Ok for those of you who have also had some troubles lately with intermittent boost problems I want to share my solution to mine. I had been having problems with the second turbo not coming on. Sometimes it would come on at switchover other times it would just drop off to like 4 or 5 psi at 4300 rpms. It seemed I was getting switchover on cooler nignts and it was due to the high boost I get when its cooler out. The problem was the Ypipe. The hose clamps had come loose and the Ypipe had been leaking just enough boost that I wasnt getting the full 8psi on my primary thats needed to trigger the secondary to come on. It would work on cooler nights because of the increased boost or early on during a drive. I made sure the Ypipe was secured today and I was getting the full 10 psi on my primary and alot better idle and spool up and constand switchover to my secondary. That problem is solved and I feel much better about it. There is another problem that has come up that i didnt notice until today and thats at 6k rpm I see my boost drop down to 5 or 6 psi and the power drops way off. I think it may be a partially clogged cat as I was running without an air pump for a while until I got a new one. Anyone who has had a clogged cat tell us your symptoms and maybe doing a downpipe and midpipe is the solution. I just dont know of any control in the turbo system that would cause sudden boost loss at and above 6k rpm other than a clogged cat. Hope this helps.

 

maybe you are hitting the fuel cut???

 

I am not showing more than 11 psi on my secondary and fuel cut doesnt occur until 12.5 psi. So unless my autometer boost gauge is that inacurate I think its safe to say its not fuel cut.

 

uh, the fuel cut is around 11 starting at around 5500
http://www.scuderiaciriani.com/rx7/fuel_cut_info.html