The Official Garrett G25 Turbo Talk (550/660)

[1on1]

I am not sure if you guys are aware but it appears Garrett released a new line of turbos in a T28 housing. It appears these turbos are meant for 1.4-3.0 liter engines and can produce 550/660 horsepower. Maybe this might be a replacement for the gt2871r and want to know what you guys think. Like how they come with a v-band setup but it appears, these turbos are simply made for top mount manifolds. Has anyone here have or plan to purchase this turbo for their build?

G25-550:
https://www.turbobygarrett.com/turbobygarrett/turbochargers/g-series-g25-550

G25-660:
https://www.turbobygarrett.com/turbobygarrett/turbochargers/g-series-g25-660

[Kingtal0n]

I remember back when they released the 'amazing' gt25r or whatever that supported 350bhp. now like ten years later its double?! I think that is a good benchmark for where we have gone from.

wow
https://www.turbobygarrett.com/turbobygarrett/sites/default/files/styles/turbochargers_-_compressor_map_450x520/public/media/import/compressor_map/G25_550_Comp_Map.jpg?itok=lfA7K_bA

This one on a 2.0 looks pretty amazing.
07psi would take you to 300rwhp
15psi ""390rwhp
21psi ""430rwhp close to max output

A good street setup with a little N2O fogger and E85 or methanol would put that 2.0 over 500whp on most dyno

[1on1]

yea, their new line up is pretty nuts. Small form-factor turbos that produce high hp. My concern is because I saw the videos from Adam LZ and Monky London, and it caught my interest.

Adam LZ (G25-550):
mLmNd8CWvGo?t=364

Monky London (G25-660):
G1eCmJh_UME?t=436

[Croustibat]

I have been waiting for feedback on these for quite some time now. Thing is, between pricing and lack of availability, it looks like not many people buy them.

And i do not feel like being a guinea pig for that kind of money. So... still waiting. i'd go with a g25 550 on a 1.8L engine, target is around 450whp with some room on e85 with headwork, solid lifters and cams among other things. I'd like to go bottom mount though.

[KiDyNomiTe]

I am curious about these. I have been more than happy with my GTX2863, coming from a GT2871. I can't imagine what this feels like.

[jedi03]

this is a great idea...im curious as the super charger guys found out that they are good til a point then they make no power I was told the speed of sound as it sucks no more air...but will be good to find out if this is legit!

[brndck]

they should let me beta test the larger one. if I can get 500whp on 91 octane, at 18psi, I'd be a happy camper. Hopefully they'll release more info and pricing soon

[1on1]

I can't wait for updates from either youtubers until they tune their cars. I am wondering if this would be a nice replacement for a stock sr20det with slight mods (retune, z32, and 740cc).

[Kingtal0n]

they should let me beta test the larger one. if I can get 500whp on 91 octane, at 18psi, I'd be a happy camper. Hopefully they'll release more info and pricing soon

for fun
It doesn't really matter how much boost once the turbo has enough capacity. It matters how much RPM you spin the engine.

For example say you limited rpm to 6000. Well no matter how much "bigger and better" the turbo gets, even the best turbo in the world at 18psi is not going to touch 500whp with a 2.0L engine.
Ex math,
122x6000/3456 = 211CFM * 0.069 = 14.6lb/min * (2.22) = 320 horsepower without drivetrain losses.


So now lets take a 2.0L engine at 7psi with a "very efficient turbo" except this time we spin the engine to 9,800rpm

122x9800/3456 = 345.9 * .069 = 23.87lb/min * 1.5 = 358bhp

So less boost, more power, because more rpm.

but you knew that.

[NiSilS14]

One of the local tuners here in CO did a STi with g25-660. 501whp @26psi with e85. I could imagine this spooling better and making better power on a different 4cyl.

eoem4Gv06ec

[brndck]

for fun
It doesn't really matter how much boost once the turbo has enough capacity. It matters how much RPM you spin the engine.

So less boost, more power, because more rpm.

but you knew that.

Very true! But thank you for taking the time to demonstrate WHY it works out this way!

[tuzzio]

I'd love to see one perform on a pump gas KA.

Wish E85 was more available in my area, cause I'd turn my 3076 to the fuckin moon

However, these are a seriously fucking stout turbo for a T2 frame.

[brndck]

I'd love to see one perform on a pump gas KA.

Wish E85 was more available in my area, cause I'd turn my 3076 to the fuckin moon

However, these are a seriously fucking stout turbo for a T2 frame.

yeah, def with the added displacement of a KA over an SR, the torque curve with the 660 would be fatty!

[derass]

Doesn't it get to a point where the small T2 turbine wheel and housing become too restrictive?

[tuzzio]

Doesn't it get to a point where the small T2 turbine wheel and housing become too restrictive?

Yes, but this is a prime example of how manufacturers raising the bar of efficiency.
Most people upgrade before maxing a turbo out, anyways. 450 on a T2 framed turbo is stout. The fact that 500+ is even possible speaks volumes.

When most people think of 500HP they think of something like a 3076. Companies releasing a smaller turbo that is more efficient is the coolest thing.

[e30gangsta]

One of the local tuners here in CO did a STi with g25-660. 501whp @26psi with e85. I could imagine this spooling better and making better power on a different 4cyl.

Ej's are so difficult to make power on. I would love to see this turbo bolted up to a k24 or something similar.