240Z TwinTurbo

iTrader: (25)

Unfortunately, it will likely not be that easy, but that may depend on how much boost you are running. If you purchased the stock IX, HKS or Greddy unit I previous indicated and hooked up the top port to the intake and the bottom port to a boost source prior to the throttle body it would likely help or even solve your problem. However, you will likely run into the same issue as the stock IX bov as it will begin to leak at a certain boost level (25psi or so). This is because you have the same pressure on the top/bottom of the actuator, which essentially negates its affect and the force on the surface of the valve eventually overcomes the spring force causing the valve to open.

The thought is that above a certain boost level(15-20psi) the solenoid blocks off pressure to the bottom port and now you have boost on the top port holding the valve closed along with the spring pressure, which should keep the bov closed at higher boost pressures.

Its on my list of things to do, but it will take a backseat to the install and testing of my new GTX3576r turbo that was shipped friday

tscompusa

iTrader: (31)

oh my .. bigger turbo already.

jameswwt

Hi, wonder is there any pics to show how does the "hooked up the top port to the intake and the bottom port to a boost source prior to the throttle body"
In my case, yes my top bov is hooked direct to the intake and turbosmart race port bov does not come with the bottom port.

Hope Turbosmart USA able to advise me

240Z TwinTurbo

iTrader: (25)

That is the same issue I have with the TIAL as they all are top port only. I think turbosmart makes a controller for the top port actuator that cuts off pressure to the top port under light load, which might help to achieve the same thing if the spring pressure is light enough. That may be something I try with my TIAL prior to switching to a dual port unit.

http://www.boostcontroller.com/index...category%3D354

http://www.jakelatham.com/1gDSM/projects/dejon_bov/

A simple test of the TurboSmart controller concept may be to unplug the top port from the BOV and then plug the line to the intake. See if the spring pressure is light enough to open under part throttle acceleration eliminating surge. In theory, with a super light spring, when boost is applied to the top port the surface area on the actuator is significantly more than on the valve so it should keep the valve closed.

240Z TwinTurbo

iTrader: (25)

As background, my GTX3076r has bad surge problems ever since I went from the stock IX BOV to the Tial QR unit w/ 10psi spring.

I unhooked the top port on the Tial QR and plugged the source at the intake manifold. Took the car for a drive and it completely eliminated the part throttle surge. If I boost past 10psi you can hear the valve open and the car won't build boost. Under part throttle acceleration where the car used to surge and shutter badly it is now completely smooth.

I need to now determine how I will open the top port and under what conditions. The TurboSmart unit works off TPS, but I am skeptical this will account for all scenarios. Definitely something I need to think about.

Here is what is listed on the TurboSmart page:

Sensitivity: How sensitive the controller is to negative changes in throttle movement.
Duration: How long the solenoid stays open to bleed out the air from the BOV (i.e how long the BOV is open for) The solenoid will reactivate when the BOV controller reads positive throttle movement to close the BOV and pressurize the intake system.
Enable: Keeps the solenoid energized. This can be used as a boost limiting function as the BOV will bleed air out lowering the boost levels entering the engine.
Disable: Disables the BOV controller and returns the intake system to its factory setting.

240Z TwinTurbo

iTrader: (25)

It took me some time to locate some pics. This was my first twin turbo setup on my Z using the HKS racing BOV. You can see the bottom port of the bov goes straight to the IC pipe, which is before the TB. This is the exact configuration of the stock IX BOV.

jameswwt

Thank you so much 240Z but the problem is my turbosmart race port bov dont have a bottom and its only with the top port which ive connected directly onto the intake.

So, can i try an Evo 8 or 9 oem stock plastic bov?

240Z TwinTurbo

iTrader: (25)

You have a few options...
- Keep what you have and live with it
- Call TurboSmart and ask them about their electronic bov controller as a potential to solve your surge issue.
- Swap to a dual port unit like the IX bov, but you will have issue holding boost above 25psi
- Swap to a dual port unit like the Greddy/HKS and hook up a solenoid to the bottom port as described in the DejonTool link I previosly provided.

wingless

iTrader: (15)

Jeez enough with the BOV. Your problem is boost control as you have shown yourelf by turning off the EBC which is obviously not opening the WG before you hit the surge line on your way up to your target boost. Dial that back if you can, Tephra's V7 ROM is awesome because you will hit the surge line in different places depending on gear and load plus you can crush spikes with error correction. \thread.

240Z TwinTurbo

iTrader: (25)

If you read POST #1 it is most likely BOV related.

wingless

iTrader: (15)

Right... So you have too much pressure in the charge pipe colliding with a spinning compressor wheel.

You can:
a. Vent excess pressure through the BOV (leaking)
b. Back of WGDC driving the comp wheel at lower % TPS/load/RPM

Do whatever you want, but one is designed to tune and can be dialed in to a variety of load and pressure situations and the other requires changing parts and is largely static. FWIW OEM does both.

Nice picture of your engine though.

jameswwt

Hi Wingless,
mind to advise which area should i dial on my Greddy profec B II B/C?
Ive tried lower the Gain to the lowest min % (5%) and the surge is still there.
Is it the Set Gain which i need to dial? The set gain is basically control the turbo boost response.

Thanks

wingless

iTrader: (15)

I wish I could help here, but I have never messed with one. I would start tweaking and logging... Sorry. I have already plugged V7 enough I think

jameswwt

Ok thanks anyway...

mrfred

iTrader: (50)

my guess is not surge but instead the bov fluttering. its a pretty common issue that can show up at different rpm/boost combos depending on turbo, bov, spring, preload ... a different bov/dv may mostly eliminate it or move it to a different rpm/boost combo. even though i don't think its surge, i think wingless has the best solution provided that your wga can provide the needed part-throttle boost reduction. most people are running 18+ psi wga actuators that can't provide the necessary lower boost.

sounds like you are describing a dejon tool stop leak kit that is designed for the stock 9 dv. i tried one, and it would cause the dv to flutter at part throttle when trying to hold boost around the value that the pressure switch would operate.