Help Understand GTT Boost Setup

[Kinkstaah]

Auto is at least 10% (from my real, actual experience with different torque converters and manual on the same setup)

~185rwkw at 11.6psi (peak!) is entirely what one would expect without a FMIC or anything else on the intake, it does bleed off towards the higher RPM so it's what, 9psi there?

Note: There is nothing that can be done about this with a manual boost tee. If you want to hold it steady and gain more top end, well - You will need electronic boost control.....

[DraftySquash]

On 17/2/2025 at 9:19 PM, Kinkstaah said:

Auto is at least 10% (from my real, actual experience with different torque converters and manual on the same setup)

~185rwkw at 11.6psi (peak!) is entirely what one would expect without a FMIC or anything else on the intake, it does bleed off towards the higher RPM so it's what, 9psi there?

Note: There is nothing that can be done about this with a manual boost tee. If you want to hold it steady and gain more top end, well - You will need electronic boost control.....

Yeah that was kind of the same feedback my tuner gave me. 
the boost tee is until I can sort out my plan for the electronic boost controller and what I’d get, where I’d mount the dash etc. 

I’m happy with this until I can figure it out. Not a big fan of the A-pillar gauges. I’d like to get a clean install of the boost gauge - something digital like GFB. 

Something like that might fit neatly where the ashtray is and look clean. I feel like replacing the OEM triple gauge is a bit extreme for a weekender like my skyline. And it’s not making crazy power to need all the additional sensors/gauges. 

[Milkmun]

Glad it all went smooth. How long did the tuning process take?

[DraftySquash]

On 17/2/2025 at 10:00 PM, Milkmun said:

Glad it all went smooth. How long did the tuning process take?

It was roughly 3.5 hours. 
 

car went in around 11:00 and I was done around 2:30

He did the initial runs, install the BC and then Nistune install and tune. 
The best part was sitting in the lobby and hearing the skyline on full throttle at the dyno 😂😂

[joshuaho96]

12 hours ago, DraftySquash said:

Yeah that was kind of the same feedback my tuner gave me. 
the boost tee is until I can sort out my plan for the electronic boost controller and what I’d get, where I’d mount the dash etc. 

I’m happy with this until I can figure it out. Not a big fan of the A-pillar gauges. I’d like to get a clean install of the boost gauge - something digital like GFB. 

Something like that might fit neatly where the ashtray is and look clean. I feel like replacing the OEM triple gauge is a bit extreme for a weekender like my skyline. And it’s not making crazy power to need all the additional sensors/gauges. 

I would not replace the gauges. A well setup tune should never require any of that. I'm of the opinion that if you can't safely hand over a car to your parents to drive it's not fit for purpose and more engineering work should be done. Honestly I'm not a fan of external boost controller boxes either but if you have to you can shove the controller into the glovebox or something once it's set up. Tee it off the OEM MAP sensor. Also you probably want to put a two pin plug on the new solenoid, bolting it to the OEM location works. Just separate the wastegate line and compressor outlet so it will work on a 3 port solenoid, kevboost was walked through how to do this on an RB26, same idea just different locations on an RB25. You may have to remove the restrictor in the OEM hoses if they're still in there. 

[GTSBoy]

21 minutes ago, joshuaho96 said:

I'm not a fan of external boost controller boxes

Absolutely nothing wrong with a Profec or similar. He's on a Nistune, so external boost control is a better option anyway.

 

[joshuaho96]

2 hours ago, GTSBoy said:

Absolutely nothing wrong with a Profec or similar. He's on a Nistune, so external boost control is a better option anyway.

 

Yeah, it's more a personal pet peeve. I would rather go standalone purely to avoid putting in a Profec or whatever other standalone EBC.

[MBS206]

5 hours ago, joshuaho96 said:

Yeah, it's more a personal pet peeve. I would rather go standalone purely to avoid putting in a Profec or whatever other standalone EBC.

Sometimes a piece of hardware built to do one job excellently, can be better than a piece of hardware trying to do 20 jobs "well enough".

[joshuaho96]

2 hours ago, MBS206 said:

Sometimes a piece of hardware built to do one job excellently, can be better than a piece of hardware trying to do 20 jobs "well enough".

Isn't the whole point of this integrated circuit thing to put a bunch of hardware all in one little package? Integration also brings its own benefits, at least in theory. If you were to put an electronic wastegate or do an N54-style vacuum wastegate that is normally fully open but closes under vacuum integrating everything allows you to do tricks like full wastegate bypass at cold start to warm the cats or in eco-mode under a certain torque request to reduce exhaust pumping resistance. Or full bypass as a limp mode if a certain amount of knock is detected. Or managing the compressor so it never reaches the surge point.

None of this is strictly necessary per se but standalones generally have good enough boost control. PID control isn't exactly some crazy difficult problem to solve.

[MBS206]

32 minutes ago, joshuaho96 said:

Isn't the whole point of this integrated circuit thing to put a bunch of hardware all in one little package? Integration also brings its own benefits, at least in theory. If you were to put an electronic wastegate or do an N54-style vacuum wastegate that is normally fully open but closes under vacuum integrating everything allows you to do tricks like full wastegate bypass at cold start to warm the cats or in eco-mode under a certain torque request to reduce exhaust pumping resistance. Or full bypass as a limp mode if a certain amount of knock is detected. Or managing the compressor so it never reaches the surge point.

None of this is strictly necessary per se but standalones generally have good enough boost control. PID control isn't exactly some crazy difficult problem to solve.

The issue still requires a human to get all the logic right, and each thing being done takes up processing power. Meaning less processing power for other tasks to occur too.

It also typically means a team of size 10, is working one everything, vs 5x teams of 3 working on separate products, so less man power to review and perfect it all.

 

That's the typical issue of AIO. It's also why manufacturers of cars even split tasks out into separate systems, and share data as required

[Milkmun]

On 17/02/2025 at 10:08 PM, DraftySquash said:

It was roughly 3.5 hours. 
 

car went in around 11:00 and I was done around 2:30

He did the initial runs, install the BC and then Nistune install and tune. 
The best part was sitting in the lobby and hearing the skyline on full throttle at the dyno 😂😂

So what now? Enjoy it and go cruising or more modifications?

Few meets/cruises happen in the west every now and then, should definitely take it out.

[joshuaho96]

10 hours ago, MBS206 said:

The issue still requires a human to get all the logic right, and each thing being done takes up processing power. Meaning less processing power for other tasks to occur too.

It also typically means a team of size 10, is working one everything, vs 5x teams of 3 working on separate products, so less man power to review and perfect it all.

 

That's the typical issue of AIO. It's also why manufacturers of cars even split tasks out into separate systems, and share data as required

I really find it hard to believe that boost control demands enough compute that it needs its own module. Especially if the only real logic is closed loop boost control + adjustable boost target based on a dial or ethanol content.

[DraftySquash]

On 18/2/2025 at 9:52 PM, Milkmun said:

So what now? Enjoy it and go cruising or more modifications?

Few meets/cruises happen in the west every now and then, should definitely take it out.

It’s time to take her out more on weekends!! 
First thing is a wash. I’ve got my citizenship ceremony this weekend and I’m going to roll up in her 😂😝

Next up will be getting the mechanic to look at my fuel sender O ring around mid-March. I’m saving up for a different front bar so that would be after that. But she’s running happy, so I can sleep easy and slow down. Not chasing power for now. 
 

yeah, I’d like to take her down to some meets. but when you’re not on social media anymore, it’s not easy to find those out on time 😂

[Milkmun]

On 19/02/2025 at 11:02 AM, DraftySquash said:

It’s time to take her out more on weekends!! 
First thing is a wash. I’ve got my citizenship ceremony this weekend and I’m going to roll up in her 😂😝

Next up will be getting the mechanic to look at my fuel sender O ring around mid-March. I’m saving up for a different front bar so that would be after that. But she’s running happy, so I can sleep easy and slow down. Not chasing power for now. 
 

yeah, I’d like to take her down to some meets. but when you’re not on social media anymore, it’s not easy to find those out on time 😂

Congratulations on the citizenship, that's huge. Needs to be celebrated with a skid, true Aussie style (post vid) 😂 

There's a cruise this Sunday to Lorne if you're keen, meeting at Derrimut. PM me for more details if you want to come and I'll happily meet up with you beforehand.

[DraftySquash]

On 19/02/2025 at 10:08 PM, Milkmun said:

Congratulations on the citizenship, that's huge. Needs to be celebrated with a skid, true Aussie style (post vid) 😂 

Hahaha thanks mate

 

 

On 19/02/2025 at 10:08 PM, Milkmun said:

There's a cruise this Sunday to Lorne if you're keen, meeting at Derrimut. PM me for more details if you want to come and I'll happily meet up with you beforehand.

That's very cool! But I've got a lunch booked on Sunday with the fam bam. But I might come to the first meetup at least. Will PM you