I can't really tell what's going on. Sometimes when I'm accelerating under 60%+ throttle, I'll get a half second delay and the boost will suddenly jolt. I haven't been able to see what's going on on the boost gauge when this happens but I saw it out of the corner of my eye and the needle path looked pretty regular. I did a search on boost spikes and my interpretation from the reading is that all of a sudden you'll get a huge boost but in my case, it almost feels like its when the secondary is coming on. This usually happens right after I switch gears so I can't tell if its the secondary or the primary. It doesn't happen regularly, but when it does, it'll do it 2 or 3 times in a row. It doesn't seem to have to do with warming up the car cuz its happened after 20 min drives. The motor's got only 5k+ miles and the turbos are pretty new. Any input would be much appreciated. Thx in advance.

-Chris

 

Check this site:

http://www.autosportracetech.com/RX-7/rx7stuff.htm

rynberg clued me in on this. It's a great resource for twin turbo control trouble shooting and provides diagrams for the faulty parts you'll need to replace. I'm using this site to diagnose secondary turbo control issues, and without this site, I'd be lost!

 

After searching for an hour, this is the only old thread that somewhat explains my problem...

Picture this, your in 3rd gear at 60% throttle and you go up to only 5,500 rpm (just a little boost) then you shift to 4th and only apply again about 60% throttle and hold it then after about 2 seconds the boost needle pops up to 3-5psi ( like a mini spike) and comes back down to where it was with a very quick blow off valve type of whistle. Remember the whole time in 4th I'm holding the throttle at the same point...

Now, to me it sounds like something is stuck and releasing late, maybe a solenoid or something. I do have another minor problem with my boost that I have feeling this is related to.

I do want to add that I recently checked both pressure/vacuum chambers, check valves, all the silicone hoses and also the CCA, they all checked out fine.

Is this normal?? Any input would be apprecitated. Thanks.