Problem: No primary boost, FD seq, lots of info
10-24-14, 06:55 AM
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Problem: No primary boost, FD seq, lots of info
Tried something i new was gonna fail, i posted on the retard group "RX7" on fb....
So, here goes:
"
Car: Rx7 FD 1993 TT
Problem: No boost on primary turbo
Mods relative to the problem: brand new BNR stage 3 twinturboes in Sequential mode, AEZknightz simplified 100 psi solenoid kit with viton check valves, new silicone hoses all round, apexi pfc w/commander (tons of other mods, but not relative to the problem at hand)
It happened after i`d parked the car overnight. First thing i thought of was solenoid hoses popped off, but i could not find any. I have my solenoid kit over by the ABS unit, so all the solenoid hoses are pretty much in the open exept the ones going to under manifold and to the vacum chambers. All seemed attached. Second, i checked the butterfly valve in the Y-pipe. It`s supposed to click shut when you power on the car, and it does(to close for the secondary turbo), so its shut, and the air does not vent from turbo one via an open valve and out the charge relief valve.
When i floor it, i notise that there is a slight power increase like when the primary turbo comes online, and the boost level rises from negative to zero, and touches 0.01-0.03 on the commander, and the power surge is exactly where the primaries come online, so they seem to be spooling up. But, the boost level is just flat at 0 +/- 0.03 until the secondary comes online, the valve opens and pressure is as stock from secondary and up.
The only solenoids left from the stock car is the precontrol and boostcontrol solenoids up on the UIM.
As it has litterally poored down all day here, i have not been able to remove Y-pipe and psysically feel primary and secondary spool up under idle, nor have i been able to inspect any other than the new solenoids and silicone hoses before it started to **** down again...
I just wanted to pick your brains abit before i go out and check some more tomorrow. Do you recon the problem might be the precontrol/boostcontrol solenoids? What is your thoughts on this?
I dont have a mityvac, so i cant check, but as i said, its pissing down today as well, so i want to do some preliminary data gathering...
My two rotaries and 323 rotary project on the picture for attention:
"
So, here goes:
"
Car: Rx7 FD 1993 TT
Problem: No boost on primary turbo
Mods relative to the problem: brand new BNR stage 3 twinturboes in Sequential mode, AEZknightz simplified 100 psi solenoid kit with viton check valves, new silicone hoses all round, apexi pfc w/commander (tons of other mods, but not relative to the problem at hand)
It happened after i`d parked the car overnight. First thing i thought of was solenoid hoses popped off, but i could not find any. I have my solenoid kit over by the ABS unit, so all the solenoid hoses are pretty much in the open exept the ones going to under manifold and to the vacum chambers. All seemed attached. Second, i checked the butterfly valve in the Y-pipe. It`s supposed to click shut when you power on the car, and it does(to close for the secondary turbo), so its shut, and the air does not vent from turbo one via an open valve and out the charge relief valve.
When i floor it, i notise that there is a slight power increase like when the primary turbo comes online, and the boost level rises from negative to zero, and touches 0.01-0.03 on the commander, and the power surge is exactly where the primaries come online, so they seem to be spooling up. But, the boost level is just flat at 0 +/- 0.03 until the secondary comes online, the valve opens and pressure is as stock from secondary and up.
The only solenoids left from the stock car is the precontrol and boostcontrol solenoids up on the UIM.
As it has litterally poored down all day here, i have not been able to remove Y-pipe and psysically feel primary and secondary spool up under idle, nor have i been able to inspect any other than the new solenoids and silicone hoses before it started to **** down again...
I just wanted to pick your brains abit before i go out and check some more tomorrow. Do you recon the problem might be the precontrol/boostcontrol solenoids? What is your thoughts on this?
I dont have a mityvac, so i cant check, but as i said, its pissing down today as well, so i want to do some preliminary data gathering...
My two rotaries and 323 rotary project on the picture for attention:
"
10-25-14, 01:10 AM
#2
I don't think the precontrol and wastegate solenoids are able to reduce boost below wastegate spring pressure (about 7psi).
Check the operation of the charge control valve, if it is open at low RPM the secondary turbo essentially acts as a huge boost leak... primary boost will flow out the secondary turbo backwards rather than into the intercooler and engine.
Also check that the primary turbo's intake isn't blocked or collapsed. I once had a plastic dividing wall inside the airbox become dislodged and block flow to the primary turbo inlet.
Check the operation of the charge control valve, if it is open at low RPM the secondary turbo essentially acts as a huge boost leak... primary boost will flow out the secondary turbo backwards rather than into the intercooler and engine.
Also check that the primary turbo's intake isn't blocked or collapsed. I once had a plastic dividing wall inside the airbox become dislodged and block flow to the primary turbo inlet.
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