My initial motivations for buying an e60 535i were completely practical.
I’d looked at an older e66 760Li (my previous two cars were V-12 7-series cars), I looked at a pre-LCI e60 M5 as well. I was scared away by the potential for some major failure, and the fact that, because I was paying with cash, any of those models in my price-range tended to have higher mileage than I was looking for.
That brought me to the e60 550i. At the time, I had a fundamental objection to the V8 5-series, mostly brought about by their drivers, who, in their demeanor, usually seem to be overcompensating for the fact that they haven’t bought an M5, or overload the car with Sport options that they really don’t deserve. I attempted to talk myself into the 550, but when I started researching the car, all of the reviews seemed to make one recommendation: It’s not worth it, get the 535 instead. It’s lower maintenance, less expensive, lighter, has all of the same options, and almost as much horsepower. The twin-turbocharged N54 inline 6 was always intriguing to me. I’ve been a sucker for BMW straight-six engines since the day I started driving (my first car was an e30 BMW 325 with the venerable M20 straight 6 – I miss it daily).
When I got the 535, I was pretty pleased. It was my first 5-series, and it was just as powerful as my last 7-series – it wasn’t quite as comfortable, but it handled way better, and I was satisfied. It did what it said on the box – but it seemed to be missing…something. It didn’t feel “BMW-ish”. It felt a little restrained, as though BMW was holding the leash too tight when they designed it.
The first thing I did was, naturally, research performance enhancements for the car. I correctly assumed that due to the turbocharged nature of the engine, it would be relatively easy to reliably extract a significant amount of additional horsepower from the engine. Dinan offered both a Stage I and Stage II performance upgrade for the car. They weren’t inexpensive, but they did offer a 60+ horsepower increase above stock. I’d had good experiences with Dinan performance products in the past so I decided to go ahead and buy the Stage 2 engine software.
The Dinan software did what it said on the box – the car was definitely faster, but it still retained a relatively smooth, stock feel, with relatively little turbo-lag and good drivability. It was like someone had taken the stock vehicle and turned the knob up a notch or two – but it still felt like it was being held back.
A few months later, I was browsing on the internet and I noticed Dinan had added a Stage 3 performance upgrade package to their site – for $1500. It boosted engine power to roughly 400. After doing some more research, I found a curious product called the JuiceBox, by Berger Motorsports. The JuiceBox was a software upgrade, like the Dinan system, and it also promised 400 horsepower, but it was different in that it was inline of the Engine Control unit, and it had many more functions – for example, it adjusted the instrument cluster and car controls, so you could vary your boost level via the steering wheel controls, or open the valves on the exhaust system on start-up, or turn the fuel gauge into a boost gauge. I was intrigued, and when I saw that it was a mere $600, I immediately purchased it. It also came with dual cone-intake filters that replaced the stock air box, and a USB cord for interfacing it with software on a laptop or computer.
When it arrived, I immediately installed it, a process that took perhaps a half-hour. After flipping through the options several times, I stumbled upon the setting to open the exhaust CAN valves, and I triggered it. Immediately the car reverted to a throaty straight-6 grumble at idle, a definite change from it’s usual muted whirr.
And then I took it for a test drive, and my world changed. This car was a monster. It had slipped it’s leash. Chirping the tires in second gear (it’s an auto), flying through the gears…it had been quick before, but now it was legitimately fast. We took it up on the interstate, and floored it. It immediately shot up to 60, and sailed on up to 120. Holding it at that speed for a minute, I floored it, and the car, from 120mph, threw us back in our seats. It is literally amazing.
Perhaps most astonishing of all, it’s still mild-mannered to drive around town, when you just want a sedate cruise. As long as you don’t get into the boost, it’s as civilized as you’d like, and it still gets ~30MPG highway. It’s really amazing.
But when you want that power, my god. And the sound. Before, you couldn’t even tell that the car was turbo-charged. Now, it whirrs, wooshes, and puffs like it should, and the sound adds a whole new level of dynamism to the car. It’s an amazing change.
I’m currently using Map 2, one of the several performance programs that are available, and the most conservative. You can purchase even more upgrades, including an additional fuel pump, and uprated turbo-chargers, to further increase the power.
I’ll be posting a video as well as a how-to guide in the near future.
All in all, the best $600, and the best 1/2 hour, I’ve ever spent.