Posts Tagged ‘ Pre Cat Removal ’

Corsa E VXR Front Pipe and Remap

In our workshop today was this 7,000 mile Corsa E VXR with the latest version of the 1.6 Turbo engine, B16LES. The first job was to remove the restrictive pre cat (first cat) and fit one of our straight through downpipes (pre cat removal pipe). Once fitted it was round into the dyno cell for remapping with full rolling road set up.

Corsa E VXR Pre Cat Removal

Corsa E VXR Pre Cat Removal

Running on Shell V-Power (99RON) fuel the results were 235bhp and 248 lb ft torque, with power and torque gains right across the rev range.

Corsa E VXR Remapping

Corsa E VXR Remapping

Astra J VXR – Stage 1+ Upgrade

This Astra J VXR came to us for a Stage1+ conversion. This was a lovely low mileage example which had covered under 4,000 miles and was finished in Buzz Blue paintwork.

The first part of the process was to check the vehicle on the rolling road and benchmark it. This car made 278 bhp and 319 lb/ft torque.

Astra J VXR

Astra J VXR

The second stage of the process was to remove the factory pre-cat and replace it with a high flow straight through front pipe, removing the restrictive catalyst.

OE Pre Cat (Left) Pre Cat Removal Pipe (Right)

OE Pre Cat (Left) Pre Cat Removal Pipe (Right)

Then it was back onto the rolling road for mapping, data logging, map optimisation and full calibration and set up. The results on 97RON fuel; 319.99 bhp and 366.84 lb/ft torque with a much greater spread of power and torque which can be seen on the graph.

Astra J VXR Standard and Stage1+

Astra J VXR Standard and Stage1+

Astra J VXR

Astra J VXR

Astra H 2.0 Turbo Mapping

We recently remapped this Astra H SRi 2.0 Turbo model. The 3 door model with the Z20LEL engine leaves the factory with 170PS and was booked in for a repalcement 70mm pre-cat removal pipe, a high flow panel filter, ECU remapping and full rollinh road set up.

Once on the rolling road after an initial inspection and run up a split factory recirculation valve was diagnosed which was causing a loss of boost, and if left can lead to turbo failure. This was replaced with one of our Courtenay TurboSmart uprated recirculation valves which are a much stronger and better made unit removing the rubber insert of the OE unit that tears causing the failure of the OE valve.

After full datalogging, bespoke mapping and optimisation the car produced a very respectable 224 bhp and 255 lb ft of torque, an excellent result from a 96,000 mile engine. The torque was been kept nice a smooth from 2,700 rpm – 5,000rpm without a peak mid range torque spike which can lead to  problems for the factory clutches causing them to slip.

Astra SRi 2.0 Turbo 3 Door

Astra SRi 2.0 Turbo 3 Door

The Courtenay Sport Blog

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