1. Keep to the factory spec for the overall wheel diameter. This is the size of the rim plus tyres, and if you make the rims bigger, then you can use a lower profile tyre to keep to the original size. You can usually find this size on a sticker on the front door. If unsure, you can check with us. Likewise, you should use the recommended tyre pressure. This is important for the car body to keep rolling forward and push back the engine the moment the Surbo is activated.
2. In between filter element changes, remove the element and shake the dust off to allow more air in.
3. For carburetor vehicles, have the spark ignition timing tuned to factory spec where adjustable. Also important is the CO (carbon monoxide) emission level--tune by computer to as close to 0% as possible.
4. For wet batteries, top up the battery level, as a lack of electrolyte means a smaller store of available electricity, so the alternator has to load the engine more and make it consume more fuel.
5. Straighten and shorten the air intake layout to minimize friction and bend losses. The Surbo should be fitted nearest to and most directly at the throttle (but before any minor air connection to prevent bypass), to get and deliver the maximum back pressure in the air intake. Note: for before-filter installations, although the filter is in between, these have the advantage of free air before the Surbo.
6. Try to connect to cold air wherever possible as colder air has a higher density. For example, you can connect the air inlet to an opening in the grille.
7. Upgrade to Twin Surbos as these simply have better low end torque and have stretched the mileage on single-Surbo cars. The Twin has been shown by the dynamometer to deliver 10% more torque between 2500-3000 rpm so if you spend more time in that region (eg. during cruising) it will give better economy than the single Surbo.
8. Our general guideline is that maximum torque at the low and mid rpm range go hand in hand with fuel economy, because most of the driving time is spent in these ranges. It may not be advisable to shift gears upwards at too low an rpm, as the starting rpm in the next gear may be too low for power. So, you will have to press more on the accelerator, and end up spending more time in the low gears that are not economical. The rate of fuel injected at any moment is proportional to throttle travel x rpm x no. of cylinders. For a given car it must depend mainly on throttle travel (how much you press on the accelerator) and rpm (which you can control via gear selection). The total consumption is the sum of throttle travel x rpm x time spent in each gear over the journey.
9. If your vehicle is manual, have the clutch adjusted lower so that gearchanging can be faster and more Surbo power preserved during the gearchange. If the gearchange and clutching is in completed in one second, it syncs with the Surbo system which also takes a second to charge.
If you are not already using Surbo in your vehicle, and have a problem with fuel consumption or a lack of power, you can contact us for advice. If you have just purchased a used car, we can help you check if it is the existing modifications that are causing the problems.
Above: video of Volvo XC90 T8 with Surbo, sprinting to 130 kph.
Above: video of Volvo XC90 T8 with Surbo, sprinting to 211 kph.
Above: video of Volvo XC90 T8 with Surbo, sprinting to 224 kph.