suggestion for those with trying to fix 10-5-10 pattern
 

I am debugging my 10-5-10 pattern with the stock solenoids controling boost (with a apexi power FC installed) and have a few suggestions for those trying to solve thier own 10-5-10 pattern. Ususally the dip to 5 is either a TCA issue (not opening fast enough) or a PC issue (not pre-spooling the secondary).

1) Tap your boost gauge into the secondary turbo output, a good line to tap is next to the CCV actuator, on the secondary side of the y pipe.

Do some test runs and check the pressure readings, if you see nothing untill transition, then a quick rise, then it is NOT getting pre-spooled and it is most likely the PC and not the TCA. This is what I saw. If you see it rise before transition (being pre-spooled) then its probably not the PC and is the TCA.

2) Tap into the pressure that the PC actuator sees, I tapped the top line of the PC solenoid. You can tap near the actuator if you want, just make sure you are between the PC actuator and the solenoid, this will show you what the actuator is seeing for pressure.

Do some test runs and check the pressure readings, I think your are supposed to d see some presure up to the pre-spool point, then it should go up past 7-8psi (sping pressure needed to open the actuator) until transition point, then jump up to full pressure. This is not what I saw on mine. I saw a steady 5 psi all the way till transition, then a jump to 10+. This showed me that somthing is wrong with the PC control since it is not seeing enough pressure to open the PC actuator before transition and pre-spool the 2nd turbo (hense the 5 psi transition boost level)

I have to thank laracer for the wonderful plots and graphs of his actuators, they helped alot.

I will try pulling the pc pill out and see how that affects the pressure the pc actuator sees.

Also, if you do these tests and it seems like the TCA (probably not my case) then tap the vac side and pressure side of the TCA to make sure its getting both, a loos of one side will make it open slow and cause a big dip at transition.

Great info damian!

One thing I learned was that the pressure reading right at the pc actuator (or any other actuator) is different than the reading at the solenoid. Because the air is moving pretty quickly through the lines, there is a pressure drop across the line leading from the actuator to the solenoid (well, that's my theory anyway). So I always try to take readings right at the actuator. This is a pain since it means pulling all those hoses everytime you want to connect a T (I thought about just leaving T's permanently connected, but they do tend to affect the control system a little - slowing it all down).

Also, I remember a while ago I tapped into the secondary like you said and also didn't notice any prespool. However, I'm pretty sure I'm getting prespool since adjusting the prespool needle valve makes a BIG difference in primary boost. Not sure exactly why I didn't "see" the prespool in the secondary.

Don't you just love vacuum hoses.

hmm, good reply laracer, I may retry the tap next to the actuator to get a more accurate reading of what it sees.

your comment about not seeing prespool but still affecting primary boost is very interesting, and I actually think it might be correct, the CRV is open at this time, venting the secondary boost (thus the gauge reads no pressure), right?

however that means I should have seen nothing, then an instant jump to 10ish at transition, but I get a rise from 0 -10 not a jump.

another test would be to disconnec the CRV vac line so that it stays closed , that way pressure would build in the secondary side and you could see it on the gauge, not a test you want to do many times though since its probably not good for the 2ndary turbo.

comments?

well, dam...i just took out the pills on both lines for testing purposes and I shold get a great transition since the PC solenoid sees all the pressure (no restriction pill).... however my boost pattern was 8-5-8 but with the same slow dip...so I unplugged the electrical pc connection (this keeps the PC solenoid closed so then the PC actuator sees ALL the pressure) and still the slow dip...so now I think its a messy combo of the TCA and PC.... jesus, it never ends, I'm gonna replace the entire car I think (hehehe)

good luck dude....keep pluggin' away at it!

I've got a low transition too argh!!! :mad:

How about we try to fix 10-8-8 pattern :(

graph
 

After doing some log tests (I love the power FC and datalogit) here is a graph of my boost pattern:
https://www.rx7club.com/forum/attach...postid=1893794

notice the slow rise after the dip, showing that the pre-spool is not happening...(or TCA is opening really slow?, or CCV is opening slow?)

should look more like this one I edited in photoshop:
https://www.rx7club.com/forum/attach...postid=1893797