Took my 2015 Vanquish to the shop today to get baseline horsepower and torque figures before I change the plugs and coils, clean and flow test the injectors, and do an oil change/air filter change. I figured I'd see how much power the car has lost over the last 40k miles and run it again after doing the service, but I got some interesting results this afternoon.

We ran it in 4th and in 5th gear, and both were within a few hp of each other, but 4th gave a smoother curve. Ended up with 521 hp and 447 lb-ft at the wheels. Assuming about 12% mechanical losses, that's around 595 crank. From the factory, these are rated at 568, so I wonder if a previous owner had the ECU tuned. Or maybe Aston underrated these engines.

it'll be interesting to see how it runs after the work is done. I'll be reporting back, though it might take a while. I plan to do the servicing myself but I work a lot.

 

Nice numbers!

 

Sweet car!

 

nice, maybe it has a tune. will be interested to see the numbers after service work.

 

I have the same year Vanquish.
Last summer it had the primary cats removed along with a secondary cat upgrade and remap. Also the 3 way switch for the exhaust flaps.
It was done in the UK. The primary cats were below threshold so I took no chances.
I have to say, it transformed the car.

Looking forward to your progress.

 

I dont think coils and plugs will make any difference because with the numbers you just got, they are performing perfectly. The air filters may make a very marginal difference and if you run a slightly thinner oil, you might grab a couple more horsepower. You could certainly improve the output if you were not already using the highest grade pump fuel, but those numbers look like the car is running very strong anyway. Make sure the new inlet manifold gaskets fit nicely and do not shroud the ports.
Try cleaning out any oil from the throttle bodies too, I ported mine and found some additional power, but that was on a DB9.