Costs can quickly increase if you want to add more horsepower to your car, especially if it is a current European car. When a naturally aspirated engine is changed, the results can be less than ideal. But sometimes, if you do a little research, go to a junkyard, and are ready to do some of the work yourself, you can make some good changes for a reasonable price. That was what this BMW project was all about. When I talked about improving my beloved E82 BMW 128i, I talked about adding a three-stage intake manifold and then properly flashing a European OEM E87 130i engine tune, also known as the 1 Series, that we should have had here. Folklore says this change can give the 1er’s 3.0 liter N52 inline-six engine a significant 30-horsepower boost at the start. It would cost less than $300 for the manifold, new seals, DISA valves to make sure air gets to all the right places inside, and a free tune from BimmerLabs.com. I finally figured out how much money my little Brimmer makes. I’m sorry I didn’t get as strong as I had thought. Science was able to find some significant benefits. The Dyno tells the truth. A dynamometer is used to determine how much horsepower a BMW’s back wheels are putting out. If anyone still needs clarification, it looks like a vast car track. I went to Advanced Engine Dynamics in Corona, California. The lovely people who work there are just as excited about pulling my heavy little Bimmer as they are about the finely tuned machines they usually work on. After I put in the manifold and carefully followed the instructions on BimmerLabs to “flash” the ECU (teach it how to work and get the most out of this new induction type), the car felt noticeably faster. After I fixed the manifold and tuned it, I wanted to know how much power my car had. Before the change, AED said that the rear wheels had 202 horsepower and 181 pound-feet of torque, which anyone would think was a good number, especially since its data sheet had round curves. To get the best spark, I repaired the coil packs and plugs, cleaned the air filter, and ensured the Bimmer had the most recent 91-octane fuel in the tank. Before I got a new/used manifold and tuned my engine, my 128i had a Turner Motorsports intake and a Magnaflow cat-back exhaust, giving it 232 horsepower and 208 lb-ft of torque at the crank. This was based on a typical drivetrain loss formula of 15%, which means that about 15% of the power from the engine doesn’t usually make it to the road. So more than the grade for the stock. The Only Truth After turning the 1er down and doing three pulls, it made 208 horsepower and 199 lb-ft of torque, less than I had hoped. My car’s bigger brother, the US-spec E9X 330i, was rated at 255 horsepower when it was new, and the E87 130i was rated at 260 horsepower at the crank. Taking the smaller two numbers, I hoped my car would send at least 214 to the tire. I wasn’t let down, though. There was a lot to be happy about, though. First of all, the loss of six horses is a little small. Second, the N52 started to go fast. Toby, who owned the AED, never thought about how it felt or how its shapes of power looked on a graph. Not suitable for a car that has gone 95,000 miles and a lot of track miles. After that, there was a lot of low-end power. Before, the power curve looked great, but now it looks even better. It would be easy to pass on the highway in sixth gear because it makes so much power at low revs. Lastly, Toby said the engine wanted to keep running when it hit Redline. With the new tune, the car wants to keep getting more power past where the original song stopped, maybe for another 1,000 RPM. I’ll have to study, but a tune that slightly raises the Redline would be acceptable from a reliability standpoint and might even add a few horsepower. The Steps That Come Next My car doesn’t have 255-260 horsepower for a few reasons. The Euro 130i tune is very European because it is designed to work with the higher RON fuel found on the continent instead of our lower octane ratings, especially California’s sad 91. Toby said that heat soaking was very much a thing in this situation. My Turner intake is designed to keep heat out of the bay because it is separated from the rest of the bay when the hood is closed. However, the cooling system and intake of the car work differently on a dyno than in real life. I can figure out how to get more air from the front of the vehicle to flow into it. Last but not least, I might look into an aftermarket tune that takes advantage of the perks of the three-stage intake manifold. Using this method alone helped them make significant gains, but it might not align with the rules in my area for reducing emissions. There may also be a need for more engine repairs. Friends, keep an eye out!
