Posts Tagged ‘ 3″ Exhaust System ’

When is a 3″ Exhaust NOT a 3″ Exhaust?

We recently had a Corsa VXR in for mapping and rolling road set up. The car was previously fitted with (by another company) a Full 3″ Turbo Back Exhaust System and uprated intercooler – which should be ideal for performance.

Our K06 turbo, an 80mm air flow meter and some higher flow injectors were added into the mix (the engine had previously been strengthened with forged pistons and steel rods)…….

Imagine our surprise when no matter what we did software wise we could achieve more than 266bhp, when around 300bhp was the aim with the components we had.

So When is a 3″ Exhaust NOT a 3″ Exhaust??…..

When it looks like this:

Restrictive Centre Section

Restrictive Centre Section

You can see from the restriction caused by the baffles that narrow the bore of the exhaust through the centre pipe, that the bore size is greatly reduced. This obviously reduces flow, increases exhaust back pressure and hampers performance massively.

In fact when the car went from a Stage 1 Remap, to having this particular exhaust fitted the customer did report he thought that the car felt slower!

Not only was there a problem in the centre section, but the tail pipes had the same problem:

Restrictive Tail Pipe

Restrictive Tail Pipe

Needless to say once we had found the restriction we switched the cat back section for one of our Courtenay Piper developed 3″ systems, which does not feature restrictive internal baffles and finished off the mapping, successfully achieving 306bhp, gaining over 45bhp mid range, 40bhp peak to peak and 50 lbs ft torque mid range!

Corsa VXR Graph

Corsa VXR with K06 Turbo Before and After removing a poor flowing 3″ exhaust

Astra J VXR 76mm Exhaust System

The first pictures of our New Stainless Steel Sports Exhaust System for the Astra J VXR have been released and can be seen below.

The exhaust system comprises of a full turbo back 76mm system, including sports cat. It has been trial fitted to the test vehicle and checked on our rolling road. The vehicle is now undergoing ‘real world’ on-road testing and once our final evaluation has been carried out, we will be able to release the system for sale, which we hope to be in the next few weeks.

Astra J VXR Development News

Courtenay Sport are pleased to announce that the new Astra J VXR exhaust development is under way as we type.

Following the success of the Piper 3” Astra H VXR system we have once again teamed up with Piper exhausts for this development.

The system will be a full 3” with single or twin silencer options, both tuned to give a sporty sound. More details and pictures to follow soon.

The Courtenay Sport Blog

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