Most of the time tuning naturally aspirated engines can yield a small power increase. Even things such as Porsche Carrera's and Audi RS4's gain very little, but sometimes you come across something like this BMW. This is the BMW 325i, a naturally aspirated 3.0 6 cylinder engine which as standard produces 218 bhp (as BMW claim).
This particular car was using regular 95 ron fuel and the owner was set on only using that. We explained about the importance of fuel quality, especially in a naturally aspirated car where peak power is made very late in the rpm range. Nevertheless, we began tuning the car with our CustomPro software and 95 ron fuel.
The graph below will show the car was never running the 218 bhp claimed by BMW and a lot of this could be down to the fuel quality. The owner wanted to concentrate on introducing power earlier which we succeeded in doing. When standard the car produced 200 bhp at 6,500 rpm, with our CustomPro remap, the car now produced 200 bhp at 4,900 rpm, with an additional 50 bhp still to go!
We've since had feedback from the owner explaining how dramatically different the car feels to drive. Since then he has also began using Tesco Momentum 99 ron fuel and felt even more of a difference.
"Have just driven back home to York following the remap: a significant and noticeable improvement in power and acceleration!! 50bhp increase is pretty good for a naturally aspirated engine"
Power gained: 50 bhp
Torque gained: 51 nm @ 5,400 rpm