GMR 600 Supercharged Vantage

I was told the Aston Martin V8 Vantage could have been launched with a supercharged version of its engine. However, Aston Martin's then-CEO, Dr. Ulrich Bez, was firmly against forced induction so we ended up with a naturally-asirated 4.3L V8, which was essentially a very heavily modified Jaguar 4.2L engine.

That engine is wonderful at higher RPMs - it sounds superb, revs freely, and has enough power to keep things interesting. But it needs to be pushed to perform. Below 3500 RPMs the engine is sluggish and lackluster, and it was widely panned upon its introduction as being underpowered. I've written about the root causes of this and how to fix it, so I won't rehash that here. Instead, I'll talk about the car that could have been. I'll talk about a car that has enough power to please even the most haughty of keyboard jockey curmudgeons, but is still as balanced an easy to drive as the car that was. In this article, I'll be talking about GMR's 600-hp supercharged V8 Vantage.

I want to make a few notes before we begin. First, I switch back and forth between American and British English. Sometimes it's just easier that way and I'm writing as it comes naturally to me. Second, I'm an American that's used to driving on the left-hand side of a car and right side of the road. Third, American roads are much wider than British roads. Fourth, the purpose of driving the GMR 600 was to experience the supercharger. I'll talk about other aspects of the car, like the suspension, but only briefly. Okay, let's get started.

GMR Design UK

I had first contacted GMR exactly one and a half years ago. I was feeling out my options for performance upgrades and their supercharger kit looked like it'd fit the bill. The response I got back was less than encouraging. I could either pay to fly them out to where I was living at the time so they could do the installation, or I could ship my car from the US to their shop in the UK. Either way, it was going to be a costly premium to a costly modification, so the conversation didn't go far. Fast forward to today (well, to a week ago), and not much has changed. They still don't have a distributor in the US. What has changed, however, is their stance on things.

The challenge for them is that they've poured a ton of time and money into developing their supercharged upgrade for the V8 Vantage. It performs beautifully and truly transforms the car for the better. But if it isn't installed properly, or if there's a pre-existing issue with the car, then there could be very serious and very costly results. While the caution is understandable, they've realized that they're also restraining their potential return on investment.

I'm very fortunate to have built up enough of a network and reputation that GMR became interested in hearing what I had to say about the US market for their product. Meanwhile, I was interested in them opening up to the US because Clare really wants a supercharger on our red V8 Vantage project car. Our good friend James from Aston Installations was hosting us during our trip to the UK, and he arranged for us to meet up.

We got to GMR's shop in Wellington, Somerset, in the early afternoon on a Monday. They're located in a tightly-clustered business park with scarce parking - not uncommon in England but still something I'm trying to get used to given the abundance of space we have in the US. They made sure we had a place to park James's rental Renault when we arrived, but had to move it again to get the demo car out when it came time for our test drive.

Paul and Graham are the two main figures behind GMR. Paul is the Business Manager and Graham, whose background is aerospace engineering, is the designer and engineer. They were pleasant and welcoming, immediately making us feel comfortable in their shop. It was clear from their tone that they were confident in what they'd made.

To the side of the main room was an assembled supercharger, intake manifold, and fuel system - a temporary display set up on wooden blocks so we could see the heart of their kit. The machining of the manifold was beautiful. Attention to detail could be seen throughout, and it hinted at how complete and thorough their product is.

GMR 600 Supercharger.jpg

GMR's long-running demo car was sitting inside their shop, ready to go, but I didn't see it. I was too busy guffawing at the New Vantage sitting nearby. It was the very same one we'd spotted in the car park at Silverstone the day prior - the one I'd taken pictures of and had planned to post on the forums asking who it belonged to because it was by far the best spec'd New Vantage I'd seen. Turns out it belonged to Paul's wife.

After a hearty chuckle about the coincidentiality of it all, we walked into the garage. The demo car sat there, alongside another. The "GMR 600" Vantage has clocked over 119,000 miles, and it showed. It wasn't in the best shape. The paint was heavily blemished in a few places, there was a gaping hole where the navigation screen should have been, and the tell-tale paint chipping of a well-used car spread across the weary 8-bar grille. To a casual observer, this wasn't a very nice example of an Aston Martin.

But I'm not a casual observer.

GMR Main Area.jpg

I'm told its supercharger had been equipped before the car had clocked 10,000 miles. That means its been supercharged for approximately 110,000 miles - that's more miles than most completely unmodified Astons have driven. If the grille hadn't been beaten to hell by then, I'd wonder how many times it'd have been replaced at that point. If the paint was perfect, I'd have scrutinized the miles it'd supposedly have driven. The missing navigation? Simple. They hated the factory Volvo unit and literally ripped it out of the car. Luckily, James and Lenny can sort that, so I'm hoping to see something interesting come out of our ongoing conversation.

Paul and Graham gave us an overview of their company, their product, and their demo car. I liked what I saw. The parts they created were beautiful, and I could tell they'd thought through the esoteric questions that usually never get asked, let alone answered.

It came time to drive the car, and I asked Graham to take me out to show me what the car could do. I hopped in the passenger seat and Graham fired up the engine. I was expecting it to be much louder, but it was just a quiet growl. I wanted Clare to take a video of the car starting up, but there really wasn't anything to capture in it. It was, frankly, very uneventful.

We pulled out of the garage and made our way through tight village roads. I asked questions about the car, and Graham answered each. The car rides on Pirelli PZero Corsas. The navigation had been ditched because it was terrible. The exhaust system was a combination of GMR and GT4 parts. Most surprisingly, the clutch was from a GT4 as well.

I was worried when Graham told me about the clutch. Race car clutches can be notoriously difficult to drive on the street, especially in stop-and-go traffic. They're made for performance rather than comfort. That means they can have a stiff clutch pedal, juddering badly at low speeds, and harshly engage when shifting.

Clutch life can be drastically reduced when a car is given as much extra torque as a supercharger provides. Graham assured me that it hadn't been an issue for them. As with any other manual Aston, clutch life was more dependent on how it's driven. The GT4 clutch was more capable of handling torque than the original factory clutch, and I wondered how the clutch from a V12 Vantage would compare.

After a few minutes we reached a wide-open area where we could turn around and swap seats. Click the button below for Part 2 of this review to see how my turn behind the wheel went.