Garrett G Series

[Kinkstaah]

1 hour ago, ActionDan said:

I shy away from EFR in track conditions due to questions around wheel speed/heat capabilities. It seems EFR are absolutely the king of the street though, response/power etc. 

Cmon.

This is due to people on SAU (and all JDM people) picking appropriately sized turbos for a 5 second pull and the best results on a dyno or the street.

"I want full boost at X rpm, and X power, and I will use the smallest possible turbo to do it!"

Garretts have historically been a little bit happier to take that abuse.

Turbos sized for track use are always bigger than the above quote. EFR's are used on Indycars. EFR literally stands for Engineered For Racing!

[No Crust Racing]

*shrug* I have no first hand experience so I can only go off what I see online. 

I'll prob go GTX2 for abuse factor and price, I have dumped too much coin on this long block already lol 

[Dose Pipe Sutututu]

I would like to experience a car with a properly setup G Series with a TS housing (non on the market yet, unless non-Garrett), I would assume the transient response would be just as good as an EFR if not better.

I've driven a S15 with a TS 6758 and was very impressed (however it was also a 2.2L SR20)

And agreed with @ActionDan I rather not have to always worry about being within the operating parameters and stressing/worrying about the shaft speed every time the car is started.

And this is a Garrett thread, there's an EFR thread for all you guys to talk about how great the turbo is.

[robbo_rb180]

@Plattsy has now fitted a G30 to his car and from Dyno and track results its impressive.

 

[Kinkstaah]

4 hours ago, Dose Pipe Sutututu said:

I would like to experience a car with a properly setup G Series with a TS housing (non on the market yet, unless non-Garrett), I would assume the transient response would be just as good as an EFR if not better.

I've driven a S15 with a TS 6758 and was very impressed (however it was also a 2.2L SR20)

And agreed with @ActionDan I rather not have to always worry about being within the operating parameters and stressing/worrying about the shaft speed every time the car is started.

And this is a Garrett thread, there's an EFR thread for all you guys to talk about how great the turbo is.

This is a Garrett thread, but were people aware Garrett have also mentioned maximum shaft speeds the entire time? It's just that BW were more open about it. Everything ultimately has a limit. The G25 also has a speed sensor option as well... and I think it was just BW pioneering putting a sensor in there for people to use that lead to people being mindful of it and then viewing it as a limitation..

I'd personally pick a G25 purely for packaging, seriously. Heat and lines and shit is also a thing!

This is a 400+ rwkw SR20. I mean you'd have to have a pretty damn good reason to argue for anything else than a G Series in a modified road car right now where you have to consider space at all, for any reason.

[No Crust Racing]

Tidy.

[Dose Pipe Sutututu]

Any dose videos?

[cliptonz1]

Anyone running a g35-900 yet?

[IB_8229]

Folks, reading through the last few pages of posts here, let me chime in with my personal experience on not one, but two Garrett G35-900 turbos i have been through. The first failed at ~2030 km. the second failed at ~2300 km.

The nature of failure was very gradual, with a faint, low frequency "Police siren" or "wooooo" noise accompanying spool, that gradually got louder to the point where the compressor inducer was seen to make contact with the compressor housing, and the shaft was bent. 

Oil feed lines on both were brand new. No oiling issues, as all Oil parameters are monitored. No coolant supply problems either. 

Tune was carried out by the most respected JDM Builder and tuner here in Dubai, and happens to receive, build and tune vehicles from all over the middle east and north Africa.

The first turbo was sent to Garrett for inspection, and they responded with the following: 

880695-5001S

Analysis Findings : Rotor damage - Overspeed -
Technician Conclusion: Turbocharger returned with rubbing wheels vs. contours. Damage of compressor piston rings and overheated of ball bearing as a consequence of Turbo overspeed. During overspeeding cycles, the excessive growth of the compressor wheel may cause a permanent deformation (growth) of the central bore of the wheel, which forms into a barrel shape and is characteristic of a wheel which has been taken beyond its normal operational speed limit. Recommendations: The reason for turbocharger overspeeding needs to be investigated on the vehicle. Possible contributing factors: performance tuning, fuelling problems, poor combustion causing high level of deposits in VNT (vanes blocked). Actuator not controlled correctly: ECU problems, command from ECU not reaching actuator, wiring/connection faults, actuator hose leakage, PWM valve faulty, hose blow-off etc may be contributing factors. Blocked/restricted air filter or hoses.

The turbos failed due to overspeed, and were not happy pushing 2.5 bar of boost for extended durations. Both failures were consistent in nature with respect to how they occurred as well as the time period/mileage as the tunes and driving style were more or less identical in nature. 

I did not bother sending in the second unit for a claim. 

I would recommend Either Garrett GTX Gen 2 as those are extremely robust, (I have run a GTX3071r , and GTX3076r in the past) or Precision CEA to avoid going through similar hassles.

I am now swapping in a Precision 6466 CEA Gen 2.

Hope this helps some of you decide. If you do purchase a G Series Garrett turbo, don't make the mistake i made; do buy a turbo speed sensor, and follow it religiously as part of the tuning process. 

[White GTS-T]

Were you monitoring turbo wheel speed at all? What engine were you running the ~36psi on? 

[IB_8229]

18 minutes ago, White GTS-T said:

Were you monitoring turbo wheel speed at all? What engine were you running the ~36psi on? 

No, as stated at the end of my previous post, i was not monitoring turbo wheel speed at all, which i should have done. The point is to share my experience so people are mindful of monitoring wheel speed as they get tuned and don't make the mistake i did.

This was on a 2015 Subaru STI with a stock displacement and compression 2.5L EJ257. Other Turbos like the Garrett Gen2 and Gen1 GTXs are not as 'delicate' if that makes sense. 

I say 'delicate' because the G35-900 is rated to 900 Crank hp and on my setup, it was making 656 awhp (which is under 800 crank hp).

2 of my friends with similar setups and power levels on the GTX3582 gen 2 rip all day and have been running strong for thousands of km.

[Full-Race Geoff]

thank you for sharing your story, i know it sucks to destroy a turbo (especially 2).  but this type of severe overspeed failure is what happens when you "guess" on a turbo size (not helped by the turbo manufacturer marketing absurd HP capabilities).  The point im trying to make here is proper turbo matching is important.  Your conclusion that the inconel "gtx is a stronger turbo" is something i disagree with

to put this in perspective, (sorry i know its a g series thread) look at the case of a 2.5L EJ25 on matchbot.  i set max rpm to 8000rpm and boost level = 36psi on EFR 8374.  The red dots show the problem of overspeed by 7000rpm and would fail the turbo

But look at the same comparison with EFR 8474.  this is safely operating on the map, away from overspeed and the turbo will live for hundreds of thousands of km use.  

Edited October 6, 2020 by Full-Race Geoff

[IB_8229]

2 hours ago, Full-Race Geoff said:

thank you for sharing your story, i know it sucks to destroy a turbo (especially 2).  but this type of severe overspeed failure is what happens when you "guess" on a turbo size (not helped by the turbo manufacturer marketing absurd HP capabilities).  The point im trying to make here is proper turbo matching is important.  Your conclusion that the inconel "gtx is a stronger turbo" is something i disagree with

to put this in perspective, (sorry i know its a g series thread) look at the case of a 2.5L EJ25 on matchbot.  i set max rpm to 8000rpm and boost level = 36psi on EFR 8374.  The red dots show the problem of overspeed by 7000rpm and would fail the turbo

But look at the same comparison with EFR 8474.  this is safely operating on the map, away from overspeed and the turbo will live for hundreds of thousands of km use.  

I agree with what you're saying; makes perfect sense.

It is a simple case of off the map operation.

How would one go about sizing the turbo for a given application; what factors are involved? 

[Lithium]

5 hours ago, Full-Race Geoff said:

not helped by the turbo manufacturer marketing absurd HP capabilities

SOOOO much this.   Fun detail if you are paying attention, at PR 3.5 the G35-900 has 0 compressor flow advantage over a Gen1 GTX3582R and it drops back rapidly from there.   A Gen1 GTX3582R is probably capable of more power reliably and arguably with better response (for equivalent exhaust housing size) than a G35-900 on a 4cylinder.

Edited October 6, 2020 by Lithium

[burn4005]

G35-900 is rated at 900hp but only flows ~80lb/min. And even less at higher pressure ratios.

They got very optimistic with their ratings compared with previous generations.

An efr8374 flows a full 79lb/min all the way up to a 2.5 bar boost (3.5PR) and they only rated it at 750hp.

I blame Garrett's Marketing department.

 

Precisions.. like 6262 and 6466... who the f**k knows but they must derate them as everyone drives those things waay beyond their rated flow. And they just smoke rather than die.

Edited October 6, 2020 by burn4005

[Dose Pipe Sutututu]

1 hour ago, burn4005 said:

I blame Garrett's Marketing department.

This...

[Full-Race Geoff]

 

20 hours ago, IB_8229 said:

How would one go about sizing the turbo for a given application; what factors are involved? 

 

Turbo Matching is the primary service Full Race provides for our customers.  Most shops do not do this.  Our staff members are trained on how to properly match turbochargers their 1st day working here.  But you do not need us to do it, you can do this yourself by working through the matchbot webpage and watching the youtube tutorials. 

It amazes me how many shops, garrett authorized dealers, and high end race teams we work with never perform proper match analyses.  On a daily basis i am surprised and continue to learn - Many times i will have an assumption, then check the match and realize the assumption was incorrect.  the only way to have confidence is to crunch the numbers

 

15 hours ago, burn4005 said:

G35-900 is rated at 900hp but only flows ~80lb/min. And even less at higher pressure ratios.

They got very optimistic with their ratings compared with previous generations.

An efr8374 flows a full 79lb/min all the way up to a 2.5 bar boost (3.5PR) and they only rated it at 750hp.

I blame Garrett's Marketing department.

 

Precisions.. like 6262 and 6466... who the f**k knows but they must derate them as everyone drives those things waay beyond their rated flow. And they just smoke rather than die.

I have seen precision turbos fail from overspeed also. all manufacturer turbos will fail when overspeed occurs.   The difference is precision turbos have no compressor map, no speed sensor port and are relatively large in diameter. And garrett turbos have these datas but do not have a user friendly interface to calculate operating points.  It seems that many precision owners often select a bigger turbo than necessary (this avoids overspeed) as they focus on top end HP,  but they will sacrifice response or time-to-torque.  

17 hours ago, Lithium said:

A Gen1 GTX3582R is probably capable of more power reliably and arguably with better response (for equivalent exhaust housing size) than a G35-900 on a 4cylinder.

respectfully disagree lith - A friend/ex employee had a GTX3582R vband singlescroll and swapped to G30 vband singlescroll when they were released.  The response was night and day improved with the G30.  GTX35 is not even remotely close in terms of response.  Inertia is king when it comes to this metric

Edited October 7, 2020 by Full-Race Geoff

[Lithium]

1 hour ago, Full-Race Geoff said:

A Friend/ex employee had a GTX3582R vband singlescroll and swapped to G30 vband singlescroll when they were released.  The response was night and day improved with the G30.  GTX35 is not even remotely close in terms of response.  Inertia is king when it comes to this metric

I'm not so surprised about the G30, but I mentioned the G35 - which is what this discussion is about. 

[Butters]

So thoughts on the g35-1050 rating then ?    What do you think is a real rating 

 

Hawkins rear wheel I think was 880hp with the g35-1050 and that was with the biggest rear housing. 

[burn4005]

It's real flow is 90-95lb/min corrected so 900-950hp in old money turbo ratings (or Borg equivalent) so about the same flow as an 8474 which Borg eates as a 950hp turbo. The Garrett is a bit more efficient on the compressor side of things in the meat of the map but that doesn't affect the peak power rating, where both turbos are trailing off 60% at their peak flow.

Edited October 7, 2020 by burn4005