Help with SC boost
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,120
Likes: 1
From: Biloxi Ms
Help with SC boost
Hey guys
Question:
Today it was 93 degrees out with probably 90% humidity
I gave a couple of pulls on my car and noticed that the boost didnt get up to the normal 7.4-7.6 psi it used to but would only maybe go to 6.2
I have a Maggie SC with the 7.4psi pulley on it and a MagnaCooler
Is this something i should be worried about.
If i didnt watch the boost i would have never noticed the difference.
I then later did some pulls in 84-86 degree weather and it still showed 6.2-6.4
what happened to the 7.6 I was running?
The only thing I did was change the thermostat to a 160 degree one, versus the 180 i had in there before
Any ideas?
Question:
Today it was 93 degrees out with probably 90% humidity
I gave a couple of pulls on my car and noticed that the boost didnt get up to the normal 7.4-7.6 psi it used to but would only maybe go to 6.2
I have a Maggie SC with the 7.4psi pulley on it and a MagnaCooler
Is this something i should be worried about.
If i didnt watch the boost i would have never noticed the difference.
I then later did some pulls in 84-86 degree weather and it still showed 6.2-6.4
what happened to the 7.6 I was running?
The only thing I did was change the thermostat to a 160 degree one, versus the 180 i had in there before
Any ideas?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Look for black dust around the Maggie pulleys up front and in back. You may need to adjust the tension in the back or you may need a better tensioner like one from ECS. I have one for sale that I only used for 500 miles. PM me if you're interested. Also, make sure your blower/intake bolts didn't come loose. They will blow boost past the intake seals if they come loose.
Race Director
Joined: Apr 2005
Posts: 10,179
Likes: 2,306
From: Wesley Chapel, FL Las Vegas, NV
Look for black dust around the Maggie pulleys up front and in back. You may need to adjust the tension in the back or you may need a better tensioner like one from ECS. I have one for sale that I only used for 500 miles. PM me if you're interested. Also, make sure your blower/intake bolts didn't come loose. They will blow boost past the intake seals if they come loose.
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,120
Likes: 1
From: Biloxi Ms
well it just seemed weird that suddenly it went from 7.6 psi almost constant to 6.4 psi almost constant
i mean to me that seems more like a setup or tuning problem.
like ie. it was the pulley
since anything else i would think you would see fluctuation and not constants
i mean to me that seems more like a setup or tuning problem.
like ie. it was the pulley
since anything else i would think you would see fluctuation and not constants
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
I agree with Vegas. The boost gauge might have an equalization screw on the back. You might want to check for that. At least make sure your boost is on 0 when the engine is off. Is there dust around any of the pulleys front or rear? Is your belt glazed?
Race Director
Joined: Apr 2005
Posts: 10,179
Likes: 2,306
From: Wesley Chapel, FL Las Vegas, NV
Mechanical or Electric Boost gauge. Maybe a leak in the vacuum/boost line ?
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,120
Likes: 1
From: Biloxi Ms
i think it is a mechanical (its a dakota digital). didnt install it
but i think it is one that t's into the vac lines of the sc.
again not sure
as for dust, i dont know yet. it has been raining here and i havent gotten a chance to go look at the car uncover it or anything.
hell my butt barely got out of this chair today ;-(
but i think it is one that t's into the vac lines of the sc.
again not sure
as for dust, i dont know yet. it has been raining here and i havent gotten a chance to go look at the car uncover it or anything.
hell my butt barely got out of this chair today ;-(
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski