well, today I installed a boost guage, and I tested my boost in 3rd gear. It was normal, it went to 10, then back to 8 then back to 10, but it ends up at around 7-8 for the rest of the time....does anyone know what can cause this problem? thanks in advance.

 

According to the "official" Mazda boost test your results would be within spec as long as the drop off to 8 happens toward redline. However, I know many people who are able to keep 10 psi all the way to redline. I believe a better boost controller (even a DIY home depot one) will help with this.

 

Road test with boost gauge
Drive to third gear with normal acceleration

Accelerate from 35 MPH at WOT until passing 4,500 RPM

A slight and smooth increase in power should be felt at approximately 4,500 RPM. This will be about 65 MPH.

RPM PSI
3,000 10
4,500 8 as secondary turbo comes on
4,500 + 10 recovers almost immediately
6,000 + 8 and holds to redline

These readings indicate normal operation. Readings will vary with altitude and temperature, (i.e. lower temperature = higher boost).

Taken from: http://www.scuderiaciriani.com/rx7/boost_problems.html

However when I did it, I got 1.0 bar after transition and let off, but if I'm in 2nd gear I will only get 0.5 bar.

 

thanks!