Revisiting the TRF101

The TRF101 has been languishing on the shelf for a while now.  I did have an initial good impression of the car, but it became apparent that the car just did not steer enough on carpet to be really fast.  One thing I did notice was that it seemed to have better acceleration than most of the other Tamiya cars I had.  That seems like a crazy thing to say, but maybe there is something to it.


One thing I noticed from Fred Medel's quote in an early post about the car was the mention in passing of the rear end and the car's stability: "With the TRF101 the car enters the turn with immense stability and there is no sign of the car wanting to continue to turn after applying throttle after the 180. It's just that stable. I believe this is the case because you now have a solid front end like the F103 on top of having the side links further apart."

That may be the key here - the width of the side links.  The Xray style setup does have the battery sideways, but also ultra wide links compared to most of the Tamiya cars.  Even more intriguing to me is the similarity to the SpeedPassion Sp-1.  The rear end is almost identical, and I can say that the SP-1 made a lot of traction.  The first time I ran it on asphalt, I was able to run the exact same laps and time I did as I did with the F104WGP I had been working on for quite some time.  It was also very good on the not so good Pardus tires.

So maybe that stability helps the car put the power down.  I was never a huge fan of the way the Version II F104 cars accelerated, but the 101 was good.  Looking back, the thing that held the car back for me was the lack of steering .  A simple change of the upper arms makes the front end the standard F104 spec, so it was worth a little investment of time to see  if the TFR101 could be brought to life.

At the track, I first ran my F104WGP to baseline things, since I had just run it at the Access Hobbies TCS race.  It was good there, so I figured the comparison would be good, especially since I planned to simply transfer the tires to the TRF car.

I was able to do a 9.7 hotlap, but that was sort of a freak lap.  The rest of the laps were closer to a 10.0 average.

Putting the TRF car down, what I noticed right away was that it was really consistent.  While I was a couple tenths off of the WGP car on average, I could knock out the same lap over and over.  What the car was missing was quick transitioning in a couple S sections on the track.  At first I had the car set up with the #2 plastic camber adjuster (.5* camber) and copper side springs, the softest.  I had good success with the WGP car set to 2.5 camber, so I changed the TRF to 2.5 as well, and changed the side spring to gold, the second stiffest.

Now the car had the ability to transition quickly in the S sections.  I was able to consistently do 9.9 and 10.0 second laps, and it still retained it's stability.  I added a bit more front and rear droop as well which helped the car get a little more into the track.  The best part was that I could stand on the brakes, which was important for the short chute in front of the driver's stand, and the end of the sweeper.  I really enjoyed driving the car, as it was a dragster point to point.

In the next few runs, I tried some slight adjustments to the droop settings, to fine tune things.  I also tried some of the other side springs, but settled again on gold.  One thing that did make a difference was the center spring.  I had tried a few, from the ultra heavy purple to a red sedan spring.  What seemed to be best was a white sedan spring.  The softer springs actually made the car a little unstable, and the really heavy one slowed it in the S turns.

One other option was the steel axle.  For my style, I usually go a little faster with a steel axle, and it helped me as the car was now completely locked yet turned hard.  Overall, I was surprised at how good this car was with a little time tuning it.

In the end, I feel like the results were unexpectedly good.  The car was so enjoyable and worked so well, I just wanted to keep putting runs on it.  My WGP car was really good at the TCS race I had attended, but I think my results might have been even better if I had run the TRF101. The consistency and corner speed were excellent. Really, this car just needed the standard F104 front end to come to life.  I had been considering selling this car, but I think I may just hold onto it a bit longer....