readers write

Radio Control Car Action, Apr 2004

WRITE TO US! Send snail mail to "Letters," Air Age Inc., RC Car Action, 100 East Ridge, Ridgefield, CT 06877-4606 USA, or email readerswrite@airage.com. Letters may be edited for style and length. Sorry, we cannot reply to every one.

WHY PULL-START?

Why does the OFNA Hyper 7 PCR include a pull-starter? Since it comes with a starter box, OFNA could have left the pull starter off to get more power from the engine, [email] Paul Marr

Actually'pulstarters rob the engine of only a very negligible amount of power. We once radar-tested an RC10GT with a pull-start O.S. CV engine and then removed the pull-starter and retested it. There was no change in the acceleration or top-speed data. If the difference isn't enough to show up on the charts, then it isn't enough for me to care about! Especially in a big-block, 8-port engine like the Hyper, you'll never feel a difference. And look at the bright side: if you forget to charge up the starter-box batteries, you'll still be able to fire up your buggy.

-Pete

FOUR-WHEELIN'

Hey guys, awesome mag. I haven't learned more about anything else in such a short time than what I've learned about RC from your mag. I wonder whether there's a national 4WD stadium-truck racing class? Playing off that, what do you guys think of the RS4 MT2? I'm looking for something that could be fun to bash around but is also fast on the track. I'm also quite an HPI fan, so I'd like to drop my precious dollars (I don't have a lot of spare cash) on a company I believe in. [email]

Matt

Actually, ROAR does include a provision for 4WD trucks in the "1/10-scale Fuel Truck" class rules. The rules for 2WD and 4WD trucks are the same, except for minimum weight: 2WD trucks must weigh at least 60 ounces, but 4WD trucks can weigh 64 ounces. Unfortunately, it's rare to see the class actually run in a sanctioned racing event, which is a real bummer, since the trucks are a blast to drive, especially on a track. As for the MT2, it's just about the best four-wheeler out there. Look for a review soon.

-Pete

HONORABLE DISCHARGE

I have a DuraTrax IntelliPeak charger (reviewed in the January issue), and I'm happy with it. I have a question about the cutoff voltage on the discharge cycle. Every article I've read recommends discharging NiMHbatteries to no lower than 0.9 volt per cell or 5.4 volts for a 6-cell stick, yet both of these chargers have a much lower cutoff. What gives?

Ray Davis

Atlanta, GA

I looked up the charger's specs on the Tower Hobbies website, and you're right: the discharger cuts out at 2.6 volts, which is 0.43 volt per cell. Tower's "Tech Notes" goon to say that the cutoff is fixed, so if you want to stop discharging at a higher voltage, you should monitor the pack with a digital voltmeter or just use the IntelliPeak's voltage display. Since the experts say 0.9 volt per cell is best, I'd heed their advice instead of relying on the built-in voltage cutoff.

-Pete

BIG ON MINIS

About a year ago, someone wrote that no companies make a mini Maxx. Now, a year later, companies are answering the call - or at least, they have the technology to do it. With Mini-Zs, the Mini-T, the Mini-Z Monster and the Tamiya TLT-1 you can have a miniature world! That's pretty cool in my opinion, but since everything is getting smaller, it needs to stop sooner or later, or we won't be able to see the stuff! It must be cool for you guys to test these minuscule wonders, [email]

Drummond Buchenroth

We're on it. We already tested the Mini-Z Monster (last issue) and Mini-T (February issue) and our TLT-i just arrived! Now, let me end my reply before I'm no longer able to resist making a "Different Strokes" joke, Mr. Drummond.

-Pete

BUILD IT, AND THEY WILL COME

If I had any manufacturing connections, I'd go into business with this idea myself, but I don't, so I'm hoping you guys can throw it out to the RC industry for me. What the RC world needs is a completely rebuildable, high-quality glow starter. I've tried the cheap ones, and I've tried the good ones, but they all go bad sooner or later. I'd be happy to pay more for a glow starter with a replaceable center contact, postive clamp/release mechanism, accurate power meter and heavy-duty construction. The option of an included quick-charger would be great, too. Anybody out there listening? [email]

Bill Wyatt

Well, anyone? Put me and Bill on the waiting list for a high-quality, rebuildable glow starter.

-Pete

TWO-SPEED ELECTRIC?

I would really like to get a fast car, but I don't want the hassles of a nitro vehicle. Most nitro cars only go about 10 to 2omph faster than electrics because they have 2-speed transmissions. Why don't the RC manufacturers put a 2-speed in electric cars?

Kyle Horcher

Fox Lake, IL

Nitro cars can benefit from a 2-speed because piston engines generate maximum power at high rpm. The 2-speed is there to provide an "easier" first gear, so the car can accelerate more quickly. The transmission doesn't really increase top speed, it just decreases the time required to reach top speed. Electric motors, on the other hand, develop maximum power at low rpm and don't need an "easy" first gear to accelerate well. At high rpm, an electric motor doesn't have the power to exploit an upshift to a lower gear ratio. Two-speed trannies aren't often seen in electric vehicles simply because the minor potential for performance gain is usually outweighed by the cost and complexity of a 2-speed system.