[IridiumRS400]

Contact Hussein @ Racebox in Houston.

500 WHP is doable with E-blends, FBOs, tuning and about $5-7k. 600 WHP is going to require triple that amount, which includes strengthing of the transmission and drivetrain. For example:

Infiniti — Pure Drivetrain Solutions

Note: Ignore their hp/tq limits, just keep in mind the torque limits of the stock transmission.

I'm assuming you have a RWD Q60, which you'll likely be traction limited above 500WHP unless you go with drag radials and rear LSD.

 

[IridiumRS400]

that’s a very reasonable price. Would you recommend upgrading stock turbos or would the stock ones do fine?

If your Q is primarily a daily driver, the stock turbos with tuning, FBOs, and pump gas will provide very good low-midrange torque (my Q put down 502 WTQ on a Dynojet AWD dyno). For me, it's typically not worth spinning the engine up to redline. That said, few stock cars (except an RS3 or C8 Corvette, for example) out there can beat my Q from a dig.

If your goal is generating the most horsepower, than an upgrade to Pure Turbos Stg II, FBOs, & E85 will net a nice bump from midrange to the top end, although sacrificing some low end and increased lag.

Depends on what you want to achieve.

 

[IridiumRS400]

If I had money burning a hole in my pocket, the R/T Tuning turbo upgrade is supposed to behave more like the stock turbos in driveability:

R/T Turbos for the VR30 Q50 and Q60

Here's the breakdown from an estimate I received in December 2021 ($12k):

 

[IridiumRS400]

I have a 2017 Q60 with

Lower/upper down pipes
Cat back
Hks bov
Ecu tek by goracebox
E30 flex fuel
Low pressure fuel pump
LSD with 3.1 ratio
Stage 2 VR30 turbos

I want to reach 600whp but don’t know what to upgrade as far as keeping the car reliable, Could anyone give me some ideas?

Instead of the Stage 2 turbos, which are going to be very peaky for daily driving, I would speak with Hussein about the full-frame turbos with the Garrett G25s.