The APR Stage 1 ECU Upgrade is the first step towards tuning your engine. It produces up to 340-352 HP and 302-312 FT-LBS of torque. APR Stage 1 is available for 91 AKI, and 93 AKI in North America, and 95 RON, and 98 RON in the Rest of the World. Only use fuel equal to or higher than specified. Compared to the previous B6/B7 S4 which used a 4.2-litre V8 engine, the B8 S4 uses a smaller displacement 3.0-litre TFSI V6 engine, but now with the addition of forced induction via an Eaton mechanical supercharger. At the time of testing there were no performance upgrades for the B6 S4 V8 engine. All cars used 93 octane fuel running fuel specific programs where available. Stock B5 S4 6-speed manual ; Chipped B5 S4 6-speed manual ; Stage II+ B5 S4 6-speed manual (chip, downpipes, full exhaust) Stock B6 S4 6-speed manual. The following data was collected Cons. Mild refresh. High price. Non-linear brake feel. All-new for the 2017 model year, the 2021 Audi A4 is a midcycle refresh of the sports sedan. But some refreshes are milder than others. The Here are the differences for those that might think that the RS4 engine has only a few minor "tuning" differences. These come from the Audi 4.2-liter V8 FSI Engine Self-study Program The main technical differences between the base engine and the high-revving engine lie in the following: * Crankshaft/connecting rods/pistons * Timing gear 09 4.2 Oil Filter Cannister Leak. 4.2 V8 Discussion - 4.2 FSI Vacuum Diagram - I recently changed my brake pads and replaced one of the secondary air hoses on my 2008 a6 quattro with the 4.2 32V FSI engine (BVJ), and now I have misfires on all my cylinders and no other errors from VCDS other than mass airflow sensor readings being erratic which Audi S4 4.2 V8 2003-2005 BBK 4163ccm 253kw Car Repair Manual Engine size: 4163ccm: Power: 253kw: Idle speed: 640-720rpm: Compression: 10.0-14.0bar: Minimum The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums The 4.2 is a sluggie snail, end of story. But if you got oneyou are in luck because you can find a 2.7T long block with turbos for as little as $400-$500. Or you guys can swap in a 4.2T for like 4-5k, if you can find one. Last edited by aysix; 10-11-2013 at 07:58 AM . 10-11-2013 08:51 AM #9. rollerton. xW3iRZ3.