Should have mentioned fuel pump, that's a given because cheap and easy (for once!). With aftermarket ECU won't need MAF so just couple of pods in the factory location should do the trick. Have a couple of front mount kits so will pick the best of the two and run with that. How long has yours been running that config and power madcow, has it been reliable?
So far its been fine. I have done a single hill climb event, have not put it on a high speed track yet. It has done daily duties for almost 12 months before someone tried to steal it. If you plan on tracking it, get a catch can setup.
I have approximately that power level. To give you an idea: GT525 turbos @ 19psi 550cc injectors (95% duty at peak power) Fuel pressure regulator at 50psi base Chipped ECU All the usual bolt ons With this setup I am maxing out the AFM, just under 5.1v. Been running reliably for 3+ years, estimated 350rwkw.
Won't be tracked, most likely just a few roll racing events. Already lined up an Adaptronic M2000 ecu, working on injectors now.
GT2860RS turbo 76 trim 0.86 A/R has a flow capacity of about 300-360HP and works well with VG30's. You'll need exhaust manifolds, 5 bolt dumps, Nistune or aftermarket ECU, bigger injectors and fuel pump (or 2 stock tt pumps if 2-0), aftermarket engine mounts. 2.5-3" exhaust with high-flow cats, frontmount or bigger sidemount's will help. With froged bottom end, stock valves and stock cams you should be able to make 500hp with 98RON all day long... You can pick up Cheap China Ball Bearing Turbos for USD 350-500ea + Freight. (Check if wastegates are closing properly before installation) If worried about that go with brand names turbos... For the ease of insulation I would recommend that you weld 90degree double bent on turbo outlet side as exhaust manifold and engine mount may be on the way. Regarding LPG and (Complete gas research system). They make old venturi type systems... You will need some injected Vapour/Liquid type systems for turbo setup. If you choose injected vapour system you can use only old LPG tank. Liquid system needs tank with a inbuilt fuel pump. Vapour system kits from China going for around USD 150 + freight.
Go something bigger than the NISMO 740cc. My tuna said the 740s were not maxed out at 16psi on E85, but he couldn't get more fuel into it. He suspected it was the pump. Apparently the OEM fuel wiring cant deliver the current the big pumps need.
I'm guessing you didn't read what I posted originally in regards to what I had, and where did you pull LPG from? I mentioned E85, not LPG. Just spoke to my fuel system guy, 1000cc is the same price as 750. No brainer that one! Noted re pump wiring, I was looking at a Walbro 460 or thereabouts, is that what you are using? Head studs I have seriously considered given the reasonably cheap price of entry but why valve springs? I'm not planning on revving the thing into the stratosphere (got JZ power elsewhere for that).
What 1000cc? I am interested, I wasn't able to find any decent 1000cc sidefeeds, I couldn't justify the price + loosing too much of a stock look of the motor. I am running the Walbro 485: https://conceptzperformance.com/blog/defeating-the-stock-fuel-control-system-addendum/ - Even if this is not common on every car, it would be worth doing regardless, I plan to do it on my car and send it back to the tuner.
Injectors are JECS flow matched items. Bear in mind these are drop in for a S2 injector rail, are you running the same or S1 with adapters?
Valve springs because cheapish (around $400 off the top of my head), no extra labour, and old springs often lose tension over time.
