In this new multiple part article, we look at the development of a new Monaro from a showroom stocker to a quarter mile In this new multiple part article, we look at the development of a new Monaro from a showroom stocker to a quarter mile performer.

Chipmaster, in Maddington, recently acquired a new CV8 Monaro to aid them with their R&D work with Gen III Commodores. Daniel, from Chipmaster, decided to adopt a step-by-step approach to modifying the car that could be used by LS1 owners, as their budget would allow. The aim was to make more power on the dyno and also improve strip times with a totally streetable package and hopefully make at least the same power as a 300kW GTS at a fraction of the cost. We intend to keep the car totally street legal and be fully emission compliant so this rules out the use of Nitrous as it is not legal on the street.

The first task bed in the motor with a 1000km drive to stabilise the Motor, Then it was time to introduce the Monaro to the dyno. The first pull on the dyno netted us 168.7kW at the back wheels; this translates pretty well to 220kW at the flywheel (allowing for 30% drivetrain losses).

The first dyno graph compares the auto Monaro to a standard manual GTS .As you can see we have quite a way to go to get to that level. The next step was to take the Monaro to the track in its totally standard form and see how it would perform, all the motoring books estimated we would run a 14.5 ET. The first few passes were spent getting an idea of how to launch the car and if manual shifting was going to be of any benefit. As it turned out stalling the engine on the line to 1500rpm and leaving the gearbox in “D” for drag gained the best times with consistent 14.51@96.9mph passes and a 2.36 60ft time. That was right on the money for a new car.

The next stage was to see what a standard HSV R8 tune installed in the PCM would do for the car. In theory this should lift it to 255 kW at the flywheel (this is something Daniel would not normally do but he needed to gauge how much effect the exhaust would have when we upgraded it and how much the PCM was affecting the car), after carefully merging the R8 and the Monaro PCM calibrations together so as not to loose lean cruise and some other features the HSV does not run it was back on to the dyno and the results were 191.3 kW at the rear wheels – a 23 kW gain.

A series of passes later and we were able to net a consistent 13.98@98.5mph and a 2.29 60-foot time; so it definitely showed we were starting to make some horsepower

The next step was to wheel the car into the shop and replace the exhaust system, a variety of systems are available but Daniel’s preference was for the four into one Di Fillipo system - especially since he was planning on a head and cam upgrade later. An added benefit was the new pair of high-flow cats that came with the system. This meant that the complete original system could be left intact in case we wanted to bolt it back on when the car is sold.

Back to the dyno with the R8 tune-up and power was up a further 5 kW to 204.7 kW at the wheels, a good result but not as much as we had hoped for . Contrary to common belief, no low down torque or power losses occurred from fitting the four-into-one headers. Obviously, the best results would be achieved from a custom tune on the dyno to maximise the exhaust’s potential rather than the base R8 tune as used by most tuners.

An intensive dyno session ensured optimising both the fuel curve to get maximum power and tuning the spark curve to gain maximum torque. This netted the increase Daniel was looking for, lifting peak power to 221.1 kW at the wheels and increasing bottom-end torque as well , this is a total gain of 52kw at the rear wheels from a exhaust upgrade and careful PCM tuning . Next, it was back to the track to see how the CV8 would go with the exhaust upgrade and new tune-up. A new time of 13.67@102.3mph, with a 2.196 60-foot time, was registered. A good improvement but Daniel felt it should have been quicker, one thing he noticed was that the air intake temperatures were climbing to 55 degrees while staging and logging with Efilive showed that timing was lost from this increase - time for some cold air.

At this point the Monaro had just about reached its target, making more power than a GTS except at the very top-end, after 5500rpm, due to the higher flowing heads, improved camshaft and increased rev limit of the GTS. Bottom-end torque also improved dramatically over both the GTS and the original Monaro. The wide-open-throttle air/fuel ratios were also better and more consistent. While the car felt very strong on the street, it was lacking the initial urge off the line that the GTS has. Some of this is due to the GTS being a manual but more pertinent was the GTS’s 3.9 diff ratio compared to the CV8’s 3.07:1. It was time to put the Monaro back on the hoist for a diff change; 3.77:1 was selected as it would not compromise highway driving with the auto and would also return good fuel economy.

What a change! The car felt like a rocket ship on the road, being able to turn the tyres with ease and prompting Daniel to ease-off the auto trans calibration a little as the car was turning the tyres heavily on the first to second gear change. Back to the track and immediately it was different to drive, it now had to be gently eased off the line, otherwise uncontrollable wheel spin would ensue. This hurt the 60-foot time a little but helped our top-end speed and ET as it kept the engine in a better rpm range. ETs fell to 13.54@105.5mph with a 2.273 60-foot time. Slicks may be required from here on in but at this stage the budget won’t allow them so we will proceed and see how we go.

In the next issue, we will look at cold air inductions and the possibility of removing the MAF from the auto Monaro , both these will be required as dyno and track datalogging have showed a intake restriction is present and the air intake temps are still too high for optimium performance

Stop Press , as we went to press the Monaro has had a cold air intake fitted and better conditions at the drag strip to record a best of 12.98@109.5mph , more on this and other developments next issue