GT2554 - the turbo that get's no respect
#1
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GT2554 - the turbo that get's no respect
So I'm trying to make a final decision about either the BEGi S2 or S3 systems; the only difference being the S2 has the GT2554 and the S3 has the GT2560 turbo. The system I end up with will be used on the wife's '95 M/T daily commuter and my weekend scratcher. We're in California so that means 91 Octane and no funny business under the hood. 185 brake hp is the initial goal, then perhaps a bit more after navigating it's first smog test.
Anyway, I printed out both turbo efficiency curves and at 8psi boost = 1.8 pressure ratio, and 20.4 lbs/minute flow rate both the 54 and 60 turbos look great; likewise up to about 225 hp, after which the larger 60 looks like it begins to become the better choice.
But, I've yet to find anyone who really thinks the 54 is a good choice, even considering my modest objectives. It's like the Rodney Dangerfield of turbos. Mostly it's damning by faint praise, like, "it's a sweet little turbo but really you want the bigger one", but sometimes it's more like, "don't bother, you'll want the larger turbo real soon anyways." Sometimes I'm left wondering why they even sell them; the cost difference is $69. Hell, that hardly fills the tank any more, but yet for some strange reason I'm still curious about them and how they'll run.
I know some of you are running 54's, and some of them are making way more power than I'm looking for right now. Maybe some of you have even run both, and can fill me in on their differences. How do you you folks like them and would you do it again, or is once enough?
Oh, yeah. I asked this question in the Noob section, and some of you have already given me your feedback. I really appreciate your advice, Samnavy, Rafa, and Braineack! But understandably there's not much traffic there so I'm casting with a larger net this time cause this question is still bugging the hell out of me.
Anyway, I printed out both turbo efficiency curves and at 8psi boost = 1.8 pressure ratio, and 20.4 lbs/minute flow rate both the 54 and 60 turbos look great; likewise up to about 225 hp, after which the larger 60 looks like it begins to become the better choice.
But, I've yet to find anyone who really thinks the 54 is a good choice, even considering my modest objectives. It's like the Rodney Dangerfield of turbos. Mostly it's damning by faint praise, like, "it's a sweet little turbo but really you want the bigger one", but sometimes it's more like, "don't bother, you'll want the larger turbo real soon anyways." Sometimes I'm left wondering why they even sell them; the cost difference is $69. Hell, that hardly fills the tank any more, but yet for some strange reason I'm still curious about them and how they'll run.
I know some of you are running 54's, and some of them are making way more power than I'm looking for right now. Maybe some of you have even run both, and can fill me in on their differences. How do you you folks like them and would you do it again, or is once enough?
Oh, yeah. I asked this question in the Noob section, and some of you have already given me your feedback. I really appreciate your advice, Samnavy, Rafa, and Braineack! But understandably there's not much traffic there so I'm casting with a larger net this time cause this question is still bugging the hell out of me.
#6
Haven't had it on the dyno yet, but I would think I'm in the 200whp range. I've got a shitty tune on the car right now, and a pretty restrictive exhaust. I have traction issues in 1st and 2nd running 215/50/13 v710. It doesn't have that kick in the *** my TD04H-15G did, but I know that the car is faster now. The power delivery is so different it really doesn't feel like the same car as it did with the Greddy kit. Yes I know comparing the Greddy to a 2560 is not even remotely a good comparison.
The GT2554R is the **** in my book!
The GT2554R is the **** in my book!
#8
Idk what the lb/min flow rate of the 1.8L is at 250hp but the GT2560R looks like its effiecient in a much broader range of pressure ratios and flow rates. The GT2554R looks like its a bit smaller of an area to work with. But for a street car if you want that instant power and drivability I would say the GT2554 would work well because the boost would come on quicker, but I've heard the spool difference between the two is barely noticable. But IDK from experience, someone whose driven both would have to comment.
#9
i have a 2554R on my 1.8L and im very happy with spool time and HP numbers. i dyno'd 180 whp and 175 wtq @ 7psi w/ walbro 190 fuel pump, 2.5 inch exhaust (with cat) and stock injectors. i have since put bigger injectors, turned the boost up to 10 psi and took out my cat converter. if i had to guess my power now id guess around 195ish/200whp? oh and this was on a dynojet and running off the rising rate fuel pressure regulator.
#13
Assuming both are set up and tuned properly:
GT2554 Lag is not part of its vocabulary, there simply is none. Better low end torque than any of the very well set up MP62 hot and coldsides I've driven. At 10-11 psi they are magic. Weak top end without an I/C past 3rd gear (heatsoaked intake tubes). With a good over the rad I/C, it's a close to a perfect powerband and response as I have ever driven in a Miata.
GT2560 Very little, but always some lag. About 60 more hp potentially. Good at 10psi, but really happiest at 12-14psi.
I have driven maybe 15 different 2560's and have yet to experience one that had zero lag. Personally, I hate even the slightest bit of lag. Faster on the track, sometimes yes. More fun, never.
Building a street car, I'd always choose the GT2554R. Building a pure track car, a GT2871 and a stroker. The GT2560 is perfect for neither IMO.
GT2554 Lag is not part of its vocabulary, there simply is none. Better low end torque than any of the very well set up MP62 hot and coldsides I've driven. At 10-11 psi they are magic. Weak top end without an I/C past 3rd gear (heatsoaked intake tubes). With a good over the rad I/C, it's a close to a perfect powerband and response as I have ever driven in a Miata.
GT2560 Very little, but always some lag. About 60 more hp potentially. Good at 10psi, but really happiest at 12-14psi.
I have driven maybe 15 different 2560's and have yet to experience one that had zero lag. Personally, I hate even the slightest bit of lag. Faster on the track, sometimes yes. More fun, never.
Building a street car, I'd always choose the GT2554R. Building a pure track car, a GT2871 and a stroker. The GT2560 is perfect for neither IMO.
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#15
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I run the same compressor wheel as the 2860, with a larger turbine (journal bearing T3).
I have driven in a few miatas with small t25 and while i love the low end, i hate the top end. but emilio is right, they are a blast!
with that being said, id pick a 2860 over a 2560, since they both has the same compressor wheel and the 2860 having a larger turbine, it will make more up top. If setup correctly I don't see why it cant spool just as well, hell my t3 makes 13psi at 3800RPM. Based on my dyno plots, I have more low-end than most 94-05s with 2560s.
I have driven in a few miatas with small t25 and while i love the low end, i hate the top end. but emilio is right, they are a blast!
with that being said, id pick a 2860 over a 2560, since they both has the same compressor wheel and the 2860 having a larger turbine, it will make more up top. If setup correctly I don't see why it cant spool just as well, hell my t3 makes 13psi at 3800RPM. Based on my dyno plots, I have more low-end than most 94-05s with 2560s.
#18
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For mere mortals like me, your turbo (which by the way is the one I have in my car right now) is not the best option. I see most of my car's power coming in only after the RPMs are above 4,000.
I would suggest the 2560 in the case of the OP. I think the small difference in spool is going to be negligible and he will have the chance to get more whps out of his car as he learns to tune it.
I issue I wanted to comment on for the OP to think about: one good thing that big turbos have is that they're more forgiving when anyone trying to tune the car makes a mistake. They don't stress the engine as much as the smaller ones.
#19
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This is great information, gentlemen, and I appreciate all of your input very much. There's no other place I could have gotten this much useful information, from so many sources, so quickly. Thanks to everyone!
Using Garrett's approach, 250 brake hp requires almost 16 lbs boost (2.38 A/F ratio) and a 27.5 lbs/minute flow rate. Plotting that on the GT2554R efficiency chart puts the point way at the upper right of the very last line, and at the 60% efficiency level. Maybe it's doable, but only barely, and a very big intercooler is probably a good idea.
On the GT2560R chart the point is also at the upper right corner, but right between the 72% and 73% efficiency lines; it's a good match for those numbers. Any more HP and you're looking at the next size up.
By the way, J.T., do you drive a white NA with blue racing stripes? Saw one yesterday going through Sacto.
On the GT2560R chart the point is also at the upper right corner, but right between the 72% and 73% efficiency lines; it's a good match for those numbers. Any more HP and you're looking at the next size up.
By the way, J.T., do you drive a white NA with blue racing stripes? Saw one yesterday going through Sacto.
#20
Na I don't have a car at all :( lol
I found max boost and am gonna guess that it doesn't quite take 16psi since theres people doing it lower. I would do the calculations but I'm a lil lazy.
Edit: I'll put my foot in my mouth, I threw some numbers at the equations and came up with around 15psi. So a PR of right about 2. my bad
I found max boost and am gonna guess that it doesn't quite take 16psi since theres people doing it lower. I would do the calculations but I'm a lil lazy.
Edit: I'll put my foot in my mouth, I threw some numbers at the equations and came up with around 15psi. So a PR of right about 2. my bad