Blow-off valve tuning

[TeeLew]

I run a TurboSmart RacePort blow-off valve and have ran it for a couple years as it was delivered. On basically every gear change or moderate throttle lift gives a soft woosh. It's just too much. I don't need to draw attention to myself on the street and I've noticed is causes a complete boost dump with throttle modulation and power recovery after a gear shift (manual) is laggy (not as good as stock). So Ryan (tuner) said give the spring kit a try and make the blow off higher. I stuck it to the stiffest combo they list in the book, to see how that works.

Well, I like it. When I'm normally driving the car, there's no blow-off. On gear shifts, the power comes back faster. When I'm making full boost (24 psi) and lift (to shift or just brake), I get a short powerful blow-off. It doesn't have any turbo chirp or compressor surge, so I don't think there's really any downside to what I've done. It seems like I have to be making maybe 15 psi or so and lift to get the valve to pop. Below that, there's not enough volume to back-pressure anyway, so I don't think it matters. If it's at full boost, then you get the dump.

A BoV is a poppet valve. Poppets are reasonably good at low-frequency pressure spikes, but they suck at modulating flow. It's all or nothing. I found if I had to lift and then re-apply throttle in a corner (yes, I'm a hack), then I was getting an unusual turbo lag. It was all being caused by the hyperactive blow-off. Now I want to get back between some cones and see how it acts.

Has anyone else played around with this?

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[Flattop]

Curious, have you seen any performance benefit from the BOV? I've seen claims the factory valve leaks boost, but little data to back that up. I`m running the FP tune, maybe a more aggressive tune with higher boost would benefit from a better valve?

 

[FreePenguin]

Curious, have you seen any performance benefit from the BOV? I've seen claims the factory valve leaks boost, but little data to back that up. I`m running the FP tune, maybe a more aggressive tune with higher boost would benefit from a better valve?

Stock intake, with kn air filter and stock blow off valve is best

and trust me I went through a bunch of set ups, charge pipes, hks bov, intakes.

Imo. Fp tune with stock charge pipes and stock bov with drop in filter is just as good as it gets.

 

[TeeLew]

Shhhhh.

 

[Flattop]

That's pretty much where I'm at. I did add an Airaid intake pipe as it might help a little and shouldn't have any adverse effects. All the air filter test data I've seen says filtering efficiency is inversely proportional to airflow, and there isn't much airflow to be gained from a drop in, so I'm still using Purolators and the Airaid filter is still in its box.
So getting back closer to the original topic, sounds like the BOV is primarily for auditory amusement.

 

[TeeLew]

That's pretty much where I'm at.

Oh goody, 2 of you...

 

[Ranebowcyxx]

I run about 10" of vacuum at idle, should i go to a harder spring setup?

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