The history of legendary model engine maestro Mario Rossi is well documented and a story most RC enthusiasts will be aware of – having dominated the model engine field during the last 20 years. Best known for his long association with the ‘godfather of RC engines’, Novarossi – Mario flew the nest for a fresh challenge with the Gandini brothers – designing and developing GRP’s engines and in-house production, after that he founded the REDS brand with his son Marco.
After some years spent developing their ideas and concepts together with Lavorazioni Meccaniche (the factory behind Sirio and Orion engines), the pair decided to change technical partners, and landed on the Milan based Picco Micromotori to produce their complete line of engines.
In the last 12 months we’ve witnessed the ascension of REDS – signing World Champion Cody King signalling the company’s market focus wasn’t only on Europe but further afield as well.
“The R5T is a high end racer engine – the top end of the market and as such we expect it to outperform expectations..”
The unit NeoBuggy received for review was REDS’ top of the line R5T Team Edition engine. Hand assembled by Mario Rossi himself, it comes with a signed checklist, assuring the top quality of the build and the precision of the parts. The packaging is a little old fashioned, nothing special about it, minimalist and maybe an area customers would expect more on, but every racer knows it’s what’s inside the box that you’re really paying for and what counts.
“…use the extra power available to get out of some awkward situations be it a difficult ex girlfriend or simply clearing a tough jump section.”
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We did notice the lack of any rubber caps for exhaust, air or fuel intake, many engine companies supply new units with these and the caps tend to be very useful during manteinance, preventing dirt or foreign particles entering the engine
In our case we received the combo – the engine and a REDS 2104 exhaust, a XS (extra short) manifold. The individual parts are all finely machined, not a single flaw was found here. The engine is a 5 port, 2 booster unit with ceramic Swiss ball bearings, the crankshaft sporting two brass inserts for perfect balance.
Before starting the unit Neo Stig pulled the R5T apart, to get a closer look and was impressed with the amount of oil that was used during the original assembly (by Mario Rossi) – an often overlooked stage which is also crucial one, the efficiency and characteristics of the engine often defined during the very first moments of starting and having a well lubricated engine is critical.
The head is pleasing, drilled for lightness and finished with laser engraved logos on a matte black colour. The crankcase is also black, and features two handwritten signs on the mounts: “Team” on the right side and the M.Rossi signature seal of approval on the other.
The crankshaft feels smooth as silk, supported by the finest Swiss bearings whilst the piston/sleeve combination feels great and the engine isn’t tight at all despite being brand new. This will make the break-in easier, without additional stress on the conrod, will make the fuel consumption lower.
The backplate is machined from alloy and receives an RDC “Diamond” treatment, used to harden the part avoiding any kind of friction between the rod and the backplate itself. Turning our attention to the Carburettor, its a classic Picco; two restrictors that allow the user to choose between a 7mm and 6mm diameter, to adjust the powerband and obtain the right fuel consumption according to the track and the driving style.
Along with the engine-pipe combo we also received the REDS clutch system, a classic 3 shoe system, very easy to assemble and maintain, complete with a vented bell machined from steel. We had to use a Losi clutch bell though, as the REDS one wouldn’t fit the Serpent buggy.
So to break in; the first start was a breeze, an easy job for the starter box as the first drops of RunnerTime fuel reached the plug and ignited. Break in went flawlessly with 4 full tanks on the starter box japanese style. Do note that the carb is already tuned for this technique, so we only needed a slightly richer top-end, we’d would like to point out that the engine never stopped during the procedure. After the japan style phase came to an end and the engine had cooled down, we continued the break-in, burning off two tanks on the track, leaning the engine each three or four laps until reaching a decent tune we used to burn another tank. Breaking-in the engine this way will ensure reliability and will prevent the engine from overheating or suddenly stopping without any apparent reason due to the piston-sleeve being too tight.
Once done with the last 125cc, we started the R5T again and set off to reach the fine tune, to be honest no map or directions required, it was straight forward. This is where the real test started, and our usual testing track grounds would test the unit to it’s limits.
The track had recently been redesigned, some parts remained quite dirty, which allowed us to test the pure power of our REDS R5T on the clean lines as well as the smoothness on the slippery, dusty new section. From the first laps the feeling on the trigger was good, the powerband easy to control and very linear. When up to temperature the XS manifold proved ideal to smoothen the bottom power on one of the dusty corners, a slightly longer one could grant even more power for the clean high traction sections.
What we found really interesting is that there is enough power to play with the trigger, pulling it almost only halfway to obtain enough speed to post proper laptimes. That is very interesting when you try to optimize fuel consumption and avoid wheelspin that cost you laptime, fuel and tyrewear! With some engines you just can’t actually partialize the throttle, as you need to go full throttle to clean them out and see some speed, but with the R5T you can just drive smooth and use the extra power available to get out of some awkward situations be it a difficult ex girlfriend or simply clearing a tough jump section.
The sound from the 2104 pipe is discrete yet crisp & clean and quite distinctive, the pipe itself seems to be very well matched with the engine’s features, even if it would have been nice to try a longer manifold. After a good liter of fuel burnt, we started experimenting with fuel consumption, giving the 6mm restrictor a try, which was great on the dust, but wasn’t satisfying on the high traction surface, in such a hot (around 30°C) situation, as the bottom power seemed to fade a little bit. For sure you could try a 6mm restrictor with a longer manifold to increase power at low rpm’s.
Back to the experiment itself, we didn’t find much difference between the two configurations as we had to pull the trigger harder on the 6mm, the engine stopping after 9 minutes and 43 seconds on a measured 123cc tank. Back to the 7mm we obtained a time of 9.37 before the engine stopped, so it’s pretty much the same. The difference with the larger restrictor is the driver has to pay closer attention to manage the generous power in order to save fuel and use only what his car can unload on the track.
Talking temperatures, with the smaller restrictor we saw slightly higher temps – in line with the decrease of bottom power experienced. For sure, the 6mm is a must try on low traction or colder conditions, maybe with a longer manifold, the driver will still be able to partialize the trigger and go up for more than 10 mins per fuel stop. Neo Stig was satisfied, the results meant pitting at 9 mins in a 45 mins main final, a respectable result on the Neo test track.
In conclusion, the REDS experience has been a soothing, relaxing one – never once did we see red (yep that was a pun!) throughout the review process, from break in to fine tuning. Special mention to Mario Rossi and his attention – matching piston and sleeve to perfection not forgetting good reliability and predictable but powerful with a smoother powerband than a Picco, with the adage that it stays clean throughout the whole acceleration process, allowing you to partialize and use the right amount of power. However the best feature may turn out to be versatility – mixing and matching restrictors and manifolds to get the perfect feel (for our test driver the pipe was the perfect fit already so no need to go changing clothes there!)
The silky powerband suiting the Savile Row tailored gentleman – a driver with his own identity and mystique who does his talking on the track, not in the paddock.
The R5T is a high end racer engine – the top end of the market and as such we expect it to outperform expectations, be that from a painless break in as a result of the careful assembly or simply having half a throttle trigger left of power if need be. The R5T is more subtly sophisticated though; a suave engine for the discerning connoisseur – not another overpowered Italian Stallion in the hands of a trigger-happy newbie.