They would be putting a 340 into the factory basket as a lift pump for the surge tank and then put my existing 450 and a new 450 into the surge tank to deliver the fuel to the engine.

It’s need some work to work with a return set up. I highly recommend contacting Cjm for the twin pump surge set up. Ran it down to two dots few weeks ago at the track. When I wasn’t overheating it never starved

return fuel line will be better on a boosted car
the radium is return-less, it bleeds off pressure back into the surge tank.

to quote phunk

"fuel pressure drop at high power is a result of the pressure drop that occurs across the fuel lines. By regulating fuel pressure at the pump, rather than at the rails, you will always have fuel pressure drop as HP goes higher and higher."

basically you want the regulator at the rails, not the pump.

radium will handle your fuel starve issues, and fine if you're not pump a lot of fuel
but the cjm return fuel system + anti starve canister is going to be better for higher HP

OK, that makes sense

So it would be better to just replace what I currently have (except the 450 pump) and go with the CJM setup instead of retrofitting to keep most of what I have with the Radium setup?

Why can't you use the Fast 500E fuel return/regulator etc.

The only thing you'll be replacing is the CJM top hat to a CJM twin pump + canister no?

The radium setup is returnless so you'd either have to modify it or remove the Fast 500E fuel return kit.

Changing to CJM twin pump + canister is probably the cheaper AND better option.

The Radium can be modified to have a return. MA did it on Johnxxx's car from what I remember.

I am getting both the CJM setup and Radium setup quoted out from them but I am leaning more towards the CJM setup based on what you guys are saying. Jotech is going to be running the Radium setup on another Z so thats one of the other reasons why that solution came up as an option.

Spend the money once. Radium will work. But Cjm is worth it’s weight on gold. It’s was designed for the 370 with a return system.

Yup, that's what I have.

Thanks! Looks like I'll be going with the CJM setup sometime in the near future. Since the car has been in the shop for a while I'm planning on enjoying it for a bit and getting used to this power level before I upgrade the fueling system and tuning to its full potential.

Can’t wait to see this thing around town.

Red line is E85 and blue line is 93 Octane. This car definitely pulls a lot stronger now haha

Took my car in to EDI (where all my GTR buddies take their cars now) to do more upgrades. Ended up going with the CJM twin fuel pump assembly with the twin pump canister and 1300X injectors. Hit 700whp but had to back off at the top because injectors were maxed (not getting enough fuel). Looks like my stock fuel rails are the last bottleneck so EDI is going to re-plumb my fuel lines and fabricate his own solution to getting GTR fuel rails on the car to get better flow.

Waiting on our tuner to fly in later this month since he wanted to tune my car and a few other GTRs in person so I'll be dropping my car off a few days before he comes in to get that done. They are more than confident we will be around 800whp safely by the time they are finished.

800whp on those turbos is not wise. The drive pressure (EMAP) is done at around 21psi of boost. If you try and push it higher torching a headgasket will be in your future. Shot for around 750-775whp on E90 Ignite red. On pump E85 you will be done at around 725whp.