Old vs New Engine Power Difference

[seningen]

Originally Posted by thstone

Ever wonder what the power difference might be between an original high mileage Boxster engine and a high-end full rebuild?

Shown below is a dyno plot of hp and torque for the old engine (Green) vs the rebuilt engine (Red).

Net result: +17hp at 5900 rpm (max).

This data is from the same car, same ECU, same exhaust, same intake, same dyno, same operator, and same air temp. Its as close to an apples-to-apples comparison as I could create.

Old Engine: Original '99 stock 2.5L engine with 136,000 miles along with 89 track days.
Rebuilt Engine: Complete full rebuild professionally done by Hergesheimer Motorsports. Almost every friction surface new. Completely stock. 500 miles and one race day.

Sorry for hiding the absolute hp and torque scales but racing is competitive. I hope you understand.

Yeah, but what does the butt dyno say :-)

I've got a 2.7 here that we just rebuilt and it feels stronger than my 100k mike 3.2!

Mike