The Carisma M48S Subaru Impreza WRC is a new ⅛ scale RC rally car, and if you have read my review article, you will see that while the car looks nice and has some nice little features for the money, the performance of the car was very disappointing. 

I’m the first to admit I’m not one of those people who love to have the fastest RC car or drive by the speed of the car. However, 17mph on a car this size isn’t great. Especially when you think of the speeds the rivals of this car can achieve on 2S and 3S. 

The reality of this car out of the box isn’t that great.

Carisma’s decision not to go 3S was a big mistake. The other questionable decision was in the gearing they decided to go with on the 2S brushless setup. It runs a 44-tooth spur gear and 12-tooth pinion gear on mod 1 gearing. By running a 2S set up the gearing could have been better for it to run at a higher speed on 2S.

So having a bit of a chat with the team here, we have decided to get the current motor and ESC out of the car and try and get it running a bit closer to the leading class cars, the HPI WR8 Flux and the CEN 2023 M-Sport Ford Puma Rally.

So I started work on removing the cover where the spur and pinion are and then removed the motor mount so we could get to removing the Carisma racing sport-tuned motor. When we removed it, there were a couple of things we noticed. The first was one of 2 screws not coming out of the motor mount as it was that tight in. After help from Simon, we eventually removed it to find the screw was bent on installation from the factory. Not only that, but the grub screw to secure the pinion gear on the motor shaft was also installed at an angle. The worst bit was when we turned the motor by hand it had a really bad grinding feel to it. Maybe this could have been the reason for it only doing 17mph out of the box, but the fact I have only used 1 battery on this and this is the first time I have started to do some work on it hasn’t impressed any of us here.

With the motor removed, we fitted the new Etronix Photon 3665 size 2900kv brushless motor and then decided on what size pinion we could get in. It’s a shame as there is so much space on the chassis for a wider motor mount and bigger casing for the spur and pinion gear where you could go to town on changing the gearing to get some much better speeds. Carisma lost a trick there as at least customers could have adjusted the gearing on the 2S setup to get it quicker too. With the restrictions we have on the mount and casing, we were able to change from the current 12-tooth pinion to a 15-tooth pinion gear. One we had in stock was a Traxxas pinion gear under part number TRX6487X, and so we decided to get that fitted. 

So with the spur and pinion meshed (always using the guide my colleague Steve has here), it was time to get it fitted back in the car and also get the cover for the motor re-installed.

Now the new motor is installed, all that is left is to fit the ESC and wire the motor up to it and we are all good to go! Make sure you have a very small size Phillips screwdriver to remove the cover on the receiver box as the screws securing the cover are extremely small. Also, you will notice you will have to remove one of the ESC mounts if your ESC is too big (like mine) but I secured it down with some good double-sided tape and it isn’t going anywhere.

So here we have it! A 4S-ready Carisma M48S Subaru Impreza WRC. This is something I’m looking forward to taking out and seeing what difference it has made to the performance of the car. Will it be closer to the HPI WR8 Flux and the CEN 2023 M-Sport Ford Puma Rally? I’m hoping for a much better increase in speed and also hope I will be able to get the car sideways a bit with the extra oomph the installed system should give the car. 

Find out shortly when the next article when I will be comparing the difference of the car on its original setup to this new setup. Fingers crossed it will be worth it!