Well, last issue we left off with the gearbox strengthened to handle our next series of upgrades and a 3000 rpm high stall torque converter had been installed.  The first converter we tried was a TCI 3000 high stall, as we were waiting for our custom Dominator converter to arrive and we were keen to see how our Aussie converters compared to the tried and proven American components.  On the road the TCI felt strong with wheel spin possible at any time, in fact the car now felt so strong on the road we were unable to get traction at any point and it became quickly obvious that we would need to revert to slicks at the track as there was no way we could harness the power on street tyres.  Seat of the pants feel was just awesome.

 

But first it was off to the dyno to see how the converter affected our power curve.

Not surprisingly, at the same rear wheel speed the engine was doing more revs and as such power was greatly increased at lower wheel speed but the biggest surprise was the 20 kW loss of power a the top end.  Data logging on the dyno showed we were not getting a significant amount of slip at high rpm but the converter seemed more inefficient than the standard unit.

 

It was time to head off to the strip and see how it was all going to pan out.  A series of passes later, after trying different launch techniques, we had a disappointing  best time of 13.01 @ 105 mph (169 kmh), looking at the time slips our 60-foot times had dropped from 2.29 to 2.02 so in theory we should be running at least 0.27 seconds faster than our previous best.  Looking at the mph shows we are down 4 mph on our previous times - that lost 20 kW was starting to show at the track as well as on the dyno.

 

We put this down to the converter being inefficient so we were looking forward to slotting the Dominator 3000 high stall in and seeing how it performed.  Back to the dyno and we found we were still losing 20 kW compared to the standard converter, perplexed we headed off for a test drive.  Jason from Dominator Torque Converters commented that this was not an uncommon experience with high stall converters on chassis dynos.  In his experience the dyno does not allow the converter to lock up fully, the result is a lower recorded peak power figure.  The dyno graph supports this theory as power is up significantly in the low to mid range area as the converter allows the engine to pull higher rpm at a given road speed.  The car felt very strong down low and was a pleasure to drive with the lockup in the converter making it feel like the stock converter until the throttle was squeezed enough to unlock the converter and let the engine flash to 3000rpm, instant throttle response was there to be had.  

 

Back at the Kwinana Motorplex we were again disappointed to find the car was going no faster and was still down in mph as well.  More encouraging was a customer’s car that had emulated our combo in project Monaro was able to run its first 12.97 @ 110 mph (177 kmh) on street tyres, with a stock converter on the same night.

 

Back to drawing board in an attempt to analyse what had happened.  One big change was the slicks which, being 2-inches taller than our street tyres, may have caused our effective diff ratio to increase, dropping the engine out of its efficiency range.  This combined with the power loss may have contributed to the slower times. Just prior to going to press, the standard converter was put back in and the car run up on the dyno – the 20 kW was back.  Things are now looking good for the next phase of our upgrades. - the supercharger.  This little puppy should be slotted on before the next installment.

 

An old mechanics proverb goes something like "if it don't go then make it look like it does" so project Monaro has had a facelift with a new set of wheels to compliment its new look.  Having always thought the Monaro front looked a little "astra"ish we decided to upgrade it with a new look utilising the latest VY SS front to give the coupe a more aggressive look.  This was pretty straight forward, unbolting all panels forward of the windscreen and bolting on a complete new front clip.  The large aggressive front opening will also benefit us when the intercooler goes in with the supercharger installation.

Click here for Part 5

Source:

Chipmaster.

9452-0213.