R33 RB25DET oem turbo replacement options

[KyoyaR33]

Howdy all

Im in a little predicament and wondering what everyone’s thoughts are?

I’ve had my long block rebuilt and am in the market for a turbo due to my old one having metal shavings from crank bearings (cause of rebuild) go throughout the turbos oil lines and there wheel has a little play.

I’m not really aiming for any power, just trying to keep it as oem as possible, but I can’t find a turbo that’s built for the stock ecu or find something that would be a standard replacement.

Anyone have any ideas or suggestions 

[tylink720]

If you are fine with China turbos, Maxpeedingrods makes a bolt on turbo. Ive had mine for two summers now and it seems to be holding up ok. 

[Duncan]

Your profile doesn't say where you are, but you can get your current turbo rebuilt by any competent turbo shop, places like Precision Turbos or GCG

They can replace the core with a modern ball bearing unit and should be able to source same or slightly larger wheels to fit in you housing. Note if you change the core you may need new oil and water lines too

[GTSBoy]

Stock equivalent turbo replacement is a bit of a nightmare. The old Hitachi ceramic things were pretty good for their time, but they have primitive, vintage aerodynamics. The only thing they have going for them is a light turbine**, and there are plenty of other light turbine options these days, in both materials and CNC manufacturing methods. So, the old stocker makes absolutely no power at all compared to its physical size and its (not very low) boost threshold and response.

** and the ONLY thing that was good about the ceramic turbine was that it was light. In all other respects it is a nightmare.

To get a turbo that is anywhere near equivalent in terms of power capacity (ie, to avoid it being "bigger" and needing tuning/fuelling/etc) you have to physically downsize. And that is not a "stockish" replacement. Doesn't just fit where the old one did. At least a frame size down, probably need a new dump, probably need new inlet and outlet piping made on the compressor side, new hose connections as D said above. I say, if you have to suffer that much work, you might as well do the same work to fit an even bigger (than stock) turbo, have more power (and hence have to do injectors, ECU, etc), and love life, instead of suffering with stock power levels.

Or, you get a light highflow from someone like Hypergear. A highflow that has not been pushed too far from stock. There are still modification consequences here though. HG's cores are smaller than the massive Hitachi core, so it is shorter, moves the compressor housing backwards and requires mods to the air side piping. Plus new hoses. Looks stock, mostly fits where the stock one did (with the previous caveats mentioned), makes a bit more power but can be run at stock boost levels and not cause too many ECU problems.

But, seriously. It's 2024. Like - 25 years since the R33 came out. It's time to put an ECU in it. I Nistuned my car (on RB20 ECU then later again on the Neo ECU) and it was the single best thing possible for minimal money. Dial out the R&R bullshit, fix up the fuelling and timing to make it more efficient for normal driving (cut fuel consumption by >10%). Nistune is not an option for you unless you change the ECU, so you might as well just do a standalone. it will be worth it. And then you can tune it up to the limits of the injectors and AFM, which is pushing 200rwkW and enjoy some actual squirt, instead of the lazy barge-like motion you get from a stock engine, turbo and management.

[silviaz]

3 hours ago, GTSBoy said:

Stock equivalent turbo replacement is a bit of a nightmare. The old Hitachi ceramic things were pretty good for their time, but they have primitive, vintage aerodynamics. The only thing they have going for them is a light turbine**, and there are plenty of other light turbine options these days, in both materials and CNC manufacturing methods. So, the old stocker makes absolutely no power at all compared to its physical size and its (not very low) boost threshold and response.

** and the ONLY thing that was good about the ceramic turbine was that it was light. In all other respects it is a nightmare.

To get a turbo that is anywhere near equivalent in terms of power capacity (ie, to avoid it being "bigger" and needing tuning/fuelling/etc) you have to physically downsize. And that is not a "stockish" replacement. Doesn't just fit where the old one did. At least a frame size down, probably need a new dump, probably need new inlet and outlet piping made on the compressor side, new hose connections as D said above. I say, if you have to suffer that much work, you might as well do the same work to fit an even bigger (than stock) turbo, have more power (and hence have to do injectors, ECU, etc), and love life, instead of suffering with stock power levels.

Or, you get a light highflow from someone like Hypergear. A highflow that has not been pushed too far from stock. There are still modification consequences here though. HG's cores are smaller than the massive Hitachi core, so it is shorter, moves the compressor housing backwards and requires mods to the air side piping. Plus new hoses. Looks stock, mostly fits where the stock one did (with the previous caveats mentioned), makes a bit more power but can be run at stock boost levels and not cause too many ECU problems.

But, seriously. It's 2024. Like - 25 years since the R33 came out. It's time to put an ECU in it. I Nistuned my car (on RB20 ECU then later again on the Neo ECU) and it was the single best thing possible for minimal money. Dial out the R&R bullshit, fix up the fuelling and timing to make it more efficient for normal driving (cut fuel consumption by >10%). Nistune is not an option for you unless you change the ECU, so you might as well just do a standalone. it will be worth it. And then you can tune it up to the limits of the injectors and AFM, which is pushing 200rwkW and enjoy some actual squirt, instead of the lazy barge-like motion you get from a stock engine, turbo and management.

Is it possible to get your turbo high flowed that is capable of 270kw and cap it off at 220kw for example via a boost controller?

[GTSBoy]

1 hour ago, silviaz said:

Is it possible to get your turbo high flowed that is capable of 270kw and cap it off at 220kw for example via a boost controller?

Well, yeah, obviously. But then you have a turbo with 270kW "design", meaning it will have the higher boost threshold and lag of a bigger turbo, but only doing the work of a smaller turbo. That's the suck.

That's actually exactly where I am right now, because my stocker exploded and I got Tao to do a highflow for me. I got a low pressure actuator on it and don't push it past ~10 psi or so, where the stocker was being run at ~12 psi. it makes a little more power than the stocker did, but it lags like a bitch. But, if I run any more boost it starts to ping and the ECU goes into panic mode, which cuts all the fun, so it clearly needs to be tuned. But, until such time as I (which is not I, it's my bro-in-law) can actually get the dyno working again, and get some injectors, and do all the swap over of those and the R35 AFM, I can't attempt to use the turbo the way it really deserves to. So what I have now is something that drives worse than what it did before it filled the cat with little pieces of turbine.

I will tune it eventually, and probably only push it up to ~250-270 rwkW, which is pretty close to the max for that highflow anyway. I would imagine that by getting the tune right, and with newer betterrer injectors, we can probably make the boost come on a little earlier than it does now.** And if I do not think that the top end reward is worth the low end sacrifice, I will sell it off and convert to a G30, because the smaller ones of those come on boost very nicely on a 25 and make more power than I realistically need or want. The only reason I didn't do it at the time the turbo blew up is that I wasn't ready to sink a lot of money into an Artec manifold, reverse rotation turbo, the AFM and injector upgrade that would have been immediately compulsory, and the dyno was being problematic.*** It was easier and faster to just put the highflow on. And then, as I mentioned in an earlier post, even that is not "easy", because Tao's highflows use a shorter core than the Hitachi, so the compressor housing moves backwards in the bay, necessitating that all of the pipework had to get modded.

** And maybe just maybe, check the valve clearances and put new shims through, because I have recently seen firsthand on another motor that sloppy clearances on the shims can cost a lot of effective timing and lift and really slow an engine down. 3S-GTE in a Caldina got new shims, closing the clearances from just above the max to right down near the minimum, and it is a massively different car to drive. On boost the better part of 1000 rpm earlier!

[silviaz]

36 minutes ago, GTSBoy said:

Well, yeah, obviously. But then you have a turbo with 270kW "design", meaning it will have the higher boost threshold and lag of a bigger turbo, but only doing the work of a smaller turbo. That's the suck.

That's actually exactly where I am right now, because my stocker exploded and I got Tao to do a highflow for me. I got a low pressure actuator on it and don't push it past ~10 psi or so, where the stocker was being run at ~12 psi. it makes a little more power than the stocker did, but it lags like a bitch. But, if I run any more boost it starts to ping and the ECU goes into panic mode, which cuts all the fun, so it clearly needs to be tuned. But, until such time as I (which is not I, it's my bro-in-law) can actually get the dyno working again, and get some injectors, and do all the swap over of those and the R35 AFM, I can't attempt to use the turbo the way it really deserves to. So what I have now is something that drives worse than what it did before it filled the cat with little pieces of turbine.

I will tune it eventually, and probably only push it up to ~250-270 rwkW, which is pretty close to the max for that highflow anyway. I would imagine that by getting the tune right, and with newer betterrer injectors, we can probably make the boost come on a little earlier than it does now.** And if I do not think that the top end reward is worth the low end sacrifice, I will sell it off and convert to a G30, because the smaller ones of those come on boost very nicely on a 25 and make more power than I realistically need or want. The only reason I didn't do it at the time the turbo blew up is that I wasn't ready to sink a lot of money into an Artec manifold, reverse rotation turbo, the AFM and injector upgrade that would have been immediately compulsory, and the dyno was being problematic.*** It was easier and faster to just put the highflow on. And then, as I mentioned in an earlier post, even that is not "easy", because Tao's highflows use a shorter core than the Hitachi, so the compressor housing moves backwards in the bay, necessitating that all of the pipework had to get modded.

** And maybe just maybe, check the valve clearances and put new shims through, because I have recently seen firsthand on another motor that sloppy clearances on the shims can cost a lot of effective timing and lift and really slow an engine down. 3S-GTE in a Caldina got new shims, closing the clearances from just above the max to right down near the minimum, and it is a massively different car to drive. On boost the better part of 1000 rpm earlier!

Ah ok, reason I asked was for the sake of not having to upgrade everything if the turbo couldn't be capped.

[GTSBoy]

And I forgot to add my *** footnote to the above post, which was that the pipework mods would be even more significant than what had to be done for the highflow. So just add that onto the list. Pipework mods are no killer, just made the tasklist longer at a time when extra tasks were not welcome.