Avalon Vortex Review and Track Test

Anyone who races 1/10 on-road will have heard of the Avalon Vortex. Breaking cover early this year, its no-compromise, extreme-downforce design caused quite a stir, not just in the looks department, but more importantly on the track, where many top-level drivers instantly took to it as the impact on lap times was noticeable.

I picked mine up way back in April, before they were widely available (they were just being sold trackside), but as is normal, I got distracted with other things and only recently got around to giving the shell a run at one of my local clubs.

I'm not going to go on about the aesthetics of the shell. Like most things in life, we all have our own preferences. However, it is certainly distinctive, with its long front section and raised rear 'boot'.

The mould lines are clear. There is a strange look to the Lexan, with an almost plank-like texture, but once painted this isn't noticeable.

I had to fit 8mm of spacers under the rear body posts to align them with the rear mounting points. These are 100mm apart, so the inner post position was used.  

This is a club-race test shell, so it got a Juan-coat special in my favourite Tamiya PS colour. The decals are pre-cut and, once applied, I honestly think it looks quite good.

The shape of the shell is very much like a wedge, and while a lot of attention has been paid to the longer 'duck lips' at the front, the rear of the shell is also very high compared with the average racing shell. As mentioned earlier, I needed to fit a lot of spacers under the rear body-post retainers to mount the shell correctly.

 

At the track : Day One

Tuesday club night arrived and I popped the Avalon Vortex onto the TRF421X and took it out for a spin.

It only took a few laps to really get a feel for the amount of grip the Vortex was producing. It is quite a departure from any other TC shell I have driven before. Avalon has definitely pushed the envelope when it comes to high downforce.

However, it's really not the silver bullet you might think it would be.

The downforce is there, but it's deployed in a very unusual way. Primarily, it really loads the front axle, but this seems to come at the expense of the rear of the car. I could push hard into the corner, but then the rear would break away in an unpredictable manner. Effectively, I wasn't able to commit to the corner in the way I wanted to.

After the first heat, I started making a few set-up changes. I would normally run 7.5k or 10k in the rear diff, but I went down to 5k. I also softened off the bump steer to give the car a more linear feel approaching the apex.

The second round was better. The changes helped, along with the grip coming up.

The unstable rear end still wasn't cured, though. I would find myself starting to gain confidence and start to push and then the rear would suddenly snap. Some laps it would be fine; others it would let go. On basic hairpins it was fine, but through the larger sweeping sections of the track I was just waiting for it to snap.

The other changes I made were to the droop and springs. I added quite a lot of droop, enabling the wheels to load up a little more. I also started changing the springs, going much stiffer at the front while reducing the shock angle to compensate a little. This made it softer initially, but gave it a more progressive feel as the car loaded up the wheels.

With these changes, and the ever-rising grip, the car did feel a bit better. Although it still wasn't great, and I feel I would have been much quicker with a more conventional shell.

I did amuse myself by running the car with no body pins, just to make it clear to my fellow pit buddies quite how extreme the downforce was!

After a disappointing day at the track, I was fairly convinced I wouldn't be trying the Avalon Vortex again for a while. But race day soon arrived, so I decided to give it another go, although I wanted to try a few more things first.

 

The breakthrough

The main change was replacing the kit rear wing with a spare Xtreme Twister wing.

The supplied Vortex wing on the 0.5mm shell is very, very soft. It flexes easily in your hand; just placing a small amount of pressure on it results in it flopping backwards. So fitting any stiffer rear wing should help the performance of the shell.

I had also tweaked the settings a little more to make the chassis slightly lazy, allowing the extreme aerodynamics of the shell to compensate and make the car responsive but still driveable.

From the beginning, it was clear that things were much better. The car was a different beast on the track. It wasn't perfect, but I could now start to lean on it much more.

 

With one final fettle of the settings (I raised the rear of the shell by 0.5mm to give it some rake) I placed the Avalon Vortex-topped TRF421X down on the track and gave it a run in the final qualifier.

It felt really good :)

I had a precise front end, almost the best I have experienced for a long time, but now the car was much more dependable through the faster sweepers. I had finally got the chassis and shell working in harmony for the smooth, fast lines needed for Stock racing.

I made up a huge amount of time and ended up in a good position in the A-Final. A total contrast to the week before..  I was looking forward to the final, but that was a complete disaster, so let's not go there. ;)

Final thoughts

My final conclusion is that the Avalon Vortex really is an interesting shell.

I can see why it is popular with Mod racers, as it responds well to point-and-squirt, attacking lines. However, in its basic form it really was hard work for Stock racing on medium/high-grip carpet.

Swapping out the very soft rear wing made the biggest transformation to the handling, and I can imagine that would also be true for Mod racing. I feel that adding the slight rake to the shell also helped tweak the car towards where I wanted it to be.

Will I keep running it?

That's the dilemma. I've now got the shell working well at the track. It's not perfect, but its rotation through sharp corners is quite exceptional. However, I'm not a fan of the large front overhang, as it feels odd when spotting corners.

There's also the knowledge that the set-up I've ended up with is quite different from what I would normally run, so it feels counter-intuitive despite the lap times.

I personally think the shell has shown that there is still plenty of room for manufacturers to experiment. Maybe this type of design will become the norm, and what currently feels like a strange set-up will become de facto for this new wave of shells.

Should you try it?

Why not? But have a spare wing and your set-up tools ready if you really want to see its potential...