Digi7ech

iTrader: (1)

I got a Tial 7lb spring bov yesterday because the Apex one failed.

Well, I get lovely compressor surge for a second before the BOV dumps.

Anyone have some ideas on how to try and make the BOV react quicker or at a lower boost level?

It looks like the 7lb spring is the lowest they go.

I really don't feel like blowing more money on another bov and getting it welded to my pipe.

Here's pics of the setup.
I'm running S5 turbo and 10-14psi.




I know there's probably bad methods like torching the spring a bit but I don't know what that does to spring dynamics.

Ry87TII

Well I would def not bring any type of heat to that spring at ALL!!! Is there an adjusting screw anywhere on that bov to go hard or soft??

Juiceh

iTrader: (4)

What you are hearing is not surge it is reverberation. Not a good thing. Try a different spring in the BOV or is there a way to adjust the BOV?

fastrotaries

I have Tial and I adjusted the spring via the nut on top. some FD owners were experiencing problems and they resolved the issue by calling Tial themselves. Apparantly very good customer service.

Digi7ech

iTrader: (1)

The nut on top?

I haven't looked at it during the day but I don't think there is one. Unless the Vacuum port doubles as a nut under it?

SpeedOfLife

iTrader: (16)

Could you elaborate more on this BOV reverberation? I may be experiencing the same thing once in a while.

Digi7ech

iTrader: (1)

I think we're talking about the same thing when I say comp surge.

The pressure wave goes back towards the turbo and jack hammers the compressor as it tries to exit the only way it can.

I believe on lower pressures the pressure wave hits the turbo a few times until the pressure becomes great enough that the Tial opens and dumps that nasty air.

that nissan guy

iTrader: (2)

where is the vacuum line on the bov going? have you tried tapping into the acv block off plate? you may want to start checking into your vacuum source and looking for restrictions...

arghx

iTrader: (3)

A good vacuum source is the lower nipple on the front of the UIM. I have my BOV getting vacuum from my ACV blockoff plate though.

I used to get compressor surge under light throttle when I had my BOV teed into that nipple that is usually used for the stock pressure sensor (the one on the UIM).

Digi7ech

iTrader: (1)

I've got it teed off from my boost gauge and boost sensor.

I don't have an ACV so that vac port is no longer there. I may see about stealing some from the brake booster line(rear runner on my jspec manifold/not on the uim)

I was searching google for Tial compressor surge and this is priceless.
This was from www.honda-tech.com
"so much research into a BOV. i wish my turbo could make that compressor surge sound without harming it"

******* ricers. Surge is a bad noise.

that nissan guy

iTrader: (2)

that is a very bad vacuum source... not only are you watering down the signal to the boost sensor and gauge but that hose is too small to give you good response with a bov that big... what you need to do is remove the acv block off plate, drill and tap a hole to install a brass barbed fitting in the plate, reinstall, and pull your vacuum signal for the bov from there... hands down best place for it...

Digi7ech

iTrader: (1)

I think i'll toy around with vac source before I think about tweaking the spring.

Digi7ech

iTrader: (1)

Teed it off my LIM rear runner/ Brake booster line. This is found on S5 Jspec manifolds. US manifolds have the Metal bump where it is but it's not tapped.

Much better response now. It actually catches 5psi and blows off.

I'll report tomorrow when I drive to work to see if higher psi is ok.