Xray XT8

It’s been a long time coming, but is it worth the wait?  We’ll soon find out as we delve into Xray’s brand new truggy, the XT8.  Truth be told I’ve been gagging to get my hands on this kit and even reviewed the XB8 EC last month just to get my taste buds tingling.  After all, a truggy is just a 1:8 scale buggy with an extended chassis and longer A-arms isn’t it?
Well, on first appearance you may be fooled into thinking that, but as you look into it, you can see an awful lot of development work has gone on to make it a kit in its own right.  If you struggle to see the differences, chief designer at Xray, Juraj Hudy, has recently put a nice column up on the Xray website explaining some of the development process.

An Insight

I won’t take the easy option and copy the entire content of Juraj’s column, besides, he deviates into boring car talk at the end, however it’s interesting to read that development on the Xray truggy actually started two years ago.  Of course the norm then was to whack hub extenders on a 1:8 scale buggy and stick on some raised shock towers.  That was fine until Hot Bodies launched the Lightning Stadium and redefined the class, then Hong Nor followed suit with the X1 CRT and the battle of the truggies began.  Add the fact that Juraj just wasn’t happy with the way their first attempt handled and you can understand why the project was shelved. 

Seeing the development in the class, Xray knew a whole lotta work needed to be done.  Purpose made A-arms needed to be designed and if they were going to get it right, a whole new drive train needed to be added.  Fortunately they’re a clever bunch at Xray and these revisions were duly made and we got our first glimpse of the XT8 at the International Toy Fair in Nuremburg at the start of the year.  Unfortunately further changes were required after its first outing at the Pro-Line indoor challenge at Easter, since the smaller 125cc fuel tank it was packing proved to be a real disadvantage when everyone else was using a larger 150cc tank and stopping less.  Xray were then stuck between a rock and a hard place, do they delay the kit further and produce a new tank, or get it on the shelves and keep their customers happy (albeit that they would moan about the small tank). Thankfully Xray made another correct decision and delayed the kit for another month while they produced a new larger fuel tank.

Build Me Up Baby

As I’ve already admitted, I was quite keen to try this truggy out and amazingly (for me) I started building it within 24 hours of it arriving!  Fortunately building the XB8 the month before proved to be a real advantage because not only was I very familiar with the build process but I could also easily spot the differences.

Again I’ll try to avoid going through every stage of the build because it doesn’t deviate too much from every other buggy and truggy kit out there.  This does mean that you start by building the diffs and while Xray provide you with a basic set-up sheet, I wasn’t too impressed with it and was therefore very glad when Jon Dell sent us a copy of Xray’s top team driver Jon Hazlewood’s set-up.  It was an added bonus that this set-up was from round one of the truggy nationals at our very own MaxBashing track, I almost feel special!

Drive Ratios

As part of Xray’s commitment to making the XT8 a kit in its own right and not just a truck version of their buggy, the overall drive ratio has been altered.  This is essential for any truggy as its wheels are a whole lot bigger and if a normal buggy gear combination is used, the acceleration would be slower than my reactions first thing in the morning.  The cop-out option here is to considerably increase the size of the main spur gear and whilst this achieves the desired objective, it does mean that you are raising the overall centre of gravity as the centre diff needs to be mounted even higher.

In order to avoid having a spur gear that runs the risk of slicing a hole in your body’s roof, you need to change the size of the crown and pinion gears in the diffs.  This is just what Xray have done and the XT8 features 10 tooth pinions and 43 tooth crown gears rather than the 12 tooth pinions and 40 tooth crowns found in the XB8.  This gives the XT8 an internal drive ratio of 3.69:1 compared to the buggy’s 3.54:1.  Interestingly (well, if you’re a bit geeky) we’ve heard some of the Xray buggy drivers are using the XT8 pinion and crown gears in their XB8s to lower the rotational mass and improve its acceleration.

Changing the crown and pinion gears doesn’t completely overcome the difference the larger wheels make though and a slightly larger spur gear is still needed.  Therefore the XT8 comes with a 48 tooth spur as opposed to the 46 tooth spur found in the XB8, giving the truggy a higher primary ratio of 4.3:1 compared to the buggy’s 3.33:1.

All these changes obviously affect the final gear ratio (I bet you were just thinking that weren’t you?) and the XT8 therefore ends up as 15.88:1 whereas the buggy is 11.79:1.  If you’re wondering just what the final gear ratio actually is, it’s the amount of times the engine turns over during one revolution of the wheels and because the XT8’s wheels are much bigger than the XB8’s, it needs this higher ratio in order to have decent acceleration.  I hope that all made sense because it confused me to start with and I must give my thanks to the guys at Apex Models and Kev’s Racing for helping me get my head round it all!

Set-Ups

With the drive ratios all understood and taken care of, the other thing that will affect your truggy’s handling are the oils used in the diffs, and whilst Xray’s basic set-up suggests using 7,000 in the front and rear and 10,000 in the middle, Hazlewood’s set-up uses 5,000 in the front, 7,000 in the middle and 4,000 in the rear which seems a much more sensible idea - I mean, 7,000 in the rear, where on earth did that come from?

The only other major change from Hazlewood compared to the stock recommendation comes in the shock set-up.  Both suggest using the supplied dark blue (firm springs) and 600 (or 60) weight oil, however the stock set-up suggests using two 1.4mm holes in the front pistons and two 1.5mm holes in the rear shock.  But after a bit of a chat with Jon Dell (Hazlewood’s mechanic/pit man extraordinaire), he said to use four 1.4mm holes in all of the pistons because (according to Dell) after building it the pack of the shocks was too much so drilled two additional holes in the shocks.  Dell was also kind enough to point out that if you don’t have a 1.4mm drill piece you can cunningly drill two 1.5mm holes in the pistons that come already supplied with two 1.3mm holes to achieve the same effect (this is what I did).

Pure Quality

As I continue through the build I’ve got to admit I was constantly impressed with the quality of components used in the kit, this wasn’t a great surprise having built the buggy but it is so nice to see and makes the process a pleasure rather than a pain.  There wasn’t one instance where something didn’t quite fit right or indeed was actually missing.  The manual makes the build a very painless process and is very well explained and like the buggy, all the components for every stage are in separate bags so if you finish a stage and there are parts left, you’ve screwed up somewhere.

Of course all the usual Xray bling is in place, from the black anodised T6 7075 radio tray, shock towers, front plate and centre diff brace to the gorgeous looking T6 7075 hard coated aluminium chassis which is also milled out to make it as light as possible.

Xray’s trademark HUDY spring steel is also used throughout the kit, the pure strength and bronze colouring of this really makes things like the turnbuckles and CVD drive shafts stand out and of course, set this kit apart from any other manufacturer.