Posts Tagged ‘ 76mm Exhaust ’

Astra H VXR – from Standard to Stage 3

Another one of our more recent jobs was to give this Astra H VXR Racing a much welcomed performance increase.

Booked in for a full Stage 3 conversion, the vehicle came to us as a standard spec car. We fitted our full 76mm (3″) turbo back exhaust system, our full height CSR front mounted intercooler, an uprated actuator with new bracket and finally a set of cooler running iridium spark plugs and a CS high flow foam panel filter were added. Mapping and set up saw a very respectable 289.5bhp and 336 lb ft torque, considering the heat at this time of year doing its best to reduce power.

For further details on the conversion, pricing and additional tuning information please visit our webpage on Astra H VXR Tuning >>>> HERE <<<<

Astra H VXR Stage 3

Astra H VXR Stage 3

Piper Exhaust for Corsa VXR Nürburgring

Corsa VXR Nurburgring Tail Trims

Corsa VXR Nurburgring Tail Trims

Working closely with Piper Exhausts, a 76mm stainless steel tailbox has been developed for the Corsa VXR Nürburgring. Added to the existing 76mm system for Corsa VXR, a full 76mm system is now available for this car, to help release maximum performance.

As with the current system, the first main cat is removed and options include twin or single silencer systems with or without a motorsport cat.

Cars fitted with a full system will require an ecu remap to ensure optimum safe running and to overcome any issues with the emissions, as the VXR Nürburgring is a Euro 5 compliant model from the factory and removing the large factory fitted pre cat and just using a high flow motorsport cat will require an ecu recalibration to give correct fuelling and emissions.

Piper offer a range of tail trims, however the options shown here, 4″ (100mm) Slash Cut, is probably one of the best.

Pricing is as follows:
Full 76mm System with Motorsport Cat* Twin Silencers £1385.00
Full 76mm System with Motorsport Cat* Single Silencer £1240.00
Deduct £255.00 for a completely decatted* system

Cat Back System Twin Silencers £750.00
Cat Back System Single Silencer £610.00

*Note: A motorsport cat will pass current UK MOT emissions. In some countries motorsport cats may not be road legal. Please comply with the relevant laws of your country. Removing both cats may not be road legal and will lead to an MOT emissions failure.

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Map Optimisation and Set Up Pays Off – Astra VXR

Another question we are constantly being asked is about remapping and correct set up and why this is better than a hand held unit.

Many people like the convenience of installing a map from a hand held unit (and are often ‘sold’ the same results as bespoke mapping, which invariably is not the case), but without checking it or seeing what it is doing for the car, the results are simply ‘hit and miss’. Put simply unless ecu software is properly checked and optimised to each car, you are unlikely to get the results you are expecting (or have been sold!)

Here’s a graph for an Astra VXR which we were asked to dyno which had a lower front mounted intercooler fitted, a full 70mm Remus Exhaust System and an unchecked map from a hand held unit. The resulting dyno figures show the map gave worse results than the factory software (where we have seen 270bhp on a car with exhaust and intercooler fitted):

Astra VXR Competitor Stage 3

Astra VXR Competitor Stage 3 : Before

This set up, correctly mapped should really have been producing at least 285bhp, not 252bhp!!

At the customer’s request, we changed the intercooler for one of our Full Height Front Mounted VXRacing Intercoolers and fitted a full 76mm system. Once properly remapped, datalogged and set up on the rolling road we achieved:

Astra VXR Courtenay Sport Stage 3 : After

Astra VXR Courtenay Sport Stage 3 : After

And finally here are the before and after graphs, showing the differences. Much more power and torque right across the rev range, which will totally transform the drive of the car:

Astra VXR Stage 3 Comparison

Astra VXR Stage 3 Comparison

The Benefits of a Good Exhaust System – Astra VXR

On more than one occasion we have extolled the virtues of a good, free flowing 76mm sports exhaust system for Astra VXR to get the best performance results out of remapping correctly.

Well here is another classic example……..

The car in question is an Astra VXR 2.0 Turbo which was fitted with a Stage 1.5 Hybrid K04 turbo (with exhaust wheel cut back), a large full height front mounted intercooler and a ‘one-off’ made to the car exhaust system which in places reduced to 50-57mm.

Once mapped the results were as follows:

Astra VXR Stage 3 : Poor Exhaust System : Before

Astra VXR Stage 3 : Poor Exhaust System : Before

Results: 278 bhp and 318 lb ft torque.

Upon examining all the evidence from the rolling road and datalogging, we concluded that the exhaust system was the limiting factor. Some might say it was easy for us to blame the exhaust (which we didn’t supply)….. why could it not be the installed software??

Well, we could comfortably rule out software based on the fact that all our maps are optimised on the rolling road and datalogged. so we knew we couldn’t get any more ignition timing into the software or take any more fuel out (without risking safety).

So we had the car back a couple of months later and fitted our full 76mm sports exhaust system, changed nothing else and ran the car back on the same rolling road, resulting in the following:

Astra VXR Stage 3 : 76mm Exhaust System : After

Astra VXR Stage 3 : 76mm Exhaust System : After

Yes, no word of a lie results of 305bhp and 348 lb ft torque, aided by the Stage 1.5 hybrid turbo, the full 76mm system and the cold February dyno cell temperatures.

Here is the before and after graph. The gains speak for themselves. Lots more power and torque right across the rev range:

Astra VXR Stage 3 - Good Exhaust vs Poor Exhaust : Before and After Results

Astra VXR Stage 3 – Good Exhaust vs Poor Exhaust : Before and After Results

So if you are trying to decide on which exhaust system to fit to your Astra VXR, we think we’ve just made the decision much easier for you. A good exhaust system may cost a little more, but you will get the benefits from fitting it.

The Courtenay Sport Blog

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