TRF419 Floating steering mount

Since February a few of us have been experimenting with a range of new parts including a floating steering mount.

The theory behind the floating steering is that even at full load on the corner the steering posts will not be moved by the chassis flex, ensuring a more direct steering feeling. Obviously there are two ways to conquer this:

1. Fit a steering bridge, to make the chassis more rigid between the posts.
2. Move the posts off the chassis to allow the chassis to flex.

I have been running a steering bridge for some time as I like it, but I was keen to explore the floating steering solution as it seems to be de rigueur with some of the current touring cars such as the Arc R11. So we decided to see if this solution would work and perform well.

I designed the part to ensure that the steering geometry was still the same as the current TRF419, and it would also be able to use some standard Tamiya Parts to ensure that people could have the right shade of blue on their chassis. (the outer servo mount could be swapped with a TRF417/416 servo mount instead of the 3D printed part.

I used 3D printing to do the inner and outer mounts and also used it to measure up the final upper mount (Just to get the dimensions working).

Here is the prototype.

I 3D printed the top arm to check the measurements.

As you can see above I had the main servo mount all sorted (Note for these pics I had used a TRF417 servo mount instead of my 3D printed part because I like the blue). The next thing is to look at the steering posts. I disassembled the TRF419 steering and rebuilt it to work well in an inverted position.

The inverted steering ready to float?

It was quite simple to sort out, I just removed the steering bridge and placed it on the underside of the arms. I then measured the steering and found that I only needed to add 6mm of shims on each steering post to get the steering geometry at the same level as the current TRF419 set-up.

The system nearly set-up and ready to install

I had to use some 12mm screws to mount he steering arms with the 6mm shims and the steering assembly was now near enough finished.

I just had to add the battery spacer screw (Essential unless you have another centre spacer otherwise the batteries will swing and hit the belt. I also mounted the antenna holder.

Feeling detached!

As you can see the steering is now floating from the chassis, so the next thing to do is to take it to the track for some testing.

Testing sessions

I have managed a few tests over the last couple of months. Initially I was just checking that the parts worked well, so I could redraw any components, some of the changes have happened to the inner servo mount (Including the internal battery spacer) thanks to this. Once I was happy that it was all working well in the tests, I thought I would give it a go at  a proper race.  I wanted to test the steering to the maximum so I took it to a very tight local track (some parts were less than 1 metre wide at the chicane). So I had the car ready and was keen to see how it would perform.

At the track

As was always the case, the racing was great and I had some good competitors ensuring that I had to perform. The track was very tight, however the grip was initially quite low and it took a while to find the fastest lines when doing the qualifying heats.

The TRF419 v2?

I was keen to push the car on the tighter sections to see how the steering felt. It was ok but I was unable to really feel any noticeable difference maybe down to the limited grip.

For the next race I swapped out the steering to my standard set-up with the steering bridge and no floating steering. I improved by a lap, and the car did feel sharper. The thing is the grip itself had really started to come good at the track so this could explain the better lap time much more than the change in steering configuration.

I had qualified FTD in TC so I decided to swap back to the floating system to see if I could improve upon my best time that I had previously achieved with the bridge by using the floating set-up.

The race was ready and I launched off and maintained a healthy lead. The X-ray of my main competitor was about a couple of seconds behind me after about a minute. The drivers were all being courteous and moving out of my way as I was lapping them. Despite the very tight track I managed to not loose much time, and I was really locked into some good lines. The steering was clean and as the grip became better as the tyres reached their optimum temperature, the car was still very consistent and I could become more aggressive, building up a really substantial lead. Here is the problem, I just wanted to win so with about 3/4 lap I just maintained my lead and didn't keep pushing the car like I would have done in the qualifiers so I took the win, but my time was actually slower than the qualifier by around 3 seconds.

Overall,

So at the moment it is all rather inconclusive. The car was certainly ok to drive with the floating set-up, but if it goes down to pure race and lap times I performed a better result with the steering bridge. I will experiment a bit more with this set-up, as will some of the other guys with the parts.

Wide front end, low towers, high precision stabiliser mounts and floating steering!

Looking forward to testing the car more, to decide if the steering should be up in the air or have it's feet on the ground :)