high altitude smoke
Thread Starter
|
2nd Gear
Joined: Aug 2016
Posts: 2
Likes: 0
high altitude smoke
I have a 1997 F350 crewcab 4x4 dually. It's all stock except the Hydra programmer. I live outside of Denver at 5000' elevation. The truck runs great at this elevation. When I go to the mountains at 9500' it doesn't seem to make boost, runs out of power, blows heavy smoke. I don't have a boost guage, but it appears to be running rich. I'm getting these readings with key on engine off:
Barometer 34.3kpa
EBPV 85.8kpa
MAP 84.8kpa
Thinking about a turbo and injector upgrade but not sure what to do. Any advice is appreciated, thanks
Barometer 34.3kpa
EBPV 85.8kpa
MAP 84.8kpa
Thinking about a turbo and injector upgrade but not sure what to do. Any advice is appreciated, thanks
Mountain Pass
Joined: Aug 2019
Posts: 190
Likes: 2
From: Racine County
Don't completely quote me on this but I do believe that you will need more airflow because the air up that high is not as dense as down low so you need to find a way to flow more air to match the air density at the lower elevation. You will probably need injectors at that point as well because you will struggle to light the bigger charger on stock injectors.
Mountain Pass
Joined: Aug 2019
Posts: 190
Likes: 2
From: Racine County
I agree yet disagree, if you kept the stock wheel and went to a smaller housing you would run out of top end air so that would depend on what RPM range the OP is running in. If he is trying to run lower rpms that would work but if he is typically running higher rpms you will run out of top end airflow. If you went to a larger turbo with a larger wheel and then went with a midsized housing that would be my choice because you have more air to work with. Combine this with some slightly larger injectors and you have both more power and better at altitude performance. Just my $0.02
More Turbo
Joined: Dec 2002
Posts: 664
Likes: 129
From: Columbia, MD
The barometer reading seem off. 85 kpa is right in the range for 5,000 ft elevation. 34 kpa would be about 25,000 ft elevation. Sea level is just over 100 kpa, and 9,000 ft would be about 70 kpa. The baro reading may be fooling the PCM and chip to overfuel, yup, rich... and smoke. A boost gage would be a good diagnostic, to see what is happening at the different altitudes and smoke conditions... and the rpms and throttle at each.
What really matters for the engine is the mass of air flowing through it... oxygen to burn the fuel. Lower pressure air is less dense, higher pressure air is more dense. At 5,000 ft, ambient pressure is about 10% less than sea level, so you need about a 10% boost in pressure... about an additional 1.5 psi on the boost gage... just to maintain power. At 9,000 ft ambient is 20% less than sea level, you need about an additional 3 psi of boost to maintain sea level power. With these additional boost levels, you're not increasing the mass of air through the engine relative to sea level, you're just holding constant with altitude, and so don't need bigger injectors. If you're already smoking, you already can dump in more fuel than you have air to burn.
What really matters for the engine is the mass of air flowing through it... oxygen to burn the fuel. Lower pressure air is less dense, higher pressure air is more dense. At 5,000 ft, ambient pressure is about 10% less than sea level, so you need about a 10% boost in pressure... about an additional 1.5 psi on the boost gage... just to maintain power. At 9,000 ft ambient is 20% less than sea level, you need about an additional 3 psi of boost to maintain sea level power. With these additional boost levels, you're not increasing the mass of air through the engine relative to sea level, you're just holding constant with altitude, and so don't need bigger injectors. If you're already smoking, you already can dump in more fuel than you have air to burn.
Laughing Gas
Joined: Aug 2016
Posts: 855
Likes: 466
From: Albuquerque and Colorado
I’d suspect the programmer. My truck is stock and lives at 5000’ . Of course it makes a little less power at altitude but it doesn’t feel like it’s out of boost. It does smoke a little on the passes above 10000’ but it’s not what I consider heavy smoke.
Trending Topics
Tuned
Joined: Feb 2004
Posts: 343
Likes: 30
From: Maryville, TN
I would think an intercooler would be helpful to get the most out of the charge air density, or lack of, at that altitude.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Thread
Thread Starter
Forum
Replies
Last Post
Whitson Metalworks
1999 - 2003 7.3L Power Stroke Diesel
30
Oct 26, 2015 08:27 AM
bnd74
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
57
Mar 25, 2012 04:39 PM
billcollector
1999 - 2003 7.3L Power Stroke Diesel
2
Jul 2, 2010 06:10 PM
gunnars92f350
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
7
Feb 22, 2008 09:53 AM