The results shown here were measured without any attempt at tuning the carburettor. The idle jet was changed so that tickover could be maintained at a constant speed. It was decided that there was no point in tuning the engine until the exhaust manifold had gone in. The engine was running weak at high revs, which means that a bit more power could be got out of it.The manifold was delayed because PMC (Peter Maiden Components) had sent a Nova manifold instead of one for the Astra. They wouldn't send the correct one until they had the original one back. This annoyed me.

The effect of the higher lift and duration cams is very clear here. There's a a gain in torque and power at high speeds but a loss at low speeds. The cross over point is 4000rpm. The max power has now increased by 9.5% from 84BHP to 92BHP. To really see any benefit from this it would be necessary to drive with the engine speed over 4000rpm.

Interestingly, the PMC dyno sales curves showed a power increase for all speeds above 2000rpm on a Nova 1.4. The only difference in the set ups was the exhaust manifold.