3800 SC II boost info.

[skot917]

Does anyone have a guideline of what SC boost should be produced at rpm/throttle position? I think my 97 GS is underboosting.
Thanks.

 

[murphinator]

if you are seeing 4 psi by any chance it is a boost bypass valve or boost bypass solenoid issue

warm climate stock car around 6-7 psi cold climate during winter I have seen 10 psi stock car

boost doesnt equal power on these cars the exhausts on some cars can be pretty restrictive and cause boost stacking

 

[skot917]

Thanks Murphinator. I'm currently lucky to get up to 4. I think after some research and then testing it may be either the boost control actuator or solenoid, or both. Are these GM only parts?

 

[murphinator]

gm if you want new with a side of good ass raping

buy them used you would have to get 5 bad ones in a row to add up to the cost of new

you can pull the vac line from between the 2 and block it off temporarily to get full boost but it will boost when you dont want it to boost also so use caution

both parts are easy to swap so I just swap from one of my known good cars until I determine what part was bad , got any friends with L67's ??

 

[skot917]

Thanks Murphinator,
I think I've tested the BCA and BCS well and they don't seem to be the problem. Is there a way to check the boost with a pressure gauge, to see if my digital gauge is faulty?

 

[murphinator]

sure , plenty of people have installed aftermarket boost guages on these cars , I havent personally I just use my digital one and verify with my scanner

I would think you would be plumbing in somewhere between the port under the snout , around the fpr , or around the bbv/bbs so somewhere around that front valve cover. anyone witha boost guage lurking that can verify ?

 

[skot917]

Didn't even think of checking with a scanner... will do so now.
Thanks!

 

[flyboy367]

disconnect it and have someone tune it with a dhp. the bbv workes under vaccume just fine it doenst need the computer to do its job too