GTX3076R GEN II VS GTX3576R GEN II on RB26

[joe89]

Hi there.

Which will be better for street forged RB26? Botch turbo's are for 750[crank]hp - my power goal is 650-700hp on 93octane. GTX3076R will have 0.83 T3 twinscroll  and GTX3576R probably 0.61 T3 twinscroll. I hear GTX3576R spool better than -5. I need the fastest possible spool for that power level. Even i prefer 650hp over much lagged 700.

It's true GTX gen 2 spool faster than gen 1?

BTW how realistic is G25-660 with 650hp @ RB26?

 

 

Edited February 14, 2019 by joe89

[iruvyouskyrine]

9 hours ago, joe89 said:

Which will be better for street forged RB26? Botch turbo's are for 750[crank]hp - 

3076 Maybe in Americaland but not in Australia

9 hours ago, joe89 said:

GTX3076R will have 0.83 T3 twinscroll

No, too small. 1.01 required. Also they don't do a T3 twinscroll as far as i am aware.

 

9 hours ago, joe89 said:

 GTX3576R probably 0.61 T3 twinscroll

See above

9 hours ago, joe89 said:

I hear GTX3576R spool better than -5. I need the fastest possible spool for that power level. 

Yes a 3576 should be much much better than -5

9 hours ago, joe89 said:

It's true GTX gen 2 spool faster than gen 1?

In my experience is much of a muchness

9 hours ago, joe89 said:

BTW how realistic is G25-660 with 650hp @ RB26?

Less likely than the 3576 doing it

[Dose Pipe Sutututu]

46 minutes ago, iruvyouskyrine said:

No, too small. 1.01 required. Also they don't do a T3 twinscroll as far as i am aware.

Not as a full complete kit, you need to buy the supercore and order the rear housing separately

I'm still waiting on my divided 1.01 T3 rear housing from Sparesbox, however I have a nice GTX3576R Gen 2 supercore at home.

[Darmanin10]

I have a gtx3576r on my rb26. Will eventually turn it up when I upgrade the fuel system

 

[Dose Pipe Sutututu]

2nd piece of the GTX3576R Gen 2 puzzle, now just waiting for the 1.01 twin scroll housing.

No dispatch notice yet, but was told this week.

[Lithium]

Oh wow, I've clearly missed some developments with the Dose Pipe beast - nice, be interesting to see how that goes!  Big hot side, any reason for going the 1.01 instead of the .83 housing?

[Dose Pipe Sutututu]

Wanted the car to be linear and not snap necks, although my mates have been telling me to go with the 0.83 TS housing.

Let's see, if I'm not overly impressed might have to drop it down a housing. But my gut feel (based loosely on pure broscience) tells me it will work out pretty well.

[WantGTR]

5 minutes ago, Dose Pipe Sutututu said:

Wanted the car to be linear and not snap necks, although my mates have been telling me to go with the 0.83 TS housing.

Let's see, if I'm not overly impressed might have to drop it down a housing. But my gut feel (based loosely on pure broscience) tells me it will work out pretty well.

Should have got a 42r and left the 35 for the response losers lol

[Lithium]

1 minute ago, Dose Pipe Sutututu said:

Wanted the car to be linear and not snap necks, although my mates have been telling me to go with the 0.83 TS housing.

Let's see, if I'm not overly impressed might have to drop it down a housing. But my gut feel (based loosely on pure broscience) tells me it will work out pretty well.

Keen to hear how you find it.  I'd have gone with the .83 as well, but it will be a very interesting setup to see how works as it's going to be something a bit different

[Dose Pipe Sutututu]

19 minutes ago, WantGTR said:

Should have got a 42r and left the 35 for the response losers lol

Salem Habib, wallah don't be worried, I'm not gonna run a speed sensor on my turbo and send it

Race you soon bruh.

[Dose Pipe Sutututu]

20 minutes ago, Lithium said:

Keen to hear how you find it.  I'd have gone with the .83 as well, but it will be a very interesting setup to see how works as it's going to be something a bit different

I've been stalking the Evolution M forums, as well as some random Russian YouTube videos with the same turbo on Chasers albeit Gen 1.

Back to back from 0.83 to 1.01 there was a bee's dick difference in response however a bit more top end. 

[Lithium]

28 minutes ago, Dose Pipe Sutututu said:

I've been stalking the Evolution M forums, as well as some random Russian YouTube videos with the same turbo on Chasers albeit Gen 1.

Back to back from 0.83 to 1.01 there was a bee's dick difference in response however a bit more top end. 

Oh wow, I've missed that one - been following 240Z's experiments which have been pretty cool but I've not seen him try the .83.  In his testing the 1.01 GTX3576R was real laggy from memory, he went to a GTX3582R with the ATP T4 1.06 housing (which actually have a much smaller cross section than the Garrett T3 divided housings, so actually downsized despite the a/r)  and picked up spool.

Who did the .83 to 1.01 comparison?

[Dose Pipe Sutututu]

Noone did the comparison, but from amalgamating different results from various results it appears going to a larger housing (of course keeping it TS) people have lost not much boost respons vs. RPM however however tends not to nose over.

I saw those results from 240Z going from a 0.82 OS to a 1.06 TS and actually getting better response.

I got the whole GTX3576 idea from the Evolution and WRX guys, so hopefully once it's all running we can get some data.

[Lithium]

2 hours ago, Dose Pipe Sutututu said:

I saw those results from 240Z going from a 0.82 OS to a 1.06 TS and actually getting better response.

I got the whole GTX3576 idea from the Evolution and WRX guys, so hopefully once it's all running we can get some data.

Ahh yeah, that's one of those big cases where "a/r" is a bit of a flawed measurement as you kinda need the "area" value as well to get a real gauge of the scale being dealt with.  A 1.06a/r T4 twin scroll housing from ATP was pretty equivalent in effective size/flow to the .82a/r T3 Garrett open housing, but more efficient due to being a divided housing so despite being a bigger number - it wasn't much "bigger" in effect, if at all... but more efficient being divided so still flowed a bit more but also at no real cost to response.  Arguably better transient response, a mate did the same conversion (.82 T3 open GT35R to a 1.06 T4 divided one) and the thing felt much better on the road.

Garrett's T3 divided housings actually are much more "equivalent" to the open housings, so if you want the divided equivalent of a .82a/r T3 open housing then you get a .83a/r T3 divided housing - as opposed to going up an a/r like you would with some options. 

Basically the .83a/r Garrett T3 twin scroll housing is much more comparable to the ATP 1.06a/r T4 housings used in those comparisons than the 1.01 is - though realistically its a bit hard to compare.   One thing is for sure, you're not likely to choke your compressor

Anyway, I've been looking forward to seeing a GTX3576R on an RB25 and know you'll have done it well so very much look forward to seeing how it goes, kudos for trying some cool shit out     Hopefully the result ends up driving the way you want it to anyway, and it's worth knowing that if on the off chance the spool isn't as good as you were hoping - you can try going down a size in exhaust housing and are unlikely to lose too much up high.

 

 

Edited February 21, 2019 by Lithium

[Dose Pipe Sutututu]

25 minutes ago, Lithium said:

Anyway, I've been looking forward to seeing a GTX3576R on an RB25 and know you'll have done it well so very much look forward to seeing how it goes, kudos for trying some cool shit out     Hopefully the result ends up driving the way you want it to anyway, and it's worth knowing that if on the off chance the spool isn't as good as you were hoping - you can try going down a size in exhaust housing and are unlikely to lose too much up high.

That's the best part, just swap housing no fab work and off I go again

 

26 minutes ago, Lithium said:

A 1.06a/r T4 twin scroll housing from ATP was pretty equivalent in effective size/flow to the .82a/r T3 Garrett open housing, but more efficient due to being a divided housing so despite being a bigger number - it wasn't much "bigger" in effect, if at all

Interesting to know that, I never really looked deeper into the overall surface area and volume of the housings.

[Lithium]

26 minutes ago, Dose Pipe Sutututu said:

Interesting to know that, I never really looked deeper into the overall surface area and volume of the housings.

I kinda wish I made more measurements when I had one of the ATP ones in my hands, they're pretty unusual to come by these days.  

[Dose Pipe Sutututu]

Update time, albeit a bit dataless lol.

Just got the car back tonight and I can tell you I've made the right choice with the twin scroll GTX3576 Gen 2 with 1.01 rear housing.

Because I decided to remove all the after market gauges in my car (boost, afr, fuel temp, ethanol %) I had no idea what was really going on without a laptop.

So drove it around with 6 month old E85 in the tank and with the same timing map as before with only the turbo on gate pressure (1 bar) and it exceeded my expectations to simply put it.

At 3k rpm you could hear the turbo working by 4k rpm it was clearly on and moving. Transient response by feel was decent too.

I'll plug up over the weekend and produce some useful logs

Only think I can think of that's holding back the setup now would be the FMIC ($100 eBay HDi special).

[Lithium]

10 hours ago, Dose Pipe Sutututu said:

Just got the car back tonight and I can tell you I've made the right choice with the twin scroll GTX3576 Gen 2 with 1.01 rear housing.

So drove it around with 6 month old E85 in the tank and with the same timing map as before with only the turbo on gate pressure (1 bar) and it exceeded my expectations to simply put it.

At 3k rpm you could hear the turbo working by 4k rpm it was clearly on and moving. Transient response by feel was decent too.

I'll plug up over the weekend and produce some useful logs

That sounds real promising, if nothing else - if it is doing what makes you happy then that's perfect as it should have plenty of hotside flow.

In regards to some of the a/r stuff above, I'm not quite at the "eat hat" stage but I am prepared to if it comes to it - the data Garrett provide on the turbine housing flow stuff is real ambiguous... you "liked" my comment in the Hypergear thread relating to someone I know losing a fair bit of power going from an open .63 to a divided .61 Garrett hot side so you can see where this is coming from. 

On further investigation Garrett don't specify in their turbine flow maps if their ".61" turbine flow maps are for open or divided,  and perhaps they are only talking about the open housing and they aren't actually providing any flow info for the divided ones.  I know one source definitely implied it was the divided ones but I am starting to question that, I've tried putting word out to the right channels to get clarification on that but so far no joy but it is something which would be VERY helpful to have.   Andrew Hawkins made quite a lot of power with the divided .83 on his RB26 with the GTX3582R so it seemed reasonable to assume that they aren't shabby.

Either way, if you are happy with the response of the 1.01a/r divided GT3576R Gen2 that is great - the Hypergear you were running before was pretty laggy from memory, but still.... the Gen2 76mm compressor is proven to be capable of a heap of power, so this setup is heading in the direction of delivery some very good goods   Nice work, looking forward to data!

[Dose Pipe Sutututu]

To add, the ATR45SAT, although a very capable turbo didn't wake up till about 4500rpm and had pretty much nothing prior. Would have been perfect on a 2.8 or a 3.0L!

The GTX3576 Gen 2, albeit pretty much the same ish size of the Hypergear turbo is on and moving so much sooner. It's day and night difference, also the dose is phenomenal - like a Hans Zimmer concert (he's touring Australia again, so going).

[hypergear]

On 07/06/2019 at 9:51 AM, Dose Pipe Sutututu said:

To add, the ATR45SAT, although a very capable turbo didn't wake up till about 4500rpm and had pretty much nothing prior. Would have been perfect on a 2.8 or a 3.0L!

The GTX3576 Gen 2, albeit pretty much the same ish size of the Hypergear turbo is on and moving so much sooner. It's day and night difference, also the dose is phenomenal - like a Hans Zimmer concert (he's touring Australia again, so going).

Just a quick note, the ATR45SAT you had was a 5 years old unit, current model is different, result has been updated to dyno section. More developments are underway.

And result to share:

GTX3076R Gen 2 maxed on a built Rb25det Neo on 26psi of boost, externally gated on E85 fuel.

 

Edited June 8, 2019 by hypergear