If you’ve got a Volkswagen with the 1,9-litre turbodiesel, an SAC branch near you can make it an even more efficient operator, with performance and fuel consumption benefits.

 
Tuning specialists Steves Auto Clinic are breathing new life into the Golf 4 TDi by offering an impressively refined conversion which gives it sparkling performance, and at the same time have developed a similar but even more powerful upgrade for the Polo 1,9 TDi.
And while the cars are radically different – with the latter fast becoming the thinking man’s hot hatch and the former a tried and tested all-rounder – they both bear all the hallmarks of an SAC conversion.
That means a holistic approach starting with extensive research and development, followed by independent local testing, ensuring long-term mechanical integrity and real world gains: plenty of modified cars make additional peak power, but this needs to be usable in terms of driveability and overall efficiency.
Both are fitted with similar powerplants and while there are differences in the actual injection method and technology, SAC uses the same basic approach to unleashing more power and torque.
The Polo’s more modern engine is also fitted to a number of other VW, Audi and more recently SEAT models, and owners of these vehicles would also benefit from similar upgrades.
Key features of an extensive underbonnet makeover include:
  • “Plug ‘n Play” Electronic Control Unit optimisation
  • An upgraded replacement turbo
  • Gas-flowed cylinder head
  • A 63 mm free-flow exhaust system with catalytic converter removed
  • Air intake system upgrade
In the case of the Golf, power swells from 81 to 108 kW, an increase of 33 percent. The Polo, which starts off with 96 kW, lit up the dynamometer at SAC Engineering with a max of 125 kW and a torque increase of about 18 percent. These numbers place it firmly in the upper echelon of the hot hatch class.
Before & After Tests
– Volkswagen Golf4 / Polo 1,9 TDi –
All tests conducted using a Racelogic VBOX GPS-based data acquisition system

 
SAC Polo TDi Standard Polo TDi SAC Golf4 TDi Standard Golf4 TDi
ACCELERATION:
0 – 60 km/h: 3.8 Secs 4.22 Secs 4.2 Secs 4.62 Secs
0 – 80 km/h: 5.97 Secs 6.56 Secs 6.5 Secs 7.41 Secs
0 – 100 km/h: 8.2 Secs 9.27 Secs 9.1 Secs 10.96 Secs
0 – 120 km/h: 11.6 Secs 13.4 Secs 12.9 Secs 16.32 Secs
0 – 400 Metres 16 Secs 16.85 Secs 16.6 Secs 17.98 Secs
TERMINAL SPEED: 141 km/h 133.7 km/h 135.4 km/h 128.3 km/h
0 – 1,000 metres: 29.5 Secs 31.7 Secs 30.4 Secs 32.79 Secs
TERMINAL SPEED: 175.7 km/h 166 km/h 170.2 km/h 156.3 km/h
VMAX: 218 206 198 191
FLEXIBILITY:
60 – 100km/h (4th): 5.5 Secs 6.5 Secs 6.6 Secs 8.84 Secs
60 – 100km/h (5th): 8.1 Secs 9.6 Secs 9.8 Secs 12.29 Secs
60 – 120km/h (4th): 5.9 Secs 6.9 Secs 6.9 Secs 10.18 Secs
60 – 120km/h (5th): 7.1 Secs 8.7 Secs 9 Secs 13.08 Secs
 

Test Conditions
All Tests conducted at Gerotek Proving Ground at Reef altitude. Car magazine tests conducted at sea level. All Gerotek test results are an average of two runs in opposite directions. Fuel tank full, driver only. Test data compiled by Adrian Burford of Roadworks, using Racelogic Vbox Test Equipment.