HPI Blitz Short Course Truck Review

Posted:  Wednesday, October 21, 2009
Written By:  Gary Katzer
Copyright:© 2009 Horizon Hobby, Inc.
HPI Blitzes the Short Course Class

I know what you're thinking—HPI Racing isn't an off-road company. Sure, they make some pretty killer electric and nitro monster trucks. Granted their sister company, Hot Bodies, is the current IFMAR 1/8-scale off-road champion. But what do they know about producing a 1/10-scale electric truck? Oh, and not just any stadium truck, we're talking about a Short Course truck. Well, set your doubts aside, open your mind and take a gander at our latest test sled, the HPI Racing Blitz. While it borrows a few elements from its cousin, the e-Firestorm, this is a totally new truck that has been built from the ground up to be the fastest, easiest-to-drive, most user-friendly and best-looking Short Course Truck to date.

I had the opportunity to see the debut of this truck at the end of July when I attended the Short Course Nationals, held at RC Madness in Enfield, Connecticut. I was amazed how quickly the HPI team of Jesse Robbers, Erik Shauver (lead designer of the Blitz), John Schultz and weekend hired gun Tony Phalen were able to wrench on the truck, make changes, then see an immediate impact on track. Erik and John both ran the Open and Spec classes meaning they were frequently swapping out gear diffs for ball diffs. I'm here to tell you they had it down to a 5-minute effort! Other changes such as roll centers, shock positions, toe-in and others were made in no-time flat. I was very impressed by the tuneability of the Blitz.

Ok, so the truck looked easy to work on by the folks who helped design it. "Big deal" you might be thinking. True, the real testament is how the Blitz handles on the track. Whether in the Spec or Open class these four trucks looked like they were forgiving to drive, easy to hustle and had the speed necessary to compete at the top levels. After talking with Erik for some time after the event I was jonesing to get my hands on a Blitz for my own test. As the summer dragged on I would call the HPI guys up here and there, asking when the truck would be ready. My patience, or lack thereof, has finally been rewarded as the Blitz has finally arrived. From its officially licensed Maxxis wheels and belted tires, 15T Firebolt motor, forward/reversing ESC and great- looking body I couldn't wait to hit the dirt with this truck.

Speed Specs
Blitz 2WD Short Course Truck
Manufacturer: HPI Racing
Part Number: HPI103171
Vehicle Class/Type: 1/10-scale Short Course Truck
Target Audience: Beginner to Intermediate Short Course Truck Fan
Kit/RTR/BND/Race Roller: RTR  

Test Items Used:
Dynamite: 7.4V 5300mAh 2S 25C Li-Po, Hard Case: Deans (DYN5360D)
Reedy: 5000mAh 7.4V 35C Li-Po Battery (ASC709)
Thunder Power: 5000mAh 2S 7.4V Pro Race 40C Li-Po (THP50002SPRD)
W.S. Deans: Male Ultra Plug (WSD1302)

Track Notes
The Blitz comes out of the box completely ready to hit the dirt, meaning all someone would need to do would be install the 8 AA batteries in the transmitter and charge the battery pack (sold separately). Me being me, I had to add another step into the mix so I swapped out the stock Tamiya-style connector on the ESC with a Deans Ultra Plug. This is simply to better accommodate the connectors on the Dynamite, Reedy and Thunder Power Li-Po packs I planned on using. After a few minutes on the bench with my soldering iron I was ready to hit the track. And what a track I'd be testing on. It had been some time since I had a chance to head to JTEC Racing and Fun in Tilton, Illinois, but the arrival of the Blitz was the perfect excuse for a visit. I was thankful that the track layout from the Horizon Shootout, which had gone down a week before, was still setup. While I didn't race in the Shootout the layout looked both fun and challenging for  drivers and their equipment. This seemed like the perfect place to test the Blitz.

Top Speed/Acceleration
When I learned the Blitz was including a 15T motor I was a bit concerned that it might leave a little on the table speed-wise compared to others that included a larger 12T motor. From the first pull of the trigger I was really impressed with how the Blitz accelerated, both on the main straight and over obstacles. For this long of a track I was sure that I would need to install a larger pinion or smaller spur gear. I never did either as it felt like the stock gearing was right in that sweet spot. While I didn't have a radar gun with me I'd estimate top speeds were close to if not over  30 mph.

Jumping
I'm going to get this out of the way at the very beginning: I love the way the Blitz jumps! It doesn't matter if you hit the face of a jump off-center, turning in the air, carrying too much momentum or hit the jump perfectly, the Blitz soaks up everything you throw at it. I know many people criticized HPI for using composite body shocks as standard equipment. Everyone at the track who bench-tested the truck with the "squish" test remarked how smooth the stock bouncers felt and that smoothness can be felt on the track. Ruts, bumps, riverlets or just plain bad driving was absorbed by the Blitz's suspension.    

Much like the Team Associated SC10 the Blitz features mud flaps mounted to the rear bumper. Much like on the SC10 I also found the mud flaps to be a little on the long side, causing the rear of the truck to get kicked askew occasionally on landings. I trimmed 3-4mm off the bottom of the mud flaps and the issue was solved. In fact, when it came to jumping, this was the only issue that cropped up. Ok, that's not quite true. We did have some gusty winds that day and there was a time or two that the Blitz got caught up in a gust while going over the Spektrum Ski Jump, causing it to blow-over. There were 1/8-scale vehicles on-track at the exact same time that had the exact same issue, so I won't blame that on the Blitz.

Handling
For those who have followed my articles and reviews over the years you'll know my one concern with an off-road car or truck is whether the vehicle will have adequate rear bite for my driving style. I'm of the belief, especially with an RTR or beginner's car, it is always better for a vehicle to have an understeer tendency than an oversteer tendency. The reason is simply that you can always let off the throttle and let the vehicle coast around the turn. When a vehicle oversteers there's not much you can do about it. The Blitz is more balanced out of the box than some of the other offerings in this class. Out-of-the-box the Blitz is very planted; however, it is still possible to pitch the truck sideways, throw up some dirt and counter-steer around a corner. For the track conditions I experienced the Blitz was very good if I stayed in the groove with just a hint of wanting to break loose if I got off-line or on the power too hard. This was most noticeable in the quick left-right sections, but in the more flowing sections it was locked in.
      
Off-Power
This is the one complaint I have about the Blitz from the box. The stock ESC is a forward/reversing unit. However, there is no way to disable the reverse feature. The way things work is that the first time you bring the trigger back from throttle the brakes are applied. If you reduce the brakes and reapply them without hitting the gas then reverse is engaged. I tend to pulse the brakes in an effort to keep wheel lock-up to a minimum, similar to how an ABS system on full-sized cars works. Well this wasn't the ideal way to drive the Blitz as the second pulse of the brakes would have the rear wheels going in reverse. I had to adapt my style to overcome this configuration. As long as you know it’s there and remember this quirk, you'll be fine. Don’t dwell on this though as the overall handling of the Blitz is outstanding and confidence inspiring.    

With the stock setup the Blitz entered the corners very well. If I over-cooked the entry I could break the truck loose but I really had to blow it. Once I made the changes I mention below the truck was dialed on entry, even if I was off-line. I could have used a little more steering perhaps and I think a front geometry change or moving the rear shock out to the standard position may have helped. I don't know if I will play with this much as the Blitz is really quite good and very driveable right now and I don't want to mess it up.

On-Power
We have had a ton of rain over the last month or so, leaving the JTEC surface with tons of bite. I was able to get on the power easily lap after lap and the rear of the truck followed the front. The stock gearing provided the right acceleration out of the corners and it carried good corner speed. The stock tires have to be credited here too as they hooked up unlike any other stock Short Course tire I have ever driven, and I've run the four major trucks in box-stock form. The belted design translated to consistent handling from the word go. I felt very confident behind the wheel that I could get on the gas as hard as I wanted to and not pay a penalty. 

Chassis Roll
Do you want the good news or the bad? Ok, I'll start with the good, or at least what I perceive as the good. The Blitz has enough chassis roll to still keep the Short Course Truck feeling. However, it has less roll than any other truck I have driven to date. This translates into a truck that transitions from left-to-right quicker, carries more roll speed and has more corner speed thanks to this trait. The low "stadium truck-style" chassis contributes a lot to this, but the chassis plate is only part of the equation. The suspension geometry, the fluid-filled diff, the tires, everything just works in harmony to make this a fast and sure-footed ride.

Out-Of-The-Box Setup
With the box-stock setup the Blitz was very good for my driving style. As long as I stayed in the groove I could hustle the truck and it stayed under me. But if I got off-line, especially on corner entry, the rear would want to step out. After a few packs I sat down to try to even out the handling just a tad. Thankfully HPI includes a bag with some extra tuning parts in it. Things like an extra spur gear, offset front steering knuckles and different rear toe-in blocks were all there in the box. The truck comes with 3-degrees of rear toe-in to it, which should be good on most surfaces. I decided that I would install the 4-degree rear block while also moving the rear shocks in one hole on the shock tower. Curious to see what this would do to the handling, I tossed in another pack and hit the dirt.

I'd like to say that the differences were night and day between the way the truck handled after I made the changes than before but that really disses the box-stock setup. The Blitz, which was good but edgy before I made the changes, was totally locked into the JTEC track now. If anything I could have used just a touch more steering with this configuration. Now I will admit that I did perform the cardinal sin of testing in making two changes at one time, so I am not 100% sure if it was the rear toe or shock adjustment that made the difference. I just know these changes worked. I did move the battery forward to try to regain a bit of steering after the third pack; however, I did not like the way the Blitz jumped over the ski jump with this weight placement and went back to 2 foam spacers in front of the battery and one behind. I feel very comfortable that, with these two changes, I can put this truck in the A-Main in the Stock Class at any local club race. The handling of the Blitz just instills confidence lap after lap after lap.

Final Thoughts
 A class that started with just one truck has become very crowded very fast. With all these choices out there trying to decide what truck is the best for you can make your head spin. The HPI Racing Blitz helps clear the confusion and it makes a very definitive statement. As it comes out of the box I feel that the Blitz is a great spec class racer first, backyard basher second. Sure, there will be plenty of Blitz trucks that will be bought and never see the sight of a racetrack but that is where it truly excels. From a backyard basher’s standpoint this is a durable truck that looks great and delivers good speed and performance. Speaking of the looks, the Blitz nails the look and feel of what this class is all about. It looks like a full-scale truck thanks to the great lines of the stock body and the awesome Maxxis wheels and tires. I know there will be some that will discount the Blitz since HPI doesn’t have a long heritage of creating 1/10-scale electric off-road race vehicles. That’s a foolish thing to do because the Blitz does so many things well that it sets a very high standard for quality and handling. Lead Designer Erik Shauver has designed vehicles that have won at every level, including HPI’s RS4 Pro 4 shaft drive sedan. The guy knows what he’s doing, what makes sense in real-world applications and it shows on the Blitz. From the quality manual, great handling out-of-the-box, killer looks and more, the Blitz from HPI Racing raises the bar in the short course class very high. 

Postscript
I was lucky to have another opportunity to run the Blitz, and actually race it, at my old home track of S&N's Trackside Hobbies in Brookfield, Wisconsin. I arrived with the same setup I had come to from JTEC and was instantly impressed at how well the Blitz worked on this harder-packed, higher-bite surface. I entered the truck in the Stock Short Course class with a few changes from stock. I swapped out the stock electronics with some racier gear including a JR8800T servo, LRP SPX Brushless ESC, Novak 17.5-turn brushless motor and a Spektrum SR3520 receiver bound to my DX3R. From the first battery pack I was in the low 17-second range for lap times and as I became more comfortable with the layout my lap times continued to come down. By the third or fourth battery I was in the mid-16's. As good as the Blitz felt I needed more low-speed steering, especially in the chicane that immediately followed the main straight. I decided to swap out the installed trailing front steering knuckles with the optional (but included with the truck) inline ones. This did the trick as I eventually turned a 16.1 as my fastest lap in practice, yet the overall balance and comfort level of the truck was still good.

  Unlike traditional IFMAR-style qualifiers, the Short Course class tends to use on-the-tone style starts (which was the case at Trackside). I lined up outside the front row for the first qualifier and by the time the field came out of the first chicane, I was in the lead. I drove away from the field and set the early TQ with a 17/5:01 pace, 3/4-of a lap ahead of the field. In the second qualifier I started from the pole but the second qualifier got through the chicane better than I did on the start, meaning I would have to play a little bit of catch-up. I caught him going into the chicane where he turned in a bit early and got hung on the pipe, allowing me to take the lead. I had a cleaner run this round and managed to improve my time to an 18/5:16. Between the second and third rounds I decided I would make a change to the setup to free the truck up a bit. I went back to the three degree rear suspension mount and threw the truck down for the final qualifier. The setup worked as the Blitz was consistently quicker. I was on an 18/5:10 pace at one point before getting caught up with traffic and eventually wound up with an 18/5:18. 

Before the main I decided that having a truck that was planted was more important, especially in traffic, than one that was necessarily fast---so I went back to the 4-degree rear mount. I also wanted to try to get the Blitz to spring off of jumps a little better, so I moved the front shocks in one hole on the arms. In my hurry to get ready I forgot to treat my tires with the traction compound I had been using. When the tone went off, I got pummeled by several trucks and dropped back to fourth. I worked my way back to second by the end of the second lap and started tracking the leader down. In a few laps I was on his rear bumper and, while the front shock change made the Blitz launch better off of jumps, it also made it very loose. I managed to take the lead when the leader got caught up in traffic, only to have the same thing happen to me with less than two minutes to go. I put on one final charge but couldn't make up for my bad driving. I got caught up in one final crash with back markers coming to the line at the end of the race which cost me second place. I finished third overall with a truck that was fast enough to win. I had the fastest average laps of the field, fastest single lap of the night, and obviously the fastest qualifying time as I TQ-ed. My 18/5:16 would have put me fourth on the grid in Stock Stadium Truck and eighth on the grid in Mod Short Course. For a truck that was run as it came out of the box, minus my electronics, I was very impressed.