PhoenixDownVII

I guess this explains your SN "Wraith"



Go non-seq or single bro....they call it a "rats nest" for a reason..i think. lol

ccarlisi

1. If you have a problem with your wastegate control you will be limited to the spring pressure=7psi. Since you can't get any boost above 4500 we can rule out the wastegate control system.



2. If you are getting ZERO psi in secondary mode you must be vented boost out of the system.



3. Since you're getting boost in the primary mode the leak must only be present in secondary mode. Based on this you can rule out the AIR BYPASS VALVE and everything that is associated with the primary turbo.



4. The only thing on the secondary turbo that could dump all the pressure the primary and secondary turbo are making is the CRV valve. This valve is positioned on the section of the Y pipe closest to the firewall. Remember the Y-pipe is connected to the exhaust outlet of each turbo. The charge control valve blocks off the rear turbo's section of the pipe when the car is in primary only and primary prespool mode. However, when the secondary turbo is prespooling it generates air pressure in rear section of the Y-pipe. If this area was completely sealed the secondary turbo would not be able to spin freely because it would be blowing air into a closed container. This problem is overcome by using a second valve (CRV) on the 2nd turbo's section of the y-pipe to vent the boost the secondary turbo makes out into the atmosphere. When you switch from primary prespool to secondary mode the CHARGE CONTROL VALVE opens and the CRV closes, redirecting air from the CRV through the CCV and up to the IC.



5. Therefore if you really only have this problem in secondary mode it is due to

---A. a problem with the CRV control system (trace the lines)

---B. a problem with the CRV itself

---C. a leak in the rubber elbow between the CRV and the Y pipe

yellowspeedracer

first of all i know dick about these cars. but to check for boost leaks on a piston motor, get a 2.5" exhaust pipe and weld one end closed with a fitting that goes to an air compressor. the clamp that pipe to the hose that comes off the airbox and into the turbo. then turn on the compessor and you should be able to hear any leaks in the piping. on a piston engine some air will leak into the motor through the valves...i dunno about rotary.



also your WG may be stuck open. when there's a lot of carbon build up this can happen.



good luck

DUB

give the poor bastards a break...it is the first production car to have a seq. turbo sys.



Call me crazy, but I might be converting back...Already started piecing parts together...



Do I miss the ??? dunno

wraith

dude i'm getting not boost at all. zip, zilch, nadda. absolutely none.

wraith

can you explain

ccarlisi

How can you tell there is ZERO boost leaking? Can you hear the turbo(s)?



Does the car sound louder than usual?



SEQUENTIAL SYSTEM:

The TCA is the big fat actuator on the bottom of the turbo mani. I don't think that's the problem, unless there is more than one problem. If the TCA is stuck in primary mode you would get normal boost below 4500 and the power curve would flatten out above 4500. If it is stuck in secondary mode you would get boost above but not below 4500.



Similarly if the charge control actuator (CCA) is stuck in primary mode you would get normal boost below 4500 and the power curve would flatten out above 4500. if the cca was stuck in secondary mode you would get zero or next to no boost below 4500 and normal boost above.



As I said before, if the CRV is stuck open you will get little or no boost above 4500 but have normal boost below that point.



That is all there is to the sequential system. I don't think that's the source of your problem.



WG CONTROL:

if you disconnect the WG solenoids to both turbos you will still get 7psi on the primary turbo. If you forget to connect the vac lines going from the turbos to the WG actuators you will get way too much boost.



Since you don't have either symptom you can rule this system out as well.



BOV:

If the BOV is stuck open you will bleed off boost at all rpms. You would still be able to hear the turbos because they would still be getting exhaust pressure. If you have the BOV disconnected from the stock airbox, you should also hear a loud hissing noise.



COUPLERS:

Obviously, if there is a cut at any point in the piping from the turbos to the throttle body you would lose boost all the time.



THEREFORE, focus on these last two items until you start seeing boost at some part of the RPM range. The fact that you said you initially saw 3psi seems to indicate there was some kind of leak and it got worse.

vosko

TCA = Turbo control actuator



it controls the flapper that makes the secondary turbo come online



if you lay under your car. you will see it on the bottom. possibly the c-clip fell off and rod popped off

wraith

i've had boost leaks before, and i hear absolutely no leaking. i can't hear any spool from the turbo's either. the car sounds exactly the same as before. and i checked all the pre-control rod and the wastegate rod, and the c-clamps are still on. im beginning to get the feeling that they died.

DUB

don't think they just died from a hose job.