In Reply to: Re: Getting Partial Boost for my car.......help! posted by CoolM3 on February 12, 2000 at 20:39:24:
: My car is running fine, no bog or knocking with the lack of boost. I definitely felt a power degrade from experience, hence, my suspicion of a loss of boost. And no, I didn't do anything to my engine lately, except putting in a boost guage.
: : Well, if you know the SC is spooling, check the "piping", in particular between the SC and the throttle body for any place that might leak (not hold the pressure). Check the clamps closely. The entire system from air intake to the throttle body must be able to perform without leaking, especially from the output of the SC to the throttle body since it has pressure.
: : If you have only 1 psi of boost at "any" RPM under full throttle and you are sure the drive belt is spooling the SC, you more than likely have either a pressure leak or a wastgate problem. It's doubtful you have a damaged a SC itself.
: : Are you using an intercooler? Do you have a controller for the boost? Does the engine run and perform nicely (no busting out, bogging, etc) at this time even with the little or no boost? When did you notice the engine lacked the power (boost) it once had? Have you touched the engine (done anything) at all recently?
: : Bob ///M3
: : : No, actually my car makes 1lbs of boost at 3500rpm. My SC unit is suppose to make 6lbs of boost at 6000.
: : : CoolM3 (very frustrated and confused)
: : : : You say you're making only 3.5lbs of boost at 6,000 RPM; how much are you making at say 3,000 RPMs?
: : : : If you have 6 or 8lbs of boost at 3,000 RPMs (for example) it could be you're SC is doing all it can at the higher RPMs. If you have some proof that at one time it has produced a higher boost (at higher RPMs) than what you're seeing now then no doubt you have a problem. If this is true I'd first check the wastegate and then next check for vacuum leaks, etc. Many SC and turbos produce ample boost at low to mid RPMs but simply give out at the higher RPMs.
: : : : Bob ///M3
: : : :
: : : : : Hi,
: : : : : I have a 98 M3 with ERT's Vortech SC unit and I have just recently added a
: : : : : boost gauge to my car, due to suspicion that my car is not making full
: : : : : boost. And well, what do you know? Confirming to my suspicion, my car was
: : : : : only making 3.5lbs of boost at 6000rpm. Now here is my question, what could be
: : : : : causing this? Bad connection? wrong crank shaft? what?! I have been trying
: : : : : to figure it out with my bare naked eyes and I couldn't see anything wrong
: : : : : with my setup......pls help!!
: : : : : CoolM3
I would have thought that if your decrease in expected boost were due to a leak, then you would definitely notice lousy running, like balky acceleration, sputtering, and at least, check engine lights. I have a feeling its due to something else, or possibly, an mal functioning boost measurement guage.