Cen Racing TR4






The TR4 is the topic of this review and CEN boasts quite heavily about this 2 speed transmission, 4 wheel drive nitro car. For those interested in r/c nitro cars, or wanting to know more about what these cars are about keep reading. You’re about to find out whether this car is all show or all go.

For those of you who may not know CEN has for many years been developing and producing all sorts of r/c hobby products such as cars, boats, helicopters, and many parts for world famous brands. As a result they too have built a reputation for strict quality control and competitive pricing. They since have decided to take that experience to present us with a variety of products under the CEN label.

The car is nearly ready to run right out of the box. Install the batteries (not included), mount the antenna, glue the tires to the rims with a little CA, and you’re ready to roll. Since it’s recommended to break in the engine without the body I did not right away make the necessary cuts for mounting. I’ll save that until the engine is well broken in, with stable idling capabilities.






TR4 Exploded Parts View
.JPG – 48kb

Engine Handbook
.ZIP – 3.8Mb


  • High Performance 2.6cc, .16, true ABC
  • New large oversized cooling head
  • Dual-Chambered racing style tuned pipe
  • Slide Carburetor with both high and low end needle adjustments
  • Light weight 2-speed transmission, w/ adjustable shifting
  • Oil filled coil over shocks
  • Racing style fuel tank with stone filter and no leak primer
  • Adjustable rear toe-in
  • Solid double deck aluminum chassis with counter sunk holes
  • Racing style .080-rear sway bar
  • Ball Bearings included
  • High performance Teflon clutch shoes
  • Fiber brake disk
  • Adjustable front and rear caster
  • Adjustable steering Ackerman
  • Highly efficient twin belt design
  • Uses all standard sedan-hex wheels
  • Many upgrades available


  • 1:10 scale radio controlled nitro power model race car
  • Four wheel drive (4WD)
  • Wheel base 10.23″ (260mm), width 7.7″ (196mm)
  • Gear ratio: 6.4 (single speed), 5.15-7.31 (2-speed)
  • Weight approx. 3.75 pounds (1700gms)
  • Ground clearance 0.31″ (8mm)
  • Tire 2.6″ (66mm) diameter – 1.06″ (27mm) width
  • 2.67cc Racing Engine
  • 1.2hp
  • ABC Construction






The moment you pull the car out of the box you can feel it’s solidly built. Within about 15 minutes I had the car outside and started. The .16 engine starts very well which got the first few break-in tanks out of the way quickly. Using little more than idle I drove the car back and forth on my driveway. The first few tanks of any car can be a bit frustrating as the engine will frequently stall and run erratic. This is due to running the engine wet (rich) to provide the maximum protection for the engine possible. After each tank of fuel the engine was allowed to completely cool before the next tank was run through. This is part of the break in procedure to ensure all the parts seat properly providing a long lasting and strong performing engine. It’s exciting getting a new car and the tendency is to tear up the street right away. Resist that temptation, break your car in right and it will give you problem free running for a long time.

It didn’t take long to realize the car was pulling severely to the left. Despite using the adjustable trim on the transmitter I couldn’t get it to drive straight. The solution was simple though. I first set the steering trim to what I will call the zero position… meaning the trim can now be adjusted right or left an equal distance. Next I removed the steering servo arm, and moved it two notches from where it was. This produced the desired effect as I now have the steering trim set slightly to the right to keep the car driving straight at all speeds.

The transmitter has all the options you would expect to find on a stock transmitter such as servo reversing switches, adjustable steering, throttle and idle. However, it lacks the quality look and feel I would expect from CEN Racing. It does the job just fine and I suppose is a way to keep costs on the car low, but it’s not one of the favorite transmitters I’ve driven with.

Once I had 5 or 6 tanks of easy break-in running behind me I started tuning the car for better performance. This quickly gave me a headache as I just could not seem to find a happy medium where it would idle nice and accelerate under full throttle at the same time. Just for the fun of it I gave a phone call to CEN to see what they would suggest and could not believe a live person actually answered the phone. It caught me so off guard it actually took me a few seconds to regain my composure and remember why I called. Not only that, but the person that answered the phone knew how to help me! What are the chances!? Folks, this is service that just can’t be beat and puts CEN very high on my list of favorable companies in which to buy products in the future! After a few minutes of discussing my dilemma of rough idling and poor full throttle performance it was determined I was simply over adjusting the engine. Once I toned down the amount of turning I did to the high and low speed needles I had a great running car. I found very very minor adjustments to be the key in making this high performance engine come alive.

High performance engine? Oh yes! This engine and 2 speed transmission are a great combination to fire the TR4 like a bullet and propel it down the road like a missile. The TR4 covers a great deal of ground in a big hurry! I challenge anyone not to smile when the throttle is opened full from idle and the car starts screaming down the road. Think you can do it? Ok, now try not to smile when the transmission shifts into second. It can’t be done with a straight face, it’s just so viciously cool you can’t help but smile! The down side to this speed though is eventually you’ll have to stop. The brake does a nice job for a while but will fade after a couple tanks of hard running and need to be re-adjusted. This is normal and you’ll have to continue doing so as the pad where’s down from use.

I made it through another 5 or so tanks of fuel when the heat from the muffler and engine kind of wore through the rubber manifold on the stock setup and softened it enough to tear it. I don’t care much for this design as I believe it would continue to happen if you simply replaced the same part with a new one. I also wasn’t pleased that my local hobby shop didn’t have a replacement or even substitute I could retrofit. That means if I did ever need to replace it I could only get it from CEN and it would be a few days with shipping instead of a few minutes at hobby shop. I quickly called CEN and asked about a solution to which the informed me of a metal manifold and high performance tuned pipe. To continue enjoying this car without continuous muffler maintenance I knew this is the way I had to go, and I’m glad I did!

I also wanted to spice up the looks of the car so I had them send me some five spoke chrome colored wheels the same time as the new muffler and manifold. You just can’t even believe the difference it makes to the overall appearance of the car, and again I was glad I made that decision!

The car sits low to the ground, too low for casual running up and down the street. The frame measures a mere .31″ (8mm) from the ground and will find sticks, stones and small cracks in the pavement quite easily. For racing on a controlled surface the stock setting is perfect, but for casual use you will want to adjust the suspension for a little more clearance. I have scratched the bottom of the anodized frame quite nicely by running up and down the less than perfect street I live on. I’ve also shaved a little off the engine bolt heads as they stick out slightly beyond the frame. Most of the screws in the frame are countersunk and the engine bolts are too, but not enough to avoid scraping them on the pavement. This may cause a problem if I would want to remove the engine some day and can’t fit a tool on the bolts to loosen them. The car also handles like a dream because of a combination of ground clearance, wheel base, and suspension. At 10.23″ long and 7.7″ wide the car is a very capable pavement hugger. It also features a rear stabilizer bar to help keep the car flat in the corners and flat it stays. Now throw in a double wishbone fully adjustable suspension and you have a highly tunable racer.

Well I had enough fun running the car up and down the street. It’s just too fast and is begging for a wide open parking lot. I headed to a nearby park and really got the opportunity to give the car a work out. I have little doubt this is a 50 mph car as CEN claims, though I have no actual proof of that. The stock rims and tires are fun for sliding the car around and doing donuts, but for racing I switched to a better gripping tire and had a great time making laps. While I enjoy running the car with the body I felt the performance wasn’t the same. Perhaps its an illusion but the car did seem to be easier to drive and run faster without the Mini Cooper body installed. Any way you cut it this car is exciting to drive!

Take a look at the video below and you’ll see for yourself the speed, handling and fun or the TR4.





CEN Racing
1800 E. Miraloma Ave., #F
Placentia, CA 92870 USA
TEL: 1-714-792-1923
FAX: 1-714-792-1968






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