The new Garrett G25-550 turbo
 

Search didnt show anything. Has anyone tried a G25?

Looking at the specs it should be something that wants to compete with Borg Warner EFR's.

https://www.turbobygarrett.com/turbo...series-g25-550

I tried a local shop but they haven't heard anything on pricing yet.

Anyone have any thoughts/Opinions? I feel like Garrett hasnt done much to compete before this. The GTX line etc was a meh upgrade at best

2 grand
hard pass lol

https://www.full-race.com/blog/garre...turbochargers/

Full Race has some info on it. I honestly really like Garrett and have always been loyal to them. Will be interesting to see if they outperform the EFR line which still hasnt blown me away honestly.

I bet garrett loves blind ignorant loyalty.
just like Hydra

In the past Garrett was the mack daddy, I have never once had a garrett turbo fail on me and the results have always been extremely good. My turbo kit came with a Hydra so if it works why should I replace it? I guess I could blow 1200 on a MS3 but the Hydra works so ummm....?

Garrett was never the mack daddy. Garrett just had a near-monopoly on the market and had almost no competitors. Now that the market has some diversity, they are falling by the wayside, and attempting to step up their game to stay competitive.

I don't see this as a strong enough effort, and would never dumb 2 grand to find out, when you can spend hundreds less for a proven winner.

Saying "they aint neva dun me wrong so they legit" is not a valid argument when discussing new innovating technology.

In my opinion Garrett has been the best. We all have our own opinions though. Still will be interesting to see how the "G" series turbos perform.

I haven't really heard of anyone living the efr. It's fantastic on paper but never really puts down the numbers.

$2k is crazy. Guess that ship isn't leaving port..

In unrelated news ... 427wtq 6758 Miata

Holy shite!!

I don't think the G-series are actually available yet, are they?

It will be interesting to see how they stack up against the EFR. On paper, it's got the same performance advantages over the existing GT/GTX turbos.

--Ian

:rofl:

They didn't have models at SEMA, just leaflets. AFAIK the turbine wheel is still nickel-based, not Ti-Al like the EFRs. To me, the turbine wheel is why the EFR works the way it does.

I'm not an ME, but the guys at moto-IQ seem to be excited. Supposedly "Mar-M" for the turbine, whatever that is.

Nerd-O-Scope: Honeywell Garrett?s G-Series Turbochargers

--Ian

andy, welcome back, but seriously stop posting like its still 1996 when you were last here.

Mar-M-247 density 7.8g/cm3 (Garrett G-series)
Inconel density 8.1-8.4g/cm3 (depending on alloy)
Gamma TiAL density 4.0g/cm3 (BW EFR)

A dyno plot is............get this: putting down the numbers, LITERALLY ON PAPER.

Who knew, right?

Rough estimates of maps overlaid; more expensive for maybe a few more peak power? And with turbine metal density nearly double the EFR....no thanks.
https://cimg3.ibsrv.net/gimg/www.mia...8c5a02a8c3.png

It's good that they are trying to compete with the EFR lineup, but considering the price differential I still maintain the EFR is by far the top dog in the turbo world right now.

So far I've only seen one place that's posted a price that's anything other than an obvious place-holder, and that's full-race.com, and their prices on all Garrett turbos are significantly higher than other vendors. IIRC EFRs were stupid expensive when they first came out too, but prices came down a bit. I think it's a bit early to be passing judgement on price/value. :)

As for the inertia of the turbine, the moto IQ article has some interesting things to say about the design of the compressor wheel and the fact that even if the density of the turbine wheel material is higher, the strength is also higher, implying it could be made with less volume of material.

Let's see how it does on an actual engine before pronouncing that it sucks, huh? If nothing else, I'm glad to see Garrett bringing out new products. Competition is good for everyone.

--Ian

I expect the EFR to have better transient response due to the material of the turbine.
On the flipside: the G25-550 is physically smaller in every dimension: compressor wheel, turbine wheel, turbine A/R (0.49 on the T25 housing).
So I am curious to know how spool-up/boost threshold compares to the EFR6258.

I think it's great Garrett is trying to step up to their game but they got a looong way to go. The GTX Gen 1's looked pretty good but struggled in some applications. The Gen 2's got better flow but lost a ton of efficiency. The G25 looks promising to replace my twin GT2860RS (in 911 twin) but alas they don't offer a legacy t25 housing. If I am going through the effort to re-fab things for v-bands it's getting EFR's.

Oh yeah competition is always great. Once they finally catch up hopefully borg responds with the next hotness

So has anybody else been watching for updates on these? ATP only has them in reverse orientation currently.

Curious to see how they put up compared to the EFR series. Which turbine/compressor config would be the best for our application? On other car boards, there seems to be some real interest in these.

They will respond worse.

+1.

everyone wants "real data" and driving experience before talking ****, but in this case...

now hate me! :likecat:

in this case no one still has any, so it's speculation until there is some posted.

so which one of you has one on order?

I'll just lift and shift from my post on another forum November of last years (since opinions are indeed facts.........#amirite??)

In opinion, Garrett turbine wheels were 30 years outdated across the line. The NS111 wheel was great.......20 years ago. Not so much now. An updated compressor wheel can only net you so much gain

If we both have a ball of similar size, but my ball is aluminum and yours is lead, the answer of "which one will hurt more if I drop it on my foot" probably doesn't need an awful lot of data to be answered

HATER!!

:giggle:

Edited my post

Meant to say the engine blew. The turbo remained in tact.

Serious bizzznaaazzz!

no intent to start sh!t here, but the EFR CHRA (using a ruler on a CPU screen) appears to be ~2x longer than the Garrett. Steel is ~2.5x - 3x heavier, but requires a smaller wall thickness... just sayin

I was referring to the turbine wheel. The EFR's wheel is half the density and thus roughly half the weight.

The parallel is to wide, heavy wheels. They are always faster than light, narrow wheels. I don't really care about the weight of the turbo (within reason), but I very much care about the weight of the spinny bits inside.

gotcha, totally agree. Rotating assembly mass is of critical importance.

When it comes to transient response, inertia and efficiency both play a role. A bit more of one can offset the other. The G Series turbine wheels look to be of substantially higher efficiency than the ones they replace. Plus they're higher specific flow -- a given diameter wheel flows like larger one.

Of course, the compressor wheel you pair with it has to be of similarly high specific flow, else turbine-compressor speed mismatch starts kicking your ass. Fortunately it looks as though the G Series compressors are indeed higher specific flow than the ones they replace, with no compromise on surge margin, plus deliver higher efficiency. For a given power target, it is possible you could run a G Series that's one frame size smaller, with the associated reduction in inertia that that entails.

Will a G Series turbine wheel have lower inertia than a similarly flowing EFR wheel? Likely not. But the delta isn't as large as the material density difference suggests since EFR is full backdisk wheel while the G Series is heavily scalloped (full backdisks impart more structure, inertia to the wheel but can raise efficiency a touch). Also an intermetallic wheel (like titanium aluminide) will typically also require thicker blades than a nickel based one (Inconel, Mar M) provided they are to achieve similar resistance to foreign object damage. All else equal, thicker blades reduce flow and increase inertia.

The unanswered question is how does overall turbo efficiency (turbine & mechanical efficiency times compressor efficiency) of G Series compare to EFR for a given application? It is the key flip side of the response coin to inertia.

As an aside to the response discussion, the move to Mar-M 247 is pretty significant. This is the stuff that's used in the highest-temperature applications out there, whether production or motorsport,

@JKay

Agreed on most points. However, you missed one aspect; the mixed flow wheel of the 7163. That is somewhat of a game changer and what accounts for a majority of the 550 WHP capability (yeah, I use that lightly. I have personaly seen more) and efficiency with the response time of a 6758-6258.

I quite seriously had to register just to show people how retarded it is to base inertia performance on density.

And before I get too deep into this, I don't care about brand adherence or what turbo you enjoy sleeping with at night. I don't even care if the new G series ends up being better than the EFR turbos.

Now, the contention here is that "light wheel is always better" and I tend to agree to a point. You also want the wheel to be durable, and blindly copying physical designs without regard to material design has lead to many Chinese products being branded as crap. Engineers spend no small amount of time discussing material design and how it affects their work. OEMs have engineers that inspect materials deep into the microscopic level to measure grain pattern uniformity and abnormality commonality. In fact, these measurements are one of the leading causes of the "wear bell curve" that causes some parts to fail before others which in turn causes the OEMs to push really hard to ensure material consistency because it'll better help them predict failure rates.

Now, regarding the age-old "what material is better" debate. The V8 crowd flocked to aluminum rockers in the late 80's and 90's. Then about twenty years, later everyone switched back... why? Because to get the strength required for a rocker in the right areas, it required significantly more mass further from the pivot points. So the solution was: better designs out of steel. The steel designs had a lot of meat in areas it wasn't needed. Once designs were more optimized, rocker performance of good steel rockers far surpassed the aluminum rockers (of the time). Aluminum rockers are starting to make a comeback, but they're far more advanced and require more tool changes in the machining process, and thus are even more expensive than ever.

But lets analogy for a moment.
Take a string, and tie it to a basketball. Hold the string at 2' from the ball and now try to swing the ball over your head.
Now tie a string to a baseball and hold the string at 12' from the ball and try to swing it over your head.
Which will be harder to swing? The baseball. Why? Because the weight is further from the center. This is inertia 101.

This is exactly why steel generally ends up being better for rockers. The other factor is that steel takes repeated bending more favorably than aluminum, which also further reduces thickness requirements. This is also why we use steel for connecting rods, and why aluminum is only used for con rods in drag racing. The rod absolutely hates changing direction at TDC and it causes massive stress that requires the rods to be insanely fat (so big that an h-beam design is often too big for long stroke engines), just to deal with its short life expectancy. Here again, we see a scenario that the lighter material isn't generally better.

So, all that to say you can never assume that material density will lead to a better design. And I think we see this in the below comparison.


EFR7163 wheel left, G25 wheel right.
https://cimg3.ibsrv.net/gimg/www.mia...ec0d80379f.jpg


Notice that the EFR wheel has heavy thickness tapering as it meets the middle of the turbine? Likely because otherwise, the fins wouldn't stay rigid in transient moments under load. Also, I know I don't have both in my hands with a micrometer handy, but the overall fin thickness of the EFR looks thicker too. Both of these facts already put the aero in the G25's favor because all things equal thinner fan blades always work more efficiently as they're less "in the way" of the air they're pushing. Obviously, other factors come into play, and "all things equal" never is.

The next point is to look at the massive scalloping on the back of the wheel the G25 has. This is a giant amount of mass AT THE OUTSIDE OF THE CIRCUMFERENCE of the circle which will have huge benefits on inertia.

Seeing them side by side you can tell that the G25 wheel is far more "petite" than the EFR, but anyone looking at material densities should already know that because less dense materials are generally always designed thicker when comparing similar materials in similar use cases. The same is true when comparing variants of plastics, Chromoly versus DOM for cages, or bread for a sandwich (trust me, chefs think about these things because nobody wants a sandwich to fall apart nor have the bread interfere with other flavors).

So no, we won't know "which spools faster" until someone A/B's them. Which is why I've been scouring the internet. Which is how I found this thread...

As a side note, $2k for a turbo isn't insane in my book. That's what it cost me to get an OEM Subaru snail for my Outback (because some people actually prefer to leave things stock when they're not a project). If saving $500 on one turbo matters that much to you, then I don't think gaining or losing 100-400rpm of spool in 3rd gear should change your decision. BW makes great turbos. And it looks like Garrett is trying to claw some market back in this segment. We all benefit from this.

The theory is nice, sure. Scallops good, thin blades good, all good. The reality, however, is that T25 turbine wheels has had very similar scalloping for decades. Perhaps not identical from an airflow standpoint, but certainly close enough from a rotational inertia standpoint to call them identical.

Here's a GT2560R wheel for reference. Very similar scalloping. I did my best here to find what I believe is an OEM wheel, vs. a stock photo of a Chinese copy. I believe this is either an OEM Garrett Aftermarket or OEM Nissan GT2560R wheel.

Attachment 229656

And yet, empirically, the EFR responds substantially better to throttle inputs, despite being ~4mm larger in diameter. So I'll go out on a limb (pretty stout limb IMO) and call bullshit on scalloping making a substantial enough difference to overcome the difference in material weight.

As far as blade thickness, they sure look similar enough to me, perhaps the EFR is a skosh thicker, but certainly not 2x except maybe at the leading edge, where it would have almost no impact on rotational inertia. It's also impossible to see the profile of the blade as it hits the shaft.

It's also misleading at best to state in this context that "less dense materials are generally always designed thicker". We are not comparing steel and aluminum here, so your rocker example is completely out of place. A more apropos comparison would be Titanium. Titanium has roughly 60% the density of steel, but a piece of titanium with the exact same dimensions as a piece of steel will have 95% of the strength of that piece of steel. Add a few thou to make up the gap, and you have a part which has exactly the same strength at perhaps 2/3rds the weight, conservatively. I don't know if titanium rockers exist, but if they did, I'd bet they'd weigh a lot less than steel and cost an eye-watering amount of money as well.

Titanium Aluminide is in the same ballpark as Inconel when it comes to strength at temperature, so unless Mar-M is significantly better than either one (doubtful, and no info on Matweb yet), it's perfectly reasonable to infer weight from density, given that the two parts are designed to function in the same environment. The Mar-M part would have to be substantially smaller to achieve the same inertial performance as the EFR. Not "feathery", but like 2/3rds the overall size.

One last tidbit on turbine blade thickness as it relates to flow. Yes, thick blades are in the way of the air. To combat that, all EFR turbines are larger in size than their Garrett counterparts. Like, a lot larger. A GTX2863R has a 53.9mm turbine and a 63mm compressor, an ER6258 has a 58mm turbine and a 62mm compressor. If you're well-versed in turbo sizing, and you seem like you might be, you'll know that 4mm on the turbine wheel is huge. The EFR can get away with that because of that low weight. Empirically, they seem to have absolutely no problem moving nigh-unbelievable amounts of air. I've lost count of how many B1-frame EFR Miatas have cracked the 400whp mark, and I know of at least 3 that have cracked the 450whp mark, all on that 58mm turbine wheel through a 0.64a/r housing. That does not indicate a restrictive turbine side in the slightest.

Empirically, the EFRs outperform a similarly-sized Garrett GTX. They do so substantially when it comes to throttle lag and torque linearity. The T25-550 gives me absolutely no reason to believe they are substantially better than the outgoing GTX units in this respect. I might be proven wrong, but I don't think I will be.

Come on. This Garrett marketing line says it all.
G Series models offer previously unimagineable power levels by frame size and improvements in spool!
nuff said -they're not saying the G Series is offering previously unimaginable improvements in spool!

Also, the selling features of this turbo seem to be small size, and high temperature. Sounds like a good OEM solution, where you want to run 14.7:1 under boost under a tightly packed hood.
This turbo needs to spin quite a bit faster to flow the same as the EFR, which also makes it hard to compare.

I guess we will eventually find out how this turbo performs, but I would not want to be an early adopter on this.

PS. I am currently sleeping with a Garrett turbo. :(

I like how he made an account to "school us" yet speculating just like the rest of us and has no a/b results just like the rest of us.

carry on

Well, there's three pages worth of speculation now, so criticizing the critic when we still don't have much data seems a bit on the nose.

And I'd say my pocking and prodding had the desired effect, exactly. I got a knowledgeable explanation behind one's opinions backed by true findings, which is far more constructive than many of the one-liner "EFR pwns all" responses that have been prevalent.

Responses in bold. And I truly thank you for the time you took to give a knowledgable response instead of just name calling against brands or opinions.

On rebuildability, BW won't do it because they just aren't set up for it, but a couple of members here have had chipped turbine wheels (chipped due to mechanical damage during housing removal) replaced by Mike Franke at Southeast Power Systems. They are AFAIK the only authorized EFR rebuilder in the country.

On OEM use, TiAL wheels are used in the current-gen Panamera Turbo S. Porsche has been an early-adopter of BW's pointy-end tech for a while, at least as far back as their use of Borg BV50s on the 997TT, which was AFAIK the first use of variable-vane turbo tech on a gas engine (someone will be along shortly to tell me that some obscure French car from the early 90s was actually first, I'm sure).

I agree that the EFR wheels likely aren't half the weight, but I bet they get closer to that number than you might expect. The anecdote I was told was that the 58mm turbine wheel weighs the same as the 62mm aluminum compressor wheel. I didn't mean to imply that the wheel was actually half the weight, although I can see how it would be taken that way. I meant to imply a drastic difference in weight as opposed to an exact figure.

Tell you what, though - if you (or anyone else) has a bare turbine wheel and shaft with a T25 Garrett turbine wheel attached, throw it on an accurate scale and weigh it. I happen to have a bare EFR wheel and shaft floating around the shop somewhere that I can dig up and weigh.

Props :likecat:

in for shaft comparisons.......wait

:D

Seriously though: I believe we were all similarly skeptical of EFR when they just hit the scene and none of us really tried em. So there is hope for the garrett

I would have been skeptical too had I not driven Evan Witty's car at the end of 2011. He had one of the very earliest 6258s on a nigh-untuned stock '94 longblock, but it was still good enough to let me peek at the potential. I was hooked then. AFAIK Soviet bought that setup from Evan, swapped the early defective 6258 under warranty for a revised 6758, and did his 450whp+ setup.

Mar-M (246, or 247... probably the former) is a nickel based superalloy with the biggest material composition difference from Inco 713 being a big dose of cobalt (something like 10%!). There are other differences, but that's the biggie. Mar M is of insignificantly lower density than Inco. The move to Mar M is undoubtedly to double down on robustness to adverse thermal conditions.

Simply weighing the turbine shaft-wheel assemblies won't tell you much about inertia, which varies with the fourth power of diameter. Measuring inertia empirically is a bit more complex but is an established process (trifilar torsional pendulum). And again, inertia is only one part of the story when it comes to transient response (the rest being overall turbocharger efficiency which is an outgrowth of aero efficiency on turbine and compressor each, and the interplay, match-wise, of the two).

Titanium aluminide has existed on the fringes of the OEM turbo world for quite some time. As for VNT gasoline, Sav is right that some pedantic asshole will point out that the first one was the Shelby Lancer CSX in the '80s. It had a VNT25.

:giggle:

So we just got a kit for the FiST platform.

http://www.fiestastforum.com/forum/t...sh-motorsports

Question is... when are we gonna see one of these ready for the NA/NB?

Has anyone run one of these on a Miata yet? I've seen some good results from the 0.72 a/r on VW engines, but nothing on a Miata or with the teeny 0.49 T25 housing.

I know it's not a BP, but I saw a dyno from a G25-550 on a Ford Sigma 1.6 GTDI engine. 1.9 bar of boost on 99 RON (93 US R+M/2) = 455bhp, 350tq and 200tq by 3450rpm. They did another run on 110 RON which made 503bhp but they didn't show the plot. They don't state the A/R, but it's a vband setup so likely the 0.72.

That would make for a serious engine in a miata despite only being a 1.6.

https://cimg9.ibsrv.net/gimg/www.mia...055a678694.jpg

I can't see how to link it, but it's on the "EFI Parts" Facebook page from November 2019.

Still wondering if it's worth the cost to go w/ an EFR series. A 6258 would put me back roughly ~$1500 + a new Manifold/DP + adapting current exhaust ~$1100 for a total cost of ~$2600. A 25-550 is about ~2k which works with my existing setup. If the 6258 provides significantly more low end power, then I would say it's worth it for me. I (personally) care more about low end since my car is primarly a daily.

The EFR comes with the nice built in BOV, the 25-550 does not.

The cost is the big problem for me. When all is said and done it is close to $3k in cost to be comparable to the EFR.

I've seen reports that the built in bov leaks with the efr, so a common upgrade is the turbosmart kompact bov. If i do make the jump for efr, i'm hoping that isn't true. It's a small amount in terms of how much the turbo costs but prices start to stack.

I wouldn't say it leaks but it does stay open at certain low throttle situations which causes a very annoying whistle. Borg sells a heavier spring that cost me a ridiculous $35 after shipping. It does solve the problem though.

No EFR dyno I have seen demonstrates where the EFR shines; boost response and boost recovery.

For the few hundred in price difference, that is worth it's weight in gold and makes the car not only much more tractable, but overall a much easier car to drive fast.

Unless I can drive a G550 turbo on the same engine, I am sticking with the EFR for the forseable future. Garrett still hasn't caught up to the Gamma-Ti wheel on the EFR as of yet in terms of weight.

Not saying the G series won't perform however.

EFR sounds like garbage though? I know that sounds like a silly thing to add to the equation, but none of the video's I've seen have impressed me with their integrated BOV. It is less things to worry about when assembling a new kit, but don't think it's worth a swap now that we have better Garret options.

^^ An integrated CRSV is less things to worry about than an external BOV that now one will have to source, get welded to a pipe and have to fabricate the location as well as re circulation?? If you already have one sure, but if starting from scratch, that thought process does not compute

You lost me at "sounds like garbage"......

Yup if your starting from scratch I can see many advantages to EFR. On sounds, I'm talking about the whistle which does have a aftermarket fix.


Example.

The turbine whine you can hear on no-throttle because it's ready to rip pretty much all the time? What's the fix, a muffler?

Seriously, that's not the EFR whistle. The bypass whistle sounds like a duck call.

https://youtu.be/qw0ULYyCcng?t=446

7:08