R_34

I could be interested with a small caveat : I live on the other side of the planet. Taking into account what you'd want from it and arranging transport, I might not be that interested after all.

Same boat for me, I snatched a G30-660 supercore for my RB20, still trying to decide between .61 and .83 A/R, I was vouching for the .83 but the comment of geoff about the G series liking the small A/R more is confusing me.

Have an RB20 (currently sitting on a shelve), revved it to 8200rpm for around five years and it wasn't happy past 8000rpm but still pulled so i was using it past 8k regularly even if you could hear mechanical noises coming from the head. I don't know if it was the lifters not happy or valve float. I'd bet on the latter. Decently sized higlflow turbo, 630cc injectors... just basic power upgrades and 20psi boost on E85 so nothing crazy. A small chunk of a valve on the exhaust side decided to retire itself from the workforce and fly through the neighboring cylinders and the turbo for a better tomorrow. Installed a broker motor and kept the revs to 7800rpm with the same setup, miss the 400rpm a little as the limiter is much more present, but motor didn't last long and wast extremely extremely rusty in the cooling jacket. No graphs on E85, but I have one from the first motor on pump 98, 14psi/0.9b and stock airbox that showed 198 rwkw and 320Nm of torque. And the topic for RB20 dyno already exists so go find some graphs. Stock limiter on an RB20 is 7600rpm, it's plenty enough with a good and decently sized turbo on it, don't go too big as the 20 quickly becomes a dog down low. 7800rpm was a nice sweet spot for me but my turbo was waking up late. GT28 based turbo (2860RS/X2863) and the like, mid boost, stock limiter and enjoy. Street fun, decent power and powerband, reliable, can serve as a daily. I'd say install springs in it i you want to rev it past 8k, especially with more than 12psi/0.8b of boost for peace of mind. The crank was decently balanced from the factory so not much to gain from that side, but mass from the rods and piston are a little all over the place. If you plan a refresh you might try to even things out on that side.

I'm surprised the cams and crank seals didn't let go/popped off already.

It definitely does look like a g30-770.

G30 turbine flow : G35 turbine flow : The compressor flow chart : 770 : The 900 one : and finally the 1050 one : All were taken from ATP website so I consider these as legit but still take these with a grain of salt as they were not officially released.

Will do.

I'll post everything i managed to squeeze out from the ATP website in a few hours.

I got it from ATP when they were updating their site with the g30/35 to come. I managed to save all the compressor and turbine map from their site for the g30 and g35 but the g30-660.

Here you go : G30-770.

Awesome result ! A friend is thinking about stepping up on his SR. Can you give me some details about your setup or point me to your topic where you present your setup.

Some EV14 are even cheaper than that. Got 6 630cc EV14 for ~80$ each. These are stock injectors from some porsche 911 turbo or GT2 or something so pretty cheap and readily available.

Which precision was on it ?

1200+cc

Nope i just retrofitted intake camshaft and pulley from an S1 RB25 on my RB20 (coming from a R32). I drilled and taped the camshaft cap to install some kind of banjo fitting through the cam cover in the cap , a solenoid and then back to the head through the cam cover again. The solenoid is operated via the nistune ECU. It looks sketchy but it's working and not leaking so far. I'll give some pics for you if you're interested.

I just noticed your post and I'm keen to see more of your setup and results so far as I was looking at the S252SX-E for my RB20 with VTC as well. Do you have any more pics of the mods done to the housing ? Did you change the spring in the gate to improve the spool ?

You need to use only one wheel with an inducer of 62.6mm and an exducer of 83mm mated to a turbine with a 74mm inducer. Preferably in a twinscroll housing. I can't be more specific as I don't have all the details on these wheels but they seems to perform very well on RB26.

Clean the idle valve at first. It's located at the rear of the intake manifold. Once cleaned you may need to set the idle again but it should solve your problem.

They're pretty cheap too, I bought a set of 6 for 300€ delivered.

Yes they're all high impedance, at least on the PDF that bosch released to present them. AFAIK there is no 440 or 550cc. It goes from 347 to 627cc (0 280 158 123). I have the 627cc and drove them a little on 98. They were perfectly fine. The engine was starting better than with my old EV6 deatschwerk 440cc, perfect idle at 15 AFR. Driveability was also as you'd expect from a 20, there was no cons of using such "large" injectors with 98 on a rb20. They were a bolt-on affair on my engine but I run a chinese forward facing manifold, I can't comment on the stock manifold.

It is the angle formed between the blade and the tangent to the compressor wheel at the exducer of the wheel. I'm not familiar with this notion but after a very quick resarch it seems that a higher angle might increase efficiency and maximum pressure ratio. Bear in mind that these results were found in a centrifugal oil/water pump, not an actual air pump like a turbo. There is more research needed to give you a correct answer, answer that will not give you what you're looking for in terms of power and response anyway.

80 to 100°C around 125°C if 40wt. 76-85°C if you run an OEM thermostat Anything higher that 95°C with an OEM thermostat I'd call that overheating even if it's still not dangerous yet.

I'm surprised you saw more power going to 35 psi, to be honest I think the turbo is done at those power/pressure level. You're already overspeeding it. Anything beyond 50 lb/min at 35 psi is definitely in overspeed. It may explain why you ran out of "boost juice", if the turbo is maxed out, the engine is not so happy at taking timing. If you still run a maf i'd check how much air is going in your engine, if not I'd measure the inlet turbine pressure to see where you're at.

Weight of the wheel doesn't influence the rpm you see full boost. Wheel aero, balance between compressor and turbine capacity/diameter and turbine housing are the main factors. Weight of the compressor wheel somewhat matters during transient (between gear shift or when you floor it above boost threshold for example). But weight is nothing really, it is how it's distributed around the axis of revolution ie inertia that is important. And while your new wheels are lighter they're also bigger in diameter. The weight is further away from the axis and distance account as squared when you calculate the inertia. So weight means almost nothing for transient. Especially when the turbine is more than twice the weight. For the record these wheels will not hold themselves at 300k rpm. They may spin up to 165k rpm but that's about it. Fitting bigger wheel in stock housing will just net you more lag for marginally better power if any. Going bigger exhaust housing should help you unveil that theoretical power that these wheels may flow but it will add another bunch of lag. For the money you'll spend fitting these wheels and sourcing .72 a/r exhaust housing you could get a good single outspooling/outflowing and with way better transient than what you're building. If you want more response with a 26 with stock-ish twins you should stroke the engine, install a variable valve timing (hks one or made one yourself as I did on my 20), go single turbo or do the three solutions I mentioned. If you just want more power this is the same recipe except for the variable valve timing. But that's your car, your money, your life. There is just a consensus here that tells you that it is a terrible idea that has been tested before albeit with smaller gt25 turbine (hks gt2530 comes with the gt28 turbine).

Well that's equivalent to a gtx2863 compressor wheel but in 6+6 blades instead of 11+0. 2863 wheel mated to gt2510 turbine has already been tested and proven to be a fail. I can't recall if you're on gt28 or gt25 turbine but either way that's too much compressor flow for a stock housing gtr turbo IMHO.