Supercharger/Increased MPG? - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 01-21-2010, 08:16 AM   #11
Registered Member
 
bowtieguy's Avatar
 
Join Date: Oct 2008
Posts: 1,873
Country: United States
Location: orlando, florida
to confirm the thoughts of "no" here, take this illustration...

my oldsmobile had an option of a supercharger, w/ the same motor. according to the EPA, fuel efficiency was in fact decreased w/ that option.
__________________

bowtieguy is offline   Reply With Quote
Old 01-21-2010, 08:40 AM   #12
Registered Member
 
GasSavers_bobski's Avatar
 
Join Date: May 2007
Posts: 463
Country: United States
Yep. The issue with superchargers is that they're on all the time and boost pressure is dependent on engine RPM rather than load. As such, adding a supercharger is not much different from going to a larger displacement engine. As is generally understood, going to a larger displacement engine means more energy wasted to pumping losses and such since most of the engine's peak power output goes unused under the great majority of driving conditions.
On the other hand, turbochargers only spool up when there is sufficient exhaust flow (which is dependent on engine load), make use of what would otherwise be waste energy and present little restriction to the engine (which could affect efficiency) under low intake/exhaust flow conditions such as when cruising. Rather than increasing the engine's effective displacement by a fixed amount, turbochargers provide displacement on demand.
__________________

GasSavers_bobski is offline   Reply With Quote
Old 01-21-2010, 09:37 AM   #13
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Turbochargers do not make use of waste energy. That energy is pumped by the pistons.
__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Old 01-21-2010, 10:52 AM   #14
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
most turbo systems have a much more freely flowing exhaust system so the net difference in the turbo vs. a stock exhaust system (restrictive) is basically nothing.

that is just the way it has been explained to me. not sure if it is right or not but turbos usually have a much larger diameter exhaust as far as I have seen anyway.
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 01-21-2010, 11:02 AM   #15
Site Team
 
Join Date: Dec 2006
Posts: 656
Country: United States
Quote:
Originally Posted by bowtieguy View Post
my oldsmobile had an option of a supercharger, w/ the same motor. according to the EPA, fuel efficiency was in fact decreased w/ that option.
The non-supercharged version of the motor also had a higher CR, which could explain some of the difference.

No doubt that spinning an extra accessory will draw some parasitic HP, however. Even if it is freewheeling.

-BC
__________________
Think you are saving gas? Prove it by starting a Gas Log, then conduct a proper experiment.
bobc455 is offline   Reply With Quote
Old 01-21-2010, 05:37 PM   #16
Registered Member
 
GasSavers_goldie's Avatar
 
Join Date: Feb 2009
Posts: 53
Country: United States
Thanks for all the input and information. Because of your help, I have saved myself some grief and and a lot of money and have now given up the idea of installing a supercharger. I was hoping with all the mods on my truck (MSD coil, E3 plugs, Taylor wires, under drive pulleys, headers, Gibson exhaust, and a K & N FIPK) to add to my fuel economy. Some folks on this subject made mention of turbo's. While they sound interesting to research, I haven't found a company that makes a unit for my 4.3 engine. Any ideas?
GasSavers_goldie is offline   Reply With Quote
Old 01-21-2010, 05:52 PM   #17
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
for the kind of money you would spend on a turbo or supercharger setup on your truck, why not just buy a beater honda, saturn, or old chevy (maybe even a cavalier). maybe spend $2k or so on it.

I have a friend that has a BMW M3 (fast little thing with that straight 6) and he was in a similar dilema. he bought an '89 civic hatchback and is getting high 30s in it. he spent $1800 on the car. can't beat a beater
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 01-21-2010, 06:01 PM   #18
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Quote:
Originally Posted by BEEF View Post
for the kind of money you would spend on a turbo or supercharger setup on your truck, why not just buy a beater honda, saturn, or old chevy (maybe even a cavalier). maybe spend $2k or so on it.
...or just buy $2000 worth of gas.
__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Old 01-21-2010, 08:26 PM   #19
Registered Member
 
imzjustplayin's Avatar
 
Join Date: Dec 2011
Posts: 720
Country: United States
Quote:
Originally Posted by theholycow View Post
...or just buy $2000 worth of gas.
but that would only last you a year....not the same thing.
imzjustplayin is offline   Reply With Quote
Old 01-22-2010, 12:42 PM   #20
Registered Member
 
i-DSi's Avatar
 
Join Date: Nov 2009
Posts: 179
Country: United States
Quote:
Originally Posted by theholycow View Post
Turbochargers do not make use of waste energy. That energy is pumped by the pistons.
Hi Holy cow,
Turbochargers put indead a small load on the pistons, but this is only for a small part of the exhaust stroke true.
Major part of pressure for the turbine is delivered by the waste energy in the exhaust gas, as there is a relative high pressure and temperature in the combustion chamber that wants to come out and pushes on the turbine.
Only the last part of the exhaust stroke the piston has to do some effort to push it out, but that's really minor.
You can not tell me the piston has to push out all the exhaustgas into the turbine, do you?
Greets
__________________

i-DSi is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Not very precise mpg calculation larjerr Fuelly Web Support and Community News 4 08-20-2012 02:03 AM
Tools you keep in the car? GasSavers_maximilian Experiments, Modifications and DIY 57 10-08-2009 09:41 PM
Keeping my distance in traffic khurt General Fuel Topics 8 09-07-2008 04:23 AM
When filling up today to check my mileage I had an issue. HondaTorneoSiR Experiments, Modifications and DIY 2 06-12-2008 07:28 AM
Electrical power and cars. DracoFelis Automotive News, Articles and Products 2 09-16-2006 02:31 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 04:37 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.