We started this project with a horsepower goal of 800HP. This figure is pretty arbitrary. The Vantage with 4.3 engine has 380 HP from factory (400hp with the Aston power upgrade). Buying a Vantage V12 would get you say another 150 HP. We would like to have a much bigger step on top of the V12 power, and the next power level would be something like doubled the V8 horsepower: 800HP.
Experience wise we have seen 800HP on a V8 engine is about the max to keep the engine reliable on pump gas and in a city / highway environment. Let’s hope the stock parts of the car will stay fine with this added horsepower, otherwise we have to replace those later (transmission, shafts and optionally the brakes).
We needed to know ‘where we were standing’ with the current configuration so we took the car on the dyno. The dyno is a dynapack 2WD system that bolts to the axles while removing the wheels. Two brakes are applied and they measure the torque at the wheels, calculating the exact horsepower without any wheelspin or tire deformation.
Our Aston Martin 4.3 with the stock performance pack had a maximum 425Nm of torque with 80% of the maximum torque from 2000RPM up to the rev limit. The torqueline is pretty much a horizontal one so the horsepower line is diagonal with the RPM, having the max HP at the rev limit. Maximum horsepower was measured between 392HP and 400HP (if the engine warms up it makes a little less power).
The almost horizontal torque line up to the rev limit is very important for making sufficient horsepower, especially when turbocharged. With turbos most power will be made up in the higher revs so it is very important the base engine makes good horsepower at those RPMs, otherwise a base engine with turbocharger won´t make a lot more power up high at all.
Knowing our baseline is right and having a reference to compare to when we have further results, we could start working on the engine and turbo placements.