
RIDE HEIGHT: Threaded shocks

STEERING
TYPE: Dual bellcrank
TOE: Turnbuckles

CHASSIS
TYPE: Flat plate with side rails
MATERIAL: Hard-anodized 7075-T6 Aluminum
THICKNESS: 2mm

DRIVETRAIN
TYPE: 2WD
TRANSMISSION: Low-profile, metal gears
DIFFERENTIAL: Gear differentials
CLUTCH TYPE: Blitz SC racing slipper
GEAR RATIO: Optional pinion gears
BEARINGS: Full shielded

WRAP UP
HPI has been dropping their FLUX system into every one of their vehicles, resulting in some serious speed in a multitude of platforms. On top of all that power, it’s very reliable as well; I’ve run about 9 or 10 3S LiPo packs through this truck with no signs of the EMH-3S FLUX system giving up. Combine that with a very competent chassis and waterproof electronics and you have a great package that anyone can enjoy.

LINKS
HPI Racing, hpiracing.com, (217) 398-0007