Garrett G Series

[cliptonz1]

So finally got the car retuned on the new setup. Went from a gtx3584rs 1.01 to a G42-1200 1.01.

so have driven a couple times now and in honestly have to say I’m impressed. It feels just as laggy as my old setup considering how big it is. 
 

final numbers were;

1011hp (753kw) @ 37psi e85
923hp (688kw) @ 35psi e85 (high boost)
753hp (561kw) @ 24psi e85 (low boost)
685hp (510kw) @ 20psi on BP98

 

 

 

[Rand0b]

On 7/12/2021 at 9:57 AM, Full-Race Geoff said:

g35 is a big turbo.  i feel like the naming is off because it acts more like a gtx40-gtx42 frame size

On 7/13/2021 at 12:46 PM, Full-Race Geoff said:

the g30 spools like a gtx3076, with HP and airflow in the Gtx35 size range.  They are impressive turbos, but the naming and nomenclature is a little confusing, if it was up to me G25 would be called G30, G30 would be called G35, etc

Can you clarify on this some more?

Are you saying the Name vs HP rating that all the turbos should be bumped up to the next class?

G35 should be gtx40XX due to g35 power output?

the G series is more efficient so at least the g30-770 = gtx3076

why wouldn't the g35-900 = gtx3582?

 

I am on the fence of g30-900 vs g35-900

Built RB25 stock cams 6-700whp goal pump 93 Street car

willing to sacrifice some spool time (~500rpm) 

If the power delivery is better /linear for g35

Edited April 14, 2022 by Rand0b

[R_34]

Same boat for me, I snatched a G30-660 supercore for my RB20, still trying to decide between .61 and .83 A/R, I was vouching for the .83 but the comment of geoff about the G series liking the small A/R more is confusing me.

 

[Full-Race Geoff]

On 4/14/2022 at 11:25 AM, Rand0b said:

the g30-770 = gtx3076

why wouldn't the g35-900 = gtx3582?

I am on the fence of g30-900 vs g35-900

Built RB25 stock cams 6-700whp goal pump 93 Street car

willing to sacrifice some spool time (~500rpm) 

If the power delivery is better /linear for g35

theres a lot to consider when picking a turbo!  compressor diameter to turbine diameter ratio is something i think about a lot aka "match ratio".  traditional match ratios might be 1.07 to 1.11 for OEM turbos (or borgwarner turbos for that matter).  In comparison the garrett GT and GTX turbos had aggressively sized "large" compressors on fairly small turbines. 

GT3076 = 76mm compressor : 60mm turbine (1.26 ratio)
GT3582 = 82mm compressor: 68mm turbine (1.20 ratio)

now that the G series redefined what a given turbine or compressor diameter is capable of flowing, i suggest the thinking around wheel sizes might also change.  This is why the G35-900 (1.11 ratio) might outperform the G35-1050 (1.20) and the G30-770 (1.18) might outperform the G30-900 (1.26 ratio).  this gets complicated by which turbine wheel and housing are being used, on what exhaust manifold and engine configuration.  

to your question: 

G30-770 in old garrett = G3071
G35-900 in old garrett = G3576

for a built 2.5L RB25 targeting 600-700whp you could pick a range, 600?  or 700.  twinscroll G30-770 would be my vote for 550-600.  G35-900 would be a recommendation for 650-700. 

On 4/17/2022 at 1:54 AM, R_34 said:

Same boat for me, I snatched a G30-660 supercore for my RB20, still trying to decide between .61 and .83 A/R, I was vouching for the .83 but the comment of geoff about the G series liking the small A/R more is confusing me.

 

RB20s aren't stellar at spool up and torque generation and G30 turbine flows a ton.... so whatever you can do focus on generating a broad useable powerband, getting the turbo online in the least amount of rev's is usually a net positive.  focusing on dyno HP is usually ego measuring contest.  just my opinion (most people on the internet disagree with me fwiw)

[Lithium]

On 19/04/2022 at 10:48 AM, Full-Race Geoff said:

for a built 2.5L RB25 targeting 600-700whp you could pick a range, 600?  or 700.  twinscroll G30-770 would be my vote for 550-600.  G35-900 would be a recommendation for 650-700. 

RB20s aren't stellar at spool up and torque generation and G30 turbine flows a ton.... so whatever you can do focus on generating a broad useable powerband, getting the turbo online in the least amount of rev's is usually a net positive.  focusing on dyno HP is usually ego measuring contest.  just my opinion (most people on the internet disagree with me fwiw)

I only disagree with you when you're wrong

So in the spirit of that, I'm going to back up your sentiment here.   I'd use the .61a/r hotside on a G30 660 being matched for an RB20.  

While we're agreeing - also relating to your early comments regarding turbine vs compressor matches etc, this is a thing I've long bashed my head in conversations with people online about - people see a specific A/R that works in an application and decide that is IT.  Same with turbine vs compressor size, and generally assuming that they know how a turbo is going to behave from the turbine size.   Even when I knew comparatively F*all about turbos (and I still have way too much to learn) it was pretty obvious to me that aero is going to influence this, as with the dynamic between the compressor and the turbine.  As I've learned more I've only grown to further appreciate this.  

If someone chose a 1.01a/r v-band G35-1050 over a 1.05a/r EFR8474 because the G35-1050 (G8468 if you're going to refer to it with Borg nomenclature) expecting a significantly more responsive/spooly turbo that has a more restrictive hotside then they're going to end up with something a little different to what they anticipated.  Broad rules of thumb based off previous experience can work, but then there are times they will lead you WELL astray - depending on the setups.   Like even the same turbine housing/wheel combination can perform significantly different in terms of what it can sensibly support depending on the compressor it is matched to.

 

[Komdotkom]

On 19/04/2022 at 8:48 AM, Full-Race Geoff said:

for a built 2.5L RB25 targeting 600-700whp you could pick a range, 600?  or 700.  twinscroll G30-770 would be my vote for 550-600.  G35-900 would be a recommendation for 650-700. 

 

Would you run the G30-770 with the T4 1.06 twin scroll housing instead of the .83 V band on a built RB25?

[Full-Race Geoff]

yes 100%

[Komdotkom]

On 20/04/2022 at 6:02 AM, Full-Race Geoff said:

yes 100%

Thanks Geoff, there's not much information around about these turbo's your input is invaluable. 

[Rand0b]

On 4/18/2022 at 6:48 PM, Full-Race Geoff said:

theres a lot to consider when picking a turbo!  compressor diameter to turbine diameter ratio is something i think about a lot aka "match ratio".  traditional match ratios might be 1.07 to 1.11 for OEM turbos (or borgwarner turbos for that matter).  In comparison the garrett GT and GTX turbos had aggressively sized "large" compressors on fairly small turbines. 

GT3076 = 76mm compressor : 60mm turbine (1.26 ratio)
GT3582 = 82mm compressor: 68mm turbine (1.20 ratio)

now that the G series redefined what a given turbine or compressor diameter is capable of flowing, i suggest the thinking around wheel sizes might also change.  This is why the G35-900 (1.11 ratio) might outperform the G35-1050 (1.20) and the G30-770 (1.18) might outperform the G30-900 (1.26 ratio).  this gets complicated by which turbine wheel and housing are being used, on what exhaust manifold and engine configuration.  

to your question: 

G30-770 in old garrett = G3071
G35-900 in old garrett = G3576

for a built 2.5L RB25 targeting 600-700whp you could pick a range, 600?  or 700.  twinscroll G30-770 would be my vote for 550-600.  G35-900 would be a recommendation for 650-700. 

RB20s aren't stellar at spool up and torque generation and G30 turbine flows a ton.... so whatever you can do focus on generating a broad useable powerband, getting the turbo online in the least amount of rev's is usually a net positive.  focusing on dyno HP is usually ego measuring contest.  just my opinion (most people on the internet disagree with me fwiw)

My choice was G30-900 or G35-900 not the g30-770

While the G30-770 may out perform the G30-900 it would not have the same HP potential

With a Stock block w/bolt ons Street car

EVERYONEs choice seems to be the 3076 for ~4-500whp and retains great spool / drive ability

So that's why i was thinking G30-900 just to get a bit more power potential but what factor would cause one to move to the G35-900?

i know it would have a shift in power band and spool

just have not seen to many RBs running these G series turbos for comparisons

I am building this for a Great Street car

I have a Built Bottom end, FFP, Ported head and Stock cams and T3 for my Turbo Manifold

if i see anything 6XX or maybe even 7XX on the dyno i would be happy

IF the G30-900 acts like 3076 but can put down more power i think thats my go to.

But if the G30-900 is to 'small' and hits to quick i could possibly adjust Boost curve in the tune

Or when would the G35-900 be better suited

 

 

 

Edited April 20, 2022 by Rand0b

[Rand0b]

@Lithium

I just came across your thread below and looked interesting.

i know the SX-E is older technology but for G Series being over double the price

with the RB30/25 hybrid running the s362 i would think for my goals on RB25 i would need a step or 2 higher and with the extra cash saved i could get some drop in cams

what would your input be on a S366 for my setup? or comparable

With this not being a Full Effort Race/Track setup i think this may be another contender

 

[Lithium]

On 21/04/2022 at 8:48 AM, Rand0b said:

@Lithium

I just came across your thread below and looked interesting.

i know the SX-E is older technology but for G Series being over double the price

with the RB30/25 hybrid running the s362 i would think for my goals on RB25 i would need a step or 2 higher and with the extra cash saved i could get some drop in cams

what would your input be on a S366 for my setup? or comparable

 

If you want to get into specifics relating to the Borgs then put your questions in the Borg thread.

Re: Power targets, make it specific here or in there as well.  In this thread you've mentioned 600-700whp, we made 650+hp without maxing out the S362SXE.   It's an easy 600+whp turbo, so any further posts in here relating to G-series or in the other thread relating to Borg try and clarify why you believe you may need bigger than x turbo or whatever.   Mention what fuel you'll be using etc as well. 

[r32-25t]

Has anyone seen results from a g40 on an rb25-30 yet? Had a mate ask me about it the other day and I wasn’t much we could find on the topic. Looking at the wheel and housing sizes looks like it would be pretty good on a 3.0/3.2 or even a 2.8 if you used the smallest housing 

[Full-Race Geoff]

I dont know many people using the G40.  but its one of the most impressive modern 1000hp capable turbos.  people seem hesitant on them and I'm not sure why.  Fact is, G40 has outstanding wheels, great housings and modern connections.  If i were building a beast of a large displacement RB engine, G40 is the turbo I'd run

a friend with a high end porsche shop did a back-to-back-to-back thats sorta relevant here - 991TT, 4.1L, 38psi boost,
 

Precision 6466 0.82 a/r (red) vs G35-900 0.83 a/r(blue)

 

made me fall in love with the G35-900

[khezz]

On 3/8/2022 at 10:49 PM, Full-Race Geoff said:

I dont know many people using the G40.  but its one of the most impressive modern 1000hp capable turbos.  people seem hesitant on them and I'm not sure why.  Fact is, G40 has outstanding wheels, great housings and modern connections.  If i were building a beast of a large displacement RB engine, G40 is the turbo I'd run

a friend with a high end porsche shop did a back-to-back-to-back thats sorta relevant here - 991TT, 4.1L, 38psi boost,
 

Precision 6466 0.82 a/r (red) vs G35-900 0.83 a/r(blue)

 

made me fall in love with the G35-900

Wow. That’s an amazing result. Do you know if it was a gen 2 6466? I was at a cross roads with my turbo choice. Ended up going precision. All the results I saw at the time when I was in the market showed that Garrett had slightly better spool but precisions made more power. Since the goal of my car was drag/roll with some street/cruise duties, I chose power. Having said that, G40 and G45 weren’t out yet. 
 

amazing result none the less. Great post to. 

[khezz]

On 2/8/2022 at 7:59 PM, r32-25t said:

Has anyone seen results from a g40 on an rb25-30 yet? Had a mate ask me about it the other day and I wasn’t much we could find on the topic. Looking at the wheel and housing sizes looks like it would be pretty good on a 3.0/3.2 or even a 2.8 if you used the smallest housing 

Considering how well the G45 did in the motive GTR, I think the G40 would be an animal in a 3.0L RB no matter what head is on it. 

[r32-25t]

Looking at the sizes of the g40/42/45 range you can see exactly who the main competitor garrett were trying to chase is. Be interesting once a few more started being fitted

i did see one post of someone who swapped a gtx3584 for a g40 1150 and said he found it had better response and Clintoz on here said the same going from a 3584 to a g42

[BK]

On 04/08/2022 at 9:44 AM, khezz said:

Wow. That’s an amazing result. Do you know if it was a gen 2 6466? 

6466 was only ever released as gen 2. 

[Lithium]

On 04/08/2022 at 12:57 PM, r32-25t said:

Looking at the sizes of the g40/42/45 range you can see exactly who the main competitor garrett were trying to chase is. Be interesting once a few more started being fitted

i did see one post of someone who swapped a gtx3584 for a g40 1150 and said he found it had better response and Clintoz on here said the same going from a 3584 to a g42

I'm really keen to see more results of G40s, so far I've been far from impressed with them but would like them to be a good thing.   On paper they always seem QUITE laggy, though the owners sound happy with what they've ended up with... whether it's a transient response thing or they just don't mind a lazy turbo is hard to know due to subjectivity.   I do know that G42s can ggf from everything I've seen regarding them, they do the numbers but their EMAP seem high for the lag and general flow you end up with for a "modern" turbo.... so if anything this post makes it sound like GTX3584RS are absolute nuggets of turbos.   

On 04/08/2022 at 2:49 AM, Full-Race Geoff said:

I dont know many people using the G40.  but its one of the most impressive modern 1000hp capable turbos.  people seem hesitant on them and I'm not sure why.  Fact is, G40 has outstanding wheels, great housings and modern connections.  If i were building a beast of a large displacement RB engine, G40 is the turbo I'd run

Precision 6466 0.82 a/r (red) vs G35-900 0.83 a/r(blue)

 

made me fall in love with the G35-900

Yeah the G40 *seems* like it should be a good thing, if you have any real world results or anything I'd be super keen because I've been more than disappointed with what I've seen so far - I'm not hating, as obviously "disappointment" suggests I was expecting more from them.... I just like keeping abreast of what works and what different units strong and weak points are

The G35 900 result is *really* surprising for me, was there any other changes involved on that setup?  A 6466 is not a lazy turbo and a G35 900 is not a super early boost threshold turbo normally - like not bad, but this is unexpected.      We have a G35 900 for a 2JZGTE drag car (900kg car....) so quite interested to see first hand how it performs.

[iruvyouskyrine]

On 8/2/2022 at 9:59 PM, r32-25t said:

Has anyone seen results from a g40 on an rb25-30 yet? Had a mate ask me about it the other day and I wasn’t much we could find on the topic. Looking at the wheel and housing sizes looks like it would be pretty good on a 3.0/3.2 or even a 2.8 if you used the smallest housing 

I am going G40-1150 on my RB25/30 Neo. 1000 at the wheels is my goal which is a big ask but see how we get on. 

ETA in my brain ~6 months
ETA in actuality ~2 years

 

EDIT: 1.06 Vband turbine housing

Edited August 4, 2022 by iruvyouskyrine

[r32-25t]

On 5/8/2022 at 9:14 AM, iruvyouskyrine said:

I am going G40-1150 on my RB25/30 Neo. 1000 at the wheels is my goal which is a big ask but see how we get on. 

ETA in my brain ~6 months
ETA in actuality ~2 years

 

EDIT: 1.06 Vband turbine housing

I feel your pain about inflated eta times at the moment

should be interesting to see, any reason why not going for twin scroll?