I tried searching but most posts on boost pressure are about the 3000 rpm issue with FD's...

This is a bit more straight forward, it gets about 7-8 lbs of pressure when in the 2-4.5k RPM range and transitions in the 4 lbs area and goes back to 7-8 lbs... once the second turbo spins up...

I'm assuming it's one of the pressure hoses has either come off or cracked... I also understand there are 80-90 some odd hoses in the "Rats Nest" and any one could be the culprit... any tips or suggestions on how to spot the problem !? I guess I'm asking because I thought about this and pretty much cannot find a safe easy way to spin up the turbo and listen for air leaks... so what sort of trouble shooting is done in a situation like this !?

Also if I'm barking up the wrong tree on this one and someone knows something easy to check I'd sure appreciate any such help... here are some of the details that might help someone in the "know"

Stock 1994 RX-7 FD 62000 miles Touring Edition, Stock Plastic AST, nothing custom except for rims / tires and straight back exhaust from the cat back... everything in the engine bay is stock.. My first instinct was to replace the AST with an aluminum one, which needs to happen anyhow I know but if I need to sink a couple of hundred into this issue first then I need to set my priorities... as soon as this is fixed I'll replace the AST....

Thanks,

Derek

 

take a can of carb cleaner with the little straw on it. Run your motor. spray along the vacuum lines one at a time. If you motor revs suddenly, you have found your leak.

 

Great Idea !

Thanks !

 

Yup the old carb spray trick. Since you getting boost leaks already, just buy some silicone hose and start replacing them. You dont have to do all of them at 1 time. Do a few here and there. If the carb spary trick doesnt work. I suggest either you or a mechanic do the silicone hoses on your FD. This most of the time will fix your boost leak.

 

May I suggest having a fire extinguisher handy?