Vauxhall Astra J VXR

Tuning guide

The engine in the Astra J VXR is an all new design from GM, bearing no resemblance to its well-known predecessor, the Z20LEH. The J’s engine is known as the A20NFT, or LHU. The duplex timing chain system; balancer shafts and high pressure fuel pump with a direct injection (DI) system result in an impressive 276 BHP (280ps) as standard. Running a square bore/stroke at 86mm, the DI engine runs a compression of 9.3:1 from the factory. This, along with the Variable Valve Timing (VVT) and twin scroll turbo all combine to provide a very respectable 400Nm (295lb/ft) of torque.

Most standard cars typically put out around the 276bhp (280ps) quoted by the manufacturer, which is exactly what our development car saw, however we have also seen outputs as low as 260HP. Having said that, generally speaking most units produce around 320-335 lb/ft, which comfortably exceeds the standard quoted figures of 295 lb/ft (400nm)

VXR Engine ECU tuning is offered using Rabbid Tuning ECU software with its proven calibrations, extensively developed and tested by WG Motorworks at the Nurburgring. Click here for software info

For the power hungry folk, or those who simply want to improve their soundtrack - plenty of upgrades can be offered from MOT legal exhaust systems to full on track ready systems (Not road legal), along with Hybrid or Motorsport turbo chargers and engine internal upgrades. Click here for Performance Upgrades

For those Track Addicts, Nurburgring goers or simply for those who have increased their power and want a chassis to match, we can offer simple upgrades from lowering springs and performance pads to full coilover systems, uprated anti roll bars and limited slip differentials. Click here for Chassis Upgrades

The Astra J A20NFT engine results very widely, we can see 10-15HP difference in power output with 2 engines running exactly the same modications with no signs of issues. 

Pre tuning results also very, with some engines producing as low as 260HP in standard form, but the main car we see create the quoted 276hp within 2-3HP.

Our own developement vehicle was put through its paces at every state of tune, with a a full day on track testing out stage 1 software at brands hatch. Allowing us to carry out testing in the most extreme conditions to ensure the end product is satisfactory, allowing to sell as Track proven!

Moving forward testing induction kits, recieving the first post-development unit from Airtec motorsport, stage 2 was put through its paces with several laps around the Nurburgring! The increase of induction noise and exhaust note come second to the hike in power, although we started to notice power dropping slightly half way around the lap - with data logging showing confirming the intake tempertures causing the drop in power. Returning later in the year with a pre release Airtec motorsport the consiostacy was much improved with no power lose noticed even on back to back laps. At this level of tune was entered the Time Attack series at winning the class on the Snetteron 200 Track and our local track putting in an impressive 56 second lap with road tyres, springs and uprated pads / lines.

After testing a few different sized Hybrid turbochargers from Turbo dynamics, a trip around castle coombe for some track time was in order!  Where the car drove faultless which can be seen here -

https://www.youtube.com/watch?v=m8z0mLs8zfo&t=227s

 

 

WGM Level Packages info-
– All power / torque gains can vary car to car, therefore the above is an approximate guide of what would would expect,
– To optimal results, we recommend filling up with Tesco 99 or Shell Nitro- any other ‘Super unleaded’ fuel could lead to lower then expected results
– 95 RON/supermarket fuel should never be used, even on a standard factory map
– Although peak torque gains will be limited, overall ‘uder curve’ torque will increase, making a ‘flatter’ torque curve
– Our software can be customised to your specific car for optimal gains
– Stage packages do not require step by step tuning, you can go straight to the package that suits power / budget
– For returning customers who wish to upgrade to the next stage, please contact for upgrade pricing

Stage 1

The first step towards extracting power from the 2.0 Turbo engine requires no hardware changes, this is a software only upgrade. With standard boost pressure from the factory already hitting 20psi,  boost pressures are increased to 23-24psi, while smoothing out the stock two stage power delivery characteristics and torque curve, providing a massive increase of mid range torque from the standard twin scroll turbocharger.

With our 'Stage 1' software upgrades the following features are included:

  • Increased Rev limiter (7000RPM)

Expected Results, based on our Dyno Dynamics rolling Road:

300-310HP
365-375LBFT

 

 

WGM Stage 1 Tuning Package

Stage 1+

The next step to improve the standard car is to remove heat from the engine by extracting exhaust gases in a more efficient manner. The first catalyst, also known as the main cat, is the biggest restriction in the exhaust system. Fitting a decat downpipe (leaving the secondary cat still in place so as to pass UK emissions testing) will dramatically improve turbo spool, throttle response and low-end pick up, producing an extra 8-14bhp across the entire rev range, and 15-20lbft at peak.
In addition, on a track use only vehicle, a secondary decat or sports cat can gain a further ~5bhp/lbft but sadly is not road legal due to emissions testing for MOT regulations. We also recommend a high flow panel type air filter be installed to allow increased airflow to the turbocharger.

With our 'Stage 1' software upgrades the following features are included:

  • Increased Rev limiter (7000RPM)
  • Catalyst code removal to aviod EML lights

Expected Results, based on our Dyno Dynamics rolling Road:

310-320HP
385-395LBFT

 

 

WGM Stage 1+ Tuning Package

Stage 2

With the Astra J being well equipped from the factory with a 2.75” bore exhaust, we have found it is not necessary to upgrade the exhaust system at this stage. With the A20NFT engine, we found that improving the intake system alone gave very impressive gains across the entire rev range. Adding a 3″ cat back system gains only a few bhp/lbft over the normal stage 2 output

With our 'Stage 2' software upgrades the following are included:

  • Increased Rev limiter (7000RPM)
  • Catalyst code removal to avoid EML lights

Expected Results, based on our Dyno Dynamics rolling Road:

315-330HP
390-410LBFT

WGM Stage 2 Tuning Package

Stage 3

The final restriction to tackle is the intake air temperature. Having increased boost levels, the standard intercooler is now at its operational limit. Adding a more efficient intercooler with larger pipe work helps deliver more consistent power outputs in hot weather and throughout prolonged hard usage on road or track. The resultant cooler intake temperatures maximise the power from the standard Ko4 turbocharger, this is because with the uprated intercooler installed, the air charge entering the engine is cooler and more dense, therefore allowing us to optimise the ignition timing and boost, resulting in the engine now running more efficiently.

With our 'Stage 3' software upgrades the following are included:

  • Increased Rev limiter (7000RPM)
  • Catalyst code removal to avoid EML lights

Expected Results, based on our Dyno Dynamics rolling Road:

320-340HP
400-420LBFT

WGM Stage 3 Tuning Package

Stage 4

The factory size mass air flow-meter (MAF) housing maxes out around 12,000Hz or 256g/s, which equates to approximately 350bhp. With the available airflow now exceeding this level a new complicated ECU strategiy is utilised to run in a MAF-less configuration, with Volumetric efficiency recalibration.

To gain any more power at this stage, a modified turbocharger (known as a hybrid) must be fitted. To do this, we take a standard turbocharger and upgrade the internals with a larger exhaust turbine, and most importantly fit larger Billet compressor wheel. This is carried out to motorsport level tolerances. Installing a hybrid turbocharger transforms the car, giving a peak gain of ~35bhp over the previous stage. More importantly, the hybrid flows more air, allowing the engine to produce power beyond 5500rpm, where the standard turbocharger is unable to supply sufficent airflow. We have found the standard cat back exhaust system to be restrictive at this point, to which end we install our free flowing 3″ cat back system to allow these peak gains.

High lift camshafts can gain an addiontal 10-15HP at this point

Forged Internals are advised at this level of tune

With our 'Stage 4' software upgrades the following are included:

  • Increased Rev limiter (7500RPM)
  • ECU Calibration to suit 80mm MAF
  • Catalyst code removal to avoid EML lights

Expected Results, based on our Dyno Dynamics rolling Road:

350-385HP
400-440LBFTLBFT

WGM Stage 4 Tuning Package

Stage 5

Our stage 5 packages are well known for pushing the limits of the 2.0L engines, We offer motorsport turbochargers to suit all power levels. We can also offer additional supporting modifications such as : Uprated clutch/flywheel packages, uprated engine mounts, limited slip differentials, even more aggressive camshafts, uprated valve train components and forged pistons and connecting rods.

With our 'Stage 5' software upgrades the following are included:

  • Increased Rev limiter (8500RPM)
  • Complete Bespoke Remapping service,
  • Catalyst code removal to avoid EML lights

Expected Results, based on our Dyno Dynamics rolling Road:

380-500HP
Upto 450FT

WGM Stage 5 Tuning Package

OUR SERVICES INCLUDE

Dyno Testing

All ECU remaps are carried out on our State of the Art Dyno Dynamics Dynotech rolling road, which can accurately read upto 1200HP

Data Logging

Each car is hooked up to a Wide band lambda sensor to ensure correct air to fuel ratio, along with data logging tools to ensure Boost, Ignition timing parameters are all in check

Diagnostic Check

We carry out a pre and post tuning ECU diagnostic trouble code check (DTC) to ensure no faults are present before or after tuning