M@&k

I'm 99% sure it's 3" all the way, I haven't noticed any step downs, but yeah not going to hurt to double check. I can't comment on restrictiveness of mufflers and cat though. I'm getting real confused with this setup now, as I always seem to be getting conflicting information... like this housing being a restriction when there doesn't seem to have been previous examples. I'm thinking of the following options: - Get a 3.5" bellmouth dump made, maybe with higher flowing cat as well. - Install different intercooler (most likely Plazmaman kit with gooseneck / Gibson style cold piping) - Throw caution to the wind and just try 0.63 A/R IWG housing anyway I'm not willing to give up on this turbo just yet, but at the moment it's not presenting itself as a compelling option, as at this type of boost response I probably would have been better off with GTX3071. Any ideas on what to try next on stock manifold and internal gate are welcome!

That's what I would have thought. I'm getting quite confused...I've got a custom 3" stainless from turbo back. Large oval rear muffler and reasonable sized mid muffler. Dump pipe is a split design which merges shortly after outlet. Cat is a high flow. Not sure on cell count. Would a restrictive exhaust cause the turbine housing to heat up as described?

Bit of an update for those interested. Had another tuner (Hyperdrive) look at my car today, as I wanted to see if it could run some more boost and also to get some other ideas on what might be holding it back. The result is not much different from before (dyno plot below), as boost tapers and there wasn't anything they could do about it. What was more interesting is that they noted that the turbine housing would quickly get red hot followed by dump pipe. He said it's pretty obvious there's a restriction there, and when I asked if a better dump might help he was dubious as it was the housing which got hot first indicating that was the most restrictive point. This seems strange to me with a 0.82 housing... He also noted that the turn-flow cooler (Blitz SE) was also likely to be a major restriction and recommended that be the first thing to change, unless I wanted to go external gate path. That or go E85 lol. Anyway, here's the other dyno plot. For some stupid reason I decided to get the one without the baseline run on it. Might have to see if I can get a copy with baseline on.

Agreed, you'll definitely run into inner clearance issues with +35. Honestly, if you're willing to roll guards just get +22 with 235/40/18s and be happy. I didn't get 9.5 +22 and sometimes wish I did.

Offset? Photos?

12mm wider rim, so 6mm either side. But 8mm larger offset, so will sit in 2mm more than 18x9+32. You'll also have clearance problems on inside with offset larger than around +25 with 9.5" wide rim. Best if you learn how to calculate offset, or use a calculator on the net. My recommendation would be to use 18x9.5+22 with 235s and roll guards to fit. Not too difficult or expensive and proven to be a good combination for 33 gtst.

Assuming Gtst. Fronts will sit inside about 10mm, and rears outside about 15mm. This depends heavily on camber though. I have 18x10+38 which after resetting camber to 0 now sit flush, maybe the tiniest bit of poke, whereas previously looked like they had heaps of room.

Did you find out where to get the Skyline garnish from? Or is that a custom item.

Linky no worky

Fronts look like much lower offset than +35. I'd say more like +15, else running spacers. I run 18x9 +30 which would be roughly same as 9.5+35 and mine sit in much further. Looks tops though, really like RPF01s in good size and offset on R33s. Also agree on your opinion of XD9s (what I have)

Is that gate off turbine housing? Looks quite stealthy.

I'm a bit torn really. While I think the 0.63 housing is probably closer to what I'm after, I wonder if there is more to get out of 0.82 as well. Maybe first step should be trying stronger actuator and winding boost up...

Does anyone have any solid info on this mythical update 0.63 IWG housing from Garrett with larger wastegate? I've only read that they had a -M part number suffix or something, and that they all should have this from now on. Any idea when the change came in? Any idea on how to identify? Anyone actually know what changed?

Agreed. While external gate would provide better performance (when does it not?), it's not what I set out to achieve with this setup. I was looking for something like the Pro S performance; early boost, ~260rwkW and stockish look. It sounds like this is possible with a change to the 0.63 A/R housing if decent boost control can be achieved. I was previously considering an external gate off the housing, but decided it was overkill for what I was chasing. Looking at the comp map for the GTX67 it's in peak efficiency up around 20psi. The boost control issues seen by others may not be an issue if running at this pressure anyway is my thinking. I'd be happy with this. I do most of my driving below 5000rpm realistically. To be honest I prefer not to have the temptation to wind it out to redline all the time Edit: Going back and looking at the videos, doesn't seem anywhere near as impressive as in real life, haha.

3rd gear run:

Conditions were good yesterday so it was holding traction just. Will certainly kick out sideways in 2nd if road is not ideal. But certainly doesn't bake the tyres, which makes it easier to drive really. Just foot to the floor and concentrate on gear shifts. If I lived further out of the city, I don't think I would be as worried about the response as I am. More 80+km/hr speed limits and less traffic. But in the city where I am I'd like to be able access the power sooner... Anyway, here's vids as promised. Taken with my phone so not brilliant quality. Tried to get both tacho and boost reading in frame. Edit: doesn't seem to want to embed third one

I hear what your saying about this potentially working against the RB25's nature, but my aim is to make the power more accessible in street driving conditions. I rarely get the opportunity to rev out to 7k without drawing unwanted attention. Speaking of which, I did get that rare opportunity today. Found some quiet space with a friend and took some vids of pulls in 2nd and 3rd and 0-100 runs. Did a best of 5.75s as measured by GKTech thingy, but certainly room for improvement with a decent driver who can get off the line better. The runs had us both giggling like school girls all afternoon. Will post up vids when I get a chance.

I see, so similar to the Plazmaman piping kit you can get. And yes, WTF at AFM location?

What is this "Gibson style" cross over pipe of which you speak? Tried Googling but didn't find anything.

Don't get me wrong, I have no intention to change to GT28 turbine. I have every intention of getting the most out of the GTX3067. But rereading my post sounded otherwise. I only raised as a possible topic of discussion is all. I was more thinking of someone reading this thread in the future and contemplating the GTX3067 vs the GTX2867, why they would go for the larger turbine. I understand conceptually that the GT30 hotside will let the engine breath better and should be better suited to the RB25. But if that is the case, surely this must show up in results somewhere?

If you need to go to the effort of new exhaust manifold and external gate, then I don't think it's worth the effort as you have pointed out Dale. Received a follow up from Galvsport yesterday to see how it was all going, and I asked what they thought about potential switch to 0.63 housing. Will see what they come back with. AngryRB the possibility of a swap is looking more promising, but probably wouldn't happen for a little while. I'll send you PM to discuss. Another question for you gents. If this turbo is only ever likely to do 250-260kW, is there any benefit of going the GT30 turbine over GT28? I decided to go this way based on understanding that with the GT30 hotside it should be more efficient and make more power (like Pro S vs GT-RS although I appreciate Pro S also had larger trim compressor). I've noticed KudosMotorsports offering kit with GTX2867 with RB25 dump pattern, studs, HKS outlet elbow etc for ~$2,300. That's only $100 more than I paid for just the GTX3067 & turbine housing. GTX28 version seems more compelling value if it can do pretty much the same power with better response, for cheaper. Thoughts?

Joeyjoejoe....'s result is often quoted for the Pro S, but I think even he admitted it seemed to be freakishly good compared to others. More common was around 260rwkW, and a touch more with cams. I've spent a lot of time trying to find a turbo like Pro S, but haven't got there yet. Shame the Kai wasn't a worthy successor. Also, by the way you can buy the Garrett equivalent of the Pro S, but the issue is trying to find a decent turbine housing.

I feel like all four of you are saying the same thing but coming at it from different ends. Disco + Lith from compressor side saying the GTX series (and possibly this one in particular) needs high rpm to make boost so would benefit from 0.63 housing. And Dale (+ possibly Wolverine) are saying the response is primarily driven by the turbine with compressor having minor impact, so needs 0.63 housing to change performance. What I'm starting to wonder is, if you go smaller housing to get compressor rpm up earlier, do you defeat the purpose by adding restriction to engine flow so it still can't do it's thing. Kind of leaving you in no-mans land...?

I thought BHdave ran the 0.63 GT3071 on an RB? I remember reading the thread where he was struggling with boost control. ^^ That does seem to be a nice result. If I do go for the change I reckon I'll look at going to someone who can do both the mechanical work and tuning. In hindsight it was definitely a disadvantage to not be in direct contact with the tuner about the result and get their feedback. Live and learn. Edit: Also, I don't want to knock Galvsport at all. I was very happy with the quality of their work, just that I think they're probably suited to much bigger projects.

May be a great driving car but Evo X's make me vomit in my mouth a little when I see them...