Hi Everybody, I need your help for a problem ( maybe not one ), but I need the opinion of an expert.

I'm a FD owner, let me tell to you my setup :

95' FD

- Apexi Power FC
- ARC Air Box
- SMIC Greddy
- Elbow Greddy
- 4 BUR9EQP
- Magnecor plugs wires
- AEM V2 Water Inj.
- OEM ( no précat ) Down Pipe
- Test Pipe ( no cat )
- Blitz Nür Spec catback
- Aftermarket FPR
- Double Throttle Deleted
- Rats Nest Simplified ( no air pump, no double throttle, no FPR solénoid )
- Vacuums Lines of Wastegate & Pre spool are stock with pills inside.
- Forge Motosport Dump Valve
- Afr Sensor + PLX Manometer

Don't panic, the car is properly mapped by a French Specialist.

Now, my problem, there should be turbo pressure 0.85b ( 12.33 psi ), but don't want ton exceed 0.75b ( 10.88 psi ).
Where the problem could come from? I already checked if I did not have any air leaks, everything is tight, the dump valve is not leaking.
May be a bad set with turbo management on the PFC ?
The data collected by the map sensor wrong?

I don't have pressure gauge to compare, but if anyone could tell me any advice it could be cool, thank's in advance.

 

Nobody have an idea ?

 

Seems like I'm wrong more than right when trying to diagnose boost issues over the net. Probably the best I can do is point you here in case you haven't seen these yet...

My brain is just too small to completely understand this, but you'll probably have better luck:
https://www.rx7club.com/3rd-generati...tified-841821/

Turbocharger Overview (includes trouble-shooting section)
http://fd3s.net/boost_problems.html
https://www.rx7club.com/3rd-generati...-stuff-802060/

 

Thank's for your response, I potentially founded my problem, if all is ok on my car, it's maybe just a bad setting of Duty.

I'm going to check if all is ok on the car

Thank's !

 

my setup is similar to yours. what did it dyno to the wheels? i havent got dynoed yet

 

If I remember, I do aproximatively 275whp at these involontary 0.75b ( 10.8 psi ).
I would have rather 290/300 whp 0.85b ( 12.3 psi ).

 

I checked my primary Turbo, looks fine I think, no excessive play..



Anybody think I have to set up the duty ?

 

I have almost this exact setup and problem except mine has BNR stage 3 turbos different intercooler setup and has gone from 1.12 bar down to .75/.76bar. I also get a sort of screaming noise around transition rpm. I have concluded that it must be a solenoid and the suspects are as follows;
Waste gate and Precontrol solenoids. Charge control Solenoid and Turbo control solenoid. My one other theory is pre control door not operating correctly.

EDIT: Cloudrx you should really check the links Sgt blue has posted. I checked them after posting and they have given me many more ideas. I'm narrowing my problem down so will keep you posted

 

I took the time to educate me properly then all this time.

The first problem comes simply from the incorrect setting of Duty and Instructions on the PFC.

Modifying it, I managed to obtain the desired pressure, but it's really not easy to do, above that, by the time my blood pressure is lower than under hot. Having dissected the operation of the management Twin Turbo, I concluded that the hot problem was likely to come from the Dual Solenoid which runs the Pre-Control and Wastegate Control.

Regarding other Solenoids, I had already replaced a long time ago, tested cold or hot.

When you think to it, the problem is simple for the management of Turbos, it will have a Boost Controller, or just PFC who cares, there is always a concern flows halved to handle both Turbos I count in the near future to replace the pressure management by two Boost Controllers Manuals, the Hallman Pro RX. I boarded the Fd a Friend equipped with both Boost Controllers, the result is stunning.


Thanks for your response

 

So you have confirmed it to be the dual solenoid (wastegate and precontrol)?

My plan for repair if it was to be the dual solenoid was to replace the unit with two Apexi boost solenoids as they will require no wiring just a little bit of thought on mounting I'm still yet to confirm if this is in fact a good idea. My PFC was controlling boost well until it stopped controlling boost well so I don't see the point in spending $400 on a EBC.

Aftermarket solenoids.
http://lucky7racing.net/products/93-95-duty-solenoid-wastegate-and-pre-control

My proposed replacement
http://www.google.com.au/imgres?imgurl=http://rspec.co.uk/images/Solennoid.jpg&imgrefurl=http://rspec.co.uk/b-boost-controllers-b/boost-control-solenoids&h=909&w=909&tbnid=JwClCsNUFe9VsM:&zoom=1 &docid=bDsqadx4jjYVHM&hl=en&ei=cns9VfL3C8LNmwW-u4HACQ&tbm=isch&client=safari&ved=0CCUQMygJMAk

There is cheaper ones but they will need a connector wired to them or to be hard wired.

 

For me, this is a problem solenoid ..

But it was so pissed off that I think completely remove that part of the management , and manage with 2 Manuals Boost Controller ..

http://www.dsmtuners.com/attachments...ro-jpg.243286/

There are a lot of solutions anyway .

 

Completely over looked my issue last night I pulled up the sensor/switch check screen on the PFC there was not to many turbo solenoids there but I knew I could check some so after researching the operation of the solenoids I narrowed it down to specific solenoids (charge control, charge relief) I went under the assumption that no secondary boost was achieved. Charge control solenoid should have a filled in circle until prior to transition then it should just be an outline so the first rev test the ccn switched off but was a little late in doing so and the following test the charge control always stayed on this means that the secondary boost is not entering the engine because the valve (throttle type thing for turbos) would not open which causes the charge relief valve to vent boost

 

You have no boost with your secondary turbo ?

You are in the truth, boost secondary problems comes when the charge relief valve stay open or flees.. The charge control stay closed, but I think if he stay closed and the charge relief closes a 4500rpm ( normal opération ) it will damage the charge relief valve..

You can have so have a problem on the Turbo Contol Actuator, hoses become porous with time and heat, it produces lag , see if he no longer puts in motion, almost no load control that the door remains closed and preventing the secondary turbo being trained .
Last problem at this Actuator , enforcement stapple stem that controls the door tends to rust and eventually falls. I think you have to check this point first.

 

I see you dont have a mechanical boost gauge. The value of boost on the commander will be different than the actual value on the boost gauge. set the boost to what you see on the gauge and not on the commander

 

This is not the first time they tell me that ..

I would have thought that there was no more accurate than the pressure measured by the Map Sensor .

In some time I will buy a Boost Module PLX for a safe bet ...


TUX check the strapple here :



And these Hoses on the turbo control actuator

 

I'm not too sure if it's not boosting secondary at all or if it's just venting that much boost that I don't notice if it comes on. At the beginning of the issues I thought it was but then I wasn't so sure. Sorry I'm unfamiliar with the terminology strapple are you referring to the flap that opens to prespool secondary?

 

Also I'm inclined to lean away from turbo mechanical issues as turbos are pretty much brand new. turbo control actuator might need checking also.

 

I would say "clip" and not " strapple " .
The clip tends to rust and fall off, the stem of the actuator ends up coming out , as on the above picture.

The impact that the door unopened by the Actuator Turbo Control is that the secondary turbo is not driven by all of the exhaust gases, but only a small part , so the turbo will spin , but not fast enough to deliver the desired pressure ..


Look at this picture at the bottom,
The actuator is independent of Twin Turbo block.
It is attached to the manifold , so even if you are equipped with BNR Stage 3 , the collector remains apart if I remember correctly .
http://www.autosportracetech.com/RX-...BigPicture.htm

 

Oh I see I'm certain I've checked the hoses waiting on my mityvac to arrive before I can check actuator

 

Have you got the issue fix on your boost ? I got the exactly same problem as you and i still can't find out what is causing the issue.