Tricky performance question for all you #'s guys - PowerStrokeNation : Ford Powerstroke Diesel Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 32 (permalink) Old 12-28-2009, 02:31 AM Thread Starter
just a welding fool.
 
Hawker's Avatar
 
Join Date: Jan 2009
Location: CT
Posts: 1,097
Tricky performance question for all you #'s guys

I'm basing my question on completely disregarding the turbo. hopefully some of you performance guys can chime in.

for the sake of this arguement, lets say the up-pipes are 1.5" in diameter, and the flow of exhaust gas at idle is "X" cfm. If at a point in that pipe, the diameter is constricted by 25%, so now the diameter is 1-1/8", what is the effect of backpressure on the motor? is "X" cfm now "X + 25%" cfm? does the motor have enough strength to overcome it? will the idle jump up any, if any to make a difference?

Swamps
Gearhead Tuning
Diesel Innovations
Hawker is offline  
Sponsored Links
Advertisement
 
post #2 of 32 (permalink) Old 12-28-2009, 02:35 AM
wheres the fat chicks?
 
PowerstrokeR00's Avatar
 
Join Date: May 2009
Location: Pekin, IN
Posts: 1,833
Re: Tricky performance question for all you #'s guys

??????????

2000 F-350 SD ccsb=185hp
Matt's Tunes=140hp
6637=20hp
2% window tint=25hp
4in straight pipe=50hp
Custom Fuel system w/ sump=50hp
Foil,AIH,EBPV delete=30hp
Wow...I'm making 500hp
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



Quote:
Originally Posted by stroke of luck View Post
i started sharting at an early age...
PowerstrokeR00 is offline  
post #3 of 32 (permalink) Old 12-28-2009, 02:41 AM
 
Join Date: Dec 2009
Posts: 11
Re: Tricky performance question for all you #'s guys

You listed 'X' CFM as the volume of exhaust flow... constriction will increase VELOCITY but will, overall, DECREASE VOLUME. X will be 'X - Ycfm' where Y CFM represents the volume exhaust, at idle, that a 25% constriction will cause to decrease.

Will the motor overcome that? Of course, but barring any weird science you will have a decrease in peak performance
YellerMax is offline  
 
post #4 of 32 (permalink) Old 12-28-2009, 02:48 AM
PSN Veteran
 
TARM's Avatar
 
Join Date: Nov 2009
Location: Winchester, Virginia
Posts: 4,865
Re: Tricky performance question for all you #'s guys

That gives me a 20 year flash back to high school mathematics class..


So basically what you are asking is what effect would a moderate restriction of 25% of the pipes diameter have on engine performance?
TARM is offline  
post #5 of 32 (permalink) Old 12-28-2009, 02:51 AM Thread Starter
just a welding fool.
 
Hawker's Avatar
 
Join Date: Jan 2009
Location: CT
Posts: 1,097
Re: Tricky performance question for all you #'s guys

Quote:
Originally Posted by TARM View Post
That gives me a 20 year flash back to high school mathematics class..


So basically what you are asking is what effect would a moderate restriction of 25% of the pipes diameter have on engine performance?
more or less... YellerMax made some sense out of it.

Swamps
Gearhead Tuning
Diesel Innovations
Hawker is offline  
post #6 of 32 (permalink) Old 12-28-2009, 02:55 AM
PSN Veteran
 
moore20017.3's Avatar
 
Join Date: May 2008
Location: Chesapeake, OH
Posts: 2,897
Re: Tricky performance question for all you #'s guys

Quote:
Originally Posted by Hawker View Post
I'm basing my question on completely disregarding the turbo. hopefully some of you performance guys can chime in.

for the sake of this arguement, lets say the up-pipes are 1.5" in diameter, and the flow of exhaust gas at idle is "X" cfm. If at a point in that pipe, the diameter is constricted by 25%, so now the diameter is 1-1/8", what is the effect of backpressure on the motor? is "X" cfm now "X + 25%" cfm? does the motor have enough strength to overcome it? will the idle jump up any, if any to make a difference?
You pretty much described running the up pipes into a T4 flange (or smaller). Food for thought.

Up pipes are actually 1.9something ID when they go into the T4 flange they are less, trust me.

Then you add the venturi effect into the equation, this is easily researchable to everyone and anyone in physics knows what it is. If you are running the exhaust gas through the standard 2'' tube up pipes and it goes into a 4'' downpipe the gas will excelerate in the turbine as it escapes into the less restrictive downpipe, this exceleration helps to drive the turbine wheel.

Increasing the size of the up pipes will help nothing, any increase in area pre-turbine will only increase the amount of time for the turbine so excelerate, in that this larger area will have to be filled and compressed to the same amount of pressure.

2008 F-250 SCLB Larait.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
moore20017.3 is offline  
post #7 of 32 (permalink) Old 12-28-2009, 02:57 AM
PSN Veteran
 
TARM's Avatar
 
Join Date: Nov 2009
Location: Winchester, Virginia
Posts: 4,865
Re: Tricky performance question for all you #'s guys

OK, I'll bite what is your reason for asking /wanting to know?
TARM is offline  
post #8 of 32 (permalink) Old 12-28-2009, 03:08 AM Thread Starter
just a welding fool.
 
Hawker's Avatar
 
Join Date: Jan 2009
Location: CT
Posts: 1,097
Re: Tricky performance question for all you #'s guys

Quote:
Originally Posted by moore20017.3 View Post
You pretty much described running the up pipes into a T4 flange (or smaller). Food for thought.

Up pipes are actually 1.9something ID when they go into the T4 flange they are less, trust me.

Then you add the venturi effect into the equation, this is easily researchable to everyone and anyone in physics knows what it is. If you are running the exhaust gas through the standard 2'' tube up pipes and it goes into a 4'' downpipe the gas will excelerate in the turbine as it escapes into the less restrictive downpipe, this exceleration helps to drive the turbine wheel.

Increasing the size of the up pipes will help nothing, any increase in area pre-turbine will only increase the amount of time for the turbine so excelerate, in that this larger area will have to be filled and compressed to the same amount of pressure.

now that's the stuff. would you say that increasing the velocity of the exhaust gasses through the up pipes, while losing some volume would spin the turbine faster?


"OK, I'll bite what is your reason for asking /wanting to know?" i'll get to that soon.

Swamps
Gearhead Tuning
Diesel Innovations
Hawker is offline  
post #9 of 32 (permalink) Old 12-28-2009, 03:11 AM
PSN Veteran
 
moore20017.3's Avatar
 
Join Date: May 2008
Location: Chesapeake, OH
Posts: 2,897
Re: Tricky performance question for all you #'s guys

A more basic way to say what I was getting at above....you want the exhaust housing to be the restriction in the system (nothing before or after), this will cause the gas to expand/excelerate in the housing.

So this means you want a consistant size of feed ALL the way to the turbine, then after the turbine, the bigger the better to allow rapid gas expansion and cooling. The cooling will further excelerate the process.

2008 F-250 SCLB Larait.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
moore20017.3 is offline  
post #10 of 32 (permalink) Old 12-28-2009, 03:17 AM
PSN Veteran
 
moore20017.3's Avatar
 
Join Date: May 2008
Location: Chesapeake, OH
Posts: 2,897
Re: Tricky performance question for all you #'s guys

Quote:
Originally Posted by Hawker View Post
now that's the stuff. would you say that increasing the velocity of the exhaust gasses through the up pipes, while losing some volume would spin the turbine faster?
No, your volume is constant, pressure is the variable. 90% of volume is decided by the engines displacement/speed the other 10% is amount of fuel.

2008 F-250 SCLB Larait.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
moore20017.3 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the PowerStrokeNation : Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome