Engine Vaccume

[1992tracerlts]

Ok so im starting to get my parts list going, and want to get the tial Q 50mm bov. Well to figure out the spring you need to know engine vac. Well how am I supposed to know that without running the motor on the setup I will have, 8.8:1 and hopefully a gtr intake manifold if I can find one. Just trying to see what you guys are running vac wise. Or am I going about this the wrong way.

here are the springs compared to vac to show what I would need to get

6psi = vac between 8 and 11

8psi = vac between 12 and 15

10psi = vac between 16 and 19

11psi = vac between 20 and 21

12psi = vac between 22 and 23

[smoke187]

i get 20-22 at idle and 10 cruise

why a tial and not something simple like a ssqv or even synapse recirculated

[Turpro]

I get 18-20 at idle. 8-16 cruising. 28 when I let off the gas while driving.

[Shades]

19-21 inch/vac at idle...

You haven't run the engine?... no breaking it in yet?... breaking it in with the turbo setup?

I just don't understand why you need vac for a wastegate spring, the spring pressure is how much boost and how soon you want it to open.

[1992tracerlts]

19-21 inch/vac at idle...

You haven't run the engine?... no breaking it in yet?... breaking it in with the turbo setup?

I just don't understand why you need vac for a wastegate spring, the spring pressure is how much boost and how soon you want it to open.

Im not even close to that far yet lol, When time gets to it im probably going to be breaking in the motor on low boost. Idk if that is good or not? But this isnt for the wastegate, its for the BOV.

[Shades]

That's just odd that it would need a different spring for a different vac... you just need one that keeps stuff shut when it needs to, and opens ASAP when it needs to.

Well, I guess it's better than those diaphram things... yay for flutter.