hellotbone

Does anyone know the decrease on our trucks when you are climbing in altitude? Im at 807' here but when you get up say 5000 how much loss is there or is there loss with a turbo? Or is it just smokier when you get higher?

03CTDCO

I live out here in Denver and camp up in the mountains as
much as possible. For normally aspirated (NA) engines its a pretty
solid 2.5 to 3% loss per 1000". Now turbocharged cars out
here have a lot more power than NA but they too drop off
the power curve at some point. Turbo's also spin at higher
rpms in the thin air up here.
I've had my new HO CTD
for about a week now and I'm impressed with the power
it puts out at 5600 ft. I have not pulled our 30 ft trailer
up to 9000-10000 ft yet but when I do I'll let you guys know.

Mexstan

Have not seen any charts on this but I am guessing that the turbo powered engines run virtually full power up until around 12,000 to 15,000 feet. I have not detected any difference in power between sea level and around 8,000 feet.

banshee

Not sure about uncorrected dyno numbers, but I know that my dad ran 1.1 seconds quicker at sea level compared to Denver (a mile high) in similar weather. He was 14.4s at ~5000 feet and down to 13.3s at sea level. You can put those in the formula to get estimates on the hp difference. His truck weighs 6800 with him in it.

John

drawson

There is a greater loss at the altitude goes up even for turbo engien it just isn't was great as it is on normally asperated engines.
But it also goes further than that the turbo has to work a lot harder to make the same boost and the intercooler doesn't do as good as job cooling the air because there is less air pressure touching the outside of the intercooler.

I haven't actuaaly done any good dyno info at lower levels but I can tell you when I get to the Oregon coast from my place here in Utah(5500 feet), my truck spools faster, smoke alot less, and the EGTs are alot lower towing the same speeds.

wyofirefighter

I think the 3% per 1000' is fairly universal. The air density doesn't change do to the turbo! Adibatic rate of change is a rule of thumb, but a fairly accurate one, and the density of the atmosphere is the determining factor here. Just my opinion, could be wrong.

LE

I too go to the Oregon coast every year @ Labor day to ride. I tow my enclosed trailer which weighs roughly 8K loaded. I have not noticed any power increases, or boost differences from here in Utah @ 5,oooft. I did notice however, that my mielage was significantly better at sea level. I am not sure what the deal is with that. LE

98rammer

i've noticed about an 8psi boost drop from sea level to 7200ft. spool up takes and extra 1-2 seconds depending on weather and power is down. once spool up gets going, the power is there, but you can tell it's missing some.

Tom

Bearfoot2

I've travelled from coast to coast and notice no difference from sea level to 14,000 feet.

Interesting...the comments of those who notice a difference come from those with 12v and those who notice no difference, or very little difference, come from those with 24v. A couple with no signatures so don't know what they drive. Don't know if it makes a difference (I'm not a scientist, chemist, or physicist, nor a mechanic) but in this very short thread there appears to be a difference. Just an interesting thought.

Stan

chuck3

I can tell a difference when I tow my trailer up into the 8 to 9 k elev from here in the valley at 4 k, lots more smoke.

98rammer

all stock diesels put out a little smoke. if you add a fueling box ( even just an EZ) you'll get a lot more smoke. my buddies HO smokes and it's stock. it does take off a lot better though.

Tom

Scotty

Travelling throughout the West and over to Texas I did notice that my trucks acceleration at sea level was much better then when over 5,000'. My truck is a 24V.
I also noticed increased smoke on the bottom end at elevations over 5,000'. Its even more noticable over 7500'.

I was pulling a 36ft 5th wheel that weighed in at just over 13,000 lbs. Travelling through mountainous terrain at lower elevations was much easier on the fuel and the truck simply ran better.

It was not as bad as my previous 12V.

My George Foreman Grill functioned perfect at all rpm ranges and elevations. :

MSchoenheider

I think that stock trucks, or trucks with turbos that are opperating in there effiient range will perform almost identically at sea level or at higher elevations. As you go up in elevation, the atmospheric pressure feeding the turbo decreases. Sea level, Patm is about 14.7 psi. At 7000 feet, Patm drops to about 11.3 psi. At this elevation, the pressure ratio needed to achieve 30 psi gauge is 3.66 versus at sea level, a pressure ratio of 3.04 is needed to get 30 psig. So if your turbo is close to the limit at sea level, it will fall on its face at elevation.
Mark

BigBlue

I don't know. The farthest I've traveled was to the Hill Country of Texas :. I don't know if it was cause my FP was screwed up or what, but smoke was a little easier to produce. Not much, just barely. I also was only getting bout 26-28 psi of boost where I normally spit out 30-33.

03CTDCO

What is the max boost (in psi) for the new HO CTD ????
Thx, 03CTDCO