SpeedracerRX7

The reason I ask this question is because I am getting a lot of boost flutter just when the secondary turbo reaches its target or at least tries to. I have checked all my solenoids and they seem fine but still this problem persists. The reason I ask about the turbo control actuator is because my transition is also getting sloppy and this I believe is caused by the actuator. This is why I was asking if it could cause the secondary boost to flutter by not opening all the way or something. Let me know what you think. I welcome any input on this matter.

SpeedracerRX7

Does anybody have any idea why the boost would flutter, even if it isn't the turbo control actuator? Also what else could cause the secondary turbo to build boost slowly if it isn't the TCA? Please help...I have to have this problem knocked out by next weekend, I have a potential buyer coming to see it.

ech

Hmmm.... There are probably a few things it could be. For me it was the PowerFC that turned out to be the problem.

Here's a link to my thread on that.

https://www.rx7club.com/forum/showth...hreadid=119416

SpeedracerRX7

Wow that seems to be the exact same problem I am having. Here is a dyno chart of my problem. As you can see you can really see my fluxuation on the dyno. I dont' seem to have any issues with my primary boost as of yet but this is definately worth looking into. I think my next step is to go up to Rotorsports Racing and see if he will let me borrow his PFC so that he can use his datalogit to transfer maps. Here is that dyno:
https://www.rx7club.com/forum/attach...postid=1363745

ech

If you can swap PFCs with the same maps, that is a quick test. My thought was that a capacitor went bad inside my PFC which could cause a periodic grounding out.

I wouldn't rule out either a shakey WG or TC solenoid. I was thinking that is what I had, before I swapped PFCs.

It does look pretty similar - similar frequency.

Can you hear, feel, see it under regular driving, or just on the dyno? This is a silly question, but can you rule out "bucking" on the dyno?

SpeedracerRX7

Unfortunately I have already replaced my WG and TC solenoids because that is what I thought it could be first. Now that the problem persists I am fearing this ecu issue because I have had some (what seem like grounding)problems with it not allowing the car to start on hills for some reason. I had to put the stock ecu in just to start it and roll it to a flat spot and then switch back. I felt that this may be a grounding ussue but it quit eventually and I haven't had to do that in a while.

I can feel the car surging when the secndary turbo come on to answer your question. It is really anoying. I'll post the results when I hopefully switch it out on Tuesday or so. Any other opinions are welcome on this topic. Thanks.