[dradernh]

Originally Posted by USA-RET

Seems like we all put a bit too much store in published numbers, be they HP/TQ or 0-60/1/4 mile times.

Owners who want numbers they can put store in will take their car to a dyno and have it dyno'd on the same day both before and after upgrading. They'll also allow the car to cool completely between each set of pulls. That produces hard data that an owner can rely upon.

This is especially true in terms of the percentage of increase in HP and torque, as different dynos produce numbers in different ranges. My experience is that a Dynapak, for example, will produce numbers ~10% less than a Dynojet. The former was used by both Dinan and Turner Motorsports when I had cars tuned in their shops, and by the tuner I used for a BMW race car. NASA requires that RWD and FWD race cars use a Dynojet for car classification purposes - I certainly got a kick out of seeing the big numbers produced by that machine!

Originally Posted by LJA2

I don’t want to spend $1100 plus installation if the car is not going to see a material difference in performance. And with this product being new there’s no track record ...

For sure! Dinan, however, has a very long track record of reliably producing results. That's why BMW has a relationship with the company.

I just looked at the V2 data on Dinan's site. It shows a 9.7% increase in peak HP and an 8.2% increase in peak torque over the base data produced by the M240i they used. While you'll certainly notice this increase if you drive in a way that uses most or all of the car's power, it's not going to be an earth-shattering improvement in performance. OTOH, it's likely little enough additional power that you can confidently use it without worrying about damaging your drivetrain.

As always, just my 2¢.