Blow off valves .. Good or bad for our VR30?

[socalAG2]

I'm looking to possibly buy the HKS blow off valves soon but after doing some research im a little torn & confused.. It seems the larger tuners don't recommend blow off valves for our motors. I'm concerned about the health of the turbos if I go this route based on a couple of older Q forums for the VR30. Does anyone have any comments or opinions on blow off valves for the RZ34 version of the VR30?

 

[D2M]

If you are just after the BOV sound then just get an intake with a open airbox or a removable airbox cover. The stock diverter valves are right in the turbo inlet so you will get the sound just by installing an intake.

 

[Hernandooo]

If you are just after the BOV sound then just get an intake with a open airbox or a removable airbox cover. The stock diverter valves are right in the turbo inlet so you will get the sound just by installing an intake.

After upgrading the intakes to AMS and getting 3" DP's and Exhaust. I feel like the stock diverter valve isn't enough to handle the pressure, and could be causing damage

I think upgrading them to something like a Turbosmart Dual Port Diverter valve would be more beneficial for performance and reliability, and getting that swoosh sound

 

[socalAG2]

If you are just after the BOV sound then just get an intake with a open airbox or a removable airbox cover. The stock diverter valves are right in the turbo inlet so you will get the sound just by installing an intake.

I was thinking that route too.
Is there any down side with blow off valves on these motors since Nissan intentionally put that recirculation valve on our motors? I can’t find answers on that lol

 

[MCN1SMO]

My understanding is the air needs to be recirculated as the ECU accounts for this. you might see some lag when vented. as far as damaging something I wouldnt go that far but I dont think its optimal. if you are doing a build with a tune I guess you could make it work but I wouldnt be a fan of sticking them on a stock Z just for the sound

 

[Jah_Happy]

After upgrading the intakes to AMS and getting 3" DP's and Exhaust. I feel like the stock diverter valve isn't enough to handle the pressure, and could be causing damage

I think upgrading them to something like a Turbosmart Dual Port Diverter valve would be more beneficial for performance and reliability, and getting that swoosh sound

I have those same mods and even with tuning ive been told to stay away from bovs for our engines. I supposed that may be different with upgraded turbos making big power but otherwise id leave them as is.

 

[Mud]

Motive didn't seem to have any issues with BOVs

 

[Hernandooo]

Motive didn't seem to have any issues with BOVs

It's essentially upgrading the current diverter valves

 

[Kaito]

What about the Z1 Diverter Valve to Blow off Valve conversion kit?
I'm not too mechanically savvy but doesn't this use the stock diverter valve so it's function would be retained so it wouldn't affect anything?

 

[JonnyG]

Everything I have researched is these motors do not like atmospheric BOV's - the video shown above uses Dual Ports - at minimum I think you need to do dual ports - personally I'm staying away. AMS Intake, DP, exhaust and tune for me.

 

[Proto Z]

Motive didn't seem to have any issues with BOVs

I use these same Dual Port BOV - they are great.
The sound is infinitely better than upgrading intakes to an open design.

 

[thesilverbullet]

DVs are part of the emissions (anything that recirculates exhaust gases) and a good reason to install BOVs. lol.

You may need to retune a/f. In general is a good idea to retune for any flow mods. But I wouldn't think BOVs would change a/f any more than other bolt-on - intakes, downpipes, and exhaust.

Anyone know if this engine can auto adjust a/f @ WOT.

 

[VR30Infection]

The Q's with the VR30 didn't come with them at all. More than likely if there wasn't a manual Z, the Z wouldn't have them either. The purpose is to prolong the life of the compressor when the throttle is closed during boost. If you picture air flowing through the turbos and being sped up and compressed, and then when you go to shift, you let off the gas which is slamming the throttle body closed. All of that air hits the "wall" that has been created which then bounces back and forth between the throttle body and the compressor wheel. ( It actually sounds really kind of cool ) but its bad for the turbos. An auto car has the throttle body slammed shut during boost a fraction of the time compared to a stick because the throttle body is open while it shifts through the gears. If you aren't familiar with the sound, look up Buick Grand National videos. This all has nothing to do with exhaust gasses whatsoever so that isn't the issue. What our factory valves do is let the air that is in between the compressor wheel and the throttle body back into the intake track after the MAF and before the compressor (suction side of turbo). When you do a conversion to a atmospheric, the air has been metered by the MAF and then you get rid of it. So the ecu calculations can be thrown off. Its looking for some air to add fuel to, however that air is no longer present. It is more than likely not that big of a deal however I agree that a tune would be the best route. More than likely it would be a quick moment of going rich before the ecu figures it out again. I personally wouldn't stress over it. My personal concern is once tuned and pushing higher boost levels, I'm wondering if the factory valves are up to the task. If they leak, you will be leaking psi and loosing HP. No one wants that!! I haven't pulled the trigger yet but I will at some point. I need to make cool noises!!

 

[Hernandooo]

My personal concern is once tuned and pushing higher boost levels, I'm wondering if the factory valves are up to the task.

That is also my concern, as I don't feel the OEM DVs are really doing much, hence my previous statement to it possibly causing damage to the turbos (if you've modded your Intake, DP and Exhaust with/without tune). You can notice it by hearing the turbo flutter every time you let off the gas (air getting chopped up by the turbine), not a great sound or feeling. I feel like upgrading to something like the TurboSmart DVs would help remedy this. And you get that swoosh.

I'm waiting for mine to arrive, going to install asap, and have one less thing to worry about

 

[bpeckham]

I thought the Z's throttle-by-wire prevented this. Just because you let your foot off the pedal to shift, doesn't mean the throttle slams shut. The engine controller can ease it closed.

This is mentioned a bit in this thread on rev hang.