Astra H VXR Sprint

The time had come for a more powerful cordless impact wrench which would be useful not only at trackdays for removing wheel bolts if needed, but also for use in the workshop and at home for some of the more difficult to undo nuts and bolts. It is all very well having everything to hand in a workshop such as compressor, air impact wrench and such like, but when without a workshop and all the associated tools to hand you do not want to get stuck in the middle of a task.

I knew that Snap-On cordless impact wrenches were good from previous experience (of borrowed use!), but they were sadly outside of my budget for a powerful unit at around £600, plus the breakaway torque was quoted at 840Nm/620 lb ft and the 18v model only has a 2.5Ahr battery, so they were removed from the list. There are many ‘middle of the road’ cordless impact wrenches on the market, but I wanted something with some grunt, so the search began.

After some online research, reading reviews and watching some of the You Tube demonstration videos, I decided that one of the Milwaukee M18 ½″ High Torque Impact Wrenches would be ideal, having looked at several offerings from other manufacturers.

M18 FUEL™ ½″ High Torque Impact Wrench

Initially the one that caught my attention offered 610Nm of fastening torque, the HD18 HIWF, which I thought would be more adequate for what I would need. But as with all things it is always better to over spec than under spec.

In the end I opted for the M18 FUEL™ model, M18 CHIWF12. The spec on it is massive, and main feature that drew me to this particular M18 FUEL™ high torque impact wrench was its ability not only to deliver pneumatic fastening performance of up to 950 Nm max of fastening torque but it also offers up to 1491 Nm nut-busting torque. Hub Retaining Bolts, Driveshaft Nuts, Bottom Pulley/Crank Pulley Bolts can all be undone with ease. When I saw the abilities of this particular unit it was a simple choice.

So far I have been impressed with the features and its peformance. In the UK they come with a 3 year warranty, the build quality is excelent and so far it is impossible to fault. It also has a setting offering tightening torque up to 135Nm, which is great for carefully and quickly doing up wheel bolts, prior to final checking with a torque wrench.

An expensive purchase, yes, but justifiable considering its capabilities. There are many impact wrenches out there, but this particular wrench seems to cope with anything thrown at it. Highly Recommended.

M18 FUEL™ ½″ High Torque Impact Wrench

After a short period off the road for a few minor changes here and there, the car will be back together to head to the Trax Show at Silverston on 7th September, followed by a track day on Monday 29th September at Snetterton Circuit on the 300 circuit, organised by Open Track. Need to start packing in the track days between now and the end of the season.

Just a few pictures to show correct timing for the Z20LEH engine (also applies to the Z20LET, Z20LEL and Z20LER engines). Read more

Ready To Go

#different

On the rolling road over the last few days for final mapping and optimisation, with 99 Octane fuel in the tank. This was to map the ecu to take advantage of the new inlet manifold, steel rods and the K06 turbocharger to make sure fuelling, ignition timing and boost pressure were all correctly optimised. Too lean and Exhaust Gas Temperatures (EGTs) and Cylinder Head Temperatures become too high potentially causing the exhaust manifold to crack, or cause a spark plug tip to fail and burn off or worst case scenario a piston could melt. Too rich will kill power and cause possible bore wash leading to premature internal wear. The ignition timing needs to be optimised to be as advanced as possible for maximum power gains, but without instigating any knock retard due to detonation, which again will cause running issues and eat into the ecu’s safety margin, especially when driven hard on track.

On the Rolling Road

When the car was again mapped back in June 2012, after I had made the first changes to the car the engine was producing good Stage 3 power and torque of 292bhp with 342lb ft torque (290bhp and 336lb ft on another run), with ignition timing, knock retard and fuelling all correct and safe which made the car very useable on track and road. Last time the car was checked on the rolling road during 2013 it achieved 300bhp during an unloaded run, although running a little leaner due to the lack of load.

Now the ecu is being mapped to suit the new spec. With a base map configuration for the new set up the improvement was to 327bhp, however the engine was running far too lean through the mid range, then richening up above 5,000rpm so this fuelling certainly needed addressing.

A quick adjustment to the actuator was made to alter the break off pressure, further rolling road runs were made to check fuelling, boost and ignition and all the relevant changes were made to the software after consulting the data logging output.

This final mapping session with mapping changes has produced a very healthy 336bhp and 355lb ft torque (repeated on two back to back loaded runs) and even after several hot runs (heat being a big issue with turbocharged cars – they hate it and it is kills power) the engine produces around 328-330bhp, so very good for a 90,000 mile engine.

These changes have made a massive difference to the overall car with huge gains in power and torque above 3,500 rpm where it is all useable. The difference in the power and torque is clearly evident and can be seen in the graph below:

Before and After Power and Torque Graphs

For the next track day outing I have been sent a set of tyres to evaluate, and they arrived bright and early this morning.

New Tyres

Whilst the name might be one that most people would be prepared to shy away from, the Nankang NS-2R is on the RAC MSA Blue Book Tyre List 1B, which is the RAC MSA approved list for Sports/Uprated tyres suitable for competition. These are the 180 Treadwear tyre and at a respectable £108 a corner they are worthy of consideration.

I had a similar experience with some Hankook RS-2 tyres – again an RAC MSA List 1B tyre, an excellent dry weather tyre (more grip than the ‘average’ road tyre), and great in the wet – very progressive. Sadly they are no longer produced and they were not sold in huge numbers, mainly I suspect down to people being unsure of the name. However now Hankook are now OE to several respectable vehicle manufacturers.

Not expecting them to be as sticky as a cut-slick type of tyre, but if they prove to be a good track day tyre covering dry and wet conditions, similar to other tyres of this type then they will be well worth the money.

Specification:
UHP tyre with two grip level options for Fast Road/Track Day (Treadwear 180) or Sprint Use (Treadwear 120). Exceptional high-speed stability and wet weather performance plus cornering precision and grip. Used as the control tyre in the 2014 Fun Cup series.

The three main circumferential grooves on central tread can improve drainage efficiency and wet handling performance.

Unique groove wall angle design can prevent excessive stress massing to restrain irregular treadwear effectively.

Continuous tread shoulder design can improve tire stiffness and ensure cornering grip.

Optimized tread width design (contact patch wider 13% than regular tire design) improved stability while driving at high speed.

Large block design on tread shoulder upgrade stiffness and cornering handling performance.

RAC MSA Permitted Tyres List 1B:

RAC MSA Blue Book Section L Tyres 2014

Direct Link to the 2015 file on the RAC MSA website www.msauk.org
192_202_Common_Regulations_for_Permitted_Tyres_(L).pdf

For Further reference RAC MSA 2014 Blue Book >>> RAC MSA 2014 Blue Book <<<

Stumbled across these Loctite thread locking guides online. There are so many different types, this covers them and which type should be used where. Useful for reference, however the most used will be 243 Blue Medium Strength (UK/USA) and 263 Red High Strength (USA), the UK equivalent to 263 is 270 Green High Strength.

US Threadlock Guide

UK ThreadLock Guide

So a box arrived this morning with the new gearbox oil:

Amsoil 75w-90 MTG

Being an American company the bottles are 1 US Quart (946ml). The track car with the addition of the oil will take about 3 litres, and also the road car is due a gearbox oil change as well, so ordered 7 bottles to be on the safe side and have some spare.

After a lot of research, and some advice from Performance Oils Ltd, I chose AMSOIL Fully Synthetic Manual Transmission and Transaxle Gear Lube (MTG), 75w-90. Research indicated that it remains ‘in grade’ for longer at higher temperatures and also will stay in grade at temperatures up to 170 degrees C, which this oil will never see so will also be ideal in gearboxes where an oil cooler is not fitted.

It is a premium blend of the finest synthetic base oils and advanced, high-performance additives. It is formulated specifically for maximum protection in the most demanding manual transmission and transaxle applications where an extreme pressure GL-4 gear lube is specified, including those where high horsepower/high torque engines and towing or heavy loads increase transmission stress.

AMSOIL MTG prevents the thinning effects of mechanical shear. It maintains its viscosity and superior film strength for consistent, long-lasting wear protection. MTG excels in hot and cold temperature extremes that exceed the limits of conventional mineral oils. It protects against rust, keeps seals soft for long life, and is compatible with brass synchros for smooth synchromesh shift quality

Ideal for Front Wheel Drive Transaxles:
The advanced synthetic formulation provides ultimate protection for gears and bearings in front wheel drive transaxles.

MTG is a thermally stable, extreme pressure formulation that resists heat, oxidation, acid build-up and varnish. It is the ideal gear lube for high temperature applications, so should be ideal for the M32 gearbox.

Performance Features

• Reduces friction, heat and wear
• Superior high temperature stability
• Resists heat, oxidation, acid build-up and varnish
• Lasts two times longer than conventional petroleum oils
• Improves cold weather shifting

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 gives 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 I would suggest a 6 years* or 60,000 Miles* change cycle as best practice. Always use a new tensioner retaining bolt.

What is Needed……
As well as a good toolkit, with a good selection of sockets, allen head sockets, and 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), you will also need for the later engine a very high quality T40 Male Torx ⅜” drive socket and a Camshaft Locking Tool such as a Draper CLT2 (Ref: 69929) or CLT-GM2 (Ref:61276) or similar. Also 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.

The T40 Torx is required on the later engines for tightening the cambelt tensioner retaining bolt. It has a very shallow head and if you are not careful the socket can slip and/or chew out the head of the bolt. I only use a Snap On torx for this particular tensioner retaining bolt because they are particularly strong, and it gets used for nothing else other than this particular bolt so it doesn’t get general wear and tear or other damage.

Example Camshaft Locking Tools:

Camshaft Locking Tool CLT2

Camshaft Locking Tool CLT-GM2

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 (4.8Mb)
Note: You will need a PDF reader for this file

PDF – Timing Information

Remember the tensioner is tensioned ANTI-Clockwise!!

Timing Pointer – Correctly Tensioned

Note: E&OE. The above Technical Guidelines are provided for information only. No responsibility is accepted for damage, loss, injury or general stupidness. If you are not sure on exactly what you are doing when it comes to cambelt replacement, leave the job to a professional who does…. That is all.

Winter rework will soon be underway, to further improve the car, although it is extremely capable at 300bhp when last run up on the rolling road. The factory inlet manifold is pretty restrictive so on track the car relies quite a lot on the spread of torque the car offers, especially mid-range because peak power is around 5,600 rpm and much above 6,250rpm the engine power really drops off.

A little more power at the end of the straights is always useful to get past cars that on occasion (quite often as I have found out) don’t lift down the straight, despite the fact you have spend most of the previous corners ‘pushing’ them.

So the plan; make the best use of the fitted K06 turbo, fit a higher flowing inlet manifold to give more power and torque above 4,000 rpm, and still produce good power at 6,000 rpm where the current set up really starts to drop off significantly and continue to produce good power at 7,000-7,500 rpm (ideally somewhere around 315-320bhp).

Added to this will be changes to the engine oil cooler, the addition of a gearbox oil cooler, oil temperature (engine and gearbox) and boost gauges plus a replacement set of Pagid RS29 front pads (they are just about due for change having covered 2,000 miles!) and a new set of wheels and tyres.