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He brings up a good point^^ Regardless, I'd want my turbo water-cooled if it's going to see any track time at all.
That's why I brought this up. It's not only really good for the 250-280whp range, it's also a genuine water cooled turbo and lasts forever.
Watterson is right, any turbo can blow up your engine, and I also think the new GBC350 or 2560R (same price?) will meet your goals and expectations the best.
This is a 2860R gen2 @20-21psi 102octane dyno on a cold morning from an early tuning session on the Autobahn with the AFR all over the place after 4,5krpm:
That thing wants to make some jam in the upper rpm range and I don't question the results, that Andyfloyd had with the same turbo a few years ago. For the love of my semi built engine, I stay at roughly 280tq/300whp, but there is a lot of room to grow.
Do you really need this? I would be just as happy, when I have kept my 2560R...
Last edited by der_vierte; 08-17-2024 at 02:37 AM.
That's why I brought this up. It's not only really good for the 250-280whp range, it's also a genuine water cooled turbo and lasts forever.
Watterson is right, any turbo can blow up your engine, and I also think the new GBC350 or 2560R (same price?) will meet your goals and expectations the best.
This is a 2860R gen2 @20-21psi 102octane dyno on a cold morning from an early tuning session on the Autobahn with the AFR all over the place after 4,5krpm:
That thing wants to make some jam in the upper rpm range and I don't question the results, that Andyfloyd had with the same turbo a few years ago. For the love of my semi built engine, I stay at roughly 280tq/300whp, but there is a lot of room to grow.
Do you really need this? I would be just as happy, when I have kept my 2560R...
Well it's a different question when you're upgrading but if you have nothing to begin with, it's another story. Would it be worth paying 770$ to go from a 2560R to a PSR2860 ? As you said, you'd be just as happy with the 2560R and with more money in your pocket.
But if you start from zero?
Updated prices that include shipping tax to compare:
PSR2860 with PSR Billet actuator 7.4psi = 770$
GBC20-300 = 785$
GBC22-350 = 915$
GT2560R = 1055$
What about other things besides spool/response? What's more reliable or easy/cheap to maintain or rebuild? Looking at that 2860 I posted and you think "oh, the power below 3500rpm isn't that good compared to a GBC". But if you see the actual numbers, it's still like 150lbft at 2700rpm and 170lbft by 3000rpm, not a slow car by any means right? I'm wondering how much my 10:1 compression would help the 2860
I've also seen posts advocating *some* turbo lag is actually better, I can't say, my only other turbo car (besides a '99 FD3S which I wouldn't enter into comparison due to rotary and twin turbos) was a 400+ Audi TT that ran a GTX2867.
If I'd have had the knowledge/experience I have right now from the beginning, I would have picked the most responsive turbo out of that group, because they can all support 250whp very easily.
edit: the gbc 300 will be absolutely maxed out and I would only choose this for a B6 with your power goals and some track time in mind.
With a built engine I would give up some spool and go with a PSR G25 or 2860.
It's not that they spool up dramatically slower, but who needs a 450whp turbo for 250whp?
Your compression will make pretty much no difference, besides making less peak power and tq.
Most reliable out of that group should be the water cooled, ball bearing 20 year proven 2560R technology. Pulsars are also not bad, but they fail from time to time.
Garret GBC I don't know. But most OEM turbos are journal bearing and last forever, so I don't think you would have any problems with them anyways
Real good info in this thread, thank you der_vierte for your take on turbo sizing.
I was considering a GBC20-300 for my NA8 but maybe the GBC22-350 would be a better choice.
I like the idea of no extra water lines, it's my daily and I'm okay with cooling down before shutoff.
I live in a temperate environment, rarely gets above 25C here.
725€ tax included! 609€ without tax + 29€ shipping, but Cyprus is EU, right?
Can't find a better deal... GBC350 is even a bit cheaper, but that's up to you.
Better bearing/cooling vs slighty better aero.
Looking at the compressor maps, they are so evenly matched, I don't know what to recommend.
GBC has slighty smaller compressor, but bigger turbine. You'll be happy with either of those great turbos.
Real good info in this thread, thank you der_vierte for your take on turbo sizing.
I was considering a GBC20-300 for my NA8 but maybe the GBC22-350 would be a better choice.
I like the idea of no extra water lines, it's my daily and I'm okay with cooling down before shutoff.
I live in a temperate environment, rarely gets above 25C here.
Stock engine, pump gas, no track time, 220whp I'd say GBC300, but if you want to max it out like OP, go with the GBC350, if you absolutely don't want to run coolant lines.
725€ tax included! 609€ without tax + 29€ shipping, but Cyprus is EU, right?
Can't find a better deal... GBC350 is even a bit cheaper, but that's up to you.
Better bearing/cooling vs slighty better aero.
Looking at the compressor maps, they are so evenly matched, I don't know what to recommend.
GBC has slighty smaller compressor, but bigger turbine. You'll be happy with either of those great turbos.
Stock engine, pump gas, no track time, 220whp I'd say GBC300, but if you want to max it out like OP, go with the GBC350, if you absolutely don't want to run coolant lines.
Coolant lines aren't the end of the world, I suppose. Proven is proven. I do like the idea of doing something new, though.
Do you believe the GBC300 could make a flat torque curve from when it first spools up until 7,200 at 0.5bar?
The "Miata Turbo Airflow Spreadsheet" and the GBC20-300 compressor map seem to lead me to believe so.
My ultimate goal is to have a predictable and a quick, but not insane, first turbo experience.
Coolant lines aren't the end of the world, I suppose. Proven is proven. I do like the idea of doing something new, though.
Do you believe the GBC300 could make a flat torque curve from when it first spools up until 7,200 at 0.5bar?
The "Miata Turbo Airflow Spreadsheet" and the GBC20-300 compressor map seem to lead me to believe so.
My ultimate goal is to have a predictable and a quick, but not insane, first turbo experience.
I mean it's two banjo bolts and 3ft of rubber hose
The nature of these engines is to taper off with the tq at ~5k rpm, so to have a flat tq curve and a supercharger-like powerband, you want to port the wastegate HEAVILY for accurate boost control and then taper in the boost from 0.5 to roughly 0.7 bar and also experiment a bit with timing. I would run conservative at peak and a little bit more aggressive up top. Will get you to around 220-240whp in the end.
My 2860 is setup the same on gate only with a 0.45 bar spring, then it creeps slightly to 0.7 bar (cnc ported housing and hand ported flapper, maybe I could do more) and its super predictable and linear power. I believe it's 225whp up there, but that's not, where it's very efficient
08-17-2024, 01:48 AM
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