GMR 600 Supercharged Vantage, Part 3

I pulled the car into GMR's shop and climbed out of it. James, Clare, and Paul were sitting there with smiles on their faces, eager to hear my thoughts. I told them I loved it. Working the throttle of the GMR 600 was a wonderful experience, and I had to have that power for myself. We have a pair of V8 Vantages, and Clare has been wanting to supercharge our red V8 Vantage project car for some time now. I guess she'll be getting what she wants after all.

Aside from the suspension and too-quiet exhaust, I absolutely loved the GMR 600 supercharged V8 Vantage. It was well balanced, plenty fast, and felt like a proper Aston. I have no doubt that if Aston Martin had built the early V8 Vantage with a supercharged engine like that of the GMR 600, it would have been widely praised for being a wonderfully impressive contender against Porsche.

We didn't get that 911-killing car back then, but we can get it now.

A Few Considerations

Getting a GMR supercharger kit for your own car isn't easy. As of this writing, the only way to get one is if you have GMR install it themselves. It's their way of protecting themselves from improper installation or pre-existing issues with a car that could be blamed on the supercharger.

That second point is handled by getting a snapshot of the car's current state. This is done by plugging in an AMDS and downloading all the files from the car, which will show all the fault codes it has. Not all fault codes are shown to the driver by way of CELs or gauge cluster warnings and that makes the snapshot an important step in the process. GMR also inspects the car prior to and during installation to see if any mechanical issues are present.

There are a few different prices listed for GMR kits. The difference comes down to the components used in each package. The primary catalytic converters were moved into the exhaust manifolds of the V8 Vantage around MY10.25 and those manifolds need to be replaced by new manifolds without cats, thus increasing the price of the package. GMR are also developing optional components that reduce the weight compared to the standard ones and that also can increase pricing.

For those of us that already have high-flow cats on our cars, we'll have to replace them with GMR's own units. They tested with a variety of cats and found the supercharged exhaust gases were blowing out the catalyst material. They developed their own cats to solve the problem, and these are needed to safely run the supercharger. Luckily for us, there are always people interested in a deal on high-flow cats, so selling used existing ones should be fairly easy.

Potential Concerns

The idea of a supercharged Aston Martin V8 Vantage is lovely, but there are a pair of downsides that bring things back down to reality: cost and lack of intercooling.

Let's face it, £15,000 or more is a lot of money to slap down on a table. There's no way around that. It's a lot of money and generally the money spent to modify a car is never recouped if the car is sold. Given how in-depth the job is, installing the GMR supercharger kit isn't a do-it-yourself job, and that means paying a qualified Aston Martin technician to install it for you.

On the other hand, if you look at it from a "total package" point of view, you can spend £30-35k on an early V8 Vantage plus £15k on a supercharger, then you're £45-50k in on a 580 hp V8 Vantage with all the benefits (far more power, increased MPGs, similar power but less weight than a V12, and even improved emissions).

NOTE: All the monetary figures are estimates based on pricing at the time of this writing. All pricing is subject to change.

The other major concern I could have is the lack of intercooling. This was solved by using water injection, which involves adding small amounts of water to the air/fuel mixture. The water cools off the intake charge, which is the same purpose as intercooling, and it has the added benefit of turning to steam during the combustion cycle. The steam actually helps clean carbon deposits in your engine, which has long-term benefits.

Water injection can also be done constantly and doesn't rely on air movement like intercooling does. An intercooler only works if there's air flowing through it. At a stop, the intake air charge isn't actually being cooled. Water injection happens whenever needed, based on its programming, so it can function even when the car is at a standstill. The ability to be "always on" can prevent heat soak in the engine bay. I didn't ask if they inject water even at idle, but regardless of whether they do or not, heat isn't an issue. After driving the GMR 600, the inlet to the supercharger is still cool enough to touch. It's warm, but you can put your hand on it without being burned like you would with the original intake manifold.

The downside to water injection is that it requires a supply of water, and that supply needs to be replenished. The water tank holds more than 5L, and that lasts approximately two tanks of fuel. There's a float in the water tank with a level sensor. If the water runs too low, the supercharger is disengaged and you're basically driving a standard, naturally-aspirated V8 Vantage. Once water is added to the tank, the supercharger will be reengaged and you can carry on hooning.

Basics in a Nutshell

Like anything, there are pros and cons for the GMR 600 supercharger kit. Here are the basics.

Pros

  • 583 hp and 441 lb/ft
  • Better fuel economy
  • Better emissions
  • Less weight than a V12
  • Complete and thorough package

Cons

  • Expensive to buy and install
  • Large sunk cost
  • Requires professional installation
  • Limited availability of qualified installers
  • Requires water tank refills

The only additional maintenance for a car with the GMR 600 supercharger package is topping off the water tank as needed and replacing two small water filters. Tap water can be used in the tank, and the filters can be replaced at the same time as your annual oil change.

Big Thanks

Paul and Graham, GMR Design UK
James Hawkes-Reed, Aston Installations
Ben Pettis