I asked Renntech 2 questions that I have been wondering about for a while.<br> <br> 1. What is the drivetrain loss on an SLK?<br> Answer, typically for MB it is 17 to 20%. They measured it on a C coupe and it was 19%. With a shorter driveshaft, the best guess for an SLK is 18%. Therefore, my revised hp/tq estimates for my 32 after then ECU and pulley kit are: stock tested at 304/290, +40/+56 from Renntech ECU and pulley kit for a total of 344/346 at the wheels. At an 18% drivetrain loss, new estimate is 405/408 at the crank.<br> <br> 2. What is the boost increase from the pulley kit?<br> Answer: +2 psi. They measure 12 psi before the pulley and 14 after the pulley. Periokid, you'll likely see 1 full bar if you get the pulley kit on your boost gauge.