ok. i have a downpipe,catback and an intake on the stock twins and ecu. i have a turbo xs hpbc manual boost controller. the boost controller does an excellent job holding the boost at 10psi. the only problem that i have, which also happens very rarely is in the transition from primary to secondary in second gear. the boost will sometimes drop down to 5psi instead of 8psi and the needle on the gage will bounce at 5psi for a second or two and then pop up to 10. can someone tell me why?

 

I have a similar problem, except that mine also happens in 1st gear mostly. Never came around to fix it, but it has something to do with the prespool (TCA or thereabout).

Hopefully someone more skilled with the vacuum system of the turbo system will tell you exactly where to look.

 

Probably a sticking solenoid or a bad check valve.

Try the Mazda training center KOKO test and see if you have good vacuum and pressure storage, and if both the TCA and CCA operate consistently. http://www.fd3s.net/boost_test.html.

 

anyone know any reason why it only does it sometimes. it works fine more often than not.

 

Depends how much time you give (i.e. how much you floor it) to the TCA. In 1st and 2nd gear it doesnt have enough time and it sometimes causes either no secondary boost or gives you this low dip.

Check your check valves first.

I just ordered 4 new valves for myself with similar problem.

 

i wont floor it through 1st because almost everytime i floor it in first and shift to 2nd there will be about 6psi or less on the primary in 2nd. I will drive first slow and then shift into 2nd and then floor it, then when the secondary comes on it will go 8psi and back to 10 quickly or go down to 5 and sit there for a second or two then go up to 10. where can you order new check valves.

 

search Dale Clark ^

 

Yea, Dale Clark. Nice guy

http://www.clubrx.org/default.asp?id...ntent=26&mnu=8

 

thank you. im going to order some now.