See, these are the sort of things I don’t need to be doing.
Now, we all know how well turbocharged engines respond to a little massaging. That first round of modifications that we all go for – and most stop at – usually because the next step is when things start to get real expensive, and sometimes problematic. But I didn’t expect there to be such a difference, and by the sounds of it neither did Endo-san at 3DDesign.
I’m referring to the 140i I showed you a glimpse of in my previous post, a car that Endo and his crew are modifying right now.
Visually the car is pretty much complete, fitted with the company’s signature front lip spoiler and a carbon fiber lower bumper insert that replaces the black plastic section.
The 19-inch Type III 5-spokes complete the look with a nice and tight fitment and a decent ride height drop courtesy of their adjustable coilover kit.
But what I want to focus on is this, the new B58 engine that is fitted to all current ‘x40i’ BMWs. Replacing the previous generation N55 (fitted on Project Drop Top for example) which came to the end of its generation. It’s still an inline six displacing 3-litres but it’s a completely fresh design featuring a new closed deck block, rather than the open deck design of the N55 and rated at 340hp from factory.
Despite this costing BMW more during production, and making the engine weigh a little more, it makes it stronger and more capable of dealing with higher pressures.
The turbocharger is still a twin scroll design, but is 6% larger and run with 20% more boost. The result is a slight increase in power of about 20hp over the N55, but the real benefits start showing themselves when you fiddle with it a little bit.
After developing their new booster chip for this engine, 3DDesign were able to get the power all the way up to an estimated 457hp at the crank; or a nice, solid 400hp at the wheels. The only other modification that’s fitted to their development car is an exhaust system.
That’s considerably more than the typical 40-50hp you could expect to get out of an N55 with the same modifications. One other difference of the B58 is that it runs an air to water intercooler as opposed to an air-air item as on the previous generation engine, which makes intake charge cooling far more effective and possibly even better than an intercooler upgrade ever did on the N55.
Thankfully 3DDesign is located just off the Daisan Keihin express way so that’s were we took the car for a little test drive. I was blown away by the amount of pull the car has, it’s pretty much the same linear delivery that you get from stock, but with the power and torque curves bumped up the graphs.
In any gear it pulls effortlessly from as low as 2,000rpm with the biggest difference being at the top end which just keeps on going all the way to redline. On Project Drop Top, for example, the top end is pretty uninspiring and you can really feel the power trailing off.
Thankfully the car was fitted with the optional M-Sport brakes, which have a way more reassuring bite than what BMW gives you on their stock set up.
This short test drive was a definite eye opener, not only to feel how responsive this B58 is to extra boost and a refined map, but a taste of things to come from BMW. You can bet the next M2 will be taking full advantage of this new engine architecture.
Dino Dalle Carbonare