Forced Induction Superchargers | Turbochargers | Intercoolers

How much boost is lost over the FMIC??

Thread Tools
 
Search this Thread
 
Old 02-09-2007, 10:31 AM
  #1  
TECH Resident
Thread Starter
iTrader: (4)
 
pdanrichey's Avatar
 
Join Date: Nov 2004
Location: Keller, TX
Posts: 768
Likes: 0
Received 1 Like on 1 Post

Question How much boost is lost over the FMIC??

Specifically, how much will I lose on the STS kit plus the FMIC. STS claims a loss of 1/2 psi through just the piping. Now, compound that loss on top of the FMIC and I'm thinking the turbo is going to have to push 10+psi just so my intake sees 7.5psi.

Verses running a long *** vacuum line up to the engine, I'm just going to use a boost controller to adjust as needed, referencing the psi for the wastegate at the compressor housing.

Any thoughts on this?
Old 02-09-2007, 12:44 PM
  #2  
TECH Fanatic
iTrader: (4)
 
99Z28LS1's Avatar
 
Join Date: Mar 2004
Location: San Antonio
Posts: 1,886
Likes: 0
Received 0 Likes on 0 Posts

Default

i would think the .5 psi is right. i have a 8psi spring but it RAN 7.5 psi
Old 02-09-2007, 01:02 PM
  #3  
TECH Enthusiast
iTrader: (33)
 
Speed's Avatar
 
Join Date: Jul 2002
Location: Ok
Posts: 609
Likes: 0
Received 0 Likes on 0 Posts

Default

If you pull boost signal from your manifold, you will still make what ever boost pressure you were making before but the turbo will have to work a little harder to get the air through the induction track. The only change you will notice however is some more power from your system for the same boost level.
Old 02-09-2007, 01:10 PM
  #4  
10 Second Club
iTrader: (27)
 
Snyper's Avatar
 
Join Date: Nov 2006
Location: Connecticut
Posts: 1,905
Likes: 0
Received 0 Likes on 0 Posts
Default

just turn up the boost to make up for it. :-)
Old 02-09-2007, 01:27 PM
  #5  
LS1Tech Sponsor
iTrader: (12)
 
Slowhawk's Avatar
 
Join Date: Nov 2001
Location: Bridgewater,Ma
Posts: 14,865
Likes: 0
Received 6 Likes on 6 Posts

Default

Just run the signal line from the intake.It's not hard and will make sure the boost pressure stays the same rather than drop off up top.
Old 02-09-2007, 01:48 PM
  #6  
Teching In
 
JBrady's Avatar
 
Join Date: Jun 2005
Location: Houston TX
Posts: 22
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by pdanrichey
Specifically, how much will I lose on the STS kit plus the FMIC. STS claims a loss of 1/2 psi through just the piping. Now, compound that loss on top of the FMIC and I'm thinking the turbo is going to have to push 10+psi just so my intake sees 7.5psi.

Verses running a long *** vacuum line up to the engine, I'm just going to use a boost controller to adjust as needed, referencing the psi for the wastegate at the compressor housing.

Any thoughts on this?
A good FMIC will loose less than 1psi.

At least two factors are present, total system volume and restriction of flow.

Volume is total including all common space from the compressor to the intake valve(s). The smaller the volume the higher the pressure for any given increase in airflow.

Restriction of flow is how transparent the FMIC is to the mass flow. As the charge goes through the core and cools it reduces pressure. This pressure reduction is functionally just like adding system volume and means the compressor must work harder to maintain a given amount of pressure (boost). A free flowing FMIC will allow the pressure to balance between the inlet and outlet hence the limited boost reading reduction.

That said it is mostly the MASS FLOW that determines power output. On a supercharged application the lower pressure that an intercooler creates does not mean less mass flow. In fact the supercharger will take less energy to turn and add to the gains. On a turbo as mentioned if you source your WG signal from the intake manifold it will self correct. Either way your compressor will work harder and your MF should go up and with it power. Unless you are maxing out your compressor already.
Old 02-09-2007, 02:30 PM
  #7  
TECH Resident
Thread Starter
iTrader: (4)
 
pdanrichey's Avatar
 
Join Date: Nov 2004
Location: Keller, TX
Posts: 768
Likes: 0
Received 1 Like on 1 Post

Default

I have to run a long *** vacuum line up to the engine bay. I was going to do that last night but I went to Autozone and they want $4 a foot for vacuum line!!! I was like...screw that, I need 15 feet of that stuff!! I figure with a boost controller, at least it will be easy to change the boost level to get the right amount at the intake. There is a 5psi spring in the wastegate and the controller lets me go up to 5psi over that. So, if I only lose 1 through the FMIC and .5 through the piping, I'll just run the controller at 9psi and call it a day to get my 7.5psi goal, etc...
Old 02-09-2007, 06:04 PM
  #8  
TECH Fanatic
iTrader: (25)
 
trtturbo's Avatar
 
Join Date: Mar 2004
Location: Newark, Tx.
Posts: 1,810
Likes: 0
Received 0 Likes on 0 Posts

Default

They priced you the wrong line. Should be less than $1./ ft.
Old 02-09-2007, 06:14 PM
  #9  
LS1Tech Sponsor
iTrader: (12)
 
Slowhawk's Avatar
 
Join Date: Nov 2001
Location: Bridgewater,Ma
Posts: 14,865
Likes: 0
Received 6 Likes on 6 Posts

Default

Originally Posted by pdanrichey
I have to run a long *** vacuum line up to the engine bay. I was going to do that last night but I went to Autozone and they want $4 a foot for vacuum line!!! I was like...screw that, I need 15 feet of that stuff!! I figure with a boost controller, at least it will be easy to change the boost level to get the right amount at the intake. There is a 5psi spring in the wastegate and the controller lets me go up to 5psi over that. So, if I only lose 1 through the FMIC and .5 through the piping, I'll just run the controller at 9psi and call it a day to get my 7.5psi goal, etc...
We run brake line--1/4".
Old 02-10-2007, 02:53 PM
  #10  
12 Second Club
iTrader: (6)
 
Schantin's Avatar
 
Join Date: Jun 2004
Location: Ft. Irwin, California (But Virginia is home)
Posts: 1,501
Likes: 0
Received 7 Likes on 1 Post

Default

Originally Posted by trtturbo
They priced you the wrong line. Should be less than $1./ ft.
Yep, the price is wrong. I got 15' here in Hawaii (where they overcharge for EVERYTHING for under $10. And you'll damn near need all 15' of that line too to reach the front of the engine.
Old 02-10-2007, 06:35 PM
  #11  
TECH Addict
iTrader: (5)
 
DeltaT's Avatar
 
Join Date: Jun 2005
Posts: 2,404
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Slowhawk
We run brake line--1/4".
Do you get a better response with a hard line?

Jim



Quick Reply: How much boost is lost over the FMIC??



All times are GMT -5. The time now is 12:23 AM.