High altitude compensator 1HZ retrofit? (1 Viewer)

[JDM Journeys]

I'm at 8700-feet eleven. Even though I have plenty of power and torque off-road, I would like to have just a little more power on the long uphill pavement runs where I'm rolling-coal because I have my foot into it.

My experience adding the the hac top hat was that smoke was reduced a very very small amount. Egt might have also reduced a little as well but that was at my daily altitude of 1100m. At higher altitudes it was still struggling for air and smoky. The service manual talks about the HAC parameters and might be worth reading? Ultimately it was very small gains overall...

Not terrible to add with the pump in situ if you are patient.

The best high altitude compensation is forced induction and as @janyyc said that's why I finally turboed it.

 

[JDM Journeys]

Oh one more thing. You will need new fuel hard lines off the pump. The HAC version is bent differently to attach to the soft lines.

High altitude compensator 1HZ retrofit?

Subscribed! Did you have by any chance the part number for the HAC? Please share your set up too this looks like a very good option Yours should have it already installed on your HZJ78. @JDM Journeys - I’m looking forward to following the installation!

forum.ih8mud.com

 

[Eurasiaoverland]

Can anyone shed light on exactly how the HAC works? My understanding is that it simply works against governor input (from the acclerator input crank) to reduce the amount of spill ring movement. Which is to say it is exactly the same as not pushing your foot down on the accelerator pedal so far. I don't see that it can do anything to dynamic advance or internal fuel pressure.

So basically the HAC is there to stop someone who would otherwise happily bury the pedal and ignore the plume of soot coming out of the back of the vehicle. And therefore if you drive with a little sense and awareness of what's behind you, you can just moderate your accelerator input and make the HAC redundant.

Or am I missing something?

I also believe that HAC / non HAV pumps have different injection pump housings, but can't see what would be different between them.