ASHLEY’S S-DRIVE UPDATE TOWING
Regular readers will recall from mags published late last year that I fitted an S-Drive throttle controller to my 2003 Range Rover V8 and subsequently wrote about the benefits and improved ease of driving that resulted directly from the S-Drive.
As a quick catch-up, the S-Drive is an electronic pedal plug that plugs in to the accelerator pedal fly-bywire system and improves response times from the pedal to the engine management computer.
These days of course “drive-by-wire” technology, electronic potentiometers and sensors have replaced accelerator cables; instead the sensor at the pedal tells the vehicle’s ECU (engine control unit or computer) how far down the pedal has been pressed and in turn, the ECU sends a signal to the actuator to increase airflow to the engine.
Lagging behind
Where this becomes an issue is as the voltage ramps up, it ramps up slowly. Unlike old cable setups there is no instant boot mashing your accelerator because vehicle manufacturers tend to tune-in smooth throttle response to minimise strain on the vehicle and driveline. The delay from the moment the accelerator pedal is pressed, to the time the signal gets to the throttle, is otherwise known as “lag”.
This is where a throttle controller like the SAAS S-Drive is beneficial in that it reduces (and in some vehicles, eliminates) lag by giving the driver the ability to adjust the throttle’s sensitivity and shortening the response time between the accelerator and throttle body.
Á la Mode!
Further to that the SAAS S-Drive has five different modes of throttle action modification; Comfort, Sport, Racing, Eco Fuel saving, and Normal (factory setting) with a considerably noticeable difference between Normal and – say – Sports modes.
I well remember, for instance, my first drive up the road after fitting the S-Drive. It was exhilarating. There is no other word for it. I’d always considered that the V8 in the Rangie had very good acceleration, despite the vehicle itself weighing in at a little over 2200kgs.
This was especially so using the tiptronic sports mode in the gearbox.
With the S-Drive however, it was a completely different vehicle again.
Fitting the S-Drive highlighted how much ‘lag’ vehicle manufacturers do tend to tune-in for smooth throttle responses to minimise strain on the vehicle. The delay from the moment the accelerator pedal is pressed, to the time the signal gets to the throttle is eliminated almost completely depending on mode setting.
Now, a tow test!
At the time due to lockdown restrictions we weren’t able to do a genuine tow test with the S-Drive fitted. This, apparently, is where throttle controllers like the S-Drive are supposed to really shine, especially if you are towing a heavy load.
So I was actually quite happy when a 300km + round trip was required to pick up NZ4WD’s Project 12K Jeep Cherokee that was in need of some repairs (that’s another story).
Hooking up the large and heavy recovery transport trailer and only stopping to fill the tank in Hamilton, the Range Rover’s trip computer indication gave a range of 688kms after filling the tank. The trip north I used several settings on the controller to get a feel for what seemed best and more comfortable for the vehicle and myself and hopefully reasonable fuel economy, if that was indeed possible towing the all steel trailer.
In the end Comfort mode proved to be just that, comfortable and still providing good acceleration on the hills when needed.
Exactly 145kms later and on arrival on Auckland’s North Shore the onboard computer was indicating a fuel range of 630kms to empty…however the trip home would be the real test. All up with the Jeep on the trailer I probably would be towing around 2.9 tonnes.
The improved acceleration is often mistaken for an increase in
horsepower however the S-Drive doesn’t provide any additional power or torque. Now I know that, and you – if you’ve got this far = should too.
It certainly feels like it though, with the much quicker throttle response. Once again I experimented with various settings including Sport and Race modes with the Eco mode seeming to introduce more lag but with a heavy load again I settled on
Comfort and maintained a steady 90km/h.
‘Flattenin’ them hills’
And do you know what? Just like those good ol’ Duke boys the S-Drive was “Flattenin’ them hills” for the journey home – it was that smooth and hasslefree.
Filling up again after the return trip the fuel consumption was 14.6 L/100km overall, which given the load and stop-start journey through Auckland, was considered very good for the large V8 with a load.
Needless to say I have been very pleased with the overall benefits of fitting the S-Drive with a much improved driveability and fuel economy – and now the benefits when towing, which cannot be overstated.