It is currently Tue Apr 16, 2024 12:24 am

View unanswered posts | View active topics


Portal » Board index » Mechanical and Maintenance (no chat or performance) » Forced Induction

All times are UTC - 5 hours [ DST ]



Post new topic Reply to topic  Page 1 of 1
  [ 13 posts ] 
  Print view Previous topic | Next topic 
Author Message
irish91983
 Post subject: low boost
PostPosted: Tue Aug 07, 2012 2:28 am 
Offline
Posts like an L36
Posts like an L36
User avatar

Joined: Thu May 22, 2008 11:34 am
Posts: 853
Location: burlington, mass
Year and Trim: 2001 Bonneville SSEi
1992 Bonneville SSEi (Sold)
Hi all
So I noticed recently that I'm not getting full boost anymore. The gauge use to be pinned at full throttle and now it will not go past 7 psi. What could cause this

Thanks, Keith

_________________
Image
2001 SSEi Bumbles
Angel Eyes ~ Cleared Corners ~ Tinted Tails ~ Intense FWI ~ 20% Tint ~ 180 Drilled T-Stat ~ GXP Brake & Suspension Upgrade ~ Alternator Rewire ~ Intense Shift Kit ~ Headers ~ Tr 6's

1992 Bonneville SSEi (Sold)
Fan over ride~NGK Tr 55's~180 Drilled t-stat~Clear Corners~Angel Eyes~Tinted Tails~Magnaflow Cat
Top
 Profile  
 
J Wikoff
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 9:30 am 
Offline
Administrator
Administrator
User avatar

Joined: Mon May 19, 2008 7:01 pm
Posts: 17030
Location: Central Illinois
Year and Trim: 1992 SSE
2009 G8 GT
7 psi sounds like the normal level.

Have you made any changes recently?

_________________
Image
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers and 10" Subs, 1300 watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
Top
 Profile  
 
irish91983
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 12:48 pm 
Offline
Posts like an L36
Posts like an L36
User avatar

Joined: Thu May 22, 2008 11:34 am
Posts: 853
Location: burlington, mass
Year and Trim: 2001 Bonneville SSEi
1992 Bonneville SSEi (Sold)
I did a new set of belts. But how come before it would be pegged at 10?

_________________
Image
2001 SSEi Bumbles
Angel Eyes ~ Cleared Corners ~ Tinted Tails ~ Intense FWI ~ 20% Tint ~ 180 Drilled T-Stat ~ GXP Brake & Suspension Upgrade ~ Alternator Rewire ~ Intense Shift Kit ~ Headers ~ Tr 6's

1992 Bonneville SSEi (Sold)
Fan over ride~NGK Tr 55's~180 Drilled t-stat~Clear Corners~Angel Eyes~Tinted Tails~Magnaflow Cat
Top
 Profile  
 
01bonneSC
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 1:08 pm 
Offline
Certified Bonneville Nut
Certified Bonneville Nut

Joined: Sat May 24, 2008 5:18 pm
Posts: 4938
Location: Sycamore, IL
Year and Trim: 05 Chevy 'Hoe
1997 'maro (3.8L M5)
89 SkiDoo
Yeah 7ish is stock. Mine never ever pegged.

_________________
Image

00Beast wrote:
Less off-topic than Lane's Heated Steering wheel, but yeah, back to the topic.
Top
 Profile  
 
irish91983
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 1:18 pm 
Offline
Posts like an L36
Posts like an L36
User avatar

Joined: Thu May 22, 2008 11:34 am
Posts: 853
Location: burlington, mass
Year and Trim: 2001 Bonneville SSEi
1992 Bonneville SSEi (Sold)
That's so strange. My was always up around 10. Now it's only at 7 with all my mods

_________________
Image
2001 SSEi Bumbles
Angel Eyes ~ Cleared Corners ~ Tinted Tails ~ Intense FWI ~ 20% Tint ~ 180 Drilled T-Stat ~ GXP Brake & Suspension Upgrade ~ Alternator Rewire ~ Intense Shift Kit ~ Headers ~ Tr 6's

1992 Bonneville SSEi (Sold)
Fan over ride~NGK Tr 55's~180 Drilled t-stat~Clear Corners~Angel Eyes~Tinted Tails~Magnaflow Cat
Top
 Profile  
 
J Wikoff
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 2:34 pm 
Offline
Administrator
Administrator
User avatar

Joined: Mon May 19, 2008 7:01 pm
Posts: 17030
Location: Central Illinois
Year and Trim: 1992 SSE
2009 G8 GT
Higher-than-stock boost can be caused by exhaust restrictions, like a plugged cat or smushed pipe. A drop in indicated boost can be caused by mods that free up the airflow, like headers, higher ratio rockers, or hi-flow/no cat.

_________________
Image
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers and 10" Subs, 1300 watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
Top
 Profile  
 
Wes
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 3:04 pm 
Offline
Posts like a Northstar
Posts like a Northstar
User avatar

Joined: Thu May 22, 2008 8:09 pm
Posts: 2363
Location: Michigan
Year and Trim: 2002 Buick Park Ave
What John is describing is called boost stacking.

Here is a good description of it from http://www.gpona.com/forums/boost-stack ... t8975.html

Quote:
One way to look at it is, you motor is a big pump. It can only put out as much as it takes in. Therego, the more efficient that the air can get into the engine, the better. Only if you can have the same efficiency coming out of the engine. If you put a CAI, ported throttle body and blower on your car with a 3.5" pulley and you have little to no exhaust mods, that is bad. Sure, you let a whole bunch of air in, but it has no where to go. That's where headers come in. They are much less restrictive than stock exhaust manifolds. Ultimately your goal is to match the output to the input.

Boost stacking is when you have too much air trying to get into the engine and it has no where go. This actually causes the blower to heat up which also heats up the air coming in. This is bad. You want the coldest air possible coming in, this makes for better combustion. Now the Gen V blowers are a little bit more free flowing than the Gen 3's, I believe that is why you guys don't have to drop pulley sizes as low as the Gen 3 guys to get the same results. Also, the 97-03 guys have to worry about the bend in the stock DP which causes a lot of exhaust restriction. The 04+ guys don't have to worry about that fortunately.

_________________
Image
92 Olds 98. L67, Gen 3 M62, 2.55 pulley, FWI, PLIM, 1.8 YTs.

yourgrandma wrote:
High
Top
 Profile  
 
irish91983
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 3:10 pm 
Offline
Posts like an L36
Posts like an L36
User avatar

Joined: Thu May 22, 2008 11:34 am
Posts: 853
Location: burlington, mass
Year and Trim: 2001 Bonneville SSEi
1992 Bonneville SSEi (Sold)
So pretty much I'm gonna need to do rockers? Cause I already have fwi and headers with cat.delete.

_________________
Image
2001 SSEi Bumbles
Angel Eyes ~ Cleared Corners ~ Tinted Tails ~ Intense FWI ~ 20% Tint ~ 180 Drilled T-Stat ~ GXP Brake & Suspension Upgrade ~ Alternator Rewire ~ Intense Shift Kit ~ Headers ~ Tr 6's

1992 Bonneville SSEi (Sold)
Fan over ride~NGK Tr 55's~180 Drilled t-stat~Clear Corners~Angel Eyes~Tinted Tails~Magnaflow Cat
Top
 Profile  
 
Wes
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 3:19 pm 
Offline
Posts like a Northstar
Posts like a Northstar
User avatar

Joined: Thu May 22, 2008 8:09 pm
Posts: 2363
Location: Michigan
Year and Trim: 2002 Buick Park Ave
Not necessarily. The 7 psi you see is actually better than the 10 you previously saw if boost stacking is the issue. It means that your engine is moving more air, and not stacking excess pressure, and heat.

I don't understand why the belt change brought it down though. I would think that if you had a belt that was slipping, and you replaced it with a new one, your pressure readings would be reversed from what you stated.

And 7 psi is what a stock m90 is supposed to output. If your sig has all of your current mods, then 7 psi is where you should be if everything is working as it should.

Do the 01s still use a map sensor for the boost gauge reading? Is that maybe gunked up, or on its way out?

_________________
Image
92 Olds 98. L67, Gen 3 M62, 2.55 pulley, FWI, PLIM, 1.8 YTs.

yourgrandma wrote:
High
Top
 Profile  
 
01bonneSC
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 3:22 pm 
Offline
Certified Bonneville Nut
Certified Bonneville Nut

Joined: Sat May 24, 2008 5:18 pm
Posts: 4938
Location: Sycamore, IL
Year and Trim: 05 Chevy 'Hoe
1997 'maro (3.8L M5)
89 SkiDoo
So all you did was change the belt and now it only shows 7psi?

_________________
Image

00Beast wrote:
Less off-topic than Lane's Heated Steering wheel, but yeah, back to the topic.
Top
 Profile  
 
yourgrandma
 Post subject: Re: low boost
PostPosted: Tue Aug 07, 2012 9:26 pm 
Offline
Certified Bonneville Nut
Certified Bonneville Nut
User avatar

Joined: Mon May 26, 2008 6:56 pm
Posts: 2425
Year and Trim: '02 SSEi
Temperature has a real effect on boost levels as well. I've seen as high as 21psi on a 3.4" pulley on a -35*F day. If its warmer now than last time you noticed, that could be the explanation.

_________________
02 SSEi-Turning money into tire smoke, very efficiently.
Image
Top
 Profile  
 
irish91983
 Post subject: Re: low boost
PostPosted: Wed Aug 08, 2012 11:18 am 
Offline
Posts like an L36
Posts like an L36
User avatar

Joined: Thu May 22, 2008 11:34 am
Posts: 853
Location: burlington, mass
Year and Trim: 2001 Bonneville SSEi
1992 Bonneville SSEi (Sold)
It has been very hot and humid as hell here. I'm not sure when it actually started to read the 7 psi but I didn't notice it until week or 2 after my new belts. It could have been doing it for a while I don't really watch the boost gauge all the time.

_________________
Image
2001 SSEi Bumbles
Angel Eyes ~ Cleared Corners ~ Tinted Tails ~ Intense FWI ~ 20% Tint ~ 180 Drilled T-Stat ~ GXP Brake & Suspension Upgrade ~ Alternator Rewire ~ Intense Shift Kit ~ Headers ~ Tr 6's

1992 Bonneville SSEi (Sold)
Fan over ride~NGK Tr 55's~180 Drilled t-stat~Clear Corners~Angel Eyes~Tinted Tails~Magnaflow Cat
Top
 Profile  
 
01bonneSC
 Post subject: Re: low boost
PostPosted: Wed Aug 08, 2012 1:33 pm 
Offline
Certified Bonneville Nut
Certified Bonneville Nut

Joined: Sat May 24, 2008 5:18 pm
Posts: 4938
Location: Sycamore, IL
Year and Trim: 05 Chevy 'Hoe
1997 'maro (3.8L M5)
89 SkiDoo
irish91983 wrote:
It has been very hot and humid as hell here. I'm not sure when it actually started to read the 7 psi but I didn't notice it until week or 2 after my new belts. It could have been doing it for a while I don't really watch the boost gauge all the time.



Ok. I wouldnt really worry about it then. Does it seem any slower?

_________________
Image

00Beast wrote:
Less off-topic than Lane's Heated Steering wheel, but yeah, back to the topic.
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 1
  [ 13 posts ] 

Portal » Board index » Mechanical and Maintenance (no chat or performance) » Forced Induction

All times are UTC - 5 hours [ DST ]

Related topics
 Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Boost?

irish91983

12

2630

Thu Jun 17, 2010 1:11 pm

irish91983 View the latest post

There are no new unread posts for this topic. No boost

dave1003

7

4060

Tue Apr 19, 2011 1:17 pm

myfirstbonnie View the latest post

There are no new unread posts for this topic. Low Boost

danseaview

6

2828

Thu Oct 25, 2012 9:15 pm

danseaview View the latest post

There are no new unread posts for this topic. Too much boost?

BonnieBoy08

12

2830

Fri Jun 07, 2013 9:04 am

BonnieBoy08 View the latest post

There are no new unread posts for this topic. how much boost am i making

1999_pontiac_ssei

3

1862

Tue Aug 17, 2010 10:48 am

willwren View the latest post

 


Who is online

Users browsing this forum: No registered users and 4 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group
Hosted and managed by Black Label Web Solutions


phpBB SEO