Which Size Rear Housing?

[BlackBox]

Hi,

I have a rb25det neo currently undergoing a round of mods, previously dyno'd at 300kw hoping a set of poncam a and exhaust manifold will see 330rwkw.

My turbo is a gt3076 internally gated, I'm looking to put it on a 6 boost twin scroll t3 external manifold, what size rear housing would be recommended? Also how much power should I be able to get out of my .5 ar compressor housing?

[iruvyouskyrine]

.82 or .73 if garrett offer it. I knows its available on Mistu turbo's.

[BlackBox]

I have found .78

Would there be noticeable difference between them?

[iruvyouskyrine]

Not really mate, .82 will easily make the power you want and some but comparing it to a .78 you would hardly notice IMO. Unfortunately i can't comment on its pairing with the .5 A/R compressor housing, wait for Lithium or Disco to weigh in before you make any decisions though, they are the resident Guru's

[BlackBox]

Bump

[Lithium]

Hi,

I have a rb25det neo currently undergoing a round of mods, previously dyno'd at 300kw hoping a set of poncam a and exhaust manifold will see 330rwkw.

My turbo is a gt3076 internally gated, I'm looking to put it on a 6 boost twin scroll t3 external manifold, what size rear housing would be recommended? Also how much power should I be able to get out of my .5 ar compressor housing?

What fuel are you running? Where did you get the turbo? .50a/r compressor housings aren't really a thing I'd typically associate with a GT3076R, more a GT3071R thing and depending on fuel I'd imagine you are pushing close to it's limit already... on pump gas on a roller I'd have thought that is already pretty impressive, though a local (I'm not as savvy in terms of what the rear roller numbers mean in relation to "real" power made as some who will have more exposure to these dynos) if it were one of those.

Is there a specific reason you're going twin scroll? It's a fair bit of effort, especially as the T3 TS setup is potentially a bit limiting in future proofing as not THAT many things use them. I'd personally treat a .83 one as an absolute minimum for that kind of setup, and actually be pondering the 1.03 if you are looking at pushing the limits of the turbo - assuming it's a GT3076R?!

Sorry, I can't really answer on the housing thing... again, I have never encountered a GT3076R running a .50a/r so I'd be just plucking numbers from somewhere dark.

[juggernaut1]

Not directly on point but it is my understanding this is a GT35 .78 TS hsg on an RB26.

If it's legit I'm personally surprised the .78 TS hsg was capable of that power.

http://img.photobucket.com/albums/v482/str8e180/dyno2.jpg

Edited July 9, 2014 by juggernaut1

[BlackBox]

Running bp 98 . E85 is not an option.

The turbo was already fitted when I got the car,. Haven't had it off so I can't confirm that what I was told is correct.

My reasons for going twin scroll is that I'm running the standard exhaust manifold so I thought manifold would be the next logical step, and going ts would help bring boost on earlier with better response. Only disadvantage over single scroll is price?

I was originally considering pairing the 6 boost twin scroll with a forces performance 3076 but couldn't justify the expense going from a garret 3076 to a fp

Edited July 9, 2014 by BlackBox

[wolverine]

A lot of money to spend for little gain. Save your money.

[WARLORD]

listen to the wolverine

[BlackBox]

Then what is the next performance step without going to a gt35 or a setup that will induce more lag?

So there is minimal performance gain to even upgrade from the standard exhaust manifold?

Save money for what :s

[BlackBox]

Either way which rear housing would best be suited to my .5ar compressor housing?

[wolverine]

The next performance step is E85 which you are unwilling to do so that leaves a turbo change, perhaps HTA range might be the go. Any other change is likely to cost a lot of money for not much gain.

If you change to a larger turbine housing you might make a bit more power but you lose response. If you change to larger duration cams you will probably shift the power to the right. A 1.06 TS turbine housing and 6B manifold might make a bit more power at the top end but there is a lot of expense with few guarantees.

It all comes down to how important more top end power is to you.

[Lithium]

Yeah - as much of a twin scroll fan as I am, for the kind of thing you are after I can't help but feel a single scroll manifold and better matched turbo to your targets would be more cost effective vs reward. HTA3076 on a good manifold is really so far seeming like the goods, only know of 3 on RB25s (2 on this forum) but they've all made good numbers and been very responsive for that power.

I have a feeling 34GeeTeeTee made near 330rwkw on petrol with his?

[AngryRB]

Best options are E85 or Water/meth and retune or RB30 bottom end

all above options are a lot cheaper and better

Edited July 10, 2014 by AngryRB

[34GeeTeeTee]

Yeah - as much of a twin scroll fan as I am, for the kind of thing you are after I can't help but feel a single scroll manifold and better matched turbo to your targets would be more cost effective vs reward. HTA3076 on a good manifold is really so far seeming like the goods, only know of 3 on RB25s (2 on this forum) but they've all made good numbers and been very responsive for that power.

I have a feeling 34GeeTeeTee made near 330rwkw on petrol with his?

Yep pretty much spot on, its tuned very conservative on pump fuel as i only wanted it as a backup if i couldn't get E85...

Its only tuned on 20psi on PULP...

HTA on E85 was the best change i made from the GT...

[discopotato03]

If I've got this right the car previously claimed 300 RWKW and the turbo has a 0.50 AR compressor housing on it .

From memory only two Garrett turbos used a 0.50 compressor housing and they were the GT3071R and the XR6 turbos , GT3582R or GT3576R .

From numbers people throw up here I suspect its got an XR6 turbo if it really did wheel out 300 Kw and it wasn't just the "sales pitch" . That number doesn't sound likely from a GT3071R .

If money was no object and you wanted to run a high mount ext gate turbo then twin T4 is probably the go . With twin scroll big housings are supposed to be the go and 1.06 is I think as big as Garretts T3 and T4 housings get .

Personally I think some financial sanity has to prevail with these things and if a bolt on GT3076HTA does real well on PULP and alcahole then why look further .

On Neo Poncams , at least one person I know has the B type and wished they had the milder A type . If I had to change cams I'd go the mild ones .

RB30 torque is what everybody wants so they can make a nice 300 at the wheels . A fair bit of work to gain 500 revs but the only other way is to use smaller turbos and compromise the top end .

A .

[BlackBox]

Hta3076 of a good manifold (6boost ts t3 low mount) was my original plan, how is that any different that what you guys are proposing? Where is the advantage to staying single scroll?

I just thought if I already have a gt3076 then changing the rear housing to an external twin scroll would be a better idea than going out and buying an entire new turbo?

How could I conform that I do indeed have a 3076 and not 3071?

I have already purchased the type b poncams from frsport but they haven't been shipped yet, this is the first I have seen of anybody recommending the milder type a over the type b and I did quite a bit of searching, where does this notation come from?

I'm not unwilling to go e85, I am unable.

Edited July 10, 2014 by BlackBox

[GTSBoy]

How could I conform that I do indeed have a 3076 and not 3071?

Tag #s on the core.

[34GeeTeeTee]

I drove Lith mad by bombarding him with questions as i was initially going to put the TS manifold and housing on my GT setup...

After taking a punt and deciding to go the HTA instead i was more than happy with the results... It was less stuffing around as it was a direct bolt on in my case...

I run Type B poncams and find no negatives to them?