Garrett G Series

[iruvyouskyrine]

Purely simplicity. Have twin scroll twin gate on my other car and it's just so much extra shit.
For the gain in response you get i would now happily trade it for something cheaper, easier to put together and easier to work on. Also going in front of DCT 7 speed so easy to keep it in the powerband pretty easily which helps, only have to get it up on boost once and should stay on the boil.

[Butters]

Looks like they are just new covers ?

 

 

[r32-25t]

So thats them basically admitting their Mitsubishi based turbos are junk and they had to go back to using Garrett’s 

[BK]

On 06/08/2022 at 8:38 PM, iruvyouskyrine said:

Purely simplicity. Have twin scroll twin gate on my other car and it's just so much extra shit.
For the gain in response you get i would now happily trade it for something cheaper, easier to put together and easier to work on. 

Absolutely this. If knew what a bastard T4 flanges were on the Precisions to work on I 100% would've opted for v band exhaust housings.

On 06/08/2022 at 9:38 PM, r32-25t said:

So that then basically admitting their Mitsubishi based turbos are junk and they had to go back to using Garrett’s 

Yep 😆

[Dose Pipe Sutututu]

On 06/08/2022 at 9:08 PM, iruvyouskyrine said:

Have twin scroll twin gate on my other car and it's just so much extra shit.

You could have gone a Sinco manifold, each scroll is split all the way to the gate flange. Single gate, twin scroll.

Even 6 Boost has started to do the same 🥲

[BK]

On 07/08/2022 at 9:28 PM, Dose Pipe Sutututu said:

You could have gone a Sinco manifold, each scroll is split all the way to the gate flange. Single gate, twin scroll.

Even 6 Boost has started to do the same 🥲

Or he could keep the v band inlet exhaust housing and have a turbo he can remove in 30 minutes.

[Piggaz]

On 8/8/2022 at 8:15 AM, BK said:

Or he could keep the v band inlet exhaust housing and have a turbo he can remove in 30 minutes.

How often do you take a snail off?

4 nuts and a v band vs 2 v bands. Meh.

[Lithium]

Faster to take off and put on, slower to spool.  Pick your preference - though I get the impression cost and spool not being a top priority came into this which makes sense.  

[Dose Pipe Sutututu]

Just in case you change your mind @iruvyouskyrine 😎

https://www.sincocustoms.com/shop/product/209348/rb20-or-rb25-t4-twin-scroll--turbo-manifold/?variantId=440703

 

[BK]

On 08/08/2022 at 8:09 AM, Piggaz said:

How often do you take a snail off?

4 nuts and a v band vs 2 v bands. Meh.

Well, when you actually use the car frequently you do need the ability to remove the turbo easily. V-band means no gaskets for potential failure or stuffing around with flange studs or replacing nuts every disassembly.

I'm not sure what the G40 series T4 flange is like on the exhaust housing, but if they are as compact on the flange plate to exhaust housing dimensions are on the Precision 6262 / 6266 / 6466 which have group C size T4 divided exhaust housings, you need to take the compressor housing off to access your turbo drain bolts and remove oil drain to then access the front outside flange stud nut.

Then your front pipe needs to be completely removed, in my case unbolting from gate outlet too, to access the rear outside flange stud nut. No curved spanners or special sockets will help you when the assembly is in the car - it needs to be done to access the frigging outside flange nuts because of how the exhaust housings are cast. Inside flange nuts no worries, both can be accessed with a socket directly.

So it's not really meh "4 nuts with a socket" job at all in a lot of cases. A v-band in / out guarantees you can just undo 2 clamps and job done, so I can see the merit as my old HKS T51 was a dream to remove.

[GTSBoy]

Yeah - without direct personal experience on my car, I concur wholeheartedly with the (pro) V-band argument.

In an ideal world there would be (probably application specific) v-band manifolds and rear housings that would have dividers that aligned with each other so you could have the best of both worlds. I suspect we'll be waiting until sintered powder 3D printed housings become a cost-effective close-to-DIY sort of thing before we can hope for it to happen though.

[joshuaho96]

On 8/6/2022 at 5:08 AM, r32-25t said:

So thats them basically admitting their Mitsubishi based turbos are junk and they had to go back to using Garrett’s 

As far as I can tell these are replacing their GTII turbos which I'm having trouble figuring out the actual origin of. They're still selling the GTIII turbos. They are admitting that if you want the kind of power that twin GT-RS/GTIII-RS turbos provide you should be going for a Garrett single turbo instead. Weirdly enough in their chart for a full drag build RB28 the power difference between their twin GTII turbo and the single GT turbo is not much to write home about, you'd imagine they would try and figure out something more noteworthy to show for marketing purposes:

They also plan on releasing T25 and T4 flange variants and there's clearly a twin scroll manifold pictured when they mention "GT turbine setup kit for RB26".

[iruvyouskyrine]

As BK said there is much more to it that just the flange. If you have seen any of my other cars the exhaust manifolds are extremely excessive (which i absolutely love) and once again i will be doing something similar on this car. Good luck getting a twin scroll twin gate low mount G40 into an engine bay and working on it at all.

Twin scroll v band with merged single gate would be the tits but anyway......

[Butters]

I must be doing v-band wrong as I find my new vband setup much harder to remove/install over my old 4 bolts (x2). Horizontal access is really limited for the turbo vs coming from the top for the T4 flange on my old setup.  I do really like no gaskets and being able to position the turbo though.  I went a bit silly and used VBands through exhaust system, some of which I want to switch back to flanged now for fix position and lets say more flexible "tolerances"

[elsk]

Does anyone have experience with what power people are making with the G30-900 vs G35-900?

On a rb26

[Borci88]

Hey all, after some advice in regards to what turbo I should be aiming for to replace my aging -5s. If possible, I'm aiming for 500+rwkw without going 35psi, while hopefully still, being more responsive than my -5s. I haven't got a big flowing head and cams so I imagine I will be pushing the single turbo quite hard, however if possible I'd like to remain around the 25psi mark to meet my goals. Tell me I'm dreaming if I am..

 

My current setup is as follows:

 

Racepace RB28 bottom end

RB25 NEO Non-Turbo head with VCT

RB25 Neo Turbo STOCK Intake camshaft / HKS 260 degree Exhaust camshaft (mismatch I know)

No porting other than removing the humps in the exhaust ports, however the intake and exhaust ports are far smaller than turbo heads

-5 Turbos with dumps 

3" HKS Exhaust with front pipes and decat

E85 

Haltech Elite 2500

Approximately 435rwkw @ 23psi

I believe it comes on boost at around 4500rpm, unfortunately I don't have a dyno graph with RPM overlay and PSI.

 

As you can see, the head and camshafts are going to be the limiting factor and I'm not looking to change them at this stage. 

 

I've been told that a GTX3582RS GEN 2 would be the go-er, which seems like is it roughly equal to a G35-900 anyway.. and even then, due to the small head, would I be better off with a .83 dual V-Band rear housing? Or go larger and get the 1.01 dual v-band rear housing? Pulsar now also sell a .85 twin scroll T4 as well. 

 

To sum it all up, I THINK A G30-900 or G35-900 is probably the right turbo for my goals. I was thinking of using the SINCO T4 Twin Scroll mentioned by @Dose Pipe Sutututu as that's barely any more money than a 6booby and seems much better anyway. I assume a G30 isn't going to cut the mustard for 500+kw though?

For those who haven't seen, Racepace recently ran up a G35-900 with SIMILAR setup to mine and made 565rwkw on 26psi, I just don't know how laggy it is, although Racepace aren't known for building laggy cars usually. Might need to pop in and see what they say about it. (Pic attached is Racepace build not my car)

https://fb.watch/geIcPyDzBs/

 

Keen to hear everyone's opinions on it as it's quite a rare combo of top and bottom end.

[Borci88]

Not the best pic and rpm or psi are not overlayed, however you can see it is quite linear regardless. This is with the setup listed above.

[GTSBoy]

Hmm. Yes, well, the GTX3582 would have been the recco prior to G series, and now I would have thought that either of the G30 or 35 900s would have done the job for what you're after.  So I agree with your choice space. I tend to think that the G35 is probably worth a go, with the smallest rear housing that will reach the goal. I should probably let others speak to that.

If response is important, then you will likely prefer the twin scroll option over the V band options, although I** worry that the TS 0.85 rear will limit the 500kW target.

**Perhaps needlessly, again, wait for others to weigh in.

[r32-25t]

I’d use the g35 because the rb engines love the bigger rear wheels. Personally I’d use a 1.0x twin scroll rear housing, the different in response by using the twin scroll rear really makes them the only choice 

[Borci88]

56 minutes ago, GTSBoy said:

Hmm. Yes, well, the GTX3582 would have been the recco prior to G series, and now I would have thought that either of the G30 or 35 900s would have done the job for what you're after.  So I agree with your choice space. I tend to think that the G35 is probably worth a go, with the smallest rear housing that will reach the goal. I should probably let others speak to that.

If response is important, then you will likely prefer the twin scroll option over the V band options, although I** worry that the TS 0.85 rear will limit the 500kW target.

**Perhaps needlessly, again, wait for others to weigh in.

My fear is that a I'll spend all this money converting to single turbo, and a G30-900 won't even be able to crack 500kw.

 

Both the G30 and G35 come in a .85 Twin Scroll rear housing if I bought a Pulsar version which is good, however if I was to go any bigger AR then I would be sacrificing twin scroll to go to V-Band. 

15 minutes ago, r32-25t said:

I’d use the g35 because the rb engines love the bigger rear wheels. Personally I’d use a 1.0x twin scroll rear housing, the different in response by using the twin scroll rear really makes them the only choice 

I think you and GTSBoy are on the same page and I have been leaning towards the G35 all along (only with one friend of mine screaming in my ear to go G30). I'll need to go back through this thread to find some more results but I seem to remember G35-900s making very good power (500+kW) out of smaller rear housings, something which the older turbos weren't as capable of.. I also see that @Full-Race Geoff is fond of the .6x rear housings and smaller rear housings throughout the entire G series range.

 

I think G35 is going to be the goer but I'll wait a little bit and see if anyone chimes in why that would be a disastrous idea, cheers for your vital input you two!