R33 S2, Stock Boost Controller, Boost Creep.

[WogsRus]

Ok So basically this is my problem. I had a turbotech boost controller but it would simply not hold boost, the thing was all over the show. it would come up to 10 psi and then spike to 12 and then bleed off. This spike happend at about 4500-5000rpm.

So last night i connected the stock selenoid back up, new hoses with the stock restrictor, but it appears that it is ok.

So now the boost comes on much sooner and holds well at 10 psi (took dual boost off) till about 5000rpm and then i get creep up to 13 psi under full load with hardly any bleed off.

Now i have a FMIC and 3" dump, exhaust and no cat, HKS pod ect ect, the usuall support mods. This only started to happen once the cat was removed, before it seamed to be fine.

The stock restrictor is in place, but i have some question as to the connection details for the selenoid.

From my previous post i have connected mine as per the picture and the manual, both seam the same.

http://www.skylinesaustralia.com/forums/in...howtopic=137778

So why would this happen. I want to get a JAYCAR EBC but if i can't set boost as is, there might be some issues.

With the stock setup, how do i regulate boost with the restrictor in place, can somone shed some light on connections and sizing of the restrictor. At the moment it is stock. IE bigger less boost or more boost and what size do people use.

Is it posible the wastgate is too small or bugared or something. I presume if the turbo keeps overboosting it will die soon, correct.

Can somone point me in the right direction in regards to a possible fix, urgently, i don't want to blow my car up.

The car is a Series 2 R33 with a FMIC, HKS Pod, 3" dump and exhaust and no cat, SAFC II, Walbro pump, FPR ect ect, amd managed 187 rwkw.

[mad082]

where is the wastegate getting its pressure reading from?

when you did the FMIC did you just hook it up off the bov hose?

[WogsRus]

Nope i drilled and tapped a new pickup so it is picking up the boost form the outlet of the IC same setup as stock, identical, slightly smaller pickup then stock, that's about all.

[WogsRus]

anyone else?

[rob82]

anyone else?

What wastegate are you using? Is it a standard Turbo?

[WogsRus]

yep standard turbo, it just seams that the i can not stop the overboost at high rpm.

[Sydneykid]

Several suggestions;

1. Connect straight from the boost source to the wastegate actuator ie; leave the solenoid out of the circuit. That will tell you if you have a plumbing and or solenoid problem.

2. Check that the wastegate is actually able to open fully ie; disconnect the actuator arm and move the flap open with your fingers. This will ensure that the aftermarket dump pipe isn't stopping the flap from fully opening.

3. Wire the wastegate fully open and take it for drive, it should build boost very slowly and not over boost.

Once you have tried the above, post up the results and we can go from there.

D cheers

[mad082]

i would've put it before the intercooler. that way it isn't affected by cold weather. i had spiking when i had mine off the bov hose. put it before the cooler and it stopped spiking.

[WogsRus]

"1. Connect straight from the boost source to the wastegate actuator ie; leave the solenoid out of the circuit. That will tell you if you have a plumbing and or solenoid problem."

To do this, do i pick up the boost on the turbo side after the compressor or after the intercooler side, where the current stock connection is?

So basicaly i pick up from the outlet of the turbo, go through the restrictor into the wastgate with the tee bleeding off to the inlet after the intercooler?

"2. Check that the wastegate is actually able to open fully ie; disconnect the actuator arm and move the flap open with your fingers. This will ensure that the aftermarket dump pipe isn't stopping the flap from fully opening."

The Flap works fine, the dump has been on for 3 months and had no problems, the problems started after i got the cat removed. It was a littel better this morning. I will take a picture of my current setup and post it up tonight.

"3. Wire the wastegate fully open and take it for drive, it should build boost very slowly and not over boost."

Will do and see what happens, i will post results tonight.

ALSO Sydneykid, how do you find the Jaycar EBC, works well, i am looking into getting one of these for myself.

MAD082, i don't have a tap to pick up before the cooler, other then the stock one the boost selenoid uses. I can connect it from there and bypass the selenoid and us the current pickup after the cooler to vent. Would this work like this.

http://www.skylinesaustralia.com/forums/in...aycar&st=20

the second page last picture. This would bypass everything, and pick up after the turbo and bleeding back after the intercooler not the otherway arround which is stock.

I have mine connected like as per my first post picture posted up.

Which one of the three pics is correct and best way to setup.

[discopotato03]

I get the feeling that the air you are bleeding off with the solenoid control valve is going back into the system downstream of the turbos compressor ie into an area of higher that atmospheric pressure under boost . In the past I've mainly seen this air ducted either straight to atmosphere or back into the system between the engines air filter and the turbos inlet .

Also I'm not yet sure where R33's normally get their boost reference pressure from but some such as Corky Bell try to pick it up from the turbo compressor housing or close to the outlet , because if there's any flow restrictions in the inlet system causing a pressure drop the actuator will make the turbo work that much harder to make up for the loss and you won't know it .

Just some thoughts , cheers A .

[WogsRus]

So basicaly if i do the number 3 drawing and take off after teh compressor and vent after the cooler, that is a better option?

[WogsRus]

Well did all the tests definatly not the selenoid. I did all three coneection, almost blew the turbo, with the selenoid out and connected as picture 2 boost went up wayy fast past 10, same for number 3 but if i leave it as number one it seams to be ok with a 2 psi spike at hight rpm.

Checked the wastgate all good there, shuts and opens fine and if i undo the wastage then boost does not spike ect ect.

So what the hell is it.

Anyway which way do i make the hole smaller or bigger for more, less boost. The restrictor that is.????

Hay SDK how do you find the jaycar controller working for you?