Power loss at high altitude on s/c driven motor???
01-13-2012, 09:22 PM
#1
Senior Member
Thread Starter
Power loss at high altitude on s/c driven motor???
Johannesburg, South Africa (where i live) is approximately 1600 meters above sea level.
I know that high altitude adversely impacts the performance of both forced induction and naturally aspirated vehicles.
I also know that turbocharged vehicles loose less power at high altitude than do naturally aspirated vehicles. Until recently, I thought that supercharged vehicles, while suffering a greater power loss at high altitude than turbocharged vehicles, were still better off than naturally aspirated vehicles. My local tuner maintains however that supercharged vehicles suffer as big a power loss at altitude as do naturally aspirated vehicles.
Is my local tuner correct?
I know that high altitude adversely impacts the performance of both forced induction and naturally aspirated vehicles.
I also know that turbocharged vehicles loose less power at high altitude than do naturally aspirated vehicles. Until recently, I thought that supercharged vehicles, while suffering a greater power loss at high altitude than turbocharged vehicles, were still better off than naturally aspirated vehicles. My local tuner maintains however that supercharged vehicles suffer as big a power loss at altitude as do naturally aspirated vehicles.
Is my local tuner correct?
01-13-2012, 09:48 PM
#2
MBWorld Fanatic!
Join Date: Oct 2011
Location: Chicago
Posts: 1,212
Likes: 0
Received 5 Likes
on
5 Posts
03 E55 AMG, 06 Harley Road King Custom 06 Ram 2500 Cummins, 97 Firebird Race Car, 88 Cutlass Supreme
Definitely not. Superchargers will still add more power at high altitudes then a naturally aspirated motor would have.
01-13-2012, 10:20 PM
#3
MBWorld Fanatic!
Join Date: Jan 2004
Location: Salt Lake City (but not Morm)
Posts: 7,092
Likes: 0
Received 12 Likes
on
10 Posts
2003 E55 & 2014 GL550
No idea but for example my car ran 11.4 at sea level and 12.5 at 1300meter elevation with a density altitude of 1900meters. You lose about a sec and for you a bit more. I would go turbo. They do MUCH better up here. Modded s600 ran 11.7!!
Just bring your own oxygen
01-14-2012, 11:40 PM
#7
MBWorld Fanatic!
Join Date: Jul 2010
Location: Colorado
Posts: 1,477
Likes: 0
Received 1 Like
on
1 Post
07' SL65, 04' E55, 03' Evo8, 08' GSXR, DSM's...
I live in Colorado at around 6k ft and the car still performs pretty well, and have had it higher in elevation too. You will see a power loss but no where near what a n/a car would feel like. Whoever you're talking to doesn't know what he's talking about.
Aaron
Aaron
Trending Topics
01-15-2012, 12:41 AM
#8
MBWorld Fanatic!
01-15-2012, 02:28 AM
#9
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 202 Likes
on
155 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
the mathematical equation for power reduction due to elevation oxygen restriction is:
hp loss = (elevation x 0.03 x hp @ sea level )/1000
this only applies to NA motors as F/I motors are basically adjusting the power back to sea level equivalents within its mechanical means (meaning size of turbine or s/c max output is the max it can adjust power to compensate for altitude).... A supercharger can be thought of either as artificially increasing the density of the air by compressing it or as forcing more air than normal into the cylinder every time the piston moves down.
in airplanes the point of a turbocharger or s/c is to develop sea-level power as altitude increases so they will not suffer power drop (again until its mechanical limit is reached) like a NA engine will. So depending on how big your turbo or s/c is and at what percent of its max output you are running it at will determine at what altitude oxygen deprevation will start to cause power loss on you engine.
hp loss = (elevation x 0.03 x hp @ sea level )/1000
this only applies to NA motors as F/I motors are basically adjusting the power back to sea level equivalents within its mechanical means (meaning size of turbine or s/c max output is the max it can adjust power to compensate for altitude).... A supercharger can be thought of either as artificially increasing the density of the air by compressing it or as forcing more air than normal into the cylinder every time the piston moves down.
in airplanes the point of a turbocharger or s/c is to develop sea-level power as altitude increases so they will not suffer power drop (again until its mechanical limit is reached) like a NA engine will. So depending on how big your turbo or s/c is and at what percent of its max output you are running it at will determine at what altitude oxygen deprevation will start to cause power loss on you engine.
Last edited by gaspam; 01-15-2012 at 02:30 AM.
You got me there!
01-15-2012, 05:44 AM
#11
MBWorld Fanatic!
Jo'Burg is killer. Go for it on the purchase of the car if you dont have one. These cars repsond amazingly well to mods, and you will be extremely happy if you indeed pick one up.
Johannesburg, South Africa (where i live) is approximately 1600 meters above sea level.
I know that high altitude adversely impacts the performance of both forced induction and naturally aspirated vehicles.
I also know that turbocharged vehicles loose less power at high altitude than do naturally aspirated vehicles. Until recently, I thought that supercharged vehicles, while suffering a greater power loss at high altitude than turbocharged vehicles, were still better off than naturally aspirated vehicles. My local tuner maintains however that supercharged vehicles suffer as big a power loss at altitude as do naturally aspirated vehicles.
Is my local tuner correct?
I know that high altitude adversely impacts the performance of both forced induction and naturally aspirated vehicles.
I also know that turbocharged vehicles loose less power at high altitude than do naturally aspirated vehicles. Until recently, I thought that supercharged vehicles, while suffering a greater power loss at high altitude than turbocharged vehicles, were still better off than naturally aspirated vehicles. My local tuner maintains however that supercharged vehicles suffer as big a power loss at altitude as do naturally aspirated vehicles.
Is my local tuner correct?
Last edited by chawkins2001; 01-15-2012 at 06:38 AM.
01-15-2012, 06:30 AM
#12
Super Member
Join Date: Jan 2011
Posts: 615
Likes: 0
Received 0 Likes
on
0 Posts
2017 991.2 Turbo PDK 2017 C63S Coupe Ceramic Brakes 2015 CLS63S AMG Full House
My supercharged cars pull like a cyclone up in Johannesburg.
01-15-2012, 06:41 AM
#13
MBWorld Fanatic!
You have quite the stable of sleds there boet Up in Johees, I bet you have to watch when you come to robots, and where you chose to park your cars
Up in Johees, I bet you have to watch when you come to robots, and where you chose to park your cars 
