Need some advice on "Godspeed" turbochargers and GT2554R equivalents.
#21
Elite Member
iTrader: (13)
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 6,760
Total Cats: 631
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Full boost arrives on my bp4w w/ t25 around 3600rpm, although I'm way up in altitude so I have no idea how that compares. Certainly spools faster than my old 1.6 greddy by quite a big margin.
#22
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
pretty sure the sr t25 is not .86 scott
the older turbos are all journal bearings, garett sells the newer ones for s13's that are ball bearings (gt2560r) the ball bearing is shown by the R in the name. garrett doesnt sell the old journal bearing turbos.
http://www.turbobygarrett.com/turbob...R_466541_1.htm
Redtop - Garrett gt2560
Journal bearings.
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Blacktop - Garrett gt2560
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
The turbos are exactly the same except one is newer.
s14 sr20det
gt28/25 hybrid turbo
gt25 compressor side and gt28 turbine side.
Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
http://www.turbobygarrett.com/turbob...R_466541_1.htm
Redtop - Garrett gt2560
Journal bearings.
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Blacktop - Garrett gt2560
Compressor: T-25, 60 trim 56mm BCI-1 compressor.
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Journal bearings
The turbos are exactly the same except one is newer.
s14 sr20det
gt28/25 hybrid turbo
gt25 compressor side and gt28 turbine side.
Compressor: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
#24
Senior Member
Thread Starter
iTrader: (11)
Join Date: Sep 2007
Location: Killen, AL, 35645
Posts: 794
Total Cats: 10
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
It actually performs quite well on teh 1.6L it's not oversized at all.
The compressor output is similar to that of a 2554, but the T3 turbine provides more flow up top, so you can still make plenty of top-end with it (crapping out around 250).
I've driven too many 1.8L setups so I got spoiled, but that T3 was running very well on my 1.6L, better than more other turbo setups in regards to the spool/tq. I was making ~240rwtq at ~4100RPM.
The .86 turbine of the SR20 T25, while a smaller turbo, kills the spool. It already doesn't spool that fast on a 1.8L. If you could find a T25 like an SR20 one that doesn't have such a large turbine A/R, it would be a better match for a low boost setup however.
The compressor output is similar to that of a 2554, but the T3 turbine provides more flow up top, so you can still make plenty of top-end with it (crapping out around 250).
I've driven too many 1.8L setups so I got spoiled, but that T3 was running very well on my 1.6L, better than more other turbo setups in regards to the spool/tq. I was making ~240rwtq at ~4100RPM.
The .86 turbine of the SR20 T25, while a smaller turbo, kills the spool. It already doesn't spool that fast on a 1.8L. If you could find a T25 like an SR20 one that doesn't have such a large turbine A/R, it would be a better match for a low boost setup however.
If it comes to me and it grenades in a few day, I won't hold it against you...
#25
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Scott, that 240whp @ 4100rpm was on a 1.6 with a t3 super 60, am I correct?
the revvy cam profile that everyone loves on the 1.6L really prevents then from performing well under 3.5K.
#30
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
yep, he saw similar results with it:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/98352-need-some-advice-godspeed-turbochargers-gt2554r-equivalents-turbo_miata_dyno_4_2011.jpg?dateline=1388151045)
I think he was only on a 2.5" exhaust however.
now compare the TQ/Spool of a 1.6L with the SR20 T25 with a 3" exhaust:
![](https://www.miataturbo.net/attachments/dynos-timesheets-21/68304-artech-1-6-10-psi-2d010470-8960-43cd-9ff6-6c8c3d948344-12582-00000665125cad13_zpsd402f2a1-jpg?dateline=1361513000)
add like 10-12% to this to match a dynojet.
And it's not even that it spools any faster, it's the power it provides when it's spooling is much greater than the SR20 T25 (you can see this on my dyno comparing a S60 to the 45 trim). I've never seen an entirely impressive 1.6L SR20 T25 dyno plot, but like I said, they perform GREAT on a 1.8L.
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/98352-need-some-advice-godspeed-turbochargers-gt2554r-equivalents-turbo_miata_dyno_4_2011.jpg?dateline=1388151045)
I think he was only on a 2.5" exhaust however.
now compare the TQ/Spool of a 1.6L with the SR20 T25 with a 3" exhaust:
add like 10-12% to this to match a dynojet.
And it's not even that it spools any faster, it's the power it provides when it's spooling is much greater than the SR20 T25 (you can see this on my dyno comparing a S60 to the 45 trim). I've never seen an entirely impressive 1.6L SR20 T25 dyno plot, but like I said, they perform GREAT on a 1.8L.
#34
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Can you link the exact turbo on ebay they went with?
Is this the same? T3 T4 Turbo Charger Trim 50 A R 63 AR T04E Turbocharger | eBay
Is this the same? T3 T4 Turbo Charger Trim 50 A R 63 AR T04E Turbocharger | eBay
#36
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Can you link the exact turbo on ebay they went with?
Is this the same? T3 T4 Turbo Charger Trim 50 A R 63 AR T04E Turbocharger | eBay
Is this the same? T3 T4 Turbo Charger Trim 50 A R 63 AR T04E Turbocharger | eBay
#37
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Ive been all through your threads brain and underdogs build threads, ive been searching. They are all from 2010-2011 and the ebay links have expired. Sorry im trying my best >.<
Edit: Think I nailed it in an old thread. The guy posted the exact specs.
http://www.ebay.com/itm/GSP-T3-Turbo...3a7d7a&vxp=mtr
Seem right?
Edit: Think I nailed it in an old thread. The guy posted the exact specs.
http://www.ebay.com/itm/GSP-T3-Turbo...3a7d7a&vxp=mtr
Seem right?
Last edited by Fatvod; 12-31-2013 at 11:35 AM.