Picked up a tial bov that had the original spring replace with a 18psi spring. Question is will i need to run 18psi+ everytime in order to get the diaphragm to move to release the excess air?

Im sure i will be running 20+psi when the real dyno tune happens so even if it is true that i will need 18psi+ for the bov to dump air, im still worried what about normal daily driving and time when i hit maybe just 5-10psi ya know?

 

Uhh....I don't know of a "18psi" spring for a tial BOV. Here's the .pdf off tial's site for the old 50mm bov, the Q is a little different

http://www.tialmedia.com/documents/w3_tial_bov50_sp.pdf

Basically you take your engine vacuum at idle and get the spring to match, or run a lighter spring to release sooner, etc.

 

The 9psi spring was too light, you want the 11psi which I believe has no paint on it. Tim is right of course, but I went with a spring that closed the BOV on over-run because I had very high "silicates" on an oil analysis. When I put the stiffer spring in the silicates dropped and I noticed on the dyno that it was closed on over-run when the turbine shaft speed lower to "highway driving" behavior. You also need to run 3/8" reinforced fuel hose (carburetor hose) to move enough air to make it work properly, smaller vacuum hose will not let it open properly. I learned quickly that the secret to TiAL stuff is to follow their directions accurately.

Disclaimer:
Yes it will make the flutter noise at low boost which some people will call "compressor surge". Compressor surge is not a problem when the turbo isn't loaded up.

 

Tim- Yes its a 50mm tial, Very strange that there actually are no 18psi like he said the spring was but i understand why there shouldnt be haha

The spring is un-painted which would resemble the 11psi. Its possible the previous owner ment to say 18 In/Hg?

Hustler- Thanks for the heads up i guess i will just stick with it.
Also about the hose, im looking at some 3/8" fuel hose and thats HUGE. Isnt there a size that is in between normal vaccum hose size and this huge 3/8"
I'll head over to my local auto store and see what other sizes they have

 

My hose is so large that it barely grabs the barbs...but zip-ties fix that. TiAL's large canisters are big for a reason but you need a large diameter hose to feed them.

 

Ok got it, same would go for the wastegate also i bet

 

I have a 9 psi spring if you want it.

 

Correct. Once you get it right, it all makes sense and it works better than I thought possible. If you use a boost controller follow the diagram TiAL provides. My boost controller was hooked up as if it were a single port canister and it didn't work right.