I have been trying to isolate a boost problem I have been having. When the 1st turbo is on line, I hear a sharp whooshing, sounds like a boost leak, almost through the BOV but I cant find it. When the second turbo comes on line, the car pulls hard, id say more normal, and I cant hear it ( or its drowned out by the exhaust note) I have swapped out 2 different blitz valves (and the stock one) and they all work the same All hose/connections are good, unless maybe the y-pipe inlet? I havent gotten that far into the turbo. Is there a procedure to test the CCV? Does it sound like it might be? If I remove it from the system entirely what should the symptoms be like?

I suppose it could be exhaust but I highly doubt it. I have a slight ticking sound, that I believe is an exhaust leak. this sounds like a leaky

Thanks for any advice you can offer me

 

You sure you didn't pop-off/split one of the small hoses going to either the Turbo Precontrol Actuator, the Wastegate Control Actuator, or the Pressure Chamber? They are easy enough to check... so you probably already did.

Use the air compressor on the intake method to help find the leak.

 

Sounds like it could be your CCA. I would "T" into the vacuum line going to it from the LIM. Make sure you're getting vacuum until 4,500. You can go here for more info https://www.rx7club.com/forum/showth...threadid=98645 http://home.istar.ca/~dvandit/rx7stuff.shtml

 

The wooshing sound is normal pre-4500 RPM. Once there, the CRV (charge relief valve) closes, thus the lack of sound on the second turbo. This is normal, but 4-2-10 is not. If, you are missing a restrictor pill in the prespool line, you could cause the primary turbo to not spool up past 4 psi which would cause a very low to no transitional boost pattern. I am guessing that the 10 psi takes a while to reach after the transition.

 

It was running fine up until about a week ago, and then it started having this problem. I thought it was an exhaust leak at first, since I just did a catback, but the boost problem seems to eliminate that( plus I imagine itd be louder.. this sound is like SHHHHHHHHH really loud. When number 2 is running it boosts fairly quick, sluggish on the switchover though.