The Hennessey Cadillac H1000 CT5-V Blackwing is a suave sports sedan with some downright insane performance stats. 

Hennessey – the king of the USDM modified car scene – has unveiled yet another mind-boggling upgrade package to further establish its place on the throne.

Aptly named the ‘H1000’ kit, the intention here was to turn Cadillac’s BMW M5-rivalling CT5-V Blackwing into the world’s ultimate sleeper car. And when you look at the results, it’s hard to argue with that outcome.

Cadillac LMDh prototype racecars

Cadillac’s Sporty Side

First things first, let’s understand what sort of base we’re dealing with here. The Cadillac CT5-V Blackwing is a remarkable car in its own right. Refinement, performance, it can do the lot. However, a bit like its sporty Jaguar counterparts across the pond, we can’t help but feel as though its public perception is held back a bit by the badge on the front. After all, Cadillacs are cars for your grandad, right?

Well, GM is doing everything in their power to get rid of that image. They’ve been producing genuinely commendable sports sedans for quite a while now – ones which retain that Cadillac level of comfort and, frankly, look an awful lot better than some of their German rivals. In fact, Cadillac now has a Le Mans racing program, and there’s even rumors linking them to a possible entry into F1 alongside the legendary Andretti family.

So, when you buy a CT5-V Blackwing from the factory, you’re already getting a rear-wheel drive platform blessed with 668hp and 659 lb ft of torque (offered with either a 6-speed manual, or 10-speed automatic gearbox). In reality, that translates to a 0-60mph time of just 3.5 seconds, and a top speed of 205mph!

However, that hasn’t stopped Hennessey from seeing what happens you push the CT5’s small block even further…

white Hennessey Cadillac CT5 H1000

Hennessey Cadillac H1000 Specs

If you’ve read the title, you already know the headline figures: 1000hp and 966lb ft of torque. That’s bone-shakingly powerful. So, how has Hennessey pulled this off?

Well, a large part of the answer comes down to the fact they’ve thrown in a high-flow supercharger, but there’s plenty more than just forced induction going on underneath this hood. Hennessey has also put a lot of effort into strengthening the 6.2-liter LT4 V8’s internals. They’ve ported the cylinder heads, improved the lifters and pushrods, and added oversized heat exchangers. On top of that, there are enhanced intake and exhaust valves, while the long-tube stainless steel headers are another aftermarket upgrade. Naturally, those mechanical alterations are accompanied by Hennessey’s bespoke ECU management system.

The end result is a car which can reach 60mph in around 2.5 seconds, and do the quarter mile from a standstill in a blistering 10.1. As you can imagine, the top speed is well over 200mph too, but Hennessey has refrained from sharing the specifics of that.

rear of the Hennessey Cadillac CT5 H1000

Ultimate Sleeper Car?

Perhaps the best thing about this Hennessey Cadillac is that it can do all that, and yet, you won’t feel embarrassed or self-aware while driving it. It retains the CT5’s ‘quietly aggressive’ aesthetic, giving you rewarding visuals without being too in-your-face.

It should handle pretty nicely as well. Hennessey hasn’t touched any of Cadillac’s dynamic engineering, meaning you’ll still be able to enjoy features like adaptive Magnetic Ride Control, Brembo brakes, and configurable driving modes. The interior is plush and stock too. As a daily driver then, the Hennessey Cadillac H1000 would surely flourish. And just imagine the looks on the faces of the SRT boys when you drop them off the line at the traffic lights…

So, is this 2023’s ultimate sleeper car? Well, we’re struggling to think of a better one…