Atlas YM-34 Review

I had seen the Atlas car in one of Car Action's touring car special issues. It looked totally awesome! Anyway, I had thought about buying one, but the cost seemed prohibitive. In November, Integy, the importer, dropped the car's price almost $50, and I was sold.
This is how the car comes out of the box, minus electronics. Note graphite parts, threaded shocks, metal bulkhead/motor mount. Pretty good for a $200 kit.

Build Up
When the car arrived, I put it together in about 7-8 hours. The parts quality was excellent, which reassured me since the car was an unknown to me. In fact, the only flaw that really stuck out was the fact that the countersinking was not that great. Some of the plastic was a little more flexible than I would have liked, but they do offer graphite versions of most of the parts.

The metal parts were flawless, however. Having the motor mount and side plate included in the kit was excellent considering the price, especially since threaded shocks and all the woven graphite are also included too.Another nice part was that the car was not overly sloppy. While there was some tolerance, it wasn't as bad as some cars that I have put together. Not a pivot ball car, but good.

Assembly was ok despite the horrendous translation from Japanese, ("foolishness prevention"?). What saved the manual had to be the excellent drawings and parts diagrams. I didn't have much trouble figuring what was what. Someone not familiar with r/c would definitely have a hard time, though.

The diffs are of the Associated/HPI style. Once assembled, they were pretty smooth. I do recommend getting some HPI 2.4 mm diff nuts, as there is a part on the tree which uses those nuts instead of just threading the screw into a plastic nut. Delrin halves are also available for even more drive train lightening. The car accelerates well with steel halves, so I can't imagine how rocket like it would be with the plastic halves.
As I mentioned before, I countersunk the chassis, and also beveled the battery slots. For 2400s and 3000s you may need to lengthen the slots as well. Tape is the recommended battery securing system, and while the tape slots are wide and easy to deal with, Schumacher battery hold downs are rumored to fit nicely on the chassis. Tape is sort of lame, so I intend on trying the Schumacher stuff.

Once the chassis is together, the flex probably less than a Pro2, but there is still flex evident. The metal bulkhead cuts down on the flexing. I always felt that the HPI, or any 2 deck car needed a metal bulkhead, and this car is that much ahead of the game. What is also nice is that the bulkheads are not part of the suspension mounts, so there is quite a bit of adjustability that I'll get into later.

Another really great feature of the kit is that threaded shocks are stock. The shocks also can be built with a bladder, and filled from the top, or filled from the bottom Losi style. I have found so far that the Losi style bottom fill is the easiest to get the shocks consistent. Otherwise they are very smooth, and the threaded collars adjust easily.


The shock towers are also interesting in that they are slightly thicker than the chassis plate. This helps to cut down on flex. The only problem is that the kit plastic is flexible, and the diff housings, which the towers bolt to, allow the towers to move too much to be effective. Both graphite plastic and aluminum diff housings are available. Still, a better quality plastic would help quite a bit.
The rest of the parts are excellent quality. Steel turnbuckles, steel CVD type drive shafts, rubber sealed ball bearings, they all add up to great value. Like I said the only gripe is the plastic composition.

The amount of adjustment on this car really sets it apart from the rest of the cars that it is often mistaken for. "It looks like an HPI". HPIs don't allow you to change the rear roll center and kick up out of the box, nor do they have more than 2 choices for the inboard camber link position. The front also has the same features. Really, the car it is more comparable to would be an Xpress. This is a racecar more than a beginner's car.

Performance
Once built, I took off for S&N's Trackside Raceway in Milwaukee, WI. I had set the car up to the spec's from the setup sheet from Integy's website. The only changes I made from their setup was to run 10wt lighter oil in the rear, 7* of caster in the front, and to make the rear camber link as long as possible.

As soon as I threw the car on the track, it felt great. I was surprised at how quick it was as well. The car had very good acceleration out of the corner. I ran in the pro stock class for the night.

After the two qualifiers, I was 5th in the A. Not bad, but the car didn't turn in as hard as I would have liked. In retrospect, 9* of caster would have been better. After having had the car for a little while now, I see it needs more caster to turn in from high speed.
In the main, I had a very good run. I came from the back of the field to the fight for 2nd, 3rd, and 4th. After a few laps, I had the 2nd place car in my sights. I definitely was faster than him, but a "racing incident" put me back to 6th. With only about 45 seconds left, the only thing I could do was to catch the 5th place car and pass him. The other cars were too far gone.

I again raced the car at S&N's on New Years' Day. This time the race was not as successful. I managed to dial myself out early in the day. Basically, I lowered the front roll center too much, resulting in the car looking like a big Caddy out on the track. I tried to use stiffer springs and oil, but the car was only marginally better. As I found out later, the difference of the roll center's height from the center of gravity's height caused the car to sway like a pendulum. My results that day weren't too good, although I did manage to come from last starting position in my stock race to 2nd.

My latest testing seems to show the rear suspension mounts should be 2 to 4mm high, and the front 1.5 to 2.5mm. The front should generally be lower than the rear. That way the rear roll center is higher than the front roll center. I also run a minimum of 1mm kick up in the rear, and 0 to 1mm in the front. Your mileage may vary, however. This seems to be what works for carpet. I also recommend sway bars for the car.

Overall, I felt the car was excellent the first time I ever raced it. It was one of the faster cars on the track! With a little more dialing in time, I think it will be able to run with and from any of the top cars out there.