Forced Induction at High Altitude Question (2 Viewers)

[frontrange]

Is anyone predominately using a turbocharger at high altitude? I'm at over 7000 ft above sea level and planning a 2F turbo.. I'm wondering if I should just size everything as if I was at sea level, or if I should take special measures given elevation? Thoughts?

 

[Poser]

2F turbocharged engines are far from a common commodity out here....



The only one that I am aware of operates at two-thousand feet above sea level, around Las Vegas.



I would just install a fuel-injected small block.

There is no replacement for displacement.

 

[frontrange]

I'm not going in that direction. I have no problem with the second gen SBC (LT1) in my vette, I've rebuilt them, I have a spare LT1 sitting in my garage taking up space and I know the merits over an old I6. It's just isn't my choice for a Land Cruiser.

 

[BEE-JAY42]

Cummins use a compounding turbo setup to compensate for high altitudes, might pay to look into a twin turbo setup. I'd speak to turbo speacilist about it, you might find that you can use a set of turbos off a supra or something like that.

 

[frontrange]

Honestly, I don't think I could fit anything like that in a 40. I'm wondering if I should err on the side of making the turbo on the small side, given the limited charge density available to drive it. I'm also wondering if there are different types of boost control devices. Like do they work on the basis of absolute pressure (giving a larger boost at altitude) or is the boost always a set PSI above what ever the atmospheric pressure is?

BTW, my goal is more to counter the loss of power at altitude (think drivability in mountain passes) than to try to be Speed Racer.

 

[Poser]

What are you going to use for fuel delivery?

 

[frontrange]

While most people use a surge tank and secondary pump to get the required pressure for fuel injection, I've given up on that approach. Serveral attempts over the years always resulted in short term failure of the secondary pump, presumably from overheating. I'd say there is a good reason why all the fuel injected cars that roll off of the production line have pumps in the tank, so I went that way and made my own tank using a spare Corvette fuel pump inside of it. It's hard to see from this photo, but next to the sender I have AN fittings for delivery, return, and the charcoal canister. The inspection plate allows for replacement of the pump if it fails of course.

 

[71FJ40]

You can control boost through the use of different aspect ratio (AR) turbo setups and
A boost control valve

But what are you going to do for fuel delivery?

 

[frontrange]

What do you mean by fuel delivery? Pressure regulation or injection? For injection, I'm using port injection with a 3FE manifold on a 2F head. I haven't looked at FMU's yet for regulation of fuel pressure.