Sailing along at 5kph in a fit crop of wheat, only to be halted to a crawl when the unloading auger was engaged, was severely hampering harvesting progress across McGregor Farms’ 3,600ha.
The farm needed extra output from its three Claas combines to prevent the significant drop in forward speed it was experiencing when engaging power hungry features such as the straw chopper or unloading auger.
“We started looking at engine modifications in 2017 as we were struggling for horsepower on rotary combines. We farm a lot of hilly ground, and we chop around 70% of the farm, which can be very demanding on the engine when it is engaged, especially while unloading,” says Tom Hoggan, assistant farm manager at McGregor Farms.
“When we unloaded on the move, the combine would go from 5kph down to a crawl and only ever reach 3.5kph when unloading. If you weren’t careful, the CEMOS automatic system would bring the combine to a virtual stop to prevent it from overloading itself. There just wasn’t enough engine power in reserve to maintain a consistent forward speed, unload and have the straw chopper engaged. Something had to change as we were losing valuable time.”
In 2021, A&A services professionally installed an Avon Tuning ECU remap to one of the combines to maintain peak power output across all operations.
McGregor Farms is located at Coldstream Mains in the Scottish Borders, and is run by Colin and Jill McGregor, with farm manager David Fuller and assistant farm manager Mr Hoggan, alongside six full time employees. The focus is combinable crops across the acreage, which work in partnership with farmers and landowners across a 15-mile radius.
Power increase
“For our varied acreage, three high-capacity smaller combines are better than two bigger ones, which is why we went for the new Claas Lexion 8700, instead of the biggest 8900, that arrived in 2020. We ran the combine for one season without a remap to keep the one-year warranty on the engine in-tact. We don’t opt for Maxicare but ask Rickerby to annually service the combines for us.”
After the first season, A&A services installed a stage 1 Avon Tuning remap to the 8700 that has upped power by 100hp and crucially allows the extra grunt to be available all the time from the 15.6-litre Mercedes Benz OM 473 LA engine. The same block also powers the bigger 8800 Lexion, which is standard with 653hp, whereas the 8700 leaves the factory with 585hp.
Avon Tuning edit the ECU software and each new map is tailored to the machine and the customer’s requirements. By editing at source, rather than interrupting the signal, there are more parameters that can be changed to achieve the correct power and it is a safer form of boosting output. Detailed checks are also carried on the running gear to ensure that any power increase is comfortably within the limits of the machine.
“Since the remap has been added it has made a huge difference having the extra 100hp available all the time. Our forward speed can be a little quicker if we wish, but crucially the engine isn’t having to work as hard to achieve the same output, and means there is enough in reserve for the unloading auger to be engaged. Our forward speed only drops by 0.5kph now when unloading and we have enough power on the hills when straw chopping, too.”
Damp harvest
McGregor Farms has run Claas machines for decades due to excellent product and customer service from Claas and support and back up from Rickerby. The new models have offered a significant step up in output over the older 700 models, but farming in the Scottish Borders does come with its challenges.
“Due to our location, our harvests are usually late and can be very wet, so we need the combine capacity to get across the acreage when the weather allows. We need all three combines to be at full capacity to make sure we can be in multiple places at once and get harvest completed.
“The straw chopper is a big power draw, especially when we are cutting damp crops in sub optimal conditions. This is the time where we really notice the increase in power across the full engine range and it allows us to keep cutting at a good speed while chopping.”
The farm operates a controlled traffic system, where it can, with all machinery being changed to fit with the 12m bout widths. All three combines use 12.3m beds, with the two 8700 models running the ConvioFlex headers and 7XL spouts, which demand a lot of power to run when full, explains Mr Hoggan.
“We’ve noticed with the bigger and longer spouts that not only is there extra weight in the auger, but there is extra power required to fill the trailers due to the increased grain capacity. The new headers really help with power demand as the crop is presented to the feeder house perfectly and it limits the peaks in power demand that were caused by lumpy crop flow.
“There has been a slight increase in fuel use on the remapped models, which isn’t a surprise as we didn’t expect to get more power for free. However, the alternative to remapping for extra power is to buy the next model up, which is the same in all but numbers on the side and the price. If we went down this route, it would be more difficult or perhaps unfeasible for us to financially justify three combines,” says Mr Hoggan.
Previous system
This isn’t the farm’s first foray into upping the power on combines. A tuning box from a different manufacturer was fitted to the farm’s Claas Lexion 770 back in 2017 and, as Mr Hoggan explains, these worked well up until the new generation of combines arrived.
“Our older Claas Lexion 770 models were fitted with a power module on the engine to enhance performance. These didn’t edit the engine’s ECU map but were a bolt-on part that we could remove by unplugging it. These worked well and proved the theory that we could get extra peak power all the time,” says Mr Hoggan.
“However, when the first of the two newer 8700 Lexions arrived in 2020, we fitted the modules after the first year and found it prevented the DPF from regenerating and caused the combine to go into limp mode. It came to a crux during the middle of harvest, so we ended up taking the box off and completing the rest of the summer at standard power.”
In contrast, an Avon Tuning remap doesn’t require a box to be fitted to the engine, everything is software based and new maps are created to change parameters including fuel timing and delivery to release the extra power. The original ECU map from the combine is stored in case the owner wants to put it back on.
“We only want to increase power within the safe limits of the engine, we want to maintain power across the full operation and not suffer significant declines in forward speed when engaging parts of the combine that demand extra power.”