Originally Posted by Bulldogger

LET has been doing alot with the mercedes SLK32 which is same engine. Erick of LET is a great guy and honest. The 181 pulley is safe and so is the 185. The 185 just puts the fueling system at it's limit right now with available programming,the 185 is entering new territory. I am sure Renntech is correct with the comment on the 178 being safe but are wrong with the engine being at it's safe limit. Renntech only has this set-up so they tell you what they need to to make a sale. 1500 in parts and 1500 for the name and badges. I don't mean this as an insult by any means but Renntech will attain nothing different then an API pully with say an In Motion tune. Renntech sells you the kit with a ECU reprogram. Renntech isn't dyno tuning for maximum gains so basically it's what I call a canned tune, same as In Motion. Now as far as a few tenths go.... well on pinks that could cost you your ride
As far as the car goes, my SRT will be going the route of 181. I'll more then likely do the SL55 y-pipe and intake tubes or go the whole SL55 set up like Brian Brave. I'll remove the ressonator and that will be it. More then likely I'll stick with stock engine bay looks because my son and I will hit a few car shows for fun. My true love is my 2006 Duramax Diesel with SCIII and EFI live