How to modify your Turbo
Want to extract even more performance for your water-cooled Turbo? Total 911 shows you how
Want even better performance from your Turbo? Total 911 shows you how
Human nature dictates that however much some think is enough, there are others who’ll always want more. With the 911 Turbo they can have it. We’ll rule out the air-cooled machines here, such is the way of the ‘classic’ car world that these days early forced-induction 911s are considered too precious to be fettled. The 996 and 997 Turbos, however, represent something of an opportunity for those 911 buyers wanting a modern, quick, capable 911 that they can modify to their desires.
Some get a bit sniffy about tuning cars or one-off modifications, but originality be damned, especially when the potential power on tap is so persuasive. The 996 and 997 Turbo positively beg to be enhanced, doing so no different from all those back-date, retro-styled Carrera and evocations that some factions love in this sometimes divisive Porsche world. It’s your car, do what you want with it, and with the water-cooled, forced-induction cars a lot can be achieved with relatively little, or, taken to extremes, a lot can be obtained with a lot.
That begging we refer to relates specifically to problems relating to both the 996 and 997 Turbo.
Rot. Specifically around the engine, and particularly around the exhaust and turbos themselves. If they’re going to have to be replaced – and they will need to be at some point – then why not take advantage of the latest thinking with some extra performance? How much more really does depend on what you want to use it for, with anything from 50-60hp gains possible via changes as little as a decent high-flow air filter and re-map. Even a simple map and boost leak check can yield some fairly significant gains on a stock Turbo, or at least restore some lost power.
The experts agree, with Adam Reardon at Nine Excellence and Colin Belton at Ninemeister admitting that both the 996 and 997 Turbos are good cars that respond very well to tuning. Belton is quick to suggest that before embarking on any tuning to find the very best car you can, evaluate the parts you’re going to have to replace in time anyway and look at budget and options from there.
As a minimum there’s an expectation that you’ll need an exhaust, the options available to you being extensive. The most common are 100- or 200-cell sports exhausts, reducing back pressure, helping improve performance and having the benefit of sounding better at the same time. Belton had a customer come in with a 996 Turbo wanting an exhaust system: it dynoed 410hp and 577Nm of torque when it came in as standard. After a full exhaust it returned 465hp and 648Nm of torque, and adding a remap brought the figure up to 500hp and 691Nm. That’s quite a leap from the 420hp and 560Nm Porsche quoted as standard. The gains should be felt everywhere, with improved throttle response, appreciable increase in performance and, more often than not, little, if any, impact on consumption. That Belton says even this circa-£5,000 job was enough to have the 996 Turbo’s four wheels spinning under power demonstrates what’s possible even with relatively little effort.
There’s always more though, and in the case of the 996 and 997 Turbo there’s the possibility of four figures if you’ve the desire. If the simple exhaust modifications can be thought of as a stage one on the tuning ladder step, then the next is going to new Turbos. They’re often the sticking point, given they’ll cost at least a couple of thousand pounds, and there’s a pair of them. You’ll hear talk of hybrid turbos, these using the stock casings and systems around them like the wastegates and boost controllers, but using improved internals, allowing faster spooling and more power. Go that route and you’ll be pushing the power into the 600hp region, again with an engine map to suit their characteristics. You can run the stock intercoolers, too, unless you’re in the habit of 200mph blasts down runways, though the standard intercoolers are good enough for road use.
Above that and all the experts agree you’re into a different sphere regarding potential performance and budget. If you’ve done all the above and still want more, you’ll need to look at serious enhancements to the engine’s internals. Both Reardon and Belton agree that anywhere north of 600hp is going to require engine work, anything up to that point achievable via bolt-on parts and clever mapping. The conrods in both the 996 and 997 Turbos are fine up to 600hp, but above that you’ll need stronger ones fitted, while it’s wise to fit stronger head studs, too. To that Belton suggests bigger pistons and a 3.8-litre conversion, but admits the costs involved get prohibitive for all but the most committed.
Take the ultimate route and there’s up to 700hp on tap via hybrid turbos, improved intercooling, new headers, bigger injectors and freer-breathing, with huge numbers possible. Reardon says Nince Excellence ran their own car with 800hp for 10,000 miles with few issues.
The drivertrain is strong enough to take up to 600hp comfortably, though above that you’ll need to look at some strengthening if you’re not going to prematurely wear or break transmissions. The more you add, the more you need to spend, and in a greater number of areas. If the engine’s out already then why not go the forged internals route, but with either the 996 or 997 Turbo already offering so much in stock form, even modest gains are felt, and easily reversible – as they’re all bolt-on – should you ever want to return it to standard in the future.