there is a loud whooshing sound coming from my engine when i am on partial throttle. i read somewhere that it can be caused by a bad Charge relief solenoid but i have already replaced that recently when it started showing up on my engine check light. with it replaced, nothing had changed. does anybody have any ideas of what it might be? maybe a cracked crossover tube or bad gaskets in the intake somewhere? i have already replaced the lower intake gasket as well. thanks

ryan

 

Do you have a boost gauge? What is the boost pattern? Does it happen before, after, or during the 4500 RPM transition? Does it feel like it accelerates slower when you hear the noise? I ask because it will help dignose the problem.

When I had that noise it turned out to be a split coupler on the Y-Pipe that only opened when the 2nd turbo came online at 4500 and vented all my boost. I got an Efini Y-Pipe to solve the problem for good.

 

the sound happens when im at lower rpms. when i hit 4500rpms my car seems to lose its pull and it sounds really loud and raspy like there is a leak

 

Sounds like you have a very bad boost leak. Check the Plastic crossover and rubber coupler sections of the Y-Pipe. You will have to take them off to see the damage because often it will look fine, but when squeezed (or pressurized from boost) the cracks/splits open.

 

oops..by the way. my boost pattern will pull really hard at first (10-12lbs) and after i hit 4500 my car will immediately change sound like something popped off or something....and my car wont pull hard after that point. also, when i shift at those higher rpms and instantly get back on the throttle i wont get any boost and my car will just bogg. if i wait a few second and then push the gas, i will get full boost again until i hit 4500-5000rpms and it will keep repeating.

 

i read somewhere that if i dont get +4lbs of boost reving my car in neutral then i may have a leak between the turbo and intake manifold somewhere. is this true? when i rev my car in neutral i will get a pound or boost at most two pounds. hope this info helps. willing to try anything. please help. havent been able to take my car to redline for over a year

 

jus check those places and every hose that involves the turbos(which is alot,check most common hoses to go first) but its the only way to find wut the problem is...and then tell us ur findings.
geoff

 

why not, if its cuz of this boost problem...thats really bad, even worse if u drove the car a good amunt.

 

sounds like you got a little hose popped off somewhere......

 

Check Ic pipes and Y pipe

 

thanks guys.... i'll check all the hoses and stuff and let you know whats up.

 

do you have a aftermarket waistegate ?

 

yeah, but if he's getting full boost from the primary, then the IC and Y pipe are fine, no? He's leaking at transition, 4500 RPM. Like Turbo Control solenoid vacuum line is off? This gets switched "open" at 4500, right? But this would only make the secondary boost come late and weak with whoosh, not not at all and whoosh.

The charge relief vents secondary boost to the air cleaner by default, then closes at 4500 rpm when the charge control allows secondary boost to enter intake stream at or above 8 psi, right? The closing occurs due to a vacuum signal right? And that vacuum signal comes from the vacuum chamber, NOT from manifold vacuum as we are under positive pressure here. So you would boost fine off the primary, spool up the secondary, open the charge relief solenoid, and get a whoosh of vacuum as the charge relief hose is pointed to air (not connected), boost would die as the vacuum signal to the turbo control and wastegate is lost as well, and all boost operations would be shut down until engine vacuum had been established long enough to get the vacuum chamber sucked down again, right? This is what he just described, right?

go here.
http://www.autosportracetech.com/RX-7/rx7stuff.htm