for starters i have a new mazda reman with 2000 miles and 1 new turbo and another that was rebuilt all about 6000 miles ago.

It did a boost test the other day in third gear and i boosted a nine up until it hit 4500 rpm. At this point the boost level droppedand i got only 1 pound of boost and a loud sssshhhhhhhh ing sound is coming from the passenger side of the vehicle. It sounds like air escaping at a very fast rate and is very loud. Is this possibly a leak or is the turbo bad? any help will be much appreciated.

mods are pettit ecu, dp,mp cb, apex'i dual air intake

 

Did you try it again?
If you did, and it boosted to 9 again, you probably don't have a boost leak. That doesn't mean that you have a bad turbo either. I suggest that you check the vacuum hoses in front of the UIM, and behind the little black vacuum chamber. There is a good chance that you have a hose that has popped off, which is keeping the secondary turbe from coming on line.

 

Check the x-over plastic pipe on the passenger side of the engine. Look for it's coupler about a foot behind the airpump - it makes a 90 degree bend down.

 

Does it do this repeatably? Or will it only boost 1 psi all the time now?

 

Hose or a solenoid. Good luck.

 

it has been doing this for a while now. it gets to 4500 rpm and the car has like no pull what so ever. The ssshhhhh ing noise just gets louder so i dont take it over 6000 rpm.

 

Check out http://www.autosportracetech.com/RX-7/rx7stuff.htm click on 'overview' or 'troubleshooting'.
Then go to secondary turbo area, as it sounds like the primary is working just fine.

 

second turbo blow off valve (charge relief) is stuck open. at least that would cause that exact symptom. if you have access to compressed air and some kind of regulator plug both intake hoses (i used two aspirin bottles) and apply ten 10psi to the brake booster vacuum port. you will find any and all boost leaks very quickly. this will also show a bad blow off valve.

jury

 

thanks guys for all the help, it wont be until tuesday until i can get to it. any other tips or advice would be great also

 

Try swapping the wastegate and turbo precontrol solenoid electrical connections. Typically these get swapped while the engine is being worked on.

 

Pull off the hoses (Y-pipe, IC etc.) you will either find one is lose or has a hole in it.