XQ10 to XQ10F conversion review
Words by Mark Raddenbury.
So, time to join the craze and have a break from 4wd touring cars for a time. Those who know me, know I struggled a lot in 2021. Going full bore into Modified without much prep didn't do my brain any favours and I ended up a touch, out of touch, at the tail end of the outdoor season in the UK. So much so, I even cancelled my entry to the final round of the BRCA national series and took a break.
However, with the recent decisions regarding the direction the new BRCA Tenth Circuit is moving in, I've taken a wild punt to try a completely new direction this year. Frontie!
The big change the BRCA committee has come up with is fixed ESC and fixed Motor choice for the newly named 2wd nationals. With a bit of poking from my teammate and friend, Richard Ludlam, I soon had an Xpress XQ10 to XQ10F conversion kit winging its way into my letterbox from my sponsor SpeedRC.
What follows is a bungling attempt at a review to give you all an idea of how and what sort of performance you can anticipate from this conversion kit. I'd chosen to go the conversion route, as opposed to a full blown FT1 as for me, the more middle orientation of the motor on this conversion should lead to a consistent driving chassis.
As usual with Xpress, the kit is neatly laid out in the simple, but stylish black box that was delivered. All the parts needed are perfectly packaged (although no nod on if the plastic they all come in is recyclable) in separate bags that you can open as and when you might need to use that particular part/spare.
What do you get I hear you ask?
Carbon fibre chassis
2 piece carbon fibre top deck
Brass weight and new front bumper
Rear specific driveshafts
96t 64dp spur gear
Everything you need to switch over the fantastic XQ10 chassis to be a 2wd, frontie monster.
Opening the box
After a quick ponder as to the easiest direction to take the build in, I stripped out the current electrics I had on my XQ10 chassis, gave it a little air blow off and a brush down so it was as clean as possible.
I started the build by taking off the front bumper, then removing the top deck from the current build. After this, flipping the car over, I figured the easiest and quickest course of action would be to unscrew the bulkheads as well as the motor, servo mounts, lower suspension holders and steering arms from the (currently fitted) alloy chassis. This would have gone quicker, if I hadn't used threadlock on the various countersunk screws holding it all together! Something I've always done with a rebuild though, as nothing worse than your best run being ruined by a screw coming out.
Loosening off the XQ10, thread locked screws
Anyway, back to it.
After lifting away the alloy chassis and giving the rest of the exposed parts a light brush to remove any carpet pickup that had accumulated in the hard to reach spots, it was time to plan the rest of the rebuild. Checking the new XQ10F carbon chassis over, I saw no need to do the classic superglue trick on the edges, and instead give a light run over with some superfine Emery paper to make sure there were no sharp edges or flaws in the carbon layup. What followed was a bit of fiddling to line up the existing XQ10, 4wd bulkheads and get them all screwed on (gently now) and in place onto the XQ10F chassis. Once complete at the front and rear, I moved on to screw the steering arms into place, but suddenly remembered that a belt might be a good option to fit!
Not a crash, just stripped and apart!
Now onto the fun part, making the 4wd, 2wd. Removing the rear diff, as always on an Xpress, was straightforward and quickly done (especially with the XSquare bulkheads I use). Once I'd drained out the 3K, RCRaceprep diff oil, I cleaned up the diff completely and added 1.2g of 500,000 weight oil that had been recommended to me over the 1million that is usually found in a Frontie kit. I thoroughly recommend leaving the bottle of diff oil upside down to help the flow! Thicker than a frozen treacle, I almost needed a spoon to get it out. I didn't seal the diff back up straight away, and instead popped it to one side to let as much of the air filter out as possible. Aside from this, I'd also dropped off the shocks and refilled with some 450wt RCRaceprep oil at the same time. Always good practice when rebuilding to do all the oil bits at the same time and leave to sit for a while to get the air out and give as little rebound as possible.
Rear driveshafts were next up and the rear specific, half drive shafts installed neatly on fresh bearings. I do feel there's a key area that could be improved there. Instead of using just the outer parts of a current part, surely something specific could be made that would be unique to frontie chassis cars? But there again, it does cut down on the costs for the manufacturer, which is a saving that can be passed onto the buyer. I kept to my usual 4mm hexes (the red XQ10 kit ones for those who wonder) and refitted with the same shims under the inner and outer links of the upper camber arms that I had been using with the 4wd XQ10. I've also kept to the same lower "pips" setup that I had been running, just to get a direct comparison on track when I test the car out.
Rear bulkheads onto new chassis
Onwards now to the front of the car, the business end of the frontie.
I will admit I made one error at this end of the car, I fitted the servo to the one piece motor and servo mount ahead of fitting the spur gear. Something I only realised after I'd mounted the whole lot to the chassis. Certainly loving the fit of the one piece mount though. The slotted Xpress branded mount works really well and should definitely lead to keeping the front end in check on track, it also looks damn cool when you get the car upside down (hopefully that won't happen too much on track!). The motor mount is similar to the XQ10 version, with a slot beneath the motor that allows the servo lead to run neatly to the receiver.
Spot the error
Now, once I'd removed the above, it was time to get the spur on. For this, you get an alloy holder to align the spur, but you will have to use one of the pulleys from the XQ10 to achieve the drive to the front wheels. As with most of the current crop of touring cars, you get the usual 1.9:1 FDR to play with. I'm yet to experiment with sizes of spur gears that fit, for now I've used the 96t 64dp as included with the conversion as my usual 82t 48dp wasn't able to fit. I would imagine a size of 76t or lower if using 48fp would work fine though. The 96t 64dp does run fairly tight to the mount, to does run smooth and freely.
Spur on, belt on...
Time to fit the diff and sort the front end out, to make the complete transition to frontie spec. The kit includes brand new blades for the driveshafts, and I did fit these! Top tip that I use for those; pop them into a cup of recently boiled water to soften up the plastic and make fitting them a darn sight easier.
Fitting the diff was a simple matter or popping off the XSquare front upper bulkheads and dropping it in on the usual eccentric bushes and bearings. I've chosen to stick with a "high" diff profile that I have been using for a long time, so that I can properly compare the handling on track to the 4wd XQ10 version. At this point, I remembered to fit the belt tensioner to the motor mount, and this is the same as the XQ10 in that it runs on some tiny, but super smooth bearings. There is an option to run an upper belt tensioner on the front top deck, but the belt feels pretty tight currently so I've chosen to leave it off. I'm sure the belt will loosen once it's been run in though.
Finally onto the home stretch, it was time to get the 2 piece top decks installed. You get options in the kit here to either run with a flex mount or solid. I've chosen to run a flex type on the rear, to help give some more traction, but leave a solid, less flexible, front end. Coupled with the camber link stiffeners, I think the front of the car will have the grip it needs and wants to be an absolute weapon on track.
The alloy posts included for the top decks are of the usual Xpress red, and fit perfectly (as always) with hardly any shims needed at all. Back to the front of the car, it was time to get the bumper and posts installed. I've chosen to use the brass weight, to get the front end grip really solid and this is a really neatly cut piece of brass that slots in perfectly to the original XQ10 front bumper plastic mounts.
So that was it, the car was complete! Well, aside from the electrics of course. I didn't even need to do any resoldering for the ESC to motor wires, or even for the lipo wires. Just a simple case of turning them round slightly, and running the servo leads slightly differently as the receiver would now be to the rear of the car, behind a shorty lipo. You can't run a "standard" lipo with this conversion, so make sure this is something you've factored in if you chose this kit! For once, I'm glad I hadn't done my usual shortening of my servo wire, on the Ludicrous Lipo servo I had installed, and left it a standard (but coiled) length.
The car felt fantastic on the setup station and all the drivetrain feels as smooth as it did when on the XQ10.
Time to get ready for testing I guess
I won't give this too much wording, as you've probably all reached for a cup of tea by now and found it pretty empty.
One of the club members was selling a Montech MiTo and it is that shell I chose to fit. A very quick paint job was needed (which I'm pretty useless at unless it's a virtual one in Photoshop). So it doesn't look flashy on the car, but should be easy to spot on track. For outside events, I have been recommended a Blitz FK9 as it gives a good mix of speed and balance.
The bonus to being chairman of my local club is I've always got somewhere to head to when I need to do some testing. Forest of Dean Radio Controlled Car Club was the place to head to for a shakedown! A recent track change meant it would be fairly low grip to start, but I expected that to increase in the 5 hour, open practice session that we hold on Sundays. Perfect for getting to grips with how a car is handling instead of just crossing fingers on a usual Tuesday race night.
I got setup and broke out the full setup station once again to double check my numbers and make sure everything was spot on and it had been when I got the chassis conversion finished. I'd already been advised to run less rear camber than front, so went with the below as my initial setup to test with.
The initial run was very much a "see what it does" sort of run. Impressions were good! The car carried good speed and ran very easily round the tight and twist Forest Raceway circuit. The one thing I did find was that the car liked to have some lift off oversteer in the right hand sweeper we currently have, but it was on rails through any hairpin or chicane section. The usual checkover followed in the pits. Made sure all the screws I'd replaced for the swap over were tightened up and it was all as it should be.
A quick tweak of the Hobbywing ESC was needed. Gone was the 10% drag brake I usually run for 17.5t TC, as well as bringing the drive frequency up to 12hz and the punch down to 20. Removed 1mm off the rear inner camber link and added those 1mm to the front suspension upper XSquare link. Should give the back end a tiny bit more grip, whilst still allowing the front to stay planted. Back on with the additive (I was advised to fully soak front and rear, no idea if this is good or not??) and chucked a lipo on charge ready for another try.
Second run out and the car was extremely noisy! A short couple of laps and I discovered the spur gear had stripped slightly. 64dp and me don't get on, and here was another example of why not! Changed over to 70t 48dp and prepared to get back out there. Not a manufacturer error, but more a me error as I'd managed to tweak the motor in its mount when tightening earlier on.
Bye bye spur
Now back on track to a chorus from the other drivers in the pits of "Much better!". The loud noise was gone and I was able to really push the XQ10F to see what it could do. Handling in the tight sections was spot on with the car going exactly where I intended, albeit with a touch of power on understeer coming out of the corners. Round the right hand sweeper, I found the back end would try and let go, but was easily caught and gathered back up. Time to try some little tweaks ahead of the next
Ahead of another run, I'd dropped the rear shock oil down to 400 cst and put the front to 450 cst. Also going from 2.5° rear toe to 2° which should free up the back going round the hairpins, but the 400 cst damping should keep the rear planted on power.
What a difference!! Either the grips come up, or I've got better, or the setup really is now dialling in. Confidence in the car was huge and I was able to turn in some seriously good lap times. I was also able to keep the power down in sections where, before, I was having to lightly blip the throttle to keep some control. Definitely dialling into this car has helped a lot, but the setup has had a big part to play.
With time now called at the Raceway, it was time to pack on up and head on home! The setup sheet as shown, has a touch of understeer, but only really in the slow speed corners and on power on and corner exit. Safe, for sure, but still rapid and just from the practice times I was already 2 laps up on the PBs from the Frontie class on Tuesday evening.
The XQ10 to XQ10F conversion is an absolutely brilliant bit of kit if you want to go the frontie route and already have the brilliant XQ10 to use as a donor car. It builds lovely, it runs beautifully and above all, it's actually not that much of a cash outlay!
Driving wise, you'll have to adopt a slightly different style if you've been (like me) a Touring Car driver for a while. The frontie driving is much more about keeping the throttle on and less braking, especially round sweepers to keep the back of the car in check. If you've got a drag brake on, turn it off!
Just from driving the car today, it's given me a real buzz for the upcoming season and I'm certainly hopeful of some better results for all of the Xpress UK team.
Looks epic, drives epic
Thanks and mentions
As always my main thanks goes out to Valda (the fiance) for letting me do this crazy little hobby.
Massive thanks to Steve from Speed RC for being my main sponsor for a number of years. Also thanks to Rich, another of the Xpress drivers and one that's always had my back for events and keeping me positive.
Thanks also extend to Kev from Ludicrous Lipos for the awesome servo I currently use (some serious power in that!); Kieran from RCRaceprep who keeps me lubed and greased and oiled up where it matters; Mikey from Silly Goat for the awesome work he does on decals.
Also extended thanks to all the guys at Forest Raceway, such an awesome venue that wouldn't be the same without you all.
Bonus Extra Pics