Your power goal is possible, but I would not assume it can handle over 150whp/cylinder long-term without bearing wear or bending rods. They are strong motors but not invincible.
https://www.turnermotorsport.com/p-578221-b48-pure-stage-2-turbo-upgrade/
For strictly circuit work, I think the 2.0's weight balance is going to be better. I personally would like one but not for these prices so close to 3.0. I think for a lot of people, having the halo RZ/3.0 trim is worth the price difference rather than getting the 2.0 and wondering if you're...
Torque limits on transmissions, in my experience, are reliable safe ratings much like most clutch ratings. Most will hold more but it's a question of how long. In the n54 world, the trans limit was way lower but people were safely and reliably running 600wtq with the xph trans flash.
"ZF rates...
I can't truly speak to raw numbers but it's comparing apples to oranges. Direct Injection is very unlike port injectors. In the bmw n54/n55/s55 communities, we haven't truly found a limit on the injectors as far as I know just the high pressure fuel pump(s) operating at 2000psi+. Last year a...
With direct injection, there are 2 fuel pumps now. The regular 43psi in-tank pump that get it into the fuel rail and the new high pressure pump in the engine bay which flows it at incredible pressure (1500+psi) from the rail to the injectors.
I can't say I've seen reports on the Bx8 platforms but n54/n55 would have our plastic chargepipes crack even under stock boost pressure and even in the warranty mileage -- not talking about 100k engine bays. Depending on the severity of the crack, it might be as minimal as a boost leak or could...
We didn't stroke past BMW turbo motors -- we need more flow, not more torque. Will be interesting to see what happens with these BC strokers.
https://bmw.spoolstreet.com/threads/n54-stroker-build.2657/#post-29196
So a q60 rs? If you don't need a manual and don't care about the added weight of the "good seats and better quality materials", then you're already set, no?
As an ardent MHD fan, many many n54s with upgraded turbos or singles ran JB4-only successfully. Contact Terry of BMS who makes the JB4 units and he can likely steer you in his preferred direction to meet your needs. That's what's technically possible. I would highly advise getting a custom tune...
If you're a facebook user, look up "Tampa Bimmer Club" and you can find a list of reputable shops that the club has been working with for years. Additionally, Induction Performance is well-known shop that deals with high-end mkiv supras.
Apparently Toyota fitted the Akrapovic on their racecars:
https://www.carscoops.com/2019/10/the-toyota-gr-supra-gt4-will-become-your-own-race-car-for-200k-plus-taxes/