Turbosmart solonoid replacement for N75?

[Jonas_R]

@Jonas - my updated Slide #2 explains that scenario... Its fundamentally not as safe as when it fails OFF, as there will be some boost pressure trying to open the WG. We could pontificate for days about this one... A boost gauge is the only way to see any bad boost behaviour and as long as the ECU has some additional failsafe mechanisms to detect excessive boost conditions and then do something about... Light the MIL lamp and throw up a fault code for one thing, and of course turn off active boost control (turns solenoid OFF which is OK unless it is mechanically stuck ON).

PS - This post has been interrupted by the postie delivering one lil Turbosmart WGFV for me to play with

Bit confused, but if I understand it correctly the TS valve would be just as safe as the N75 in regards to stuck in OFF, however when stuck in ON it would actually give infinity boost right?

[GazzaG60]

good work Paul.

still cant help but think one would be better off with the full eboost setup rather than a solenoid and a remap.

your right about needing a boost gauge but id always have one anyway. helpful for spotting boost leaks and seeing the piont at which the gate is starting to open and how fast spool is happening.

one question as it seems most like to err on the sidew of caution.

how many people have had a solenoid stick so that the gate wont open?

i have never seen this happen on any turbo motor ever.

[S2central.net]

As the 'full eBoost setup' only caters for boost control - with RPM awareness on the eBoost2 - it does nothing for fuel and timing so you need to remap the ECU anyway for maximum benefit. The WGFV map is one of the easier things to tweak on Motonic so its no biggie and a lot less cheaper than the eBoost2. Even if you chose to go without that, you would need to tweak the turbo chip so that it didnt complain about excessive boost levels... So Motronic tweaks required.

I see that TS solenoid as a hardened / more robust version of the WGFV - nothing more, but it will be interesting to see if its truly plug and play (in single port mode) or whether some remapping is needed for that.

Getting either the factory or aftermarket WGFV to work in dual port mode will require some remapping. I don't yet know if the factory WGFV will be suitable for dual port working - the duty cycle will be lower so the physical switching time on the ports is proportionally more significant than when running high duty cycle.... At least thats how I have my head round it at the moment.

I agree that a solenoid sticking is going to be a rare scenario, but I figure it must be technically possible at least and the consequences of that need to be considered.

[GazzaG60]

all sound and logical as usual paul. i never doubt you will have any issues with the tuning.

as you will no doubt have gathered im an aftermarket ecu and ebc fan and rely on my tuning and gauge feedback to warn of any issues.

to go back to my motronic days sometimes i felt like the casr took longer to get to boost or fluctuated slightly when i was there. it didn't do it all the time though but when it did you know its more like 200hp rather than 230. fitted the EBC and the response was night and day. i could have it spool as i liked and did a hit and hold 1.1bar setup in around 10 minutes. car was plenty safe on AF and EGT. i think standard timing map is conservative anyway and the extra psi or 2 had no extra egt as the timing did the cooling.

if you have the hesitence on boost issue this will be a great fix from paul if you are not inot aftermarket or dont need it for a bigger setup.

i may look at setting the gate using the 2nd method this weekend. i cant see it needing much tuning at all. maybe a tad of juice in the higher pressure lower rev cells and thats about it. ill post up if i do to let you know the differences between the 2 dual port setups.

[Jonas_R]

Well we tried to map the car last saturday with the Turbosmart valve and it acutally worked very well in a single gear, however we encountered problems when shifting between gears. Then the boost would spike way to much, seems to me that valve cant went out air between gearshifts.
This would mean that you get more and more air pushed into the upper part of the wastegate, and then increasing the boost pressure.
Does this seem like logic explanation or should give it another go?
I would like to get it to work because it was really spooling up fast

[Jamo]

How did you have it connected?

[Jonas_R]

Like the e-boost manual suggested, think it is method 2a. On open (ON) it goes from compressor - upperpart. On closed (OFF) it goes from compressor to lower part.

[Jamo]

I still stay lower chamber better for Motronics ecu as you are only concerned with wastegate opening.

[Jonas_R]

@Jamo
What do you mean?

I locked at the eboost again, and I think it would work using method 2f, where it wents to the atmosphere. This would make sure that the upper chamber is cleared at gearshifts.

[Jamo]

The standard setup pressurises lower chamber only which means the top chamber is always at atmospheric pressure. When you pressurise the top and bottom you actually need a softer spring to get a fast enough reaction in the change of pressure between the two.

[S2central.net]

Thats an interesting idea Jamo... I wonder if the MB/MC engines of old ran a WG with a more gentle spring. Then again, don't forget the operation of the factory WGFV is different from the Turbosmart one - See my post #56 in this thread. The TS one doesn't 'vent' in quite the same way so it may be too radical for the most aggreessive two port setup. The TS one modulates connectivity from Port 2 to Ports 1 and 3 as per ON/OFF duty cycle whereas the factory item is just a gate for one port.

Frow what JOnas says I think he has it like this -

Port 1 to Upper
Port 2 to Turbo
Port 3 to Lower

This might experience the boost spikes between gears (assuming minimum duty cycle is being used to generate target boost - have you tried going lower on that)
because air is trapped in the upper chamber whilst the valve is ON... Its only when turned OFF that Port 1 is relieved of this pressure - and that is only the case if the turbo outlet pressure is lower at the time. If the duty cycle is too high then during gear changes then to much pressure gets presented to the upper chamber and you keep the WG closed for longer than you'd like... I wonder if the aftermarket boost controllers use manifold pressure (and any RPM visibility) as a means to shut the WGFV off during gear shifts - that would allow this setup to work better, but I don't think Motronic does that.... Duty cycle is maintained during gear shift I think.

What would be interesting to try is the less aggressive 2-port setup -

Port 1 to Turbo and Lower chamber via T piece
Port 2 to Upper chamber
Port 3 just a 'vent' (into MAF hose/airbox)


I haven't had a chance to try mine out yet... Been away a while....

[Jonas_R]

Paul port 1 is not relieved when the TS valve is in OFF posistion because there is only a connection between turbo and lower port. This means that port 1 - upper part is closed and maintains its pressure. You can only relieve port 1 of its pressure between gearshifts if the valve is in ON and the turbo is has lesser pressure then upper WG chamber.

I actually think that less agressive setup will be the best bet since you should avoid the built up of pressure inside the upper part of the WG since pressure is relieved everytime valve turns on/off.

Question is if this setup can generate boost of 25 psi?

Well, next mapping session I will try to see if we can get this to work at 25 PSI

[S2central.net]

Yeah - we are on the same page with regards Port 1... I had a typo in my last post - sorry...

I'll try both dual-port variants when I get time - with OEM valve and the Turbosmart one...
I reckon very low duty cycle is needed on the most aggressive setup.

I don't think 25psi is going to be a problem here - even with a single port setup... The factory WGFV can do that no problem.

[k.alle]

So what's the verdict on this Turbosmart item?
Does it work as a direct replacement for the factory WGFV with a standard or homefried ECU?

[Smiley]

Look at this thread, Pauls excellent PDF explains the difference.

http://www.s2forum.com/forum/showthread.php?t=33383&page=1