Forced Induction Superchargers | Turbochargers | Intercoolers

Boost bleeding/staying constant

Old Feb 12, 2007 | 10:58 PM
  #1  
SSkeet's Avatar
Thread Starter
Launching!
 
Joined: Sep 2004
Posts: 246
Likes: 0
Default Boost bleeding/staying constant

Okay, I have a very strange problem. STS kit with GT67 and built motor.
Boost is ref'd off the manifold.

The other day I wastegated it to 9# spring and it showed 9.5 solid for a little while. Then all of a sudden it dropped back to 8#, no more, no less. It spikes to 8 and stays there. So I put an 11# spring in....same thing, 8psi.

High boost with both springs goes to 15psi then quickly drops back to 12psi and stays there.

Do I just have a leak somewhere? I checked most of the pipes and they all seem tight. I will probably get it up on the lift tomorrow and check over everything. Any way it could be my BOV? I wonder... ?
Reply
Old Feb 12, 2007 | 11:09 PM
  #2  
JD_Z28's Avatar
TECH Fanatic
iTrader: (19)
 
Joined: Jul 2005
Posts: 1,166
Likes: 1
From: Arizona
Default

Originally Posted by SSkeet
Okay, I have a very strange problem. STS kit with GT67 and built motor.
Boost is ref'd off the manifold.

The other day I wastegated it to 9# spring and it showed 9.5 solid for a little while. Then all of a sudden it dropped back to 8#, no more, no less. It spikes to 8 and stays there. So I put an 11# spring in....same thing, 8psi.

High boost with both springs goes to 15psi then quickly drops back to 12psi and stays there.

Do I just have a leak somewhere? I checked most of the pipes and they all seem tight. I will probably get it up on the lift tomorrow and check over everything. Any way it could be my BOV? I wonder... ?
I had a similar issue and found out it was just an exhaust leak at the collector. You might want to do a pressure test on the system. How is your vacum? What PSI is it at.
Reply
Old Feb 13, 2007 | 06:50 AM
  #3  
SSkeet's Avatar
Thread Starter
Launching!
 
Joined: Sep 2004
Posts: 246
Likes: 0
Default

Originally Posted by JD_Z28
I had a similar issue and found out it was just an exhaust leak at the collector. You might want to do a pressure test on the system. How is your vacum? What PSI is it at.
I'll check it out, but vac is about 18
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 10:13 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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