Forced Induction Superchargers | Turbochargers | Intercoolers

VACUUM issue

Thread Tools
 
Search this Thread
 
Old Sep 19, 2011 | 02:28 AM
  #1  
nasty_ss's Avatar
Thread Starter
On The Tree
 
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
Default VACUUM issue

so i've been able to get the turbo on my car, and having a little bit of a vacuum issue. since it re-hooked up the vacuum gauge it's only pulling 3-4psi vacuum under idle. with the old turbo it would pull about 20psi vacuum at idle.

I have the gauge tapped in vacuum source at the map sensor line. it also is t-d to my BOV.

i've been told it might have to do with my camshaft. i'm using speedinc's TU2

Cam Duration Lift LSA
int. exh. int. exh.
TU2 236 236 .587 .587 112.5
it's on a 6.0 with wiseco -25cc pistons

looking for any advice or suggestions
Reply
Old Sep 20, 2011 | 03:31 PM
  #2  
nasty_ss's Avatar
Thread Starter
On The Tree
 
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
Default

started looking for leaks today and didn't find anything. any input would be appreciated
Reply
Old Sep 20, 2011 | 04:38 PM
  #3  
madmax4499's Avatar
TECH Apprentice
iTrader: (3)
 
Joined: Jan 2011
Posts: 379
Likes: 0
From: Tacoma, Wa
Default

i have the TU-3 and get 12 vac at idle.

how does your car run? pinch off the hose before it gets to the map, bov and see if it improves.
Reply
Old Sep 20, 2011 | 07:11 PM
  #4  
nasty_ss's Avatar
Thread Starter
On The Tree
 
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
Default

Originally Posted by madmax4499
i have the TU-3 and get 12 vac at idle.

how does your car run? pinch off the hose before it gets to the map, bov and see if it improves.
what's your compression ratio if you don't mind my asking?
Reply
Old Sep 20, 2011 | 07:16 PM
  #5  
madmax4499's Avatar
TECH Apprentice
iTrader: (3)
 
Joined: Jan 2011
Posts: 379
Likes: 0
From: Tacoma, Wa
Default

9.3 to 1
Reply
Old Sep 21, 2011 | 02:21 AM
  #6  
nasty_ss's Avatar
Thread Starter
On The Tree
 
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
Default

Originally Posted by madmax4499
9.3 to 1
mines supposed to be just under 8.5
Reply
Old Sep 21, 2011 | 08:21 AM
  #7  
rotary1307cc's Avatar
8 Second Club
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (5)
 
Joined: Jan 2007
Posts: 2,790
Likes: 123
Default

You are confused

Are you talking psi or Hg?

Big difference (two fold) most talk about vac in mm Hg not psi
Reply
Old Sep 21, 2011 | 08:24 AM
  #8  
rotary1307cc's Avatar
8 Second Club
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (5)
 
Joined: Jan 2007
Posts: 2,790
Likes: 123
Default

I have a 232/242 113 on a 10:1 370 and get 10-11 Hg at a 900rpm idle
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo
Old Sep 21, 2011 | 11:20 PM
  #9  
nasty_ss's Avatar
Thread Starter
On The Tree
 
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
Default

ran it today and it hit 8 and sorry it's def in/Hg



Originally Posted by rotary1307cc
You are confused

Are you talking psi or Hg?

Big difference (two fold) most talk about vac in mm Hg not psi
Reply
Old Sep 22, 2011 | 07:57 AM
  #10  
Ryan K's Avatar
Pathological Modifier
iTrader: (11)
 
Joined: Jan 2002
Posts: 3,626
Likes: 1
Default

Put the BOV on a separate line from the MAP sensor & gage.
Reply




All times are GMT -5. The time now is 08:39 AM.

story-0
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-1
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-2
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-3
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-4
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-5
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-6
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-7
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE
story-8
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE