Tial q blow off valves

[mega4a]

hey guys jut wondering for those out there that have used the tial q 50mm what spring did you use the chart says use a dark pink for -20in/hg but i have a 10 psi in mine what it come with from the shop and i still get abit of compressor surge .

[Mr Ree]

Is the surge happening under acceleration, or vacuum?

[mega4a]

the surge happens when change gear and come off the throttle it has a tiny bit of surge then a pssssht noise so blow off is working just seems delayed i do have short piping and ball bearing turbo maybe i can't get away from having a lil bit of compressor surge ? the blow of valve has its own vacuum line and is a bigger vacuum line 6mm inner diameter

[Soiled]

I had the same problem with mine, and am ordering a softer spring to see if it makes a difference once I get my car back on the road.

[matt dunn]

I run a tial BOV on my race car and had to get a super soft spring it it to get it to open properly,
just not quite open at idle, but opens really quickly and early,
but no noise as it's mounted underneath the inlet manifold.

[mega4a]

They are quiet sounding blow off valve its a good thing i think. i guess cause it is 50mm. what spring did you guys go with ? i was thinking of trying the 9 psi one which is meant to be according to Tial for 14in/hg-17in/hg vacuum.

[MrOizo]

Have you measured your vacuum at idle?

[mega4a]

yes of course when my car is cold i get about 20in/hg when hot i get 22in/hg