Boost compensator, do I need one? (1 Viewer)

[Sethsquatch1]

Hey all!
Still working out kinks on the new to me 1991 HZJ77 I bought a couple months ago.
One of the things it came with was a boost compensator, new but not installed.
The engine has a Holset turbo running at 12psi (per previous owner).
The engine runs strong now, I can do 80 mph with little trouble, and accelerate to keep up with traffic.
I have run maybe 3 tanks through it and get around 15 mpg.
I have never driven any other HZ so I have no frame of reference, I did have 2 fj60s and this feels like a rocket compared to them.
My question is the thread title. Do I need a BC? What exactly would it do for me? Would I see a drastic improvement in mpg or power? EGT is always a concern too, would it help it run cooler?

Any advice is appreciated. Thank you!

 

[JDM Journeys]

What trans? Tires? With my rtt off the top, I can regularly return 20 mpg (11.6L/100km). But mine is n/a and would never be a rocket unless it was falling and had reached terminal velocity.

Do you have a high alt comp on top right now?

 

[Sethsquatch1]

What trans? Tires? With my rtt off the top, I can regularly return 20 mpg (11.6L/100km). But mine is n/a and would never be a rocket unless it was falling and had reached terminal velocity.

Do you have a high alt comp on top right now?

Sorry, it's a 5 speed, 35s on it now. Has a roof rack.
Stock gearing as far as I know. Not sure on the high alt. How would I tell this?

 

[ATL Cruiser]

I cannot imagine tuning a turbo without a boost compensator. It's honestly impossible. Yes, you need one.

Read this, including the link to the site with all the graphs.

1HZ: GTurbo + PDI intercooler + 3" exhaust - https://forum.ih8mud.com/threads/1hz-gturbo-pdi-intercooler-3-exhaust.1295807/post-14642767

 

[JDM Journeys]

There are those that have boosted without a BC. But I can't add any more than that.

To identify what yours has or doesn't have right now, look at the top of your pump. If the throttle linkage is essentially at the top, then you probably have a non compensated pump. The HAC has a Chimney, or a top hat that sticks up.

For install details on retrofitting the HAC and by extension the boost compensator, check out my thread on the subject here:

Thread 'High altitude compensator 1HZ retrofit?' High altitude compensator 1HZ retrofit? - https://forum.ih8mud.com/threads/high-altitude-compensator-1hz-retrofit.1251575/

Obviously tuning the BC is a whole other ballgame.

 

[Sethsquatch1]

There are those that have boosted without a BC. But I can't add any more than that.

To identify what yours has or doesn't have right now, look at the top of your pump. If the throttle linkage is essentially at the top, then you probably have a non compensated pump. The HAC has a Chimney, or a top hat that sticks up.

For install details on retrofitting the HAC and by extension the boost compensator, check out my thread on the subject here:

Thread 'High altitude compensator 1HZ retrofit?' High altitude compensator 1HZ retrofit? - https://forum.ih8mud.com/threads/high-altitude-compensator-1hz-retrofit.1251575/

Obviously tuning the BC is a whole other ballgame.

I'm not the most educated when it comes to engines, obviously, but doesn't the turbo negate the need for an altitude compensator?

 

[JDM Journeys]

I'm not the most educated when it comes to engines, obviously, but doesn't the turbo negate the need for an altitude compensator?

My point was to show the install... If you're switching from one to the other the process should be very similar.