Sequential turbos eh? I need someone who knows WTF to do!
 

Hey everyone, I am thinking about going for the simplified sequential TT setup, but I have a few quick questions. I see 3 different ways to do so.
The main question is regarding the J and I Solenoid Valves. (J-Turbo Precontrol, I-Wastegate Control) I noticed that in the first setup "I" Wastegate Control is removed. I understand that an aftermarket boost controler takes over that duty. right? Now on the second method, the "I" and "J" are both removed. Can the Boost controler work this function? I have an Old skool HKS EVC, do you think it might be up to the task? I see that the final pic is for a vehicle NOT using a boost controller. Am I correct to assume this?

I think that I should go with the first picture, because I have an older boost controller, and am not sure if it can handle the duty of working the turbo precontrol, and the wastegate at the same time. Let Me Know if you have any suggestions.

ALSO TO NOTE: I am having reving issues with my car. I can't rev over 4600RPM if I have my foot down at WOT. But I can rev up to about 6000 if im very light on the pedal (not making boost). This signals that obviously I have a vacuum issue if boost limits my RPM band. Or could it be a fuel pressure issue? I have not been able to test the fuel pressure on this car yet.
I am hoping that 7 new solenoid valves and the simplified sequential setup will cure my problem.

1 Last thing the "air bypass valve" that I circled in the last pic is missing in my car, and is capped off. any reason for that? also the line that just randomly ends in the pic (Labled with the WTF) what should that go to? I figured that it should go to the pressure tank, but that is removed in this pic - so just cap it off???

You should not have trouble using that boost controller over both actuators together.

You're probably hitting fuel cut at 4600rpm. Adding a boost controller will help solve that problem but without a boost gauge you're still flying blind. Get one.

I do have a boost gauge, and for the most part it boosts just fine...up untill I hit the 4600rpm mark. Then I loose boost, and the motor stops reving.
Is there a way to get rid of the fuel cut? I'm boosting at .75hg...something...

Chris have you talked to Jim @ rotary dynamics?

I hope he's not the guy who set up your boost controller!!!

If the .75 is in BAR, then at 4600 rpms that should not be hitting fuel cut. What can happen is that if your CRV is not closing then you'll loose all boost after 4500 rpms. Unplug the CRV vent line which is going into the airbox and let it vent into the engine bay. As you approach 4000 rpms, the venting will get louder from the CRV. It should close around 4200 rpms and stay closed. If you still hear the venting after 4500 rpms, then most likely you have a vacuum line issue or the Charge Relief Solenoid has failed (which does happen).

You can also try switching the charge relief solenoid with one of the ACV solenoids for testing.

I hate to ask too much, but I am just starting to figure this system out. Can you tell me what the CRV and ACV are, and may I go so far to ask where they are located?
If its just a fancy name for a solenoid valve, can we please refer to this stock vacuum diagram as to the name? A through J?

Also, I don't have the factory "air bypass valve" BOV. I do however have a large greddy bov on my intercooler pipe

THANKS SO MUCH FOR YOUR HELP, I would be lost without it.

If you check the post on "Technical Manual Directory" and download the "Mazda RX-7 1993 Service Highlights"you will find a full description of this stuff and how it all works(and much much more).

If it is too tough for you too download,PM me your e-mail address and I will send you a pdf file.

CRV is the charge relief valve. Should be the valve under your rear turbo intake and leads to the rear turbo. I've had the pipe completely come off and it still generated semi decent power, basically as if i was running on one turbo so I don;t think thats the issue. I've heard of this issue before but don't remember what causes it.

thewird