Morning all! Along with some work colleagues I'm embarking on a team project to develop a sequential turbo-charger system for a 850 T5 as a bit of fun. I work for an OEM (not volvo sadly) as a control systems engineer - we are a tier 1 automotive manufacturer so there are a lot of knowledgeable people around me (thankfully!) We are going to use my car (project thread:

Anyway, I have a few questions that I am sure the forum members will be able to help me with. Ettienne as my one-stop-shop for volvo parts thus far has kindly given me a spec list of potential parts that would fulfill my needs, just looking for any shared experience on these parts, alternatives that could be looked at, or other upgrades to consider whilst everything is apart.

The aim is to see 400hp+ with really smooth delivery and buckets of torque throughout the ERPM range.

Engine wise I've gone with a S60R engine for the internals and will either match that block (shimmed obvs) with an 850 head or rebore the 850 2.3 to take the S60R internals. Any opinions on which to do? Overall what is the reliable HP limit of this engine spec in peoples experience?

I'm carrying out a full rebuild of the block and head - are there any aftermarket parts worth considering instead of OEM in the valve train/bearings/fasteners? Looking at NA cams as an option but need to do some more research on what benefits they bring.

Head porting - worth it? Did have small benefits on the NA engines I used to play with but these were the days of spending thousands to gain 10hp!! Any other comments or suggestions on the engine front would be great.

Questions to follow on transmission & management options. Don't complain about FWD - watching the other project on here about the AWD conversion with great interest, and management plans are interesting....

Thanks in advance!