Archive for the ‘ General ’ Category

Corsa VXR Engine Build

This low mileage Corsa VXR was booked in with us recently for an engine rebuild. It was a very late car with a B16LER engine.

The whole process starts with removing the engine and gearbox from the car, separating the gearbox from the engine and then stripping the engine down to a bare block and head. The block is then rebored and honed to suit an oversize 79.5mm forged piston and to achieve the correct piston to bore clearance. Once it is fully cleaned the block is then rebuilt with new forged pistons and rings, steel rods, uprated ARP rod bolts, new big end bearings, new gaskets and head bolts. On such a low mileage engine (4k) the main bearings, timing belt, tensioner, pulleys, oil pump and water pump were all as new and could be refitted. On higher mileage engines we recommend that these are replaced as necessary. As necessary the valve stem seals are replaced and the valves reseated. If either of the block or head faces need refacing this is carried out at ther same time as is additional balancing work if required.

Once the engine is built back up with its ancillaries and timed up, it is refitted to the gearbox and then fitted back into the engine bay. Engine oil, suitable for running in and coolant are added and the engine is then run up and road tested. We recommend the addition of Evans PowerCool 180 Waterless Coolant as part of an engine rebuild.

It takes approximately a week for this type of work to be completed.

Here are some pictures of the process:

It’s been a while…….

since we have found some of these on a car, but occasionally it still happens.

Transport Blocks

Transport Blocks

They are the transport blocks which are fitted in between the front spring coils each side, especially on lowered cars, which prevent the springs from compressing keeping the chassis height higher allowing for lowered cars to be moved onto and off transporters more easily and to help the front valances clear better preventing damage. Thay are however meant to be removed by the dealerhsip when the car undergoes its PDI (Pre-Delivery Inspection) for obvious reasons……..

Vectra VXR Mapping Session

This Vectra VXR came to us for mapping having already had an Insignia VXR Turbo unit and an intercooler fitted. The cats had also been removed prior to its visit. Once in our rolling road bay, a set of uprated injectors were fitted and then the car was mapped and set up on the rolling road, achieving excellent figures; 329bhp and 406 lb ft torque. These numbers were about what was expected from a car running a factory water radiator, in between our Stage2+ (320-325bhp) package and our Stage 3 (340bhp) package (which also adds an uprated water radiator) .

More details on Vectra VXR tuning on our >>>> main website <<<<.

Vectra VXR on the Rolling Road

Vectra VXR on the Rolling Road

Astra VXR Rolling Road Health Check

It is always useful to have a car checked from time to time on the rolling road, as it can show up potential running issues.

We had this Astra H VXR Nürburgring brought in for a health check on the rolling road this week, due to it feeling ‘down on power’ after a manifold swap by the owner, so running it up and datalogging it should highlight any issues.

We carried out an initial check over of the vacuum pipes, recirculation valve and actuator just to make sure nothing physical was at fault which could cause a problem. The ecu was also checked for any stored trouble codes, again to see if there was anything that could cause a running issue.

Running the car up on the rolling road whilst datalogging found the turbo to be down on boost, making less bosst pressure than expected  and resulting in 255bhp and 290 lb ft torque down on what is expected from a Nurburgring with a remap.

Additional checks were carried out to the boost hoses and intercooler fittings, which showed no leaks or issues.

After further runs, the turbo was shown only to be capable of making a maximum of 20psi overboost, and unable to make the required boost at peak power (around 5,700rpm), so identifying the root cause of the problem to be a failing turbocharger.

Astra VXR Health Check

Astra VXR Health Check

Corsa VXR Blue Edition – Stage 2

We had this lovely low mileage Corsa VXR Blue Edition with us recently.

Corsa VXR Blue Edition

Corsa VXR Blue Edition

If it was feeling ‘blue’ before it arrived, it certainly wasn’t when it left, after having a full 3″ exhaust system fitted, NGK iridium plugs, a panel filter, large bore inlet pipe and uprated recirculation valve followed by ecu remapping and a full set up on the rolling road with datalogging and map optimisation.

Corsa VXR 3" Exhaust Fitted

Corsa VXR 3″ Exhaust Fitted

Achieving 223 bhp and 238lb ft torque runing on 99 Octane V Power Nitro+.

Which Oil? Engine and Gearbox

Valvoline SynPower 5w-40

Valvoline SynPower 5w-40

Engine Oil:

One question we are often asked with regards to turbocharged engines is which oil should be used?

There are many choices of oil on the market, and different people will give you different answers as to which is best and why.

For Pre-2011 Vauxhall/Opel cars the OE spec for oil is LL-A-025/LL-B-025 (Petrol/Diesel). For 2011 on models this spec has been replaced by GM Dexos2™ spec. Dexos2™ spec oil is backwards compatible.

Our advice for pre-2011 Vauxhall/Opel petrol 2.0 Turbo and 1.6 Turbo engines fitted with K03/K04/K06 turbo units is to use a high quality fully synthetic engine oil with a viscocity of 5w-40 for fast road and track day use, which meets or exceeds API:SM SN/CF and ACEA A3/B4 classifications. This can also be used in engines fitted with Garrett or similar turbo conversions.

Our suggested choice is Valvoline SynPower 5w-40 Fully Synthetic Engine Oil which we run in our road and trackday cars and which we have also run in Astra H VXR race cars without issue. Amsoil European Formula is another suggestion for high quality oil; one of many oils available.

It is suggested for engines used for hard use that oil temperature and useage are constantly monitored which will identify if a different grade of oil is required.

2011 onwards engines require a high quality oil meeting Dexos2™ spec.

The key is to use a high quality fully synthetic oil and to keep the oil in turbocharged engines changed regularly. On modified cars it is sensible to ignore the extended drain intervals that manufacturers suggest and stick to more frequent changes. Oil that is changed regularly keeps an engine clean. Our recommendation is 5,000 mile change intervals for a turbocharged engine, especially for cars experiencing hard use, but at worst 7,500-10,000 miles.

Valvoline 75w-90

Valvoline 75w-90

Gearbox Oil:

For manual gearboxes such as F20, F23, M32, F40 we suggest the use of a high quality fully synthetic gearbox oil, viscocity 75w-90.

Our choice is Valvoline SynPower TDL for fast road use or Amsoil MTG 75w-90 for fast road and trackday use where higher gearbox oil temperatures may be sustained.

Again with gearbox oil it is always worthwhile considering regular oil changes, especially on the M32 gearbox where a 20,000 mile oil change will do no harm.

Pagid S Performance Brake Pads

Pagid S


Street Legal Pagid S Performance Brake Pads.


Pagid S Sports brake pads have been specifically designed for high performance brake system usage on public roads, but it is no secret that their origin is the race track and where they truly belong. High friction, low fade characteristics and low pad wear over a wide temperature range make these pads ideal for use on public roads, track days and in club racing. R90 Approved for EU road use.

Now In Stock for Astra H VXR and Zafira B VXR

Also available for Astra G Turbo, Astra H 1.9 CDTi, Astra H 2.0 Turbo, Corsa D VXR and SRi 1.6 Turbo

Pagid S Performance Brake Pads

Pagid S Performance Brake Pads

Astra VXR Sprint

Built specifically for use as a track day car, this car was previously a Stage 3 car producing a useful 292bhp and had been fitted with our 3″ full exhaust, CSRacing Intercooler, Pro Alloy Water Rad, Wavetrac LSD, Alcon 4 Pot calipers with 356mm alloy belled discs, 292mm Rear Brake Upgrade, Whiteline Rear ARB, DAP Road Springs, direct route hose kit and Pro Race 1.2 alloys. Building on the track day specification, other modifications have included Recaro Pole Position Seats, Rear Cage and Sabelt Harnesses.

Astra VXR Sprint

Astra VXR Sprint

After a few engine changes including K06 turbo rework, Courtenay Klasen Inlet Manifold, Steel Rods, Turbosmart Actuator and Recirculation Valve and a few hours mapping on the rolling road we achieved a respectable 336bhp and 355 lb ft torque, all useable on track increases through the mid range and top end, with the ability to rev to 7,500 rpm.

Before and After Graph:

Stage 3 K04 v Stage 4 K06  Astra VXR

Stage 3 K04 v Stage 4 K06 Astra VXR

Courtenay Sport at Trax 2014

A few pictures of our display at Trax 2014, Silverstone Circuit Sunday 7th September.
Thank you to everyone who came along on the day and for some fantatsic cars as part of the display.

Cambelt and Timing Information – Z20LEx Engines

Useful Gates Technical Information for Cambelt Timing on the Z20LEx 2.0 Turbo family of engines; Z20LET, Z20LEL, Z20LER and Z20LEH (Astra H VXR). This is not a ‘How To’ guide but additional technical information for those with enough mechanical competency to carry out a cam belt change.

Cambelt Change Cycle suggested by the manufacturer:
Z20LET :: 4 years* or 40,000 Miles*
Z20LEL :: 8 years* or 80,000 Miles*
Z20LER :: 8 years* or 80,000 Miles*
Z20LEH :: 8 years* or 80,000 Miles*
*Whichever occurs first.
Notes: The cambelt (timing belt), plastic inlet roller and tensioner are common between all the engines (i.e. the same parts). The only different is that the LEL/LER and LEH kits use a metal exhaust roller (LET uses a plastic exhaust roller). For this reason we suggest a 6 years* or 60,000 Miles* change cycle as best practice. Always use a new tensioner retaining bolt (torx head) with the LEL/LER/LEH engines.

What is Needed……
A good toolkit with a good selection of sockets, allen head sockets, male torx sockets, a 15mm spanner (or similar) to release tension on the auxiliary drive belt and a 17mm ½” drive socket and ratchet (makes turning the engine over to check tension much easier). For the later engines a very high quality T40 Male Torx ⅜” drive socket, and a ¼” drive E10 female torx socket (a slim one) is useful for removing the timing belt cover bolt next to the tensioner once the tensioner is in the ‘rest’ position.

Do not forget a suitable Camshaft Locking Tool (widely available).

On the later engines the cambelt tensioner retaining bolt has a very shallow torx head and if you are not careful the socket can slip and/or chew out the head of the bolt. We suggest akways replacing this bolt when fitting a new belt kit (often the kits are not supplied with the tensioner bolt!)

Remember the tensioner is tensioned ANTI-Clockwise!! We see far too many incorrectly tensioned cambelts.

Torque Settings (for reference):
Toothed belt tension roller to oil pump: 20Nm
Toothed belt guide roller to cylinder block (exhaust side): 25Nm
Toothed belt guide roller to cylinder block (inlet side): 25Nm
Toothed belt cover – upper part to rear toothed belt cover: 6Nm
Toothed belt cover – lower part to rear toothed belt cover: 6Nm

When changing the cam belt always check the water pump and replace if in any doubt, especially on later engines where the change cycle of the cam belt is longer.

Gates Technical Data Sheet on how to time up the engine:

PDF Timing Information

PDF Timing Information

Note: You will need a PDF reader for this file

Timing Belt Diagram Z20LEx

Timing Belt Diagram Z20LEx

Note: E&OE. The above Technical Guidelines are provided for information only. We accept no responsibility for any loss (consequential or otherwise), damage, injury howsoever caused relating to persons undertaking their own repairs. If unsure please seek the services of a professional.

Mapping Session Astra H VXR

Rolling Road mapping session to optimise software settings on this Astra H VXR, which has had some hardware alterations since it was first mapped. Before and after mapping saw gains of between 12-34bhp and 5-20 lb ft torque.

Astra H VXR on the Rolling Road

Astra H VXR on the Rolling Road

Astravan Z20LEH 2.0 Turbo Conversion

A 294bhp Z20LEH engined Astravan in for a service, MOT and some additional TLC. This van has a huge spec including Quaife LSD, Astra H VXR brake set up (front and rear) with uprated discs, CSR Intercooler, 76mm Full exhaust system, 80mm AFM and VXR injectors, uprated clutch and flywheel, a B8 damper and Eibach spring kit, rear ARB and Revolution Millennium Alloy Wheels. We carried out the coversion on thsi van several years ago now and it is still kept in immaculate condition.

Z20LEH Astra Van

Z20LEH Astra Van

Now Accepting AmEx and PayPal

Courtenay Sport are please to announce that we are now accepting American Express cards online and at our premises and PayPal for online purchases.

Now Accepting Online: Now Accepting On Our Premises:

American Express Logo

American Express

PayPal Logo


American Express Logo

American Express

Revolution Millennium Alloy Wheels

Revolution Millennium Alloy Wheels 8Jx18; now also available in Anthracite (as well as White). Spec: 8Jx18, ET35mm, 5x110PCD, 65.1mmCB. Black finish due around August time.


Revolution Millennium Alloy Wheels

Revolution Millennium Alloy Wheels

Uprated Enlarged Performance Intercooler – Astra J VXR

Astra J VXR Uprated Performance Intercooler

Astra J VXR Uprated Performance Intercooler

Once again we have joined forces with industry leaders Pro Alloy to develop our new enlarged, uprated performance intercooler kit for the Astra J VXR.

Our new intercooler is both larger in width and height than the standard unit with the core being twice as deep as the factory cooler. This represents a huge increase in available cooling area and volume and maximises the cooling available through the front of the car whilst also future proofing the cooler for use with high power large turbo setups.

The factory cooling set up has the air conditioning radiator in front of the intercooler so our first job was to remove the intercooler and then reposition the A/C radiator back, on to the water radiator. This is done so that the new intercooler is receiving the coolest air available. To further improve the efficiency we have included in the kit a lower air blade to stop the air washing away from the bottom of the intercooler.

Furthermore to maximise flow to and from the intercooler the kit comes complete with all the pipework which is enlarged to 60mm, paying particular attention to the restrictive section straight out of the turbo seen at the top rear of the engine bay. The Intercooler kit also comes complete with all the required hoses and laser cut brackets and fittings.

Price: £899

Oil Restrictor Bolt – K04 VXR Turbo

We thought we would share some information regarding oil restrictor bolts to help clarify our views on them…

Restricting the oil supply to Turbos is not a new idea or fad; turbo conversion companies have been doing this as instructed by Garret since the early 1990s.

It is true that a number of Vauxhalls have suffered from this smoking due to oil washing past the turbo oil seals.

It is true that changing the oil to a heavier weight of oil helps with this by allowing the oil to drain quicker as it is more resistant to any frothing or foaming (call it what you will) in the turbo core.

It is true that journal bearing turbos do need a very good supply of oil.

It is also true that too much oil can and will swamp the seals and in this case… the use of careful oil restriction will help; Vauxhall has also done this in production of the later K04 units.

Now we believe the original Vauxhall KO4 oil restrictor bolt was developed by Ian Percival AKA Percy (vxronline) before GM Modified the core. Ian is very knowledgeable by all accounts. He carefully calculated then made a restrictor as part of the bolt so it can be retro fitted to cure this lack of oil restriction in very early units. Our reluctance to recommend oil restrictor bolts comes not from what Ian did but from the fact that many other individuals and “ebayers” alike have jumped on the oil restrictor bolt bandwagon and produced some very inferior imitations. To this end we have been handed a number to fit, made of some very dubious soft material and we have seen some with a pressed in restrictor plug complete with a loose and rattling swarf built in, which would have killed a new turbo almost immediately! Plus we have removed many others that have been over restricted.

We hope people can now see why a number of suppliers, turbo manufactures and re-manufacturers are reluctant to recommend them. To be clear it’s not the principle or the original execution that is the problem but the others that have come along after, which when fitted can damage what was a perfectly good turbo unit, leaving the supplier / manufacture liable.

The later VXR turbochargers already have the oil flow control built into the oil gallery in the turbo itself, as is evident from the picture below centre:

Z20LEH Turbo Oil Gallery

Z20LEH Turbo Oil Gallery

If a turbocharger is smoking due to worn turbo oil seals, then the turbo already has a problem. A restrictor bolt will not repair worn turbo oil seals.

How Waterless Coolant Works.

Water is an excellent fluid for cooling whilst in a liquid state, but when water turns to steam it has virtually no capacity for heat transfer. Evans is a superior fluid for transferring heat in engines because it remains in a liquid state until above 180°C. This article details the benefits of a significantly higher boiling point.

Within an engine cooling system the hottest surfaces are those adjacent to the combustion chamber, specifically the cylinder liners and cylinder head. In these hot spots water is likely to vaporise preventing efficient cooling and causing loss of performance and unnecessary engine damage. When the coolant fails in this way the engine becomes even hotter causing more hot spots and more steam.

Evans waterless coolants will not boil around these engine hotspots maintaining efficient cooling performance even when the engine is put under extreme conditions. When water turns to steam it pressurises the cooling system putting strain on hoses and other components. The significantly higher boiling point of Evans coolants means 75% less pressure than water resulting in a less stressed cooling system.

Water contains oxygen which causes corrosion and also allows electrolytic activity which further damages engine metals (chemical limitations of water). Evans waterless coolants eliminate corrosion and electrolytic activity significantly increasing the life of the engine.

Nucleate Boiling

Nucleate Boiling

Traditional water based coolants regularly cross the thermal boundary that separates efficient Nucleate Boiling (A) from inefficient Critical Heat Flux (CHF). CHF is synonymous with the condition ‘Departure from Nucleate Boiling’ (DNB). When DNB occurs, a layer of steam bubbles form adjacent to the engine hot spots (B).

Steam dissipates less than 1/30th of the heat that water does, rapidly over-heating local metal, causing premature detonation. The high boiling point of Evans Waterless Coolants, such as Power Cool 180, prevents DNB providing more efficient cooling in engine hot spots.

Convert your car to Waterless Engine Coolant:

Evans Waterless Engine Coolant

We are pleased to confirm that we are now testing Evans Waterless Coolant. Evan’s Power Cool 180 High Performance Waterless Coolant for performance & track cars is designed for high performance engines fabricated from a mixture of cast iron, copper, steel and aluminium components. It has a number of advantages over conventional coolant, which are listed below.

Power Cool

Power Cool

Conversion to Waterless Coolant is fairly straightforward, with using Evans Prep Fluid is formulated to hygroscopically absorb water whilst flushing loose dirt and scale from the cooling system prior to filling with Evans Waterless Coolant. The job can be completed in just a few hours by either a professional workshop or competent enthusiast.

Benefits of Waterless Over Water-Based Coolants:

Eliminates Overheating
Evans Waterless Coolants have a boiling point above 180°C and will not vapourise, thus eliminating overheating, boil-over and after-boil.

Reduces Pressure
Evans Waterless Coolants generate very low vapour pressures reducing strain on engine cooling system components.

Prevents Corrosion
Evans Waterless Coolants contain no oxygen effectively eliminating corrosion.

Increases BHP
Evans Waterless Coolants eliminate pre-ignition and detonation caused by overheating, thus improving combustion efficiency and delivering more power.

Stops Erosion
Evans Waterless Coolants prevent cavitation and eliminate liner and cooling pump erosion.

Freeze Protection
Evans Waterless Coolants freeze below -40ºC.

Evans Waterless Coolants are proven to be Non-Toxic. Standard anti-freeze is toxic and known to kill pets.

From what we have seen and heard about this product so far we are confident that it will outperform all expectations.

Prices for Power Cool range from £29.95 – £64.95 and £15.99 – £39.95 for Prep Fluid.

Available by Mail Order (Tel: 01692 404313) and online.

For further information on Evans waterless Engine Coolant visit:

Power Cool 180°Download Product Brochures 2 Page Data Sheet

4 Page Brochure

PowerAlign Camber Bolts

Camber Bolts

Camber Bolts

Powerflex have announce a new ranged of PowerAlign products under the Powerflex umbrella.

The range of products will grow over the coming months. They will be more hardware based and offer innovative solutions to improve chassis geometry.

The first two products include a new range of camber bolt kits and a simple camber setting tool. By simply substituting the original upper bolts on two bolt suspension struts for PowerAlign Camber Bolts, this allows up to +/-1.75degs of camber change.

This offers an easy fix for camber issues and a perfect add-on for any suspension bush change, or for changes to camber required for a more ‘track focused’ set up.

The bolts are made using a 12.9 tensile, zinc plated high strength steel. These parts are also covered under the terms of the Powerflex lifetime warranty.

They are available in 5 sizes, to replace bolt diameters M12, M14, M15, M16 and M17 covering a wide range of vehicle makes and models.

Courtenay Sport currently stock the M12 bolts, suitable for the majority of the Vauxhall/Opel range.

M12 Camber Bolts £18.89 per pair

Camber Gauge

Camber Gauge

Along with the camber bolts, the PowerAlign Magnetic Camber Gauge, PFG-1001 measures the Camber angle on the wheel hub or brake disc and allows on-car adjustment to ensure correct wheel alignment.

This is a useful tool for setting Camber angles after dismantling and re-assembling of the suspension and is an ideal track day companion.

This easy to use magnetic gauge attaches to the hub or brake disc and graduates +/- 6 degrees and comes supplied in a durable storage case.A perfect addition to the PowerAlign range and a straightforward product to supply to customers allowing them to correctly set camber angles without expensive geometry equipment.

Camber Gauge £35.94 – Available to Order




Self Adhesive Courtenay Sport Splat!

Gel Dome Resin Raised Bubble Badge

In Black with the Courtenay Sport Logo in Silver

Measures approximately 85mm x 85mm overall

Courtenay Sport Splats are Now Available £1.80

The Courtenay Sport Blog

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